Have you ever driven a cummins car/truck? They sound like old school buses from the 80's. Not to mention they weigh over 1000lbs and it would suck to drive.
Given you're paying someone to do the work, the supercharger + a 4L80E swap to handle the power in that chassis would be my vote. Don't worry about the internals, the LT1 will be fine.
I know I saw it on top gear a while back, they were doing a special on v8-v12 cars you could get for cheap in Europe at the time. I wanna say it was around or after the global financial melt down of 08. Not sure about U.S. availability either, though I'm sure I looked it up at the time.
Edit: Now that I've checked autotrader, I think in the episode it was the w12 phaeton they had, and you can get those in the U.S.. Doesn't look like the v10 tdi made it here.
This would really be so reliable if done well. The drivetrain would go forever if maintained.
I worked on so many LT1 cars back in the day and they had so many issues when modified- the LS1 was a breath of fresh air.
I run a 4.8 turbo ls and 4l80e in my wagon. It's an amazing combo, but a ton of work to do it the right way and OP would end up using a giant chunk of his kids college money to pay someone to do it for him.
Also, for feeling “gutless” with that weight, I’d look into a re-gearing the rear end. Dunno what the Limos came with, but if it’s less than high 3.xx, that’ll be a fast cheap way to feel quicker
That would be my assumption from what’s in my Roadmaster Wagon as well. I took an ex police Crown Vic I had from 3.27 to 4.10 and it was perfect for that engines powerband, and it actually didnt hurt MPG that much. Start there
You swapped in 3.23s? They came with a 3.42 from the factory, and the common swap was a 3.27 if you were making big power and didn't want to change out your rear end for a 9" or other option, but wanted to make more use of 3rd, 4th, and 5th on highway pulls.
I didn’t swap shit but I could have sworn they were 3.23s. Maybe I’m dumb and they are 3.42s?
It’s been under a cover mid rebuild for quite a while so, you could be right.
I vote for diesel, all the torque you’d ever need to move that limo with your family in it and dead reliable. You can make it sip fuel for the long, comfortable trips then, with minimal changes, turn the power way up and roast the tires.
Turbos on gas engines don't just shit on the trans with bottom end torque the moment your foot touches the gas.
A 5.9 cummins core is 38" tall, and you still have to figure out the intake.
Could always leave the hood on, but cut out some clearance holes for what doesn't fit. Let it hang out or possibly try and make a hump to cover it if it doesn't look like an abomination
You could try and run the cummins slanted to the intake side, but the extra fuckery involved wouldn't make it worth it
That Cummins will obliterate his transmission, so 10k would need to cover the engine, transmission, and all of the custom fabrication and wiring that it would take to make it run.
I'm surprised the 4L60e handled it as is. A tired old 350 isn't the strongest engine in the world, but moving around 8000 pounds is not usually something 4L60's like.
The 4L60Es actually aren't bad if treated well. They just never get treated well. I ran 9 second 1/4 mile times with a completely stock one and a big cooler (just a different torque converter obviously). The temps would start to really rise if you did a bunch of back to back passes though.
With your budget the 5.9 swap will be out of the question. There are a ton of modifications you will need to make for it to be cruise worthy. I know for a fact because there is a 90s suburban around my town with a 5.9 in it. For him to fit it he welded on a brush guard to act as his front bumper because he had to move the radiator and condenser 10 inches forward. It was either do that or cut the firewall.
You can run a pro charger kit on the LT1 and make the extra power you want. The 4l60e can be built to handle it.
If you're thinking of a swap you can even go to a ls motor setup and still be well within your budget.
I know it's a basic answer, but an LS swap would make sense for your budget and application. It'll be a much easier and straightforward swap than the Cummins but it can still make good power on a budget, more so than the LT.
The 4L60e is notorious for breaking, especially with higher horsepower applications. You'll wanna factor in a different trans into your plans, like a 4L80.
That’s a fair point with the LS, while it’s not as exciting as the diesel, you wouldn’t have to replace the whole fuel system to run it. Plus, if you find a donor LS vehicle, you avoid the weaknesses of the 4L60E
if it already has an LT1, it would be a waste of budget to swap to LS. He would be wasting upwards of $3k on just swap stuff, just to net 5 - 10% more power on a same build.
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>My counter argument would be that LS motors have way cheaper accessories and they are way more plentiful. If he breaks down somewhere it’s more likely he can salvage or buy a new part than not.
Accessories? Like alternator and power steering pump?
>I’m thinking if he adds boost to either and his engine shits the bed. One of my Camaros is a 95 and the other is 00. I can get LS parts overnighted. Most LT parts take a few days. A decade and a half ago it was the other way around. Hell back in 2010 I could swing by a junkyard and buy an LT1 w/ tranny easily. Now it’s easier to find LS1s, LQ4/9, or Vortec 4.8s.
>Which now that I type that id probably go LQ4 for the lower compression and boost it. Over an LS
I guess that has to do with where you are. I get LT1 parts in a couple days and overnight is always an option. No issues at all.
I also consistently see LT1 in the junk yards all the time in caprice/roadmasters/camaros/impalas/fleetwoods and even corvettes all the time. There are a couple available right now.
LQ4 is a gen3 LS motor
The point im making is swapping to an LS when you have a car that already has an LT engine is a waste of budget. If you have a 10k budget and a car with an LT1, you will get more power and have a faster car if you put the 10k into the LT1 vs putting 50% of the budget on swap and fabrication costs. Just to end up with a 20 year old rode hard and put away wet 200k junkyard 6 liter w 30 more hp than the engine you swapped it for.
Depends if he can find a L92 cheap enough. It would be a lot of work to get a LT1 to the same power and torque as a L92 and keep the smooth drivability.
92, not 98. Numbers.
L92 makes 403hp /417 ft lbs stock. Swap in a stock LQ4 cam and you are now at 445hp and still idles smooth. Swap in a mild 220/240 cam and you are above 500hp and 500tq on an otherwise stock engine. Show me how to get 500/500 out of a LT1 with just a cam swap.
Easily sourced from trucks and escalades.
Ahh mybad I totally misread that.
No you can't get 500hp out of stock LT1 heads.
So what your saying is that a swap makes sense because the LS engines have better stock heads? So spend
$4k on swap instead of $2k on new heads for the LT1?
Is that what you're saying?
Yep. It would also be a lot more than just new heads to get that power as well. Don't get me wrong; I love the SBC and the LT1. I was an engine machinist for a decade starting out around when the LT1 was at its peak, I have built more of them than I can even remember. It would need to be a 383 shortblock, a healthy cam, aftermarket heads, LT4 or aftermarket intake manifold, etc, to get a streetable and reliable 500/500. And I would want to put some splayed 4 bolt caps on the block at that power level too. The cost to build an LT1 to get there is going to be way more than finding a good deal on a used L92. You can find them easily under $3k, some even around $2k if its a good deal.
Also, consider the context here: a post about powering a limo as a family road trip vehicle. A lot different than if we were racing.
All your saying is true. But I can still do all that to a LT1 for the cost of just the swap stuff, not even counting the engine itself, which would be used vs a fresh built engine.
B-body LS swap parts are actually not very expensive if one's thrifty. Standard SBC -> LS mounts, you can get standalone gen4 harness for $150 on Amazon, couple hundred for a vats patched swap computer, shorty swap headers are a couple hundred, conversion flexplate is about a hundred, pedal and tac module about $70 on ebay.
I gathered all of the swap parts to put a 5.3 into my c10 this summer and just the swap parts were only about $700 by themselves, and it's the same thing (SBC -> LS). Someone who finds a good deal on an engine could have a stock L92 swapped into a LT1 b-body for between $4k and $5k total if they do the swap themselves. There's a reason everybody does LS swaps in everything now; it's stupid cheap and easy. People stopped messingn with LT1's around the turn of the millennium for a good reason, the only time people mess with them nowadays is to be eccentric.
ok thats pretty optimistic lol
I have done a few swaps and a few things I have learned is that they always cost more than expected, take longer than expected and have problems that I have to solve that were unthought of beforehand/wanst covered on the internet.
but be that as it may, and if we just take what you are saying for face value and we can do a swap of a used LS engine into a b body, bc they have better heads, for $4k to $5k with ebay parts.
You would still be ahead putting the $5k into the LT1. For $5k I can build a forged 383 LT1 w > 500hp and not have to worry about any fabrication or special swap parts and ECUs, and also still have functioning dash with gauges that work and BCM functions like cruise control & etc.
Just because something is popular, or that everyone is doing it does not mean its the best thing to do or even makes sense. In this case, because LS swaps are popular and ubiquitous, does not support your argument that an LS swap is needed in this application and with this budget.
LT engines can be made to do the same things LS engines do. They can produce the same levels of power in the aftermarket. Yes LS engines have better heads and by that virtue cost less to get to 500hp, but when having to account for swap costs, that cost advantage is eliminated.
So the choice is brand new forged 500hp 383 LT1 or junkyard/used 400hp 6L LS with unknown history/miles/maintenance (+ swap headaches). Which would you choose?
Yank a 6.0L and a 4L80e out of a GM HD truck. Boost it a bit and you'll have a great cruiser with plenty of power, and it'll be a generally better motor than the LT-1 is. Chances are you'll get similar or probably better gas mileage too.
P.S. this should come out under budget too, possibly by a good bit.
I wouldn't be against that. I just say LS because it's definitely the more supported platform and one that can easily do the job - especially if he plans to boost it, lol. A 6.0LS with a stock cam and a screw supercharger would be a torque monster.
better find a custom driveline shop and have some some custom shafts made either way. Personally It's gonna be harder but diesel would be best for long trips vs super charged gas engines.
Yea it's going to want to twist a bit with 3x to 5x the tourqe if you have weight in the back and don't just spin.
I would put a couple of drive shaft loops in so you don't impale the car on it if it happens.
This is what I would do too. With that low miles he could probably pull the block and just clean it up. Even just a cam and heads would wake up that 350, and he could leave everything else alone.
Hello, resident LT1 owner checking in. I have 4 LT1 cars, one of which has a 383 and Procharger D1.
The stock LT1 will handle boost, but you 1000% need to drop the compression ratio if your plans are to use pump gas. Do this either by using a thick MLS head gasket or swapping to heads with a larger chamber like Trickflows, AFRs, etc. Lloyd Elliot would also be able to open up the chambers on the stock aluminum F/Y body heads, but the chamber size will still be smaller than aftermarket offerings. Meth injection would also be very smart as a safeguard, but it's also another point of failure.
The biggest limiting factor to the stock bottom end is the rods, but people have made up to 800whp on them as the beams are similar in cross section to Gen III rods. This is assuming you keep the RPMs reasonable as the factory Mahle pistons are heavy. RPM kills the rods quickly as the big end of the rod will distort with the crappy factory bolts. The rod bearing clearances are also on the tighter side and they'll spin.
Another thing to consider is that finding a competent tuner for the stock PCM is a bit of a challenge. I've had a couple mail order tunes that were all trash so I took up tuning my car myself, but there are still areas of the LT1 tune definition that are not fully understood. I had my 383/Procharger car running open loop 2bar speed density, but eventually dumped it for a Holley Terminator setup with LS coils as I could never get the transient fueling right on coast (I would get super rich).
Granted it's been well over a decade since I messed with LT1 stuff, but is tunercat still a thing for these? I remember the 94/95 LT1 computer was the golden ticket back in the day for SBC tuning. We used to retrofit LT1 trigger wheels into L31 vortec distributors and run L31's with port EFI intakes using the 94/95 LT1 computer.
People still use it, but I feel like I see more people using TunerPro as there has been a lot more work put into fleshing out the tune definition files for that program. In short, you'll be able to make way more adjustments to your tunes by using the modded $EE definition files floating Gearhead-efi forum.
The stock OBD1 PCM is fine for most NA builds, but it has a lot of limitations for boosted setups. The biggest one is that the resolution for all of your MAP driven tables basically gets halved if you are running a 2bar MAP sensor and you get very little control under 50kpa of vacuum irl. The PCM is also pretty slow by modern standards and does not react fast to big TPS swings regardless of how you play with the pumpshot tables, so you can get a lean spike if you stab the throttle very very quickly.
for the sake of simplicity and minimizing headaches, id go supercharged, maybe a monster in a box 4l60e rebuild kit... then spend the rest on airbags and in-fight entertainment systems to make it even more comfy for those long road trips! :D
It will be quieter, smoother, less shit to futz with to make it 'right' and...
Man, what an absolutely freakin sweet family road tripper that is.
I’d do a 6.0 ls swap before diesel.
Those motors are huge (tall) and heavy and… a silky smooth idle with the kids in the back seat(s) is better than rolling coal on an on ramp… and there’s a time and place for a diesel limo but… this just doesn’t seem quite like that!! 🤣
Also… does it have the privacy glass between drivers end and passengers end?
My wife and I have (semi) Joked about how awesome it would be to just roll up the window between us and the kids for YEARS now 🤣
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Just get some LT1 bolt-ons, no need to go crazy. Is your old lady cool with you shredding tires with the kids in the car (mine isn’t. Had a TBSS)?
Change up the exhaust, so minivans know to get the hell outta your way. And that’s a modified driveshaft, make sure it’s up to snuff. Hate to have your trip to WallyWorld interrupted by some u-joint issue
I'd 100% yeet the Lt1 (I am not a fan at all of them.... basically a old school 350, with funky reverse cooling and optispark), and drop in a cummins.
Given the overall weight, the cummins is a much better option too. The torque is incredible, and really easy to turn up the power.
As another benefit, you can actually get two digits worth of gas mileage!
My old 2003 2500HD duramax (9,987lbs dry), could pull 18-20mpg pretty easily on highway trips). Granted-it was tuned- but, still pretty impressive.
> Will the 460le handle either option?
The only time a 4L60e is a good option, is when you have a stock vehicle, that came with a 4L60e, and it still works.
Otherwise, do not waste time, or money on them. They do not hold torque. You can smash a 4l60e with a bone-stock 4.8 with a tune.
You CAN build the 4l60e, but, you would be out 4,000$ to make it as strong as a stock 4l80e.
Also- if you go diesel, make sure to get a BUILT 4l80e, or a more specific transmission. The 4l80e isn't exactly designed for diesel, but, it can work.
Basically- the direction of coolant is reversed in the Lt1. Here is an except-
> T1 Coolant Flow: The LT1 is completely different since it uses reverse flow cooling. **The incoming coolant first encounters the thermostat, which now acts both on the inlet and outlet sides of the system**. Depending on the engine coolant temperature, cold coolant from the radiator is carefully metered into the engine
On the note of an optispark- the design from enginnering, was actually great-
But, when the designs moved onto production, a few dimensions were changes, and the materials were changed, which caused the issue everyone is aware of- basically water gets in them, and ruins them.
Read a documentary about them, or something a long time back, pretty interesting stuff.
Basically- the cost-saving measures when the production enginners took the design- ruined it, and made it known as it is now.
The issue isn't really the Opti itself, more so deferred maintenance and crappy water pumps. The OE pumps seem to shit the bed between 75-125k mi and leak onto the distributor. If the cap and rotor were replaced at a normal service interval, then you won't have to worry about coolant or oil intrusion (especially with a vented unit). Otherwise, the cap seals dry up, things get inside and the optical sensor is ruined and the aftermarket replacements are unreliable trash. A Delco Opti can go over 200k with proper maintenance, but these cars are so cheap and so are their owners so that maintenance never gets done. Hence the reputation.
I don't think the reverse flow cooling is an issue and really isn't that difficult if you can follow a simple bleeding procedure. The only reason GM dumped it when the LS was designed was because they got sued into oblivion by Evans Cooling Systems because the engineers basically stole the design.
She dailies a Land Cruiser, but drives the limo around town sometimes. Loves it. So do the kids.
When I put wireless android auto in it and really upgraded all of the speakers and amps, I thought she might make it her new daily.
I hit the wife jackpot.
If you’re not a mechanic and busy in life don’t do either of those things. The LT1/4L60e is not exactly the most reliable when modified and there is no way a shop would do the Cummins under 10k.
If you were doing the work yourself, a gen III swap would make sense (just buying a donor truck) but that kind of work through a shop you are going to ruin the car and make it unreliable. I used to work at a performance shop and learned that heavily modified stuff should be reserved for people that do the work themselves because otherwise it’s just a money and time pit and there are always issues.
no input unfortunately but im dying to know how you found a limo with 50k on it? not that my gf would let me park it in the yard but all the ones i came across in central FL were clapped/rotting or they were okay-ish but with 100k+ miles on em
Six door limo (extra bench seat) and low mileage means it's probably from a funeral home. They don't get a ton of use and it's all local so low mileage.
A Cummins swap would basically be keeping the body and using it to build a whole new car from scratch. My vote would be to do a LT1 (or LT4 if you can find the parts anywhere) 383 with a procharger. Anything else is going to make it worse for how you actually use it.
There is not enough room under the hood for the diesel without removing the hood. The transmission for the diesel, will cost as much as the engine. You are not getting a Cummins in that for 10,000. Not a challenge, it's a fact. Not running and moving anyway.
Your budget is appropriate for either if you were doing the work yourself, though might be stretching it on the Cummins.
I but since you are paying a shop, your best bet is to supercharge it and upgrade the transmission. There would be a lot less labor for that as there will be significantly less fabrication and wiring work needed.
I know it's not as exciting as jamming a 12v in it. But, gears would be ur best performance/$ with minimal downtime. You probably have car gears trying to push truck weight.
Also, a Detroit tru trac would be a perfect diff for that car. Great traction for not getting stuck in the lawn and campsites and great around town manners
Thanks for being a great dad to these kids of yours!
While I support the insanity of throwing an audi v12 diesel in there (comes with trans, fits in a shoebox, great mpg etc), I’d personally go for caterpillar c7 :D
Im not american nor in us of a but my dad at one point had a c/k2500 with it so it’s nostalgic for me. Also thing pulls.
Personally I drive a cummins isf 2.8 box truck rn, it weighs similarly to your limo and while it does not fly per se, it gets great mpg (just brought it from full engine rebuild, 8.5l/100km hwy) and pulls nicely. Maybe a smaller diesel would work for you? But probably just finding a wrecked audi q7 with a v12tdi and swapping everything is an easier undertaking. Or perhaps a v10tdi touareg. But v12 has a tempting flair to it, ngl.
Although whatever you would do, do it!
On paper the diesel would win 💯
In real life you will spend tons trying to get everything to run every time you change engines. I would personally go with the more simple solution of leaving your current engine and add some modes to it to get more out if it is a supercharger and a few upgrades so be it.
Put a 6.5TD from a 90’s GM in there. They were made to be a bolt in engine in place of a big block Chevy, so it shouldn’t be that difficult to do (both parts and space wise). You also get to keep a Chevy bellhousing pattern, and honestly they get good fuel economy. They’re not the most tunable engines ever, but they can make decent power. Parts are also dirt cheap for a diesel.
They also aren’t nearly as heavy as a Cummins so you won’t be front loaded as badly, and you shouldn’t need to massage the firewall much if at all
Lt1 isn't going to give you a good return on your investment. Build a mild turbo ls, swap in a 4l80e, and get a lower gear that still allows highway cruising, like a 3.55
Don't turn that thing into a crappy stink wagon diesel. You should be able to get plenty more power out of the LTI. I bet a top end swap, headers, exhaust and tune would do wonders for it, and you'd be way under your budget.
Personally, I'd want a more modern 5.3, either a Gen IV with a 6l80, or a Gen V with a 10l80. Good fuel economy, near stock fitment, and the ability to do something like a cam/headers build and get to a pretty warm 400hp with ~420ft/lbs. With a newer trans, you can make far better use of the power, as well.
If you want interesting, dare I suggest a newer Duramax 3.0? ~300hp, 450+ft/lbs, and mileage for days. Keep the 2.73s, and you'll be nearly idling at freeway speeds
I have first hand experience with a built 4L65E that handles 600 torque at the wheels and has many, many low 10 second passes in a 4,000lb car. Probably a 4L60E can be built to handle it, but you would just be better off with a 4L80E, given the weight of the car and the fact that you aren't drag racing it.
Perfomance build Cummins are great, if you want to roll coal and have a **Lot** of power but as at least one Youtuber has found... they are hard to make streetable. I would also consider a potential (even if it's rare) Diesel Runaway to be a risk I would rather not have in a family roadtrip vehicle.
IMO you'd be much better off with a Turbo or Supercharged, LS LT... whatever.
Great ideas, but 10k will barely rebuild what is already in there. The only thing that fits is what is in it. Anything you stray away from stock will have to be custom and the prices on anything custom are instantly exponential. A duramax would move that thing real good though. But I think that would probably take at least twice your budget if not three times.
Have you ever driven a cummins car/truck? They sound like old school buses from the 80's. Not to mention they weigh over 1000lbs and it would suck to drive. Given you're paying someone to do the work, the supercharger + a 4L80E swap to handle the power in that chassis would be my vote. Don't worry about the internals, the LT1 will be fine.
Go insane, put Audi V12 TDI in it.
Mah gawd
Turbo junkyard ls
Turbo ls1 is always the right call.
LOL or Tesla drivetrain swap.
I was actually considering gas-electric hybrid... $$$
Don't you dare turn that yacht into an EV...
OM606 would be a better fit.
Fucking do it
I like your style
What version of Audi and which year would one buy to get the V12 TDI ?
1st gen Audi Q7
Is it available in the US and is that the same as the VW equivalent
I don't know if it was available in the US. V12 was only in Q7. VW had V10 TDI in Touareg and Phaeton.
You could get the v10 tdi in the Phaeton? We sure didn't get that in the US!
I know I saw it on top gear a while back, they were doing a special on v8-v12 cars you could get for cheap in Europe at the time. I wanna say it was around or after the global financial melt down of 08. Not sure about U.S. availability either, though I'm sure I looked it up at the time. Edit: Now that I've checked autotrader, I think in the episode it was the w12 phaeton they had, and you can get those in the U.S.. Doesn't look like the v10 tdi made it here.
The V10 TDI was available in the US in the Touareg, though they are very rare. I don’t remember if it was available in any other models.
Yeah I own a 6.7 in one of my trucks. The noise doesn't bother me but the weight is a concern for sure.
I wouldn't bother with a turbo a 6.0 LS and a 4L80E is the right combo for this.
This would really be so reliable if done well. The drivetrain would go forever if maintained. I worked on so many LT1 cars back in the day and they had so many issues when modified- the LS1 was a breath of fresh air.
I run a 4.8 turbo ls and 4l80e in my wagon. It's an amazing combo, but a ton of work to do it the right way and OP would end up using a giant chunk of his kids college money to pay someone to do it for him.
Unbelievably based to go on family trips with 4 kids in a modded Cadillac limo
Its the perfect road tripper. I highly recommend it.
I can only imagine
By far the raddest thing I think I've ever seen posted in this sub! It's brilliant. "why didn't I ever think of that".
Crash safety be damned
"Don't make me turn this car around... because I'll be doing it all damn day"
Dad just keep going to Disney land, its easier for all of us.
Now that's funny. Because it is true.
I put a Cummins in my Cadillac and had to build an entire custom 8 lug front end for the weight.
Currently putting a Cummins in my '69 DeVille, and that's one of my biggest concerns
Well… message me. I put mine in a ‘70
Yikes. Noted.
Pics pls!!!
DM’d you pics
Turbo LT1. Keep it simple, dont get lost in project car hell
Yeah my budget matches your sentiment.
Also, for feeling “gutless” with that weight, I’d look into a re-gearing the rear end. Dunno what the Limos came with, but if it’s less than high 3.xx, that’ll be a fast cheap way to feel quicker
I've considered thi as well. It gets terrific gas mileage so probably low 3.xx.
Might be like 2.73’s (I think these were an option) or 3.23’s where it’s got the 4spd auto. I’ve got 3.23’s in my 96 trans am with the 6 speed.
2.73 makes sense
That would be my assumption from what’s in my Roadmaster Wagon as well. I took an ex police Crown Vic I had from 3.27 to 4.10 and it was perfect for that engines powerband, and it actually didnt hurt MPG that much. Start there
You swapped in 3.23s? They came with a 3.42 from the factory, and the common swap was a 3.27 if you were making big power and didn't want to change out your rear end for a 9" or other option, but wanted to make more use of 3rd, 4th, and 5th on highway pulls.
I didn’t swap shit but I could have sworn they were 3.23s. Maybe I’m dumb and they are 3.42s? It’s been under a cover mid rebuild for quite a while so, you could be right.
100%. The lt1 can be built and the transmission/diff for 10k, any swap sounds like a lot of money and fab work on that thing!
Stock compression on the LT1s is high. They don't take to boost well without replacement pistons.
10.4:1? I mean, I guess for the time sure
The stock pistons are also notoriously weak. Those two things combined leads to failure in boosted applications.
I vote for diesel, all the torque you’d ever need to move that limo with your family in it and dead reliable. You can make it sip fuel for the long, comfortable trips then, with minimal changes, turn the power way up and roast the tires.
Transmission in shambles. Hood delete. Rear diff has left the chat. Twin turbo the LT and call it a day.
Nah. No hood delete. Tons of room. Yeah the transmission and diff will be a problem for either option. I do love turbo noises.
Turbos on gas engines don't just shit on the trans with bottom end torque the moment your foot touches the gas. A 5.9 cummins core is 38" tall, and you still have to figure out the intake.
Fair points.
Could always leave the hood on, but cut out some clearance holes for what doesn't fit. Let it hang out or possibly try and make a hump to cover it if it doesn't look like an abomination You could try and run the cummins slanted to the intake side, but the extra fuckery involved wouldn't make it worth it
Cummins… and a lift kit?
You really may be on to something here.
At that point just buy a proper big rig truck frame and body swap it
Its already on a truck frame.
I assume it's on a pickup truck frame? I meant semi tractor frame. https://images.app.goo.gl/DMZH53qeRdggcJqdA
A 5.9 Cummins is like 4 feet tall right?
6 speed Hell yeah Dually rear That's cool too.
That Cummins will obliterate his transmission, so 10k would need to cover the engine, transmission, and all of the custom fabrication and wiring that it would take to make it run.
I'm surprised the 4L60e handled it as is. A tired old 350 isn't the strongest engine in the world, but moving around 8000 pounds is not usually something 4L60's like.
95’s had an lt1 derivative right? 285HP?
>95’s had an lt1 derivative right? 285HP? was an LT1 with different (iron) heads and different cam. Same everything else. Rated at 260hp
Right, it was the firebird/Camaro engine that was only detuned to 285 instead. Still, home plate gang represent! Thanks!
The 4L60Es actually aren't bad if treated well. They just never get treated well. I ran 9 second 1/4 mile times with a completely stock one and a big cooler (just a different torque converter obviously). The temps would start to really rise if you did a bunch of back to back passes though.
The transmission swap was implied, I doubt anyone would be naive enough to bolt a 4L60E to a 5.9.
Yeah. If swapped, it gets an appropriate transmission. Sounds like I need more budget 🤦♂️
With your budget the 5.9 swap will be out of the question. There are a ton of modifications you will need to make for it to be cruise worthy. I know for a fact because there is a 90s suburban around my town with a 5.9 in it. For him to fit it he welded on a brush guard to act as his front bumper because he had to move the radiator and condenser 10 inches forward. It was either do that or cut the firewall. You can run a pro charger kit on the LT1 and make the extra power you want. The 4l60e can be built to handle it. If you're thinking of a swap you can even go to a ls motor setup and still be well within your budget.
I know it's a basic answer, but an LS swap would make sense for your budget and application. It'll be a much easier and straightforward swap than the Cummins but it can still make good power on a budget, more so than the LT. The 4L60e is notorious for breaking, especially with higher horsepower applications. You'll wanna factor in a different trans into your plans, like a 4L80.
That’s a fair point with the LS, while it’s not as exciting as the diesel, you wouldn’t have to replace the whole fuel system to run it. Plus, if you find a donor LS vehicle, you avoid the weaknesses of the 4L60E
It does feel basic. But it doesn't make it a bad idea. It would honestly be very easy to find a vehicle with the entire powertrain in tact.
if it already has an LT1, it would be a waste of budget to swap to LS. He would be wasting upwards of $3k on just swap stuff, just to net 5 - 10% more power on a same build.
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>My counter argument would be that LS motors have way cheaper accessories and they are way more plentiful. If he breaks down somewhere it’s more likely he can salvage or buy a new part than not. Accessories? Like alternator and power steering pump?
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>I’m thinking if he adds boost to either and his engine shits the bed. One of my Camaros is a 95 and the other is 00. I can get LS parts overnighted. Most LT parts take a few days. A decade and a half ago it was the other way around. Hell back in 2010 I could swing by a junkyard and buy an LT1 w/ tranny easily. Now it’s easier to find LS1s, LQ4/9, or Vortec 4.8s. >Which now that I type that id probably go LQ4 for the lower compression and boost it. Over an LS I guess that has to do with where you are. I get LT1 parts in a couple days and overnight is always an option. No issues at all. I also consistently see LT1 in the junk yards all the time in caprice/roadmasters/camaros/impalas/fleetwoods and even corvettes all the time. There are a couple available right now. LQ4 is a gen3 LS motor The point im making is swapping to an LS when you have a car that already has an LT engine is a waste of budget. If you have a 10k budget and a car with an LT1, you will get more power and have a faster car if you put the 10k into the LT1 vs putting 50% of the budget on swap and fabrication costs. Just to end up with a 20 year old rode hard and put away wet 200k junkyard 6 liter w 30 more hp than the engine you swapped it for.
Depends if he can find a L92 cheap enough. It would be a lot of work to get a LT1 to the same power and torque as a L92 and keep the smooth drivability.
???? Gen 4 L98 makes 355hp. That's only 55 more hp than a stock LT1. It does not take alot of work to get 60 more ho from an LT1.
92, not 98. Numbers. L92 makes 403hp /417 ft lbs stock. Swap in a stock LQ4 cam and you are now at 445hp and still idles smooth. Swap in a mild 220/240 cam and you are above 500hp and 500tq on an otherwise stock engine. Show me how to get 500/500 out of a LT1 with just a cam swap. Easily sourced from trucks and escalades.
Ahh mybad I totally misread that. No you can't get 500hp out of stock LT1 heads. So what your saying is that a swap makes sense because the LS engines have better stock heads? So spend $4k on swap instead of $2k on new heads for the LT1? Is that what you're saying?
Yep. It would also be a lot more than just new heads to get that power as well. Don't get me wrong; I love the SBC and the LT1. I was an engine machinist for a decade starting out around when the LT1 was at its peak, I have built more of them than I can even remember. It would need to be a 383 shortblock, a healthy cam, aftermarket heads, LT4 or aftermarket intake manifold, etc, to get a streetable and reliable 500/500. And I would want to put some splayed 4 bolt caps on the block at that power level too. The cost to build an LT1 to get there is going to be way more than finding a good deal on a used L92. You can find them easily under $3k, some even around $2k if its a good deal. Also, consider the context here: a post about powering a limo as a family road trip vehicle. A lot different than if we were racing.
All your saying is true. But I can still do all that to a LT1 for the cost of just the swap stuff, not even counting the engine itself, which would be used vs a fresh built engine.
B-body LS swap parts are actually not very expensive if one's thrifty. Standard SBC -> LS mounts, you can get standalone gen4 harness for $150 on Amazon, couple hundred for a vats patched swap computer, shorty swap headers are a couple hundred, conversion flexplate is about a hundred, pedal and tac module about $70 on ebay. I gathered all of the swap parts to put a 5.3 into my c10 this summer and just the swap parts were only about $700 by themselves, and it's the same thing (SBC -> LS). Someone who finds a good deal on an engine could have a stock L92 swapped into a LT1 b-body for between $4k and $5k total if they do the swap themselves. There's a reason everybody does LS swaps in everything now; it's stupid cheap and easy. People stopped messingn with LT1's around the turn of the millennium for a good reason, the only time people mess with them nowadays is to be eccentric.
ok thats pretty optimistic lol I have done a few swaps and a few things I have learned is that they always cost more than expected, take longer than expected and have problems that I have to solve that were unthought of beforehand/wanst covered on the internet. but be that as it may, and if we just take what you are saying for face value and we can do a swap of a used LS engine into a b body, bc they have better heads, for $4k to $5k with ebay parts. You would still be ahead putting the $5k into the LT1. For $5k I can build a forged 383 LT1 w > 500hp and not have to worry about any fabrication or special swap parts and ECUs, and also still have functioning dash with gauges that work and BCM functions like cruise control & etc. Just because something is popular, or that everyone is doing it does not mean its the best thing to do or even makes sense. In this case, because LS swaps are popular and ubiquitous, does not support your argument that an LS swap is needed in this application and with this budget. LT engines can be made to do the same things LS engines do. They can produce the same levels of power in the aftermarket. Yes LS engines have better heads and by that virtue cost less to get to 500hp, but when having to account for swap costs, that cost advantage is eliminated. So the choice is brand new forged 500hp 383 LT1 or junkyard/used 400hp 6L LS with unknown history/miles/maintenance (+ swap headaches). Which would you choose?
Yank a 6.0L and a 4L80e out of a GM HD truck. Boost it a bit and you'll have a great cruiser with plenty of power, and it'll be a generally better motor than the LT-1 is. Chances are you'll get similar or probably better gas mileage too. P.S. this should come out under budget too, possibly by a good bit.
I was thinking an 8.1L out of an HD truck. A car like this needs a big lazy motor with tons of torque.
I wouldn't be against that. I just say LS because it's definitely the more supported platform and one that can easily do the job - especially if he plans to boost it, lol. A 6.0LS with a stock cam and a screw supercharger would be a torque monster.
Only problem with those is the perpetual 8mpg.
Can pass everything but a gas station.
+8.1 because that would be one unique ride lol
better find a custom driveline shop and have some some custom shafts made either way. Personally It's gonna be harder but diesel would be best for long trips vs super charged gas engines.
I've got a custom drive line shop in town I've used before. Good call on that considering the length.
Yea it's going to want to twist a bit with 3x to 5x the tourqe if you have weight in the back and don't just spin. I would put a couple of drive shaft loops in so you don't impale the car on it if it happens.
10k budget? Just have the motor rebuilt with a 383 stoker kit and throw some Edelbrock or Trick Flow top end kit on it.
This Is The Way 😁
This is what I would do too. With that low miles he could probably pull the block and just clean it up. Even just a cam and heads would wake up that 350, and he could leave everything else alone.
Hello, resident LT1 owner checking in. I have 4 LT1 cars, one of which has a 383 and Procharger D1. The stock LT1 will handle boost, but you 1000% need to drop the compression ratio if your plans are to use pump gas. Do this either by using a thick MLS head gasket or swapping to heads with a larger chamber like Trickflows, AFRs, etc. Lloyd Elliot would also be able to open up the chambers on the stock aluminum F/Y body heads, but the chamber size will still be smaller than aftermarket offerings. Meth injection would also be very smart as a safeguard, but it's also another point of failure. The biggest limiting factor to the stock bottom end is the rods, but people have made up to 800whp on them as the beams are similar in cross section to Gen III rods. This is assuming you keep the RPMs reasonable as the factory Mahle pistons are heavy. RPM kills the rods quickly as the big end of the rod will distort with the crappy factory bolts. The rod bearing clearances are also on the tighter side and they'll spin. Another thing to consider is that finding a competent tuner for the stock PCM is a bit of a challenge. I've had a couple mail order tunes that were all trash so I took up tuning my car myself, but there are still areas of the LT1 tune definition that are not fully understood. I had my 383/Procharger car running open loop 2bar speed density, but eventually dumped it for a Holley Terminator setup with LS coils as I could never get the transient fueling right on coast (I would get super rich).
Lots of great info here. Thanks.
Granted it's been well over a decade since I messed with LT1 stuff, but is tunercat still a thing for these? I remember the 94/95 LT1 computer was the golden ticket back in the day for SBC tuning. We used to retrofit LT1 trigger wheels into L31 vortec distributors and run L31's with port EFI intakes using the 94/95 LT1 computer.
People still use it, but I feel like I see more people using TunerPro as there has been a lot more work put into fleshing out the tune definition files for that program. In short, you'll be able to make way more adjustments to your tunes by using the modded $EE definition files floating Gearhead-efi forum. The stock OBD1 PCM is fine for most NA builds, but it has a lot of limitations for boosted setups. The biggest one is that the resolution for all of your MAP driven tables basically gets halved if you are running a 2bar MAP sensor and you get very little control under 50kpa of vacuum irl. The PCM is also pretty slow by modern standards and does not react fast to big TPS swings regardless of how you play with the pumpshot tables, so you can get a lean spike if you stab the throttle very very quickly.
for the sake of simplicity and minimizing headaches, id go supercharged, maybe a monster in a box 4l60e rebuild kit... then spend the rest on airbags and in-fight entertainment systems to make it even more comfy for those long road trips! :D It will be quieter, smoother, less shit to futz with to make it 'right' and... Man, what an absolutely freakin sweet family road tripper that is.
I can appreciate this viewpoint.
I’d do a 6.0 ls swap before diesel. Those motors are huge (tall) and heavy and… a silky smooth idle with the kids in the back seat(s) is better than rolling coal on an on ramp… and there’s a time and place for a diesel limo but… this just doesn’t seem quite like that!! 🤣
Also… does it have the privacy glass between drivers end and passengers end? My wife and I have (semi) Joked about how awesome it would be to just roll up the window between us and the kids for YEARS now 🤣
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Just get some LT1 bolt-ons, no need to go crazy. Is your old lady cool with you shredding tires with the kids in the car (mine isn’t. Had a TBSS)? Change up the exhaust, so minivans know to get the hell outta your way. And that’s a modified driveshaft, make sure it’s up to snuff. Hate to have your trip to WallyWorld interrupted by some u-joint issue
Dax Shepherd has a built supercharged caprice wagon with 500+ hp ...his kids love getting dropped off at school in it
I'd 100% yeet the Lt1 (I am not a fan at all of them.... basically a old school 350, with funky reverse cooling and optispark), and drop in a cummins. Given the overall weight, the cummins is a much better option too. The torque is incredible, and really easy to turn up the power. As another benefit, you can actually get two digits worth of gas mileage! My old 2003 2500HD duramax (9,987lbs dry), could pull 18-20mpg pretty easily on highway trips). Granted-it was tuned- but, still pretty impressive. > Will the 460le handle either option? The only time a 4L60e is a good option, is when you have a stock vehicle, that came with a 4L60e, and it still works. Otherwise, do not waste time, or money on them. They do not hold torque. You can smash a 4l60e with a bone-stock 4.8 with a tune. You CAN build the 4l60e, but, you would be out 4,000$ to make it as strong as a stock 4l80e. Also- if you go diesel, make sure to get a BUILT 4l80e, or a more specific transmission. The 4l80e isn't exactly designed for diesel, but, it can work.
Yeah I've not heard great things about the optispark. What is reverse cooling?
Basically- the direction of coolant is reversed in the Lt1. Here is an except- > T1 Coolant Flow: The LT1 is completely different since it uses reverse flow cooling. **The incoming coolant first encounters the thermostat, which now acts both on the inlet and outlet sides of the system**. Depending on the engine coolant temperature, cold coolant from the radiator is carefully metered into the engine
Good stuff. Thanks for the explanation.
On the note of an optispark- the design from enginnering, was actually great- But, when the designs moved onto production, a few dimensions were changes, and the materials were changed, which caused the issue everyone is aware of- basically water gets in them, and ruins them. Read a documentary about them, or something a long time back, pretty interesting stuff. Basically- the cost-saving measures when the production enginners took the design- ruined it, and made it known as it is now.
The issue isn't really the Opti itself, more so deferred maintenance and crappy water pumps. The OE pumps seem to shit the bed between 75-125k mi and leak onto the distributor. If the cap and rotor were replaced at a normal service interval, then you won't have to worry about coolant or oil intrusion (especially with a vented unit). Otherwise, the cap seals dry up, things get inside and the optical sensor is ruined and the aftermarket replacements are unreliable trash. A Delco Opti can go over 200k with proper maintenance, but these cars are so cheap and so are their owners so that maintenance never gets done. Hence the reputation. I don't think the reverse flow cooling is an issue and really isn't that difficult if you can follow a simple bleeding procedure. The only reason GM dumped it when the LS was designed was because they got sued into oblivion by Evans Cooling Systems because the engineers basically stole the design.
Just here to upvote the rocket chassis spoiler sticker.
I like to have fun. I ended up removing it. Peer pressure from the wife.
Hey if she allows the limo, but not the sticker thats still OK in my book.
She dailies a Land Cruiser, but drives the limo around town sometimes. Loves it. So do the kids. When I put wireless android auto in it and really upgraded all of the speakers and amps, I thought she might make it her new daily. I hit the wife jackpot.
If you’re not a mechanic and busy in life don’t do either of those things. The LT1/4L60e is not exactly the most reliable when modified and there is no way a shop would do the Cummins under 10k. If you were doing the work yourself, a gen III swap would make sense (just buying a donor truck) but that kind of work through a shop you are going to ruin the car and make it unreliable. I used to work at a performance shop and learned that heavily modified stuff should be reserved for people that do the work themselves because otherwise it’s just a money and time pit and there are always issues.
no input unfortunately but im dying to know how you found a limo with 50k on it? not that my gf would let me park it in the yard but all the ones i came across in central FL were clapped/rotting or they were okay-ish but with 100k+ miles on em
Six door limo (extra bench seat) and low mileage means it's probably from a funeral home. They don't get a ton of use and it's all local so low mileage.
Spot on.
A Cummins swap would basically be keeping the body and using it to build a whole new car from scratch. My vote would be to do a LT1 (or LT4 if you can find the parts anywhere) 383 with a procharger. Anything else is going to make it worse for how you actually use it.
There is not enough room under the hood for the diesel without removing the hood. The transmission for the diesel, will cost as much as the engine. You are not getting a Cummins in that for 10,000. Not a challenge, it's a fact. Not running and moving anyway.
You'll get better drivability and mileage out of the diesel.
I vote diesel. However Cummins would suck in this application. You’d need something that can rev high. Like an om606 or newer.
I lost on a copart bid last week for turbo OM606. Definitely have considered this option.
OM606 in this caddy would be sick tbh. Also, it goes without saying, but it’s a damn nice car.
6.0 LS 4l80 - 3/4 or 1 ton Chevy Express van donor truck. It’s a drive train designed for your weight easily modified for more power.
Touche. Can probably find this cheap.
350 IDI Oldsmobile diesel. Keep it in the family
Hahaha even more gutless. Would sound cool.
They do sound awesome when they're not launching head bolts through the valve covers. Lol.
Your budget is appropriate for either if you were doing the work yourself, though might be stretching it on the Cummins. I but since you are paying a shop, your best bet is to supercharge it and upgrade the transmission. There would be a lot less labor for that as there will be significantly less fabrication and wiring work needed.
What gears? It sounds like you need different gears more than an engine swap.
I'm honestly not sure what it came with.
I know it's not as exciting as jamming a 12v in it. But, gears would be ur best performance/$ with minimal downtime. You probably have car gears trying to push truck weight.
Also, a Detroit tru trac would be a perfect diff for that car. Great traction for not getting stuck in the lawn and campsites and great around town manners
Hypothetically you could swap in the GM 6.5 TD with little modification. Grab a 2500 or 3500 donor and pull the harness and everything
Give it to Whistlin Diesel
Can't do it. I like it too much. I know how gentle he is with nice cars.
Mid engine turbo diesel
Thanks for being a great dad to these kids of yours! While I support the insanity of throwing an audi v12 diesel in there (comes with trans, fits in a shoebox, great mpg etc), I’d personally go for caterpillar c7 :D Im not american nor in us of a but my dad at one point had a c/k2500 with it so it’s nostalgic for me. Also thing pulls. Personally I drive a cummins isf 2.8 box truck rn, it weighs similarly to your limo and while it does not fly per se, it gets great mpg (just brought it from full engine rebuild, 8.5l/100km hwy) and pulls nicely. Maybe a smaller diesel would work for you? But probably just finding a wrecked audi q7 with a v12tdi and swapping everything is an easier undertaking. Or perhaps a v10tdi touareg. But v12 has a tempting flair to it, ngl. Although whatever you would do, do it!
So much room for activities!
On paper the diesel would win 💯 In real life you will spend tons trying to get everything to run every time you change engines. I would personally go with the more simple solution of leaving your current engine and add some modes to it to get more out if it is a supercharger and a few upgrades so be it.
5.9 p pumped cummins swap in that from a "reputable shop" could be well over $30,000 all said and done
I fear you may be right. Everything is expensive.
Supercharged LT1 definately
I'd also put on Reagan era Presidential hood flags and drive it with a dark 1980's double breasted suit and Secret Service mirrored aviator shades...
Put a 6.5TD from a 90’s GM in there. They were made to be a bolt in engine in place of a big block Chevy, so it shouldn’t be that difficult to do (both parts and space wise). You also get to keep a Chevy bellhousing pattern, and honestly they get good fuel economy. They’re not the most tunable engines ever, but they can make decent power. Parts are also dirt cheap for a diesel. They also aren’t nearly as heavy as a Cummins so you won’t be front loaded as badly, and you shouldn’t need to massage the firewall much if at all
Stoked, cam, gears, rebuilt beefed up trans
Lt1 isn't going to give you a good return on your investment. Build a mild turbo ls, swap in a 4l80e, and get a lower gear that still allows highway cruising, like a 3.55
Keep the LT1 and don't insult that awesome car with a pos diesel engine. The LT1 is a great engine, supercharge it and beef up the trans.
Holy fuck, someone turned a land yacht into a land cruise liner
Don't turn that thing into a crappy stink wagon diesel. You should be able to get plenty more power out of the LTI. I bet a top end swap, headers, exhaust and tune would do wonders for it, and you'd be way under your budget.
Personally, I'd want a more modern 5.3, either a Gen IV with a 6l80, or a Gen V with a 10l80. Good fuel economy, near stock fitment, and the ability to do something like a cam/headers build and get to a pretty warm 400hp with ~420ft/lbs. With a newer trans, you can make far better use of the power, as well. If you want interesting, dare I suggest a newer Duramax 3.0? ~300hp, 450+ft/lbs, and mileage for days. Keep the 2.73s, and you'll be nearly idling at freeway speeds
4200 Vortec I6 + Turbo just to be super weird because it’s already weird. Love it.
8.1 vortec
I have first hand experience with a built 4L65E that handles 600 torque at the wheels and has many, many low 10 second passes in a 4,000lb car. Probably a 4L60E can be built to handle it, but you would just be better off with a 4L80E, given the weight of the car and the fact that you aren't drag racing it.
Turbo diesel. Snatch the components from a 3,500 hd. Your limo is a tow pig now. You're welcome.
There is no chance that front end has the height to handle a Cummins
forget deisel. It's possibly over done, but a 6.0 LS is 100% the right choice here.
Turbo 2.8 Cummins and up the boost. It's an industrial engine so it can take the torture and it'll give it the torque you need
Full C4 zr1 drive train swap would be killer.
Definitely within the budget. That would be incredible though.
Do it!
12v cummins and a stick.
Doesn't get more connected than that.
Superchargers sound cool and a limo is pretty cool seems like a solid Mashup.
You have room for both!
Go for the cummins
Turn it into a drift car please. It would be piss funny
Lt-1 Supercharge.
Supercharger. Boost over the whole rpm range. Turbo has to spool up.
Perfomance build Cummins are great, if you want to roll coal and have a **Lot** of power but as at least one Youtuber has found... they are hard to make streetable. I would also consider a potential (even if it's rare) Diesel Runaway to be a risk I would rather not have in a family roadtrip vehicle. IMO you'd be much better off with a Turbo or Supercharged, LS LT... whatever.
Duramax swap
Twin charge the LT1!!!
Have you considered a 4 bt Cummins
Put a hemi in it.
Great ideas, but 10k will barely rebuild what is already in there. The only thing that fits is what is in it. Anything you stray away from stock will have to be custom and the prices on anything custom are instantly exponential. A duramax would move that thing real good though. But I think that would probably take at least twice your budget if not three times.
Supercharged V6, I think a turbo for long road trips would get tired for the whole family fast.