engine swap?

[terrygw63]

Going to definitely start doing my research. That sounds like the way to go 

[Pete M]

On 10/21/2020 at 11:17 AM, terrygw63 said:

Going to definitely start doing my research. That sounds like the way to go 

 

if you haven't seen them yet, the link to the big threads on the 3.4 info are in the link in my sig   

[Mark Serva]

When my 2.8 crapped out (Diz siezed and broke my camshaft--first time I've had that) I put in a 3.4. Plenty of help here on that. Had a few hassles yet nothing unexpected. Currently, need to replace my Weber carb, yet other than that engine runs peppy, plenty of torque and seems good on gas. Very pleased. Main thing is to rebalance new flexplate, nothing fancy, just some cutting off weights, rewelding on other side and balancing with lawn mower blade balancer. No high tech or machine shop time. Runs so much smoother it's really nice and no problem getting chevy parts and all cheap. Also, since it's such a tiny v6 I think it's easy to get to everything under the hood, sparks, dizzy, oil filter all easy to get to.

[ChainsawCHARL1E]

I have a 1986 comanche with a dying 2.8 liter v6 engine. Everything else is good, but my mechanic says it's not worth fixing and I should sell it for scrap. The Novak site wants $15000-$20000 for an ls or vortec swap, which means the mechanic is right. I would make more money on youtube showing this thing getting crushed. Any VIABLE alternatives to scrapping what should be a salvagable comanche?

 

(I am not a mechanic. If it is not bolt-on, I cannot do it. There are NO mechanics willing to do the work.)

[cruiser54]

3.4 Chevy V6.

[JMO413]

Chevy 3.4 is as straight forward as it gets.

[ChainsawCHARL1E]

9 hours ago, JMO413 said:

Chevy 3.4 is as straight forward as it gets.

Thanks. Will any longitudinal Chevy 3.4L v6 work, or is it just the L32 from the 1993-1995 Firebirds/Cameros? Are there new/remanufactured engines available or do I need to pull something out of a junkyard and hope for the best? I have seen new Chevy 3.4's for sale, but they are for 2006 model years.

[ChainsawCHARL1E]

https://www.ebay.com/itm/1993-CHEVROLET-CAMARO-3-4L-OHV-V6-L32-ENGINE-BW-PHOTO-FN-/312411662874?_trksid=p2349624.m46890.l49286

 

Well, at least I can buy a picture of a new l32 engine. I'll keep digging.

[ChainsawCHARL1E]

https://www.4wd.com/p/atk-2-8l-v6-replacement-jeep-engine-dc38/_/R-BBDZ-DC38#

 

What if I just got a new 2.8L engine?

[Pete M]

3 hours ago, ChainsawCHARL1E said:

https://www.4wd.com/p/atk-2-8l-v6-replacement-jeep-engine-dc38/_/R-BBDZ-DC38#

 

What if I just got a new 2.8L engine?

 

I'd rather get a new 3.4L.  the old 2.8 had a lot of shortcomings in metallurgy and oiling passages that were fixed by the time the 3.4 rolled out.    the 3.4 is a better engine.   

[ChainsawCHARL1E]

Okay, 4WD.com didn't really have anything in stock and said that nothing was coming in until NEXT YEAR! So, I called ATK directly (866-721-2315), spoke to Tom, who said I could order a remanufactured L32 3.4L longblock for $1930. Lead time is 8-10 weeks and I got an awesome shop in Cicero, N.Y. to do the swap, along with a Holley Sniper. Hopefully everything will be buttoned up before it snows in October.

 

It seems that the Pontiac Fiero crowd got stuck with the same crappy GM 2.8L V6 and does the same 3.4L swap, so this is in no way reinventing the wheel.

[JMO413]

50 minutes ago, ChainsawCHARL1E said:

Okay, 4WD.com didn't really have anything in stock and said that nothing was coming in until NEXT YEAR! So, I called ATK directly (866-721-2315), spoke to Tom, who said I could order a remanufactured L32 3.4L longblock for $1930. Lead time is 8-10 weeks and I got an awesome shop in Cicero, N.Y. to do the swap, along with a Holley Sniper. Hopefully everything will be buttoned up before it snows in October.

 

It seems that the Pontiac Fiero crowd got stuck with the same crappy GM 2.8L V6 and does the same 3.4L swap, so this is in no way reinventing the wheel.

You are correct. The 2.8 went to the 3.1 then the 3.4 with GM making design changes to better it each time. The early S10 and Blazers had the 2.8 and it was very popular to swap to the 3.4

[ChainsawCHARL1E]

A good write-up for the 3.4L swap ( http://www.lunghd.com/Tech_Articles/Project_XJ/Project_XJ.htm ) says that the old 2.8L oil pan must be re-used because the 3.4L oil pan will hit the front differential. Would a 2-3" suspension lift (which I was planning on, anyway) allow for the retention of the 3.4L oil pan? I do not want a higher lift because I am concerned that it would result in undesireable drive shaft angles.

[Pete M]

1 hour ago, ChainsawCHARL1E said:

A good write-up for the 3.4L swap ( http://www.lunghd.com/Tech_Articles/Project_XJ/Project_XJ.htm ) says that the old 2.8L oil pan must be re-used because the 3.4L oil pan will hit the front differential. Would a 2-3" suspension lift (which I was planning on, anyway) allow for the retention of the 3.4L oil pan? I do not want a higher lift because I am concerned that it would result in undesirable drive shaft angles.

 

MJs have much longer wheelbases (and so much longer shafts) and thus don't have the same issues that the wranglers and XJs might have.  you can go up to 6" of lift without troubles with the ujoint angles.  

 

but I haven't heard much talk about the pans, so I'm not certain how close it'll be.  but if you're worried, just reuse the 2.8 pan  

[UnkleRell]

If I have a 392 engine trans and computer with the wire harness would it fit in a 88 comanche cause I want to put it in there

[JustEmptyEveryPocket]

Sure. A wide variety of engines, transmissions, and harnesses can be cared in the bed of an MJ. Good luck!

[MiNi Beast]

23 minutes ago, UnkleRell said:

If I have a 392 engine trans and computer with the wire harness would it fit in a 88 comanche cause I want to put it in there

Be a bit tight on firewall and would need a set of mounts but it surly could be done. First step is having the want to do it. 

[Pete M]

56 minutes ago, UnkleRell said:

If I have a 392 engine trans and computer with the wire harness would it fit in a 88 comanche cause I want to put it in there

 

Novak should have most of what you'll need.   Advance Adapters might too.  anything can fit with enough planning and money. 

[cruiser54]

1 hour ago, JustEmptyEveryPocket said:

Sure. A wide variety of engines, transmissions, and harnesses can be cared in the bed of an MJ. Good luck!

True!! I have a Comanche with multiple carbs.

 

 

[ChainsawCHARL1E]

My GM 2.8L V6 engine died in my 1986 Comanche and so I had it replaced with a 1993 3.4L V6 Camero crate engine. It has a Holley Sniper and a DUI distributor with stock exhaust. Does anyone think it's time to upgrade to headers, dual exhaust, or larger pipes?

 

If anyone else is considering a Holley Sniper, I advise against it. The Sniper won't self-learn, as advertised, so I will need to pay a Holley EFI shop $700 to dyno and tune it. It stalls at most intersections. I should have either upgraded to the Camero EFI or used a Weber carb. Now avoiding EVERYTHING Holley.

[cruiser54]

Have you contacted Holley?

Seems to be a common issue when TPS is adjusted improperly.

[ghetdjc320]

9 hours ago, ChainsawCHARL1E said:

My GM 2.8L V6 engine died in my 1986 Comanche and so I had it replaced with a 1993 3.4L V6 Camero crate engine. It has a Holley Sniper and a DUI distributor with stock exhaust. Does anyone think it's time to upgrade to headers, dual exhaust, or larger pipes?

 

If anyone else is considering a Holley Sniper, I advise against it. The Sniper won't self-learn, as advertised, so I will need to pay a Holley EFI shop $700 to dyno and tune it. It stalls at most intersections. I should have either upgraded to the Camero EFI or used a Weber carb. Now avoiding EVERYTHING Holley.

I’d recommend you spend some time learning how to tune the sniper system. It’s very capable and user friendly for what it is. You can easily tune driveability issues with the assistance of various forums and manuals. Tuning the throttle plate opening vs iacv is crucial for idle. Use the monitor and see what’s happening to your engine when it dies at idle. Progressive linkage may also be necessary depending on which model sniper you run. 

[ChainsawCHARL1E]

So the 3.4L swap is a failure. I don't know if I was supplied with a bad rebuilt engine or if the mechanic did not install it properly or if the Holley Sniper is to fault, but, after 8000 miles, I have oil in my coolant, coolant in my oil, and both staining my parking spot at work and I'm out $12,000. I will never trust an American-made engine again and I will never trust Holley again. Maybe I can mate a Toyota 22R engine to the Aisin AX-5 transmission, otherwise the Comanche is going to get crushed.

[Pete M]

well that sucks.   but that seems like a frustrated emotional response when a clear and level head is needed.  maybe run a compression test before you literally throw the truck away.  what's the warranty on the engine?

[Mark Serva]

Sorry to hear one of us had such a bad experience with a rebuilt. I scored a rebuilt and did the swap. Pretty easy peasy yet as I was using bolt-in rubber plugs to fill the sensor holes I didn't need (kept the carb) I sneezed and dropped a little nut down the open engine. Removed it and the oil pan to find the nut stuck up in my cam area. What a PITA! 

 

Still have the old Weber aftermarket carb which I tried to rebuild to no avail. Doesn't run so well due to the crappy carb yet in certain speed ranges can really feel the increased power for the 3.4 over the 2.8. Seems GM fixed most of the 2.8 problems with the 3.4 except I used some Pontiac Fiero valve covers (with silicone gaskets) to fix the topside, endemic oil leaking. Guess it's classic GM thinking just fixing the Pontiac versions and letting the rest leak. 

 

Also, I made the mistake of not R&Ring the torque converter as it started leaking soon after the engine install. I replaced, cleaned or rebuilt pretty much everything else I could under the hood. Pretty happy with the change, hope to install a new Weber this summer--just don't look forward to the jetting hassles. If I didn't have the Weber already, I'd probable put a simpler Ford or MotorCraft 2100 series carb on instead. 

 

Good luck with everybody's swaps!