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Jacob Ochs

1986 2.8L to Turbo 3.4L to 4.0L MJ....

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Thanks a ton! This is very valuable info to me as I'm about to drop the motor in here soon, I'm not sure if the pass side Camaro mount will work, it's oddly long. Also, how did you go about using the Camaro intake as far as wiring up EFI goes?

I used the Camaro harness and computer. There was lots of wire that came out of the Comanche harness, and a good bit that came out of the Camaro harness, but in the end, it all looks clean and works really well. Obviously that won't be the case for a turbo... I bolted the 2.8L motor mounts to the 3.4L. All the bosses are there and tapped. If you want to keep A/C, you need to figure out how to use the camaro mount on the pass side, but you should be able to use the Jeep mount on the driver's side. FWIW, the Camaro frame is actually quite a bit roomier than the Comanche, so it might not work anyway.

 

Take a few pics of the Camaro pass side mount for me if you can!

Also, why do I need that flywheel?

In '86, the 2.8 was externally balanced. By the late 80's, it was internally balanced, as were the 3.1 and 3.4L's. So you need a flywheel from an internally balanced engine. I believe the same applies to the flexplate if you're doing an auto. You can see the weights if you look a the original flywheel/flexplate. I suppose you could have a machine shop mill the bosses off, but I found it far cheaper to buy a flywheel for a '90 2.8L S-10. The Camaro flywheel has a deep dish to it for some reason, and doesn't work with the Jeep transmissions.

 

Much of this is in my build thread, linked below...

Good luck!!

I'll get a picture when I'm back out there, I wonder if I could trim the mount up a bit or relocate it a little towards the rear to keep the pump...

 

 

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Thanks a ton! This is very valuable info to me as I'm about to drop the motor in here soon, I'm not sure if the pass side Camaro mount will work, it's oddly long. Also, how did you go about using the Camaro intake as far as wiring up EFI goes?

I used the Camaro harness and computer. There was lots of wire that came out of the Comanche harness, and a good bit that came out of the Camaro harness, but in the end, it all looks clean and works really well. Obviously that won't be the case for a turbo... I bolted the 2.8L motor mounts to the 3.4L. All the bosses are there and tapped. If you want to keep A/C, you need to figure out how to use the camaro mount on the pass side, but you should be able to use the Jeep mount on the driver's side. FWIW, the Camaro frame is actually quite a bit roomier than the Comanche, so it might not work anyway.

 

Take a few pics of the Camaro pass side mount for me if you can!

Also, why do I need that flywheel?

In '86, the 2.8 was externally balanced. By the late 80's, it was internally balanced, as were the 3.1 and 3.4L's. So you need a flywheel from an internally balanced engine. I believe the same applies to the flexplate if you're doing an auto. You can see the weights if you look a the original flywheel/flexplate. I suppose you could have a machine shop mill the bosses off, but I found it far cheaper to buy a flywheel for a '90 2.8L S-10. The Camaro flywheel has a deep dish to it for some reason, and doesn't work with the Jeep transmissions.

 

Much of this is in my build thread, linked below...

Good luck!!

a49591e18b6b08a1068c585be8faf8e0.jpg1a89979c1b78cfdf1719779959411f18.jpg

 

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great progress, i like all the detailed pictures.

 

question about your exhaust adapter plate you have made.

 

will you be cleaning it up after total exhaust mock up is finished?

the reason why i ask is all those inside corners will become stress risers, which will eventually promote and radiate a crack from the butting intersection of those corners

 

( i have seen this alot in aviation)

taking a file and smoothing them out actually relieves alot of the stress that intersection will see

 

 

keep up the unreal work, I want to see that engine running in the beast!!!

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great progress, i like all the detailed pictures.

 

question about your exhaust adapter plate you have made.

 

will you be cleaning it up after total exhaust mock up is finished?

the reason why i ask is all those inside corners will become stress risers, which will eventually promote and radiate a crack from the butting intersection of those corners

 

( i have seen this alot in aviation)

taking a file and smoothing them out actually relieves alot of the stress that intersection will see

 

 

keep up the unreal work, I want to see that engine running in the beast!!!

Explain the adapter plate? We're going to file off the inside the tube of the drivers side of the engine of all the discrepancies! Also me too it's been in the works and it's already drug out further than ide like!

 

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Do you plan on making a brace or two for the turbo to support the weight?  That thin turbing and a bigger turbo with high temps are going to push those welds to their limits and eventually crack.  Wouldn't hurt to make a brace or two.

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Do you plan on making a brace or two for the turbo to support the weight? That thin turbing and a bigger turbo with high temps are going to push those welds to their limits and eventually crack. Wouldn't hurt to make a brace or two.

I will be making a brace I'll probabily tie it into one of the head studs, it's 16 Guage tubing which I thought was sufficient for the build... I'm hoping! I can always have headers professionally built later in time! :)

 

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What size fuel pump would you guys suggest for the around 50lb set of injectors?

 

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Plan on making more than about 500whp?  If not, then a 255lph pump will be sufficient.  If you want a little more wiggle room, then a Bosch 044 pump would work as well, rated at 310lph.

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Thanks for the MM pic.  That sucker hangs WAY out there.  Hopefully you'll be able to bolt them into your comanche, and I'll just copy what you do...  :)

 

It's been 100F here the last few days, and my wife hasn't complained yet, but I'm sure she will eventually, so I need to get the A/C working.  

 

Keep up the good work!!

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88b24df2de858c87a41ea0d6c5587c3c.jpg polished the intake, this machine shop is taking its time. Should be back any day now and I can begin the stressful wiring I have ahead of me! Also I switched to an internal wastegate turbo to save space and time.

 

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What EMS are you using?  You could have just bought a pre-made harness for a megasquirt and cut the plug off.  might have been cheaper/easier.

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What EMS are you using? You could have just bought a pre-made harness for a megasquirt and cut the plug off. might have been cheaper/easier.

137ac64f64de78ac17b55e2246206e03.jpg it's called EMS-PRO it runs megasquirt 1s software but comes with native USB so I got it and I do have the harness but I wanted the extra wire just In case, it was only $50 for the spools and I'll be able to use it for other projects!

 

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gotta love a fresh engine.  You know it will never stay that pretty, but you gotta dress them up nice anyway lol

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gotta love a fresh engine. You know it will never stay that pretty, but you gotta dress them up nice anyway lol

I know, pictures last forever though! Also I had a question, so it has a flat tappet cam that requires me to hold the engine at 2k-3k rpms for 30 minutes for the first start. I have a decent running tune that I got from a 3.4 camaro guy for his 10psi boosted 3.4. Should I just leave the turbo unhooked for the first 30 minutes and break the turbo in after or do them at the same time?

 

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gotta love a fresh engine. You know it will never stay that pretty, but you gotta dress them up nice anyway lol

I know, pictures last forever though! Also I had a question, so it has a flat tappet cam that requires me to hold the engine at 2k-3k rpms for 30 minutes for the first start. I have a decent running tune that I got from a 3.4 camaro guy for his 10psi boosted 3.4. Should I just leave the turbo unhooked for the first 30 minutes and break the turbo in after or do them at the same time?

 

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I'd do the engine by itself and then the turbo after that, but I am sure everybody has an opinion on this different from mine.  My thinking is to avoid sending tons of metal bits through the turbo during that initial break in.  Run it to break in the cam, change the oil, then do the turbo break in.  Also, don't forget to pre-oil that turbo.  I've seen a lot of destroyed new turbochargers because people didn't do so.

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gotta love a fresh engine. You know it will never stay that pretty, but you gotta dress them up nice anyway lol

I know, pictures last forever though! Also I had a question, so it has a flat tappet cam that requires me to hold the engine at 2k-3k rpms for 30 minutes for the 22first start. I have a decent running tune that I got from a 3.4 camaro guy for his 10psi boosted 3.4. Should I just leave the turbo unhooked for the first 30 minutes and break the turbo in after or do them at the same time?

 

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I'd do the engine by itself and then the turbo after that, but I am sure everybody has an opinion on this different from mine.  My thinking is to avoid sending tons of metal bits through the turbo during that initial break in.  Run it to break in the cam, change the oil, then do the turbo break in.  Also, don't forget to pre-oil that turbo.  I've seen a lot of destroyed new turbochargers because people didn't do so.

 

 

X2 here.  Break in the Cam first, dump the oil, then the Turbo can have all your attention.  Do not forget to pre oil your nice new turbo!  Make very sure your turbo is properly pre lubricated.  Just how I would do it also.  Better to be safe.

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gotta love a fresh engine. You know it will never stay that pretty, but you gotta dress them up nice anyway lol

I know, pictures last forever though! Also I had a question, so it has a flat tappet cam that requires me to hold the engine at 2k-3k rpms for 30 minutes for the first start. I have a decent running tune that I got from a 3.4 camaro guy for his 10psi boosted 3.4. Should I just leave the turbo unhooked for the first 30 minutes and break the turbo in after or do them at the same time?

 

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I'd do the engine by itself and then the turbo after that, but I am sure everybody has an opinion on this different from mine. My thinking is to avoid sending tons of metal bits through the turbo during that initial break in. Run it to break in the cam, change the oil, then do the turbo break in. Also, don't forget to pre-oil that turbo. I've seen a lot of destroyed new turbochargers because people didn't do so.

 

 

 

gotta love a fresh engine. You know it will never stay that pretty, but you gotta dress them up nice anyway lol

I know, pictures last forever though! Also I had a question, so it has a flat tappet cam that requires me to hold the engine at 2k-3k rpms for 30 minutes for the 22first start. I have a decent running tune that I got from a 3.4 camaro guy for his 10psi boosted 3.4. Should I just leave the turbo unhooked for the first 30 minutes and break the turbo in after or do them at the same time?

 

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I'd do the engine by itself and then the turbo after that, but I am sure everybody has an opinion on this different from mine. My thinking is to avoid sending tons of metal bits through the turbo during that initial break in. Run it to break in the cam, change the oil, then do the turbo break in. Also, don't forget to pre-oil that turbo. I've seen a lot of destroyed new turbochargers because people didn't do so.

X2 here. Break in the Cam first, dump the oil, then the Turbo can have all your attention. Do not forget to pre oil your nice new turbo! Make very sure your turbo is properly pre lubricated. Just how I would do it also. Better to be safe.

That is what I was leaning towards, to add to that I don't want to be running pressure in the engine from the turbo while breaking in a cam!

 

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Avoiding the pressure would be easy, don't connect it to the intake lol   You could multitask and dry some clothes with the air coming out.  :yes:

Another little tip on the first start.  Disconnect or disable the fuel to the engine before that first start and crank it on the starter until you see oil pressure on a gauge for a few seconds.  Once you have the oil pressure, turn on the fuel then do your break in.

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If you're planning to run the '94-95 intake and throttle body, you might consider dropping the engine an inch or so in the mounts... I have the same 3.4L in my Comanche, and it's only got about 1" of clearance to the underside of the hood. With the Camaro oil pan, clearance to the axle is tight too on my truck, but with your lift, that's not a concern. :)

 

The other issue is that the 2.8L engine mount on the pass side occupies the same space as the 3.4L's A/C pump. I didn't have the camaro mounts, so I just bolted on the 2.8 mounts and used an A/C delete idler bracket, but will probably try to use the Camaro motor mount on that side eventually so I can squeeze the pump back in. (It'll be VERY tight to the frame rail, I think...)

 

You'll also need a flywheel for an '89+ (IIRC) 2.8L S-10 with the 5-speed. The 2.8L clutch bolts right up, and seems to hold at least a non-turbo'd 3.4L just fine. :)

 

I'll be curious to see how this all works out for you. A turbo on the 3.4L would be awesome for pulling passes, and motoring down the road at highway speeds...

Please keep up with the updates!! :)

I'm working on the A/C brackets now, but I need some help! (See picture) could you measure the distance from the bolt that I have circled to the frame as accurately as possible so I know how much room I have to work with? 42eda1d89c8d8562c787367071188bff.jpg

 

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d5071f7e290cc6e624ca5d5648da1874.jpgdbc096907657d4c62363c0cfa79be16b.jpg here's what I'm thinking now, don't make fun of it it's just a mock up but if I can get the Alternator to go where the A/C was and A/C where the Alternator was I'd be in buisness!

 

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