6.5 turbo(gm4) on a 6.2

[just a number]

OK hear comes all the questions.

I'm using a 6.2 pump(DB2) now which injector lines to use, the ones I've got or I can get a set of DB4 ones.

which injectors?

what for a boost limit?

gauges?

fuel pump?

oil supply and return?

I think that's it for now but I'm sure there will be more.

 

[Acesneights1]

OK, I have NOT done this yet but have gather as much intel as I could so hear's what I am told:
If you have like an '88+(I think) and have injectors that are short and straight to the heads, your home free..skip the next staement.
If you have long injectors and angled heads You will need to use short 6.5 injectors as the 6.5TD mainfold hits the long ones. One guy I spoke to said he ground the nuts a little on the INj lines and a little off the ex manifld and made it by a sliver. Personally, I'm not keen on grinding inj lines.
If your doing this on an Old Body style truck and it has fctory A/C it will not clear the A/C box.
Only two options, lose the A/C or go Banks.
Oil can be supplied to the turbo by tee'in off the OPS. The return will go where your mech lift pump goes via the 6.5 adaptor plate. You will need to lose the mech LP and go electric which is a good thing anyway. Banks did make a plate that allowed both but good luck finding one. Some have tapped into the oil pan but to me losing the fact Mech LP is the way to go./ They suck anyway.
Safe boost on a 6.2 is 7-8 psi. remember this engine was NOT desinged for a turbo as the 6.5 was, The compression is slightly higher and the factory headgaskets suck.
Defintely a boost guage.
As far as LP you can use a factory GM one off a 6.5 and splice it right in nice and neat along the chassis using two fuel line repair kits and compression fitting it right in or hack it and use rubber line and clamps. If the truck is not lifted the crossover will have to be custom made. AFAIK the factory GM crossover will hit the front driveshaft on OBS trucks unless you have a 4inch or better lift. 2wd, I have no idea. The banks kit has you use the pass side manifld backwards on the drivers side and then the crossover goes under the front. IN my CUCV I have no factory air and the truck has a 4 inch lift so the only thing it looks to me that has to go is the bump stop for the front diff which is useless anyway. I will have to swap injectors to shortys. Use the factory 6.2 lines and don't forget to give Mr. IP a little more Juice. 1/4 seems to be the standard. You will have to have the exhaust custom made and run it outside the frame rail unless you have a body lift. I'll probably start mine after Memorial day weekend.

 

[Acesneights1]

BTW a gm4 is an excellent choice for a 6.2. Don't forget a TM. I plan on using an air cleanber assmebly out of a 98+ but for now I have a cone that a site member donated.

 

[just a number]

tm=turbomaster right?
I'm gonna use the factory aircleaner, upgrade as budget permits
I figured on the electric pump, mind you with my luck.....
what's the better filter the 'box' setup or the 6.5 version?
no worries about a front driveshaft. I don't have one(2wd) and the burb I'm stripping parts from has a decent one on it and a downpipe to boot.
I was thinking just to swap the heads and save having to deal with the injector mess. nevermind the headache of trying to get the manifold off! I suppose that's gonna change which line to use. is there any difference if the IP line fittings?

 

[Acesneights1]

yes angled heads and straight have different lines. I think if you use straight heads you would probably need lines off a 93 or older with a DB2. IIRC DS4 lines are differnt at IP than DB2. It's way easier to swap injs IMHO.

 

[3500GMC]

If you have a 6.2 with long coarse thread injectors you won't find a short coarse threaded injector AFIK. The injector body is where the extra length is found, which the body is what threads into the head.

I took an exhaust gasket to my local steel supply and had a 11ga. (1/8th") spacer cut with a CNC plasma, ($30) for the turbo side. One could do this by hand too. I've heard of stacking gaskets, but opted not to do that. Minor tweaking of the crossover will be needed, but will work- at least for *manifold* fitment.

 

[Acesneights1]

He's got a 91 if it's the turck in his sig. He won't have coarse and probably has the shortys and straght heads. Biggest problem he might face is if the truck has working A/C.

 

[just a number]

Yep it's the truck in the sig. no A/C to even come close to deal with. the worst mess I gotta deal with is the exhaust manifold bolts. any good secrets to getting them out? I ended up pulling the heads of at the wreckers. so right now I've got a spare set of 6.5 heads.

 

[Acesneights1]

Actually they usually come out as bad as they look. Just a bitch to get to the back ones. Pull the wheelwell and you may need to jack the motor up. Never worked on a 2wd.

 

[just a number]

I've got the issue of the frame being in the way. there's not alot of head left on them. time for the bolt remover I guess then. any guess what size the head was?

 

[Acesneights1]

I don't remember.

 

[randomid25]

OK, I have NOT done this yet but have gather as much intel as I could so hear's what I am told:
If you have like an '88+(I think) and have injectors that are short and straight to the heads, your home free..skip the next staement.
Actually on an OBS truck, he will probably still have injector clearance issues. IIRC, the 599 block was the first block that used heads with the different injector angle. If you have a 660, its probably still the same as the other OBS trucks. You can swap for 6.5 injectors or run a spacer on the turbo manifold like i did. Its 1/4" laser cut steel with a gasket on either side. It will be tight to the frame rail if you go this route. I had to pull the motor mounts and use a cherry picker to lift up the engine to torque the manifold bolts.
If you have long injectors and angled heads You will need to use short 6.5 injectors as the 6.5TD mainfold hits the long ones. One guy I spoke to said he ground the nuts a little on the INj lines and a little off the ex manifld and made it by a sliver. Personally, I'm not keen on grinding inj lines.
Brent does alot of things that aren't too smart. He talks about alot of things he knows nothing about as well. Not the best person to listen to about these trucks.
If your doing this on an Old Body style truck and it has fctory A/C it will not clear the A/C box.
Only two options, lose the A/C or go Banks.
An s10 AC box can be modified to work also.
Oil can be supplied to the turbo by tee'in off the OPS. The return will go where your mech lift pump goes via the 6.5 adaptor plate. You will need to lose the mech LP and go electric which is a good thing anyway. Banks did make a plate that allowed both but good luck finding one. Some have tapped into the oil pan but to me losing the fact Mech LP is the way to go./ They suck anyway.
IMO, if i were to route the return to the pan, the only good way to do it is to weld a tube to the top of the pan. There isn't enough material there to hold a tapped fitting.
Safe boost on a 6.2 is 7-8 psi. remember this engine was NOT desinged for a turbo as the 6.5 was, The compression is slightly higher and the factory headgaskets suck.
Max boost per banks is 10psi and 1000* egt. I know people running more boost than that. I run 8psi max sustained and could go higher. I have felpro head gaskets without an issue so far.
Defintely a boost guage.
Boost and EGT gauges are required. Not an option if you want your truck to live.
As far as LP you can use a factory GM one off a 6.5 and splice it right in nice and neat along the chassis using two fuel line repair kits and compression fitting it right in or hack it and use rubber line and clamps. If the truck is not lifted the crossover will have to be custom made. AFAIK the factory GM crossover will hit the front driveshaft on OBS trucks unless you have a 4inch or better lift. 2wd, I have no idea.
Crossover shouldn't be an issue on a 2wd truck.
The banks kit has you use the pass side manifld backwards on the drivers side and then the crossover goes under the front. IN my CUCV I have no factory air and the truck has a 4 inch lift so the only thing it looks to me that has to go is the bump stop for the front diff which is useless anyway. I will have to swap injectors to shortys. Use the factory 6.2 lines and don't forget to give Mr. IP a little more Juice. 1/4 seems to be the standard. You will have to have the exhaust custom made and run it outside the frame rail unless you have a body lift.
Downpipe and exhaust will have to be outside the rail. Not a big deal. I built mine to hug the frame to make sure i have turning clearance. My tire has yet to rub it and running the rest of the exhaust was pretty easy. I welded hangers to the body in a few places. No biggie.
I'll probably start mine after Memorial day weekend.

Cheers

 

[just a number]

why did you run the pipe outside the frame rail? I've got more the enough space between the motor and frame to clear. and yes I measured, eyes lie tape measures don't. as for the oil return I'm still undecided whether to go into the pan straight or use the adapter.

 

[Acesneights1]

Random and I have 4wd trucks. It won't fit inside unless you have a bodylift and remove the front diff bump stop. Also as far as safe PSI I got my numbers from Peninsular diesel. That is what the tech there said would be safe to run on a stock 6.2 due to higher compression and I don't know which block he has or I have but mine is a 1990 and my injs are straight on my burb and I have the shortys. He has a 1991 so I would think he has the same since it's newer than mine.. The 6.5 Manifold would go right on mine with no mods. It's my '86 CUCV that's gonna take some foolin. Sad part is the CUCV has no A/C and the Burb does. If I keep the Burb, I'm gonna Banks it. I don't feel like ripping the a/c box apart. The only thing I wuld like to do is use a GM4 on the banks manifld and use an F intake with a peninsular upper(that Chrisk gave me, thanks man). I'm working on a possible trade for my Jimmy for a Banks kit but if unsucessful, Banks will sell the Pass manifold for 400$ new. Then I'd fab the rest. I personally don't think there intake adaptor is very good. An F intake cuts down on lag. Then again I have toyed with e Holset. Plenty of unloved ones for sale cheap from Crazy Cummins guys. Probably way too much turbo for a stock 6.2. A GM 4 with a TM is the way to go. Nice and snappy at low boost numbers.

 

[Acesneights1]

Brent does alot of things that aren't too smart. He talks about alot of things he knows nothing about as well. Not the best person to listen to about these trucks.

Ouch....
Like I said, I wouldn't be keen on doing that..
:rofl:

 

[randomid25]

why did you run the pipe outside the frame rail? I've got more the enough space between the motor and frame to clear. and yes I measured, eyes lie tape measures don't. as for the oil return I'm still undecided whether to go into the pan straight or use the adapter.

Trust me, If i had room to run it inside the rail, thats where it would have gone. Get the factory passenger side manifold off and mock up the 6.5 turbo manifold and see what you have then. Oil return isn't a biggie. Just make sure the diameter is large enough.

Random and I have 4wd trucks. It won't fit inside unless you have a bodylift and remove the front diff bump stop.

I know it will clear with a body lift which i don't have, but since his is a 2wd, I didn't think the body lift info would be relevant.

Also as far as safe PSI I got my numbers from Peninsular diesel. That is what the tech there said would be safe to run on a stock 6.2 due to higher compression .

With a good quality set of head gaskets, you can do more boost. 7psig would only barely make it worth the trouble of all the fab work you have to do. I'll be running more boost when i get an IP capable of more fuel delivery and a stronger trans. I still use 6.2 head gaskets and tty head bolts and 8psi towing my boat isn't a problem. Never had an over heating issue either.The compression ratio on a 6.5 is only VERY slightly lower than a 6.2. 6.2's have thicker piston crowns than 6.5's according to bill heath. No weaknesses that suggest to me that they can't handle some pressure, Moreso with head studs if you choose that route.

I don't know which block he has or I have but mine is a 1990 and my injs are straight on my burb and I have the shortys. He has a 1991 so I would think he has the same since it's newer than mine.. The 6.5 Manifold would go right on mine with no mods.

88 and later obs trucks starts getting fuzzy as far as what block and heads you have. Same thing with the "some have serpentine belts, others have vbelts" thing. IMHO i think gm just threw trucks together with whatever parts they had at the time. If you don't need to do spacers or injector swaps, then you are ahead of the game.:thumbsup:

 

[Acesneights1]

Yeah I just threw the 4wd info in there for anyone else who reads it. It wil fit inside with a body lift on a 4x4 but the front bump stop must go which with any kind of lift is useless anyway.

 

[Missy Good Wench]

Stock injector lines that came with your engine are fine and will work with any of the DB2 Pumps.

The later heads with the short straight in injectors is the way to go for sure and use the lines that match.

As was mentioned, the GM4 turbo will do fine.

The Banks kit used a NON wastegated turbo and it would peak at about 10 PSI.

Keep the EGT at 1100F pre turbo MAX and the little 6.2 will live fine.

Be sure the injectors are in good order. Huffing that 6.2 and having some crappy squirts is a real quick way to drill a hole in a piston.


Have fun

Missy

 

[just a number]

those suckers I know are shot. For now I may just throw the ones in from the 6.5 heads and see what they're like. It can't be much worse. if they suck well I guess it's time for some new ones. I can't complain, the current set have 260K+(163 mi) on them. where's a good spot to put the pyro? which is the better setup for the filter, the box or the 6.5's setup? mechanical or electric pump?

 

[randomid25]

I put my probe in the passenger side mani right below the turbo inlet. In retrospect, I wish i would have put it in the drivers side manifold at the collector. That would give you a more accurate egt since its not getting cooled while traveling through the crossover pipe. Either way will work.