Gm-8 on 6.2

[Darren5531]

I have searched for hours and hours trying to figure everything out that needs to be done to place a Gm-8 waste-gated turbo on a stock pre-88 6.2.

Here is what I have gathered thus far:

Find 92-93 6.5td

Remove:
1. Gm-8 Turbo
2. Passenger Side Exhaust Manifold (Drivers side too but will require minor fabrication in order to clear)
3.Oil Feed and Return Lines
4.Air Filter Box if not using alternative intake
5. Crossover Pipe and Down Pipe

As for installation I have read so many different things I am unsure on which are correct.

You can run your oil lines into the driver's side of the 6.2 just above the oil cooler ports is an oil plug.
The problem lies in where to tap oil pressure and drain oil from the turbo and getting around the A/C because of the way the exhaust of the 6.5 turbocharger points the output downward. For oil supply and drain contact Banks, they make a turbo kit for the 6.2, you can use their parts to make the 6.5TD setup work, mainly the drain plate where the fuel pump is (so you can keep your mechanical fuel pump). You'll also get an oil pressure line to tap oil pressure from a plug located above the oil filter.

I copied that from a posting in a thread about this install.

I also read you could install the electronic pump so you wouldn't have to deal with as many issues. Could be wrong I am unsure.

In conclusion what EXACTLY do you have to do in order to fit a Gm-8 turbo on a n/a 6.2 that is pre-88? Parts? Fabrication on crossover and manifolds?

I would love to have this thread turn into a sticky and write up on how to do the installation.

Thanks for your time,

Darren

[john8662]

A few have done it, it's a little unsettling as to how well it works, well, is it worth the fab time.

Check these images out of TB1's install:

http://www.thedieselpageforums.com/photopost/showgallery.php?ppuser=18942&cat=500

I Think the main issues with the install involve the A/C evaporator box!

There is a brief "sticky" over the conversion "got-ya's" in the 6.2/6.5 Tech Forum here:

http://www.thedieselpageforums.com/tdpforum/showthread.php?t=28047

For oil drain, as you've found out you have two good options. The Banks way, which leaves your factory lift pump in place.

Or, use a factory 6.5TD oil drain plate that will go in place of your pump.

But, you'll have to install an electric lift pump somewhere, could be in that location, or in the frame rail before the engine.

I haven't done this conversion though, nor would I try it in a vehicle that has the evap box on the firewall.

A custom downpipe and crossover pipe system would also need to be fabbed. You could keep your existing driver's side exhaust manifold though, as this would be part of the custom crossover pipe anyways. Most exhaust shops can handle this for you, or get the Mandrel bends and take them to the exhaust shop to fill in the blanks, for a better peforming crossover, verses the bending done at the shop.

Which turbo, GM1-8, any of them will work, with the -8 being the best of the bunch. So if you "mock" up a setup with a GM-1, you'll be set when you get your hands on an -8.

Hope this helps!

J

[Darren5531]

There is some worth while information in this thread:

http://www.steelsoldiers.com/index.php?name=PNphpBB2&file=viewtopic&t=14080&highlight=manual

[opto]

Why not find a used banks exaust setup for the early body style, then you will clear the evaporator box

[Darren5531]

Another very informative thread:

http://dieselplace.com/forum/showthread.php?t=65660

What exactly do you mean by banks exhaust system?

How do manual trannies do with turbos? I hear that they loose all boost when they shift, what is different from when an automatic shifts that makes it not loose all of the boost? I may just be confused on this subject.

[DmaxMaverick]

....How do manual trannies do with turbos? I hear that they loose all boost when they shift, what is different from when an automatic shifts that makes it not loose all of the boost? I may just be confused on this subject.


With a manual, normally you let off the skinny pedal during a shift. Let off the pedal, take away the fuel, drops the boost. An auto shifts under load, so fuel isn't taken away, and boost is retained. There are a couple methods of keeping the boost up during a manual shift, but they should stay at the track.

[opto]

the Banks exaust manifold puts the turbo more towards the front of the vehicle
also the crossover pipe is in the front I believe

[Darren5531]

Opto: Are you saying to use the banks crossover pipe and exhaust manifold and everything else off a 6.5td?

As for manual vs autos that should probably be left for another thread,but from what I read manuals really "liven" up the 6.2.

If somebody with more knowledge wanted to make a write up/ step by step install ebook, I would help in anyway I could.

[opto]

yes, but you probably will have to modify the downpipe and I don't know if there are any clearance problems due to the wastegate

for the banks setup have a look at this thread. http://www.thedieselpageforums.com/tdpforum/showthread.php?t=29232

[Robyn]

I have been involved in one such setup a couple years ago.
I was contacted to get the thing together.
The A/C evaporator is far too close to the turbo when using the stock 6.5 setup.

It can be done easily on a non A/C truck. On an AC equiped rig use the Banks Manifold and crossover.

The whole Banks system makes the most sense for the 6.2.
I recently sold one as a complete setup.

The GM8 probably could be used with the Bank manifold but there is going to be downpipe issues that will need to be addressed.
If you have a wire welder and machine tools at your disposal almost anything can be acomplished with time and thought liberally applied.

Good luck on the project

Robyn

[84 Convert]

I just did this and WOW what a difference I ended up gunny bagging the GM-3 due to trying to rebuild it myself. The WH1C I had on the shelf took its place. I ran the down pipe outside the frame. I stuck with the lift pump as is by modifying the oil pan to have a return tube and modded the pipe from the turbo to meet it.

One thing I did not notice mentioned were fuel mod either turn up your pump or look for a -4911 from a '93 truck. I have the -4911 and must say it ROCKS compared to stock. I may be turning it up once I get my intercooler installed.

Good luck!


Gregg

[ccatlett1984]

i really want to see how you route your tubing for the intercooler.

[Darren5531]

I second wanting to see some pictures of your install. Would it be any easier to put it on with the engine pulled?

Looking forward to seeing those pictures...