70 C-20 4x4 Suburban Father/Son project

[NOIBN]

The H587CP.50MM indicates that it is a Sealed Power brand hypereutectic cast piston. The .50MM in the part number indicates that it is an oversize piston. IIRC, .50mm was roughly equivalent to .020 which is a very minimal over-bore and typically the smallest oversize piston available. GM did not put Federal Mogul bearings in their motors from the factory, so they too have been changed. The 3-99 is the date that they were made, so you know that the motor has been done sometime after March of 1999 when the bearings were made. The STD indicates that the journal it came off of is standard diameter. Any undersize will be noted on the bearing. On a 6.2L bearing it should be in MM, just like the piston.

I'd say this was probably a good running engine by looking at the cylinder heads. All of the chambers appear equal in color. All of the precups look similar in color also. All of this bodes well for the overall condition of the motor. Hopefully everything major passes magnaflux (cylinder heads will most likely have some minor cracking between the induction hardened seats) and you can get the show on the road.

As was mentioned, check your source on the gear drive as they were discontinued/unavailable for around a year or two. All of the ones I know of were made by Pete Jackson and re-boxed for whoever was marketing them.

 

[NOIBN]

Here is the pic you posted that didn't show.

I wouldn't try to talk you out of finding a set that looks a little nicer than these.

 

[1leglance]

How hard is it to get to the mechanical fuel pump with all the turbo stuff? I have worked on the Banks kits on a 80's Sub and there was no way to change the fuel pump without pulling alot of other turbo stuff off for access.

Yeah I agree the pump & cross over pipe will be something to watch.
My goal is to have a new cross over pipe made and be sure to route it with the most room I can get..also to keep the heat away.


Nick-Nobin..
thanks for the info breakdown on the pistons & bearings...
I really have my fingers crossed that all will be well and I can just re-ring/bearing/gasket this puppy and get it back together.
The turbo shop said the unit looked good on first inspection, I ask for a rebuild quote just to make sure it is in top shape.

Not sure where I will track down the injector pump lines...ebay search time

 

[Rot Box]

Cool! :elkgrin:

I know Rotomasters (and even Turbonetics) were used on the earliest Banks and ATS kits in the Fords. Both of these companies used the same turbo's in both the GM and Ford diesels during the early years. I've never seen a 6.2 ATS kit in that configuration (again thats not saying much) and I'm wondering if it might be an odd ball like the early Turbo Engineering kits. The plumbing looks very similar to their Ford kits and they used Rotomaster as well... Hmm... Anyway from everything I've heard it is not hard to find rebuild parts for the Rotomaster unlike the later Mitsubishi turbochargers.

Back to the nickels and dimes... You might want to consider the ARP stud option to replace the head bolts.

 

[shortbus4x4]

The later 6.5 turbos had the crossover go to the rear and under the engine, where the bellhousing and engine bolted together. Of course they had manifolds designed for it. You probably won't be able to do much on crossover/intercooler plumbing until you get your engine back and sitting in your engine bay. The current crossover design makes getting to your fuel pump a pain it looks like but also puts alot of heat to the rubber compenents of the dampner. Will be interesting to see what you come up with the plumbing issues. Just remember that heat tape is your friend. The 84 Sub I worked on with the Banks turbo kit had lots and lots of heat tape; on the crossover pipe, the down pipe, and any other compenents that came close to the turbo. Man I wish you would have started your build about six months ago, you would be getting a complete 6.5 turbo system with turned up IP in the mail from me.

 

[Larry]

Not sure where I will track down the injector pump lines...ebay search time

Aye, aye, aye….. you have a lot of work and expenses ahead of you Lance. I agree with Nick on the injection pump to fuel nozzle lines. Those look like pieces of Twizzler Stick liquorish. You should still be able to get them though any GM dealer or General Engine Products (AM General) for a 6.5L Optimizer application. If GEP can't sell you the lines directly I bet they can steer you to a distributor that still sells new 6.5L engine and parts. Last I knew GEP was still selling the Optimzer 6500 for stationary power generators and well pumps. We used a set of brand new AM General stainless steel pump to nozzle lines on the 6.5L project Bill and I did for our Michigan friend a few years ago on his '88 Burb.

I know you are getting a lot of info thrown at you but one thing I would recommend when you go back together is not to use any gaskets on the valve covers or oil pan, such as that cork oil pan gasket in your pictures. Oil leaks were the second most common warranty expense on these engines back in the day when they had a 5 year -100,000 mile warranty in GM trucks. GM's answer….do away with gaskets and just simply glue the valve covers and oil pan on. Works great to stop a notoriously leaky engine from leaking but a real hassle to work on if you ever need to get back into the engine again unless you plan on bending the tin covers all to heck while trying to pry them off.

We used Right Stuff to glue the tin covers and oil pan back on this 6.5L as that is what my buddy that we built the Burb suggested. He worked at AM General on the Optimizer6500 engineering team so he should know. Going gasket comando with just sealant works! It never leaked!

Brand new stainless lines on the old 6.2L Stanadyne pump. This pump was later changed for a Bosch prototype pump which the lines were slighty bent to make work. Can't post pictures of the Bosch pump though but I will say the Bosch pump had a much larger centrifuge to the point intake fitment was an issue that had to be dealt with.

 

[Rot Box]

Speaking of injector lines make sure you use all of the clamps and see that the rubber isolators are in good shape. It is not uncommon for lines to crack and break when these are missing :Wow1:

I know you are getting a lot of info thrown at you but one thing I would recommend when you go back together is not to use any gaskets on the valve covers or oil pan, such as that cork oil pan gasket in your pictures.

We used Right Stuff to glue the tin covers and oil pan back on this 6.5L as that is what my buddy that we built the Burb suggested. He worked at AM General on the Optimizer6500 engineering team so he should know. Going gasket comando with just sealant works! It never leaked!

I couldn't agree more. Right Stuff is what you want here. Don't use Permatex Ultra Copper whatever you do :elkgrin:

 

[1leglance]

Thanks again for all the great info guys...I really like that I have to take notes in my own build thread
But that is why I post, not so much so others can enjoy but so that I can benefit from all the knowledge around here!

I am thinking I will get a new Flex plate as the teeth on mine are pretty worn. Normally I like to get factory parts...any thing better out there than GM?

Also I read that the later engines got a gear reduction starter....any info on that? Go with GM factory unit or something aftermarket? And if I do go with the later gear reduction unit will I need a new/different support bracket/tail hook?
Any good source for the timing cover (the lower part)...mine has a big ol' crack in it.

Anyone ever run a hard metal line to bring oil to the turbo? The owner of the shop I took the turbo too recommended the idea instead of the braided steel/rubber line I have now.

 

[Larry]

Also I read that the later engines got a gear reduction starter....any info on that? Go with GM factory unit or something aftermarket? And if I do go with the later gear reduction unit will I need a new/different support bracket/tail hook?

A starter upgrade would be well worth it. This AC Delco 336-1912 would fit the bill. Should be a direct bolt on, outside of maybe different bolts. This is the starter we used on our 6.5L project. It does have a gear reduction but not as large as reduction as the Denso I added to my 5.7L gas Suburban. If Denso makes a starter for the 6.5L I would highly recommend using it but they are very pricy for a starter (~$300-$400).

 

[1leglance]

So while I have some down time wating for things to come back from various shops lets have some fun figuring out a few things:

Tach...I would like to install something in my factory dash but I have no idea what drives the tach on a 6.2...any thoughts?

Since I will be running a hydroboost for brakes and the AC setup is going under the rear seats do I need the vac pump for anything? Can I just remove that part and block it off? I know I need to drive the oil pump but is there a later model part to drop in instead?

 

[shortbus4x4]

Does your HVAC system use vacuum to move doors and such or is it all cables? Does your transmission need vacuum? If you answered no then ditch the vacuum pump. I know the later 6.5 diesels had the oil pump drive with no pump, don't know if one would fit a 6.2. Get an aftermarket tach for a diesel and it will run off your alt.

 

[ExpoMike]

As for a tach, this is what I put in the M1010 when I had it. Very popular on SteelSoldiers.com. It has an inductor that mounts on any of the fuel pressure lines to the injector. Works great and much more acturate than the alt setups. Nice thing, it also had a resetable hour meter too.

http://www.tinytach.com/tinytach/diesel.php

 

[arveetek]

The later 6.5L's use a cap in the valley that still drives the oil pump, but allows you to remove the vacuum pump.

I deleted the belt-driven vacuum pump off my 6.5L as well.

As has been stated, if you don't need vacuum for the transmission or HVAC controls, then you can ditch the pump. My 6.5L Tahoe uses electric motors to operate the HVAC controls, and the transmission is all electronic. The pump on mine was only needed to control the turbo wastegate and emission controls. I deleted the emissions crud and installed a mechanical wastegate controller.

As for the tach, if you're wanting to use the OEM tach in the dash, you'll have to do some research on how to use one of the above ideas (alternator, injection line pulse) to mate to the original tach. It's been done, but that's out of my realm of knowledge. I would recommend researching at www.thedieselpage.com or www.thedieselplace.com Both are excellent resources for the 6.2L/6.5L family.

Casey

 

[1leglance]

Well one of the shop guys came in and told my wife that the block has cracks (she is the office manager of a diesel engine machine shop).
She went out and snapped these pics with her phone and sent them to me.
I have not spoken to the owner who runs the shop to see if he is willing to try & fix it. I do know that he wasn't real excited about working on a 6.2 in the first place
So I think I will start the hunt for a 6.2 block or complete engine in case he won't work on it, if anyone has leads.

 

[Rot Box]

Bummer.... Dang that's too bad I was really looking forward to this build A friend of mine just wrapped up a Cummins swap in a 82 crew cab. He has the original 82 6.2 motor sitting in his garage now and i'm sure he'd probably part with it for a good price. 82's are the one year only "red block" which are said to have much more iron and strength in the block making them sought after. It ran when he pulled it, but it wouldn't hurt to pull it down for an inspection imo. Its a bit of a drive, but if you are interested I can ask him about it--he's a member here, but I don't think he check in very often..