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6.2 / 6.5 hybrid

jmiller

Recruit
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Location
Lake Villa, CRIL
I received a suggestion to go with a 6.2 bottom end with 6.5 heads and oil cooler lines tapped to 1/2".

It was cheaper for the hybrid long block than any 6.5 short block price that I've seen. The suggestion came with a pretty strong recommendation.

Comments, experiences, suggestions?

:feedback:

Thanks
 
Last edited:
A late "599" block is the easiest swap.It has the oil port for the turbo already in the block.Years 91-93
 
A late "599" block is the easiest swap.It has the oil port for the turbo already in the block.Years 91-93
Some 94's (early ones) have the 599 block too. At least both of mine do. Built in Oct and Nov 93.
 
Placed my order with Jamie today. 6.2/6.5 hybrid

Time to cleanup and fix the small stuff while I'm waiting for it to show up.
 
im doing a 6.2 6.5 hybrid with a 1991 6.2 block. but i dont know where to put the oil supply for turbo. where it comes off the block on my 6.5 it just says GM6.2L and no oil passage at all. (front pass side of block).
 
There is a pipe plug just up from the oil filter use that plug get a line made (stainless with a teflon interior) and run that to the turbo. did you enlarge the block oil filter feed and return passages to the same size as the 6.5 liter block? Most don't but it is a nice thing to have the extra volume. Check your 6.5 block and the 6.2 block and you will see the differences. One note of cation, thread the oil gallery plugs in the back of the block and put pipe plugs in them and lock-tite then in. You will see what I mean when you look at it. Just a few tricks to make your 6.2 block last a nice long time. A lot of 6.2 blocks have pressed in steel plugs, verses the threaded plugs, same with the front oil galley plugs.
 
Some Tee off of the OPS for an oil supply.

I have 2 engines tee'd off the OPS as the plug is almost impossible to remove. Make sure the tee is short to avoid hitting the firewall.
 
I thought the 599 block went through '96, then they went with the 506 oil squirter block. I know that our wrecked '95 Suburban has a 599 in it.
 
How about boost pressures? I have been told the 6.2 block should be run at lower boost pressures than a 6.5 block, but i cant seem to figure out why. Same block with a slightly smaller bore....

When locating a crack free block, the 6.2's are alot easier to find vs. the 6.5's and alot cheaper. Maybe just due to lower power levels put that much less stress on the blocks from the factory.

What are you guys running for boost numbers with the 6.2/6.5 hybrids?

-Nick
 
How about boost pressures? I have been told the 6.2 block should be run at lower boost pressures than a 6.5 block, but i cant seem to figure out why. Same block with a slightly smaller bore....

When locating a crack free block, the 6.2's are alot easier to find vs. the 6.5's and alot cheaper. Maybe just due to lower power levels put that much less stress on the blocks from the factory.

What are you guys running for boost numbers with the 6.2/6.5 hybrids?

-Nick

Im pretty sure it has nothing to do with the block itself but instead it has to do with the pistons, They are not anodized like the 6.5 turbo pistons so the 6.2 pistons cant handle high heat. I also think it has to do with the precups. The 6.2 cups are smaller and can crack under high boost levels. They were never meant for or built for forced indutcion
 
Tee off the OPS just behind the drivers side head. Use a good tread sealer so you don't have any leaks. I had to redo mine after it leaked. Its a real "B" to do when the engine is in the truck.

Best to install the Tee and turbo line before the engine install, do a mock up of the intake, FFM, and turbo to get the routing correct. It will save you time in the long run. BTW, the stock hose is too short. A Tee and line came with my engine, I don't know the length.


I've been running stock boost.

The one recommendation I took when ordering my engine was to ceramic coat the pistons. This will help with heat and protect the piston when an injector starts to behave badly.

IIRC the squirter's were added to cool the piston. Since the 6.2 doen't have squirter's, you have to control heat some how. Reduce boost or use coatings.


I have about 40k on my engine. My driving style is semi binary for the most part. So the combustion chamber sees its share of heat. No ill effects to this point.
 
Im pretty sure it has nothing to do with the block itself but instead it has to do with the pistons, They are not anodized like the 6.5 turbo pistons so the 6.2 pistons cant handle high heat. I also think it has to do with the precups. The 6.2 cups are smaller and can crack under high boost levels. They were never meant for or built for forced indutcion

I was under the impression that most people arent even using the 6.2 heads, rather using the stock 6.5 heads? Or maybe im wrong..

Can the stock pistons be ceramic coated? or can they be bought at different compression ratios?

-Nick
 
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