Turbo 6.2 (6.5 turbo setup)

[madcow75]

Also a good preventative mantainence that I will be installing on my 6.2L bottom end is a stud girdle, this will help with cylinder wall flexxing and cracking. I have checked mine and no cracks yet but I still will add one.

What is stock compression in a 6.2L.

[sierra4x4]

I have to agree with Edahall. The 6.2/6.5's don't hold up very well with a turbo. Every 6.5T that I have opened up had cracks in the block and most of the heads. The NA 6.2/6.5's seed to run forever.

[Edahall]

Originally Posted by madcow75

Also a good preventative mantainence that I will be installing on my 6.2L bottom end is a stud girdle, this will help with cylinder wall flexxing and cracking. I have checked mine and no cracks yet but I still will add one.

What is stock compression in a 6.2L.

Stock compression ratio on a 6.2L is 21.5:1

[Corts60]

I really appreciate this thread. I thought only the 5.7's couldn't handle the turbo. I thought the 6.2/6.5's were good to go. Stock compression on the 5.7's were 22:1. I wonder if you could lower the 5.7's to 18:1 compression and turbo that sob.

[Edahall]

Originally Posted by Corts60

I really appreciate this thread. I thought only the 5.7's couldn't handle the turbo. I thought the 6.2/6.5's were good to go. Stock compression on the 5.7's were 22:1. I wonder if you could lower the 5.7's to 18:1 compression and turbo that sob.

From what I've seen, the 6.2L in stock form can handle about 6-7 psi of boost and still be reliable. Over that, you're asking for trouble. Of all the turbos out there, the Banks turbo was by far the easiest on the engine but also produced the least amount of boost and power.

Lowering the compression would help and would allow more boost but there's still a limit and the limiting factor is the bottom end. A strong bottom end is the reason the 5.9 Cummins can produce well over 1000 hp and the 6.2L much less.

[406 Q-ship]

Originally Posted by Corts60

I really appreciate this thread. I thought only the 5.7's couldn't handle the turbo. I thought the 6.2/6.5's were good to go. Stock compression on the 5.7's were 22:1. I wonder if you could lower the 5.7's to 18:1 compression and turbo that sob.

I was dealing with the 5.7 diesels back when they were still under warrenty. DO NOT EVER PUT ANY BOOST TO A 5.7 UNDER ANY CIRCUMSTANCE!!!!! The only place a 5.7 Olds diesel should ever be is at the end of a chain under a boat. Funny thing, I was pulling the 5.7 out of trucks, Cadillacs, Oldsmobiles, and Buicks to convert them to gas engines (worked at a place that did smog legal gas conversion), we sold the running (some broken ones too) to a New Zealander who was using them for agraculture water pumps. When run at a steady RPM the olds diesel would live forever.