new CR

[sshewins]

If we install .010 thicker head gaskets on an otherwise stock engine, what would the new CR be? The engine in question is a 83 6.2 that I'm toying with the idea of putting on 6.5 heads. Isn't the stock CR 22:1?

 

[gmctd]

The cr has varied slightly thru the years, but 0.010" won't lower any of the ratios significantly - main thing to remember is the 6.2 pistons are for naturally-aspirated service, no turbo - the 6.5 pistons have thicker crowns and are hard-anodized to withstand increased temperatures in turbo applications - other than different block\head water-passage configuration between the years, all else is same - if you just want a running engine, it is doable - if you have a heavy right foot, anticipate damaged pistons, etc.............................

 

[sshewins]

Hey! Glad to see you here Gmctd!! Yeah just kinda wanting my truck running again. Didn't quite realize the potential for piston meltdown. Didn't banks make a turbo for the .2's? I wonder if I kept the boost reasonable, it should be almost ok, for a while anyway.

 

[gmctd]

Correct - Banks sold the factory-approved turbo upgrade for the 6.2, but it was a wg-less turbo, and would not pump more than ~5-6psi into the na 6.2, so there wasn't much danger of doing any damage, particularly where the owner was unaware that the IP could be turned up to make more power - it helped for towing, but those wanting big power boost for hot-rodding the 6.2 complained loudly and longly that it was a p.o.s. - the factory 6.5 turbocharged engines were the result of those Gale Banks' GM-sponsored R&D efforts

 

[Brooklyn Tow]

So do we have Mr. Banks to thank for the"6.5TD?"

 

[Matt Bachand]

So do we have Mr. Banks to thank for the"6.5TD?"

Could also thank Henry Ford too if you want to play by those rules...

As always, great reads from GMCTD.