If that is figured right and that is what it actually is (8.96) it's fine.

 

Well according to every thing you gave here it is

 

I was using the wrong numbers to figure my DCR that's why I thought I had to use such a thick head gasket. I was concerned with the right DCR because I don't want to run into detonation problems on pump gas. The quench wasn't optimal with that gasket, but I believe the quench on the stock motor is somewhere around 0.075 if I'm not mistaken, so I wasn't as worried about that. Now that SStroker has helped me out so much I will be able to run the FelPro 1074 (0.039) w/o any problems and also have a good quench. Thanks again SStroker and also 1racerdude for helping me out!

Thanks,
Anthony

 

The reality is and it's very hard to convince anyone about it....

That it's better to have a higher static compression ratio with a tighter quench than it is to have a tall quench and a lower compression ratio, you will have more detonation with the larger quench area, becuase you can't get the air fuel ratio out of the "bad spots" of the chamber and pistons to keep them from causing detonation.

Bret

 

exactly my point Stroker. Proper quench height is very important. ulakovic22, I think you will find that the quench height from the factory is way lower than .070" . I know in the old days the factory used a pretty thin head gasket that worked well with the typical .025 in the hole piston.

To me, this whole dcr thing is WAY over rated. its just a guideline, there are other factors that can greatly effect an engines low octane tolarance. The combustion chamber design , Piston design (flat, dished or domed ect) and the quench will have a huge influence on octane requirements. The dcr is just a small piece of the pie.

DJ

 

If the piston is in the hole 0.025 and the factory head gasket is approx. 0.049 thick, wouldn't that be a rough estimate that the quench height is around 0.075? I might be way off base, and I very well may be. I'm just glad that everything is going to work out for me so I don't have to worry about it anymore.

Anthony

 

Build two engines the same, except quinch.Run the same fuel. Build one with .070 and one with .030 and thrash the hell out of them on the dyno and see which one will detonate first and which makes the most power,with all else being the same.

 

I am with the boys here. I have been running Quench motors since the 80s. they always run good on Pump gas(with in reason) and make great power.

I also agree on the factory Quench sucking so bad! My old motor was .032 in the hole and factory .052 gasket! The is a .084 Quench! I cut it down to just under .060 and she was MUCH happier New motor is setting right at .005 in the hole and a Felpro usually comes out to .040 after crush. I have about a dozen of them hanging on the wall so I am pretty sure on the crush I decided on this so I would not be stuck with just one gasket choise .045 should be fine

 

I wonder why the factory isnt using the thin shim gaskets anymore, maybe they dont work well with the aluminum heads and blocks.?

anyway quench is good

DJ

 

I would assume that the car companies got away from thin gaskets because of the higher compressions and also the use of aluminium heads/blocks. If you look at the Impalas they do have a thinner gaskets (0.029), but use cast iron heads that aren't easily warped and also run lower compression. What is the gasket thickness of the LS1's? They run both aluminum heads and blocks.

Anthony