Another low budget 360 build
so would I be better off with H405cp pistons and a thicker head gasket or even stock cast with thinner gaskets?
This question answered last.
would there be much of a difference in performance?
It would take a side by side test to allow you to feel the difference and a track to see the slip times. It would be small but very much there.
So how do you achieve quench with open chamber heads without running high octane fuel?
Odd looking pistons. Quench pad on one side, deep dish on the other.
I was originally looking at running higher compression with H116cp pistons. Could I get away with these and open chamber heads using the other components listed above and run 89 or 91 octane fuel?
Not 89. 91 if your careful.
I'm very mechanical but get stumped on calculating stuff like this.
I just want to build a good running reliable engine that has enough power to play with when I want to.
Thanks for your time
Completely understand. I went through a lot of trial and error before the internet was invented.
MoPar used to sell a head shim. This was .100 thick and designed to be intalled inbetween the head and block to lower compression for todays crappier fuels and run a lower octane. It takes away all quench. Not so good for power but it did allow you to at least drive your car. Very helpful for those nasty 13-1 & 11-1 iron headed engines of yesteryear.
so would I be better off with H405cp pistons and a thicker head gasket or even stock cast with thinner gaskets?
The H405cp is a bit lower of a ratio. You will need to do the math on exactly where it sits in the cylinder bore and how many cc's the head is, gasket thickness and it's bore size. Once you know all the specs, you can go here;
Compression Ratio Calculator - Wallace Racing and calulate the compression ratio.
Iron head and small cam = 8.0-1, moderate to big-ish cam, 9.50-1 MAX
As for the H116cp slugs, this is what I am doing.
You can run the H116CP with a .038 gasket and moderate cam if your also going with a higher stall converter and gear. Currently, I have this set up going on now but with a thick MLS gasket @ .075 to reduce detonation problems with small cams. (reduced to 9.94-1) Later, the head gasket will be replaced with a .036 (10.90-1 before head milling) and a healthier cam, (
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[email protected]) 4.10's instead of 3.55's, more converter.
(.030 = 11.07-1, .027 = 11.16-1 )
Notice the lower compression with the smaller cam. While I would like lower, it willwork with an aluminum head and 93 octane. It's cutting close. These ratio's are possible with aluminum heads. Reduce your ratio by 1 point min. with iron heads. Quench or not.
