The 8.21 DCR is pretty much aluminum head territory and much higher than the 7.54 or whatever it was that was posted previously, which I thought sounded rather low for 10.3ish static with short duration cam. Big negative on doable on pump gas. .028 drops static to 9.8ish static according to my calc's @ Wallace with no quench and can be in the detonation danger zone so .028's are not a good option either. If you have to back up timing to get it to run your killing power so not a best case scenario either.
I've done 10.5 iron headed. It needed some race gas mixed in to run right. 10.+ iron headed on pump gas ford, chevy, or mopar is not typically doable even with quench. Every pro head porter I've dealt with has told me to stay out of swirl port heads at anything beyond a minimal bowl blend and cleaning up casting boogers. Kill the swirl effect, or too much cross sectional area in the wrong place and it's not hard to end up where an untouched head moves more air with better cylinder filling/combustion efficiencies etc.
Kinda funny the program lists optimal LSA at 107. I think I hear Vizard laughing, and damn right you need to be careful what the internet weirdos link to and promote.
Wow, this thread is starting to expand way beyond my experience/comprehension.
I'm a bit worried that now I've created a problematic motor.
the thinnest gasket from cosmetic I see on thier site is .023, so not much of a difference.
I would have assumed that the .40 overbore on a stock block and the summit flat top pistons(1.560 compression height) would have created only a slight increase in compression, as its not a dished piston anymore.
I was thinking that adding the stock cam (LT1) to a stockish block would have created a stockish engine build, IE the roadmaster, iron head LT1 had 9.6:1 compression ratio.
But it appears that I was wrong.
The head porting amounts I followed, were to the 3rd cut from Charles Servedio videos ( another internet wierdo?), where he flow tests his porting changes.
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