9.14:1 static compression, 8.11:1 dynamic (light polish 64cc)
9.54:1 static compression, 8.44:1 dynamic (mill to 60cc)
9.73:1 static compression, 8.62:1 dynamic (mill to 58cc)
10.0:1 static compression, 8.9:1 dynamic (mill to 55cc)


This is a n/a motor, 114lsa (9 degrees overlap).

Not sure what to mill the heads to..

-- Joe

 

I generally don't like to mill heads and when I do I keep it modest. Option 2.

Being a little lower on compression than you might like is a minor problem compared to running the risk of not getting your intake to seal up against the heads. Not the end of the world, but even if you have the problem only once you'll wish you had given up a little compression rather than dealing with that headache.

 

Well either way, you have to re mill the intake mounting surface of the heads. I'm gonna angle mill the heads, and mill the intake mounting surface so intake sealing won't be an issue. this is plainly a static CR vs DCR vs my cam question. Shortblock is together, and thats that.. so its a simple matter of how I work the heads..

-- Joe

 

A DCR between 8.0 and 8.5 is usually the best for pump gas and iron heads. I'd also go with option 2.

My DRC right now is about 8.9 and its REALLY picky about its tune when running pump gas. Its gotta be dead on, or the motor is not going to be too happy. Keep it below 8.5 and you should be just fine.

 

What about aluminum heads? forgot to say I'm running trickflow 23* aluminum.

-- Joe

 

What quench distance are you running? That must be a small cam.

 

.044" quench, cam is 230/244 @ .050, .535/.540 lift, 114 lsa, 113 ica.

Using a DCR calc, I get the above posted numbers. For other reference, the pistons are reverse dome (mirror chamber), -16cc cups, h-beam rods, steel crank, blocked decked so the piston is .005" in the hole, and a .039" x 4.166" head gasket. The trickflows are 62cc as cast, but with a light polish they cc out to about 64cc I believe.

Now of course, this is N/A, so I guess I have the option of using nitrous. The cam should be fairly nitrous compatible, I originally had it ground because I intended on using a small s-trim blower when I was gonna use the motor in a thirdgen, but I've since bought a vette and sold the blower cuz it wont work.


-- Joe

 

option #4.
Aluminum heads, and 230/244, I think you'll be fine with that. Option #3 if you plan on using a larger nitrous shot. >200HP
Polish the chambers either way, and do the piston tops if you've got the time.


I re-edited this 4 times, after considering all those variables, .044" quench, AL heads, reverse dome pistons.

That will be a FUN ride!