Deck height ?

New class rules allow for zero deck height. Given an old style predator @ .063 in the hole, how much should I mill for optimal compression, combustion, quench etc? Milling head is not allowed.

Specs:
Billet rod n flywheel
650 carb on gas
Mod 2 cam
1.3 rockers
Flat top out of hemi predator
Loop pipe
Honda valves
18lb springs
Running 670 gears on 1/10 mile almost flat oval.

Should I mill for ~ 0 deck and run .010" gasket? .040ish gasket? Or leave it .020" in the hole etc?
 
Last edited:

astrowrench

Member
Mill it.055, leave .007 in the hole; and then you can play w/Hd.Gskts and not worry to much about rod stretch;Last year I had a very similar engine also try a stock rocker on Ex. valve one time see if it helps.and keep lash tight .002 cold
 

sCREamnClones

New member
Mill it.055, leave .007 in the hole; and then you can play w/Hd.Gskts and not worry to much about rod stretch;Last year I had a very similar engine also try a stock rocker on Ex. valve one time see if it helps.and keep lash tight .002 cold

Me(?)....I wud 'make' a (+).050 rod...:) Seriuosly....you/we can cut 'that-much' off the Pred block?
 
Me(?)....I wud 'make' a (+).050 rod...:) Seriuosly....you/we can cut 'that-much' off the Pred block?


Yep:cool: About .060 on old style and .020 on hemi. Probably more benefit on a +.020 rod in the hemi rather than milling .020 off. On the old style a +.020 rod would still leave the piston ~.040 down. However every one of these Chinese made engines may vary so better "measure twice cut once".
 

sCREamnClones

New member
Yep:cool: About .060 on old style and .020 on hemi. Probably more benefit on a +.020 rod in the hemi rather than milling .020 off. On the old style a +.020 rod would still leave the piston ~.040 down. However every one of these Chinese made engines may vary so better "measure twice cut once".
ahh sooo....thank you!
 
I am still not sold on the dome piston, as long as I can get the compression I want with a flat top (or dish for that matter).I don't want a wall for my flame to have to cross..JMO
 

sCREamnClones

New member
I am still not sold on the dome piston, as long as I can get the compression I want with a flat top (or dish for that matter).I don't want a wall for my flame to have to cross..JMO
Yeah but...? (How about a 'subtle' dome...?) Big Block Chev's and Chrysler Hemi's don't do too bad! :)
 
Yeah but...? (How about a 'subtle' dome...?) Big Block Chev's and Chrysler Hemi's don't do too bad! :)

But, in a BBC there is little choice to get compression. However,( if money is no problem) check out the chamber in a BBC Big Chief head, no need for a big dome to get compression and make mad power. I can say that I have made more power with flat top and dish pistons in my drag stuff, when I could get the compression where I wanted . Now the BBC stuff has domes..but require more timing in order to light the mixture on the other side of "the wall". This is just from my experience. :)
 

old school mike

New member
Dish Piston

I am still not sold on the dome piston, as long as I can get the compression I want with a flat top (or dish for that matter).I don't want a wall for my flame to have to cross..JMO

I agree with you, I make good HP with a dished piston .010 in the hole with a .009 gasket.
 

sCREamnClones

New member
But, in a BBC there is little choice to get compression. However,( if money is no problem) check out the chamber in a BBC Big Chief head, no need for a big dome to get compression and make mad power. I can say that I have made more power with flat top and dish pistons in my drag stuff, when I could get the compression where I wanted . Now the BBC stuff has domes..but require more timing in order to light the mixture on the other side of "the wall". This is just from my experience. :)
...for sure (my son has a set) even more so when you stuff it w/C16 and N20...:) The best-bang-4the-buck is STILL the sm-block!
 
Only reason I suggested dome piston is because he cant mill the head. Just a way to increase compression.

I got ya. We all have different ideas, I know you know what your doing. I am still learning on these little things, but most of what I have done in the big stuff seems to transfer to these, so far..LOL
 
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