above deck ?

[krazykuda]

Well they measured and it was .010 out of the hole and with a .039 gasket. Only left .029 clearance and they want .035 clearance and so they're going to cut out the heads a little bit to give room that way?

What bore adn stroke are you running? Post it and I can do a calc to tell you where you are going to be.

Fel-pro also has a gasket that is .056" thick and is 12.6 cc.

I think you will be ok, but you will have to check piston to valve clearance. Post up your bore and stroke....

 

[krazykuda]

Demand a thicker gasket. They're just wanting some more $$$ on the deal. Machine work in house pays better than ordering gaskets in my opinion

You have a good point there...

 

[moper]

Depends on the combination - but I routinely build with them positive deck. If you want to use the cheaper head gaskets at .039 thick and run milder street type compression ratios you have to in order to get an effective quench. The only engines I build with more than .035" quench are 400-based strokers because of the short piston and big bore. There's more rock at TDC, so you need a little more room for it to wiggle.

596 heads - open chamber. There is no quench, and you have plenty of room in there. The issue might be static ratiom with flat tops.
What cam are you running?

 

[j par]

Depends on the combination - but I routinely build with them positive deck. If you want to use the cheaper head gaskets at .039 thick and run milder street type compression ratios you have to in order to get an effective quench. The only engines I build with more than .035" quench are 400-based strokers because of the short piston and big bore. There's more rock at TDC, so you need a little more room for it to wiggle.

596 heads - open chamber. There is no quench, and you have plenty of room in there. The issue might be static ratiom with flat tops.
What cam are you running?

Sorry if this sounds familiar - it's a copy/paste from my "question of the day?" Thread a couple of weeks ago.e day! ??

horsepower could be the question of the day? !
×2 600 cfm edelbrocks tunnel ram, 596heads (home porting- smoothing exhaust ports/ opening under all seats just a little bit- not getting carried away here I'm a first timer) then back to the shop for valve job-1.60/1.88 . Solid cam (regrind) cam- duration@ .50 - 259/267 lift gross 546/566 lash .026/.028 lob sep. 104/110
Av. 107. 273 rockers. 360 block, scat stroker (cast) crank, scat I-beams, icon forged flat tops - 10.8 : 1 with 70cc heads.*

Of course this will be in my 73*duster
gutted
4 speed
355 sure grip
26 in street slicks

 

[moper]

Sounds like you've got enough cam to not sweat the 10.8:1 - that was my concern. I don't think it will be an 87 octane deal - but you should be able to tune it to run well on pump high test. You really could use the larger valves if they are in the budget tho. If you're blending the throat into the bowl and gasket matching, you can install 2.02 or 2.05s/1.65s with no troubles and they will help the 4" combo.

 

[j par]

Checked the shop today and they where fixing to cut the heads open a tad. Here's a picture of there outline.View attachment 20150205_093705.jpg

 

[RustyRatRod]

Using the OP's flat top pistons and a closed chamber heads I could see going through the process of building a quench motor. With an open chamber and a flat top piston the squish to the exhaust valve just isn't there. I'm not a pro engine builder but have built a few in my day and this is my opinion of why you need a closed chamber for a quench motor.

read this article
https://www.rbracing-rsr.com/squishcalc1.html

Several companies make off the shelf pistons that will make a quench condition with the standard Mopar small block open chamber head.

 

[moper]

Several companies make off the shelf pistons that will make a quench condition with the standard Mopar small block open chamber head.

... provided you do a lot of checking and special machining of the chamber roof and the pistons. I did one and wouldn't do another unless it was forced. Just my opinion but the potential benfits aren't worth the $$ if you're paying to have it done.

 

[RustyRatRod]

... provided you do a lot of checking and special machining of the chamber roof and the pistons. I did one and wouldn't do another unless it was forced. Just my opinion but the potential benfits aren't worth the $$ if you're paying to have it done.

I don't disagree. I was merely pointing out that quench pistons ARE made. Almost worth building a Chevy instead of all the trouble if you're just dying to have quench.

 

[racerhog]

Just fine 0.010 out of the hole...... Run it... It's good to go..... Just keep check on the vavle springs.... sheeeesh