gurus, need a quick word on quench height
06-26-2008, 12:54 PM
#21
really? damn it. I hadn't looked yet, just going off what someone else had said. I just assumed they had it for a bored block. What bs. I have to find something that is no more than .030 to keep my quench below or at .055. I really dont want to use the .015 shims because im not positive my deck is 100 percent straight and .015 doesn't seem too forgiving.....
while i got you guys attention, assuming i can find a ~.030 head gasket, my static cr would be ~9.9.1. Im assuming there is no way in hell i can run this compression with iron vortec heads? im guessing Ill have to switch to aluminum?
while i got you guys attention, assuming i can find a ~.030 head gasket, my static cr would be ~9.9.1. Im assuming there is no way in hell i can run this compression with iron vortec heads? im guessing Ill have to switch to aluminum?
This is all part of engine building. You seem to be doing it backwards, not that it won't work. But I picked a max rpm, then pick a cam that will take it to that rpm, then pick a static compression that will give a good DCR with that cam.
06-27-2008, 11:30 AM
#22
well, according to keith blacks dynamic cr calculator, it shows my dynamic cr to be 7.9. I think that it may work if that is true.
64cc heads
7cc flat tops
.030 thick gasket (if i can find one)
4.1 gasket bore
4.040 cylnd bore
.025 deck cleareance
3.48 stroke. comes up to 9.839 static
with a 5.7 rod length and cam has 64* intake closing point at abdc @.050, it shows dynamic cr at 7.914. Do you see any discrepancies?
64cc heads
7cc flat tops
.030 thick gasket (if i can find one)
4.1 gasket bore
4.040 cylnd bore
.025 deck cleareance
3.48 stroke. comes up to 9.839 static
with a 5.7 rod length and cam has 64* intake closing point at abdc @.050, it shows dynamic cr at 7.914. Do you see any discrepancies?
06-27-2008, 12:48 PM
#23
I'd use a .015 gasket. They are rubber coated but you can spray them with perm a gasket copper, I've put new heads on old never decked blocks and never had a problem.
.055 is too much IMO.
.055 is too much IMO.
06-28-2008, 01:21 AM
#27
Yea, you should be ok in the 7.9 range or even if a .015 gasket puts you in the low 8.0 dcr range.
I've learned those DCR calculators are not 100% accurate. The one 357 I ran with close to 11:1 SCR, I used three different cams in that. Changed nothing at all but the cams and lifters, kept total timing the same. One cam was 8.4 DCR, the other two gave it 8.5 DCR. One cam and 8.5 DCR would run strong with 89 octane, the other cam with 8.5 DCR would detonate a bit on the top end with 93 octane.
As for quench, I put together a near stock 406 sbc, it had deep dish pistons, 64cc heads, small cam, .060 quench. I should have known better but that engine didn't like anything under 93 octane. It had well under 8.5 SCR.
Thats why I say keep it tight. Because it's worked for me.
I've learned those DCR calculators are not 100% accurate. The one 357 I ran with close to 11:1 SCR, I used three different cams in that. Changed nothing at all but the cams and lifters, kept total timing the same. One cam was 8.4 DCR, the other two gave it 8.5 DCR. One cam and 8.5 DCR would run strong with 89 octane, the other cam with 8.5 DCR would detonate a bit on the top end with 93 octane.
As for quench, I put together a near stock 406 sbc, it had deep dish pistons, 64cc heads, small cam, .060 quench. I should have known better but that engine didn't like anything under 93 octane. It had well under 8.5 SCR.
Thats why I say keep it tight. Because it's worked for me.
07-03-2008, 11:38 PM
#28
According to the calculator I use you're considerably lower DCR than you posted. http://www.kb-silvolite.com/calc.php?action=comp
Note where it says to add 15 degrees to the closing point at .050. According to that, you're at 6.959 DCR.
Note where it says to add 15 degrees to the closing point at .050. According to that, you're at 6.959 DCR.
