Quench?
Quench? How is it measured and what numbers to shoot for? I've been using pianoprodigy's spreadsheet ; is it in there? Also, how do you change it - just the head gasket thickness and milling the heads? I have my cam in (224.7/228.7 duration with .643/.645 lift on a 110.2 LSA) and am saving up for my heads (AFR 205's). I'm just trying to figure out how much to have them milled, and what gasket to run (probably a cometic .040) for the best performance with 93 octane.
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Joined: Dec 2004
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From: K-W, Ontario
Quench is the distance between the piston at TDC and the quench pad of
the cylinder head.
Gasket thickness and piston to deck clearance are the components needed
to figure quench height.
Milling the heads wont change quench height; that doesn't change the distance
from the piston crown to head.
As for numbers to shoot for, there's quite a bit to consider including (but not
limited to)
rod material, piston mass, max. RPM, thermal expansion, etc.
Typically for the average street/strip motor you could be safe with about 0.040-0.045"
Going tighter gets more involved.
the cylinder head.
Gasket thickness and piston to deck clearance are the components needed
to figure quench height.
Milling the heads wont change quench height; that doesn't change the distance
from the piston crown to head.
As for numbers to shoot for, there's quite a bit to consider including (but not
limited to)
rod material, piston mass, max. RPM, thermal expansion, etc.
Typically for the average street/strip motor you could be safe with about 0.040-0.045"
Going tighter gets more involved.
Originally Posted by Marc '99T/A
How is it measured and what numbers to shoot for? I've been using pianoprodigy's spreadsheet ; is it in there? Also, how do you change it - just the head gasket thickness and milling the heads? I have my cam in (224.7/228.7 duration with .643/.645 lift on a 110.2 LSA) and am saving up for my heads (AFR 205's). I'm just trying to figure out how much to have them milled, and what gasket to run (probably a cometic .040) for the best performance with 93 octane.
Hammer
Originally Posted by Marc '99T/A
How is it measured and what numbers to shoot for? I've been using pianoprodigy's spreadsheet ; is it in there? Also, how do you change it - just the head gasket thickness and milling the heads? I have my cam in (224.7/228.7 duration with .643/.645 lift on a 110.2 LSA) and am saving up for my heads (AFR 205's). I'm just trying to figure out how much to have them milled, and what gasket to run (probably a cometic .040) for the best performance with 93 octane.
read this. http://www.nitrophotos.com/240z/nitrous.html
Originally Posted by Marc '99T/A
I'd be looking at a DCR of 8.88 
Hammer
Originally Posted by brad8266
Measure it by adding the amount the piston is in/out of the hole and the gasket thickness. (Stock is -.006 + .052 = .046 Quench)
Originally Posted by thehammer69
I think you will find it closer to 8.7ish...which should be good for pump 93 octane. I base this on adjusting the the actual spreadsheet results for the ramp rate of the LSK cam lobes.
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Originally Posted by Marc '99T/A
Thanks; that's actually what I was looking for.
We must be doing it differently because I'm getting 8.88 from a chamber volume of 61 ;8.76 from 62cc's; and 63cc's gives me a DCR of 8.65. (all using a .040 gasket) Tell me if I am doing it wrong; I want to do this right. Thanks.
We must be doing it differently because I'm getting 8.88 from a chamber volume of 61 ;8.76 from 62cc's; and 63cc's gives me a DCR of 8.65. (all using a .040 gasket) Tell me if I am doing it wrong; I want to do this right. Thanks.
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Originally Posted by Marc '99T/A
Thanks; that's actually what I was looking for.
We must be doing it differently because I'm getting 8.88 from a chamber volume of 61 ;8.76 from 62cc's; and 63cc's gives me a DCR of 8.65. (all using a .040 gasket) Tell me if I am doing it wrong; I want to do this right. Thanks.
We must be doing it differently because I'm getting 8.88 from a chamber volume of 61 ;8.76 from 62cc's; and 63cc's gives me a DCR of 8.65. (all using a .040 gasket) Tell me if I am doing it wrong; I want to do this right. Thanks.
Hammer
Originally Posted by thehammer69
I get high values in the DCR calculator also. I just know from info supplied from Patrick G that you need to adjust for the ramp rate of the LSK lobes which the calculator isn't. Maybe he can explain it better.
Hammer
Hammer
Plug in 224/226 .636 .639 110LSA, thats as close as you will get with the comp grind. if you get the 66cc AFR 205's with a .040 gasket, cam installed @ 110 ICL you will have 8.45 DCR. Take .015 off the heads deck and you will have 8.77 DCR.
Originally Posted by brad8266
If its a comp grind cam you dont have to adjust for ramp, it does it for you. Is the cam ground by comp because the specs you gave dont sound like it? It ramps faster than an LSK lobe.
Hammer
Originally Posted by thehammer69
Brad..the calculator uses the .006 and .005 numbers to come up with DCR. If you look at the 224 & 228 lobe specifications for both the XER and LSK...you will see they are identical. The only way to account for ramp rate is the actual measured spec at .006...which the OP did not give us.
Hammer
Hammer
XE-R- 224/228 .581 .588
LSK- 224/228 .636 .639 Plug this number in on the sheet tabbed "Start here and enter cam specs", then go to page titeled "DCR" and it will ahve the appropriate values in there automatically.
Originally Posted by brad8266
No the 224 ans 228 specs are completely different for the 2 different lobes. Look again.
Hammer
Originally Posted by thehammer69
On the list I have...they are identical and only show different at .200" and above. As Patrick told me, you have to use the real world measured specs to get accurate numbers, the OP only gave them for .050".
Hammer
Hammer
Originally Posted by brad8266
No the 224 ans 228 specs are completely different for the 2 different lobes. Look again. the only thing that is the same is the duration @ .006
XE-R- 224/228 .581 .588
LSK- 224/228 .636 .639
XE-R- 224/228 .581 .588
LSK- 224/228 .636 .639
Hammer
Originally Posted by brad8266
yeah but you can look up the lift and duration @ .006 on the source sheet.
Hammer
Originally Posted by thehammer69
Obviously you are not understanding what I am trying to say. Those cam specs you just listed I know. PianoProdigy's and J-Rod's calculator only perform calculations based on the Intake lobes duration at .006 and .050". I will list them for you to see in a moment.
Hammer
Hammer
Originally Posted by thehammer69
Which are NOT real world numbers...you need the cam doctored numbers
Hammer
Hammer
