LSA heads...can the chambers be opened up...?
LSA heads...can the chambers be opened up...? Can't find this answer anywhere in search.
Dropping compression this way is my only way to go....?
I'm at 10.8:1, plan on full time E85, and would like to decrease it a little bit since I'm in HOT South Florida.
My current chambers are 68cc.
I have flat top pistons.
Plan to go 18psi.
.
Dropping compression this way is my only way to go....?
I'm at 10.8:1, plan on full time E85, and would like to decrease it a little bit since I'm in HOT South Florida.
My current chambers are 68cc.
I have flat top pistons.
Plan to go 18psi.
.
When material from the chamber is removed the chamber size increases in turn decreasing compression. Other than possibly swapping to a thicker gasket, or going inside the bottom end I don't see any other options.
.
Last edited by LS6427; Feb 14, 2016 at 05:19 PM.
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I mean if I am going from a 68cc chamber to a 72cc chamber with flat top pistons I should get a little bit of a drop from 10.8:1.
I will also be using full time E85.....
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Verdad Gallardo Shouldn't, though I have no experience using them with LS engines. I used 3.5mm thick head gaskets on my 2jz engine at 30+lbs with out any issues. Thick HG's are super common in the import world.Call up Cometic and see what they suggest.
Do you know about what drop I could expect from 10.8:1 cr if I used a 3mm gasket..?
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http://www.summitracing.com/expertad...ion-calculator
Use the compression calculator above to figure it out. 3mm is an extreme example I'm sure you wouldn't run a gasket that thick. Would put you around 9.3:1. (w 68cc heads)
Think .075 is the thickest you can go before the price about doubles per gasket. Should put you around 10.2:1. Just call them up or send an email. List your specs (same as on the compression calculator above) and tell them what thickness gasket you want.
http://www.jegs.com/p/Cometic-Gasket...48860/10002/-1
Use the compression calculator above to figure it out. 3mm is an extreme example I'm sure you wouldn't run a gasket that thick. Would put you around 9.3:1. (w 68cc heads)
Think .075 is the thickest you can go before the price about doubles per gasket. Should put you around 10.2:1. Just call them up or send an email. List your specs (same as on the compression calculator above) and tell them what thickness gasket you want.
http://www.jegs.com/p/Cometic-Gasket...48860/10002/-1
http://www.summitracing.com/expertad...ion-calculator
Use the compression calculator above to figure it out. 3mm is an extreme example I'm sure you wouldn't run a gasket that thick. Would put you around 9.3:1. (w 68cc heads)
Think .075 is the thickest you can go before the price about doubles per gasket. Should put you around 10.2:1. Just call them up or send an email. List your specs (same as on the compression calculator above) and tell them what thickness gasket you want.
http://www.jegs.com/p/Cometic-Gasket...48860/10002/-1
Use the compression calculator above to figure it out. 3mm is an extreme example I'm sure you wouldn't run a gasket that thick. Would put you around 9.3:1. (w 68cc heads)
Think .075 is the thickest you can go before the price about doubles per gasket. Should put you around 10.2:1. Just call them up or send an email. List your specs (same as on the compression calculator above) and tell them what thickness gasket you want.
http://www.jegs.com/p/Cometic-Gasket...48860/10002/-1
.
What about quench area with a thicker gasket? Its possible to create more trouble than you solve by going to a thicker head gasket. What happens is, when you increase the distance from the quench area on the head to the piston, you loose mixture motion in the CC. In many cases, that will INCREASE the tendency for the engine to detonate, even though you've lowered the compression. A small change in gasket thickness probably wouldn't effect quench much, but at the same time its not going to lower the compression much either.
Kind of hard to explain. It is where you machine at a very slight angle a dish over the entire area of the combustion chamber. Google it and you can find some pics. Or go to yellowbullet and do a search. Plenty info over there.
The whole point of the exercise is to first slow the flame front down (helping to widen the tuning window) and then in some cases it is done to gain a few cc's in the chamber.
The whole point of the exercise is to first slow the flame front down (helping to widen the tuning window) and then in some cases it is done to gain a few cc's in the chamber.
Kind of hard to explain. It is where you machine at a very slight angle a dish over the entire area of the combustion chamber. Google it and you can find some pics. Or go to yellowbullet and do a search. Plenty info over there.
The whole point of the exercise is to first slow the flame front down (helping to widen the tuning window) and then in some cases it is done to gain a few cc's in the chamber.
The whole point of the exercise is to first slow the flame front down (helping to widen the tuning window) and then in some cases it is done to gain a few cc's in the chamber.
After playing around with some compression calculators.....it seems I can drop my compression to 10.5:1 with using stock chambered LSA heads and LS9 .055 gaskets for my 4.030 bore.
Or drop to 10.34:1 if Richards Stage 2 LSA heads are used with 72cc chambers.
Or 10.02:1 if Richard does the max of 75cc chambers....(spoke to him this week)
I think with full time E85 I should be fine with any of these.
What do you think???
.
Last edited by LS6427; Feb 17, 2016 at 08:17 AM.