dockter71
New member
what is the minimum amount of squish for a stock motor? Or can someone lead me to a link on the forum to help explain.
Thanks
Thanks
A Kennedy
New member
On that engine I would not run any tighter then .042" Anymore questions email me at kennedy_fab@yahoo.com
what is this squish that you speak of? I was going to plane my head but don't know how much I should go. Any info would be great. 2000 srx 700
MountainMax
New member
it's the clearance between the top of the piston and the top of they cylinder head, the gap when the piston is at top dead center that's is the combustion chamber, if it's too small you can raise HP and promote detonation, or too big and you loose HP, get it just right for the fuel you want to run.... higher compression/less squish, needs higher octane fuel.
Canuck
New member
Just a little info about my understanding of squish.
- the reason for squish is that the squish area allows the combustion chamber to be smaller and it creates extra turbulence in the fuel charge when the piston approaches TDC
- too much squish clearance decreases the turbulence of the fuel charge, gives less power because the fuel charge in the squish band burns late in the combustion process, and increases the risk of detonation.
- the greater risk of detonation from having too much squish comes from the fuel charge in the squish band burning late in the combustion cycle.
- too little squish clearance and there is the possibility of your piston contacting the cylinder head.
- by cutting the head you are reducing the squish which leads to a higher turbulence of the fuel charge, and less wasted fuel charge in the squish band but you are also increasing the risk of piston to head contact.
- when most cut their heads they just mill off a few thousands and don't recut the squish band. The squish band is now tighter and the compression ratio is increased. The risk of detonation now comes from the increased compression ratio and not the tighter squish band. In most cases the tighter squish band isn't a problem unless you go too far and the piston contacts the head.
- the reason for squish is that the squish area allows the combustion chamber to be smaller and it creates extra turbulence in the fuel charge when the piston approaches TDC
- too much squish clearance decreases the turbulence of the fuel charge, gives less power because the fuel charge in the squish band burns late in the combustion process, and increases the risk of detonation.
- the greater risk of detonation from having too much squish comes from the fuel charge in the squish band burning late in the combustion cycle.
- too little squish clearance and there is the possibility of your piston contacting the cylinder head.
- by cutting the head you are reducing the squish which leads to a higher turbulence of the fuel charge, and less wasted fuel charge in the squish band but you are also increasing the risk of piston to head contact.
- when most cut their heads they just mill off a few thousands and don't recut the squish band. The squish band is now tighter and the compression ratio is increased. The risk of detonation now comes from the increased compression ratio and not the tighter squish band. In most cases the tighter squish band isn't a problem unless you go too far and the piston contacts the head.
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