I have not standardized the compression ratio yet. Each set is custom at this point.
Piston Bowls
- Thread starter Fingers
- Start date
I have not standardized the compression ratio yet. Each set is custom at this point.
Any way you can make them higher? Say an 18:1? I hate the feel of a low compression motor. I won't be racing it or pulling so I don't need to worry about spinning it over to fast.
I would make sure your block does not need decked before going to high. Talk with John aka Fingers or Guy @ SoCal first. The normal cast race piston is in the hole .005 without decking. Evan had his block decked .005 and these pistons were out around .016 to .018 area to be safe he used grade D head gaskets to have enough valve to piston clearence.
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Higher is easier than lower. I don't have to dodge the oil gallery with the higher compressions.
FWIW, stock pistons, or for that matter ANY piston that has had a chamber in it can not be used as a blank to make these oval chambers.
I'm confident enough with the results so far that I am going to be stocking blank pistons in 0.020" over.
Available for any Dmax. Std, 0.020" over , and 0.040" over bores. I will be stocking 0.020" overs when my order get in.
what do the .020 and .040 overs run? not sure how much the block i got needs over to clean up
FWIW here is a rendering of what I ended up with for the piston top.
Isnt this similar to the drawing i quickly made on the 2 or third page?
Oh wait you deleted it ? But i remember sending you a drawing pretty similar to this design and you said iyou werent sure what i was getting at? I guess you understand now
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Isnt this similar to the drawing i quickly made on the 2 or third page?
Your drawing is still posted up on page 23
Wow i feel dumb i thought it was at the begining of his thread,sorry id like to get a price on .20 over im gonna start stocking up on build parts
Someone asked recently what I thought I know about these pistons that GM and Mahle didn't.
Actually, I think we both know the same thing. Cutting a chamber into the top of piston requires the piston to contain the explosion radially (outward) as well as in the downward direction. The forces are not unlike throwing a fire-cracker into a paper cup.
I know they knew because they embedded two steel rings into the castings to help retain the force. One is the steel fire ring grove, the other is just below the oil gallery. Without these rings, the pistons would crack on a regular basis even in a stock configuration.
Actually, I think we both know the same thing. Cutting a chamber into the top of piston requires the piston to contain the explosion radially (outward) as well as in the downward direction. The forces are not unlike throwing a fire-cracker into a paper cup.
I know they knew because they embedded two steel rings into the castings to help retain the force. One is the steel fire ring grove, the other is just below the oil gallery. Without these rings, the pistons would crack on a regular basis even in a stock configuration.
Update-We are impressed to say the least. Thanks!:thumb:
http://www.youtube.com/watch?v=FcYzgC_qIEE&list=UUXn_OZIzpAd7YmbxZRIyaxA&index=1&feature=plcp
http://www.youtube.com/watch?v=yKyQ-nbKnrE&feature=relmfu
http://www.youtube.com/watch?v=fBcwSC-t8sk
http://www.youtube.com/watch?v=FcYzgC_qIEE&list=UUXn_OZIzpAd7YmbxZRIyaxA&index=1&feature=plcp
http://www.youtube.com/watch?v=yKyQ-nbKnrE&feature=relmfu
http://www.youtube.com/watch?v=fBcwSC-t8sk
Great runs Brett and Mark! The truck sounds awesome. I assume the lockup controller is working properly?