Internal debate on pistons and compression
#1
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Internal debate on pistons and compression
OK so here is the deal. I finally got back to starting to gather things for my 408 build. I currently have Diamond blower pistons -28cc, Info below for those not familiar, But i keep hearing and being told to shoot for 9.5.1 compression. And looks like this might be a bit hard to do with these? I mean if i shoot for 9.1 or close to it will there be much difference? I want something i can drive on the streets when i want. Take a small trip to the other side of the island, and back. And something i can take to the strip. Just not sure if i should get rid of the pistons and go with a lesser dish, Or just use the ones i have. More info about the setup so far. Is im running an F1a procharger. And brute speed blower cam. witch are both currently in my stock bottom end ls1 at the moment, Aslo for the new build have Lunati pro billet rods. But still looking for a crank. most likely going to go with a callies. Not sure yet on compsstar or dragon slayer.
Also i read about coating pistons. I also have read allot of post talking about the coating coming off. So not to sure on to coat or not to coat? any feedback is great, thanks.
"Inboard style piston designed to clear most counterweights and reluctor wheels
• Forced induction applications up to 25lbs of boost
• Offset wrist pins for quiet operation
• Ratios configured for .000” deck height @ 9.240” with an .053” gasket
• Standard 1.5mm x 1.5mm x 3.0mm ring package
• Premium H-13 wrist pins included
• Gasket volume = 11.8cc’s
• Top ring down from piston crown = .300”
• Valve relief depth = .165” intake and .107” exhaust"
Bore Stroke Rod C.D. Weight Pin CC’s 62cc 66cc 70cc Ring Set Part#
4.030 4.000 6.125 1.115 420 .927 x 2.200 -28.0cc 9.1 8.8 8.5 09064030 11576
Also i read about coating pistons. I also have read allot of post talking about the coating coming off. So not to sure on to coat or not to coat? any feedback is great, thanks.
"Inboard style piston designed to clear most counterweights and reluctor wheels
• Forced induction applications up to 25lbs of boost
• Offset wrist pins for quiet operation
• Ratios configured for .000” deck height @ 9.240” with an .053” gasket
• Standard 1.5mm x 1.5mm x 3.0mm ring package
• Premium H-13 wrist pins included
• Gasket volume = 11.8cc’s
• Top ring down from piston crown = .300”
• Valve relief depth = .165” intake and .107” exhaust"
Bore Stroke Rod C.D. Weight Pin CC’s 62cc 66cc 70cc Ring Set Part#
4.030 4.000 6.125 1.115 420 .927 x 2.200 -28.0cc 9.1 8.8 8.5 09064030 11576
#2
FormerVendor
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What cc chamber are your cylinder heads? Where is the cam installed what ICL?
Coating can be good or bad.
Coating can make the piston harder to burn up which means you burn up a head, intake or exhaust valve first instead of the piston.
Pistons are cheaper than cylinder heads, but if you never really push this set-up that hard you may not have such luck.
Coating can be good or bad.
Coating can make the piston harder to burn up which means you burn up a head, intake or exhaust valve first instead of the piston.
Pistons are cheaper than cylinder heads, but if you never really push this set-up that hard you may not have such luck.
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I have not got heads of yet. Its still open.... What do you mean where the cam is installed? Its in my current motor at the moment. The stock ls1, Well besides cam, Springs and push rods, Sorry for my ignorance. IM not sure what you mean by ICL, Learning as i go, thanks for you response
#6
FormerVendor
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I have not got heads of yet. Its still open.... What do you mean where the cam is installed? Its in my current motor at the moment. The stock ls1, Well besides cam, Springs and push rods, Sorry for my ignorance. IM not sure what you mean by ICL, Learning as i go, thanks for you response
I meant installed center line(ICL). Plays a factor in cylinder pressure on the intake and compression stroke which will play a part in compression.
Cam is easy to change, if you're willing to change it as someone else said.
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#8
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What's the score with the piston design ? Ive seen a few like that recently. It is a rather unusual crown compared to more traditional pistons.
usually they either go for a full dish, or a chamber/dish shape to almost follow chamber shape
usually they either go for a full dish, or a chamber/dish shape to almost follow chamber shape
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The center bump is for rod clearance on the underside. it is normally only used on short pin height stuff.
Coatings are helpful in high temp engines for thermal reasons and scuff resistance. They will cause no downside unless they are extremely thick and flake. They help reduce piston to wall clearance which helps sealing.
I would not get hung up on compression and use your own common sense. Most people with high ratio engines seem to have very short engine life or don't run very good et/mph.
Kurt
Coatings are helpful in high temp engines for thermal reasons and scuff resistance. They will cause no downside unless they are extremely thick and flake. They help reduce piston to wall clearance which helps sealing.
I would not get hung up on compression and use your own common sense. Most people with high ratio engines seem to have very short engine life or don't run very good et/mph.
Kurt