454 HP425 Chevy pistons - what would you recommend?
02-23-2015, 09:13 AM
#21
Registered
iTrader: (3)
Agreed ^^ You must measure things to be sure. Tons of guys claiming they have 10:1 engines because that's what the catalog said it would be.
The compression thing gets analyzed over and over. There are soo many things going on inside a cylinder during combustion , that number on paper is simply that, just a number. Things like cam timing , chamber shape, crevice volume, swirl, quench, spark timing, flame front, pulse waves, spark plug design, air density , and so on, are all factors in combustion . The difference from 8.75 to 8.89, is of minimal concern in my opinion, and not worth reinventing the wheel on a setup that has been working for you. Concentrate on the setup of the ignition timing, fuel tuning, etc. Install the .030 pistons, maybe a .050 head gasket if need be, and go have fun.
The compression thing gets analyzed over and over. There are soo many things going on inside a cylinder during combustion , that number on paper is simply that, just a number. Things like cam timing , chamber shape, crevice volume, swirl, quench, spark timing, flame front, pulse waves, spark plug design, air density , and so on, are all factors in combustion . The difference from 8.75 to 8.89, is of minimal concern in my opinion, and not worth reinventing the wheel on a setup that has been working for you. Concentrate on the setup of the ignition timing, fuel tuning, etc. Install the .030 pistons, maybe a .050 head gasket if need be, and go have fun.
03-01-2015, 04:18 PM
#25
Gold Member
Gold MemberThread Starter
thanks for the great advice - I shall go with the Sealed power L2399NF30 at 4.280ins - polish the crowns and do some measurements as suggested to make sure Im about 8.8CR which is realistic.
Weiand supercharger guide does however state 8:1CR is good for blowers period but also says that mild boost up to 9:1CR is good so I'm kinda confused. I was never a fan of fat gaskets so hopefully it will all work with a 0.039 gasket.
Think Ill stick with a new stock Crane 132561 cam and stock Crane Anti-Pump Up Hydraulic Lifters 99277-16 as Im only running 50hrs a year and I cant find a direct replacement n a roller system.
Build for April should be good.
cheers
Weiand supercharger guide does however state 8:1CR is good for blowers period but also says that mild boost up to 9:1CR is good so I'm kinda confused. I was never a fan of fat gaskets so hopefully it will all work with a 0.039 gasket.
Think Ill stick with a new stock Crane 132561 cam and stock Crane Anti-Pump Up Hydraulic Lifters 99277-16 as Im only running 50hrs a year and I cant find a direct replacement n a roller system.
Build for April should be good.
cheers
Last edited by Nicolasticity; 03-01-2015 at 04:19 PM. Reason: add roller ref
