mike tkach

iTrader: (3)

so here is a tricky question,should a builder go with less compression and more boost or more compression and less boost?

getrdunn

iTrader: (7)

That's interesting merc sets up 1075's .100 in the hole. I've heard and read of builds close to that but just goes against everything I was taught.

In regards to above post I guess once again I could look at what merc does. My initial conversation with Valako was to keep the compression down around 8.5 or even 8 and throw the boost at it. I'm open for suggestions on what makes the most sense. This is a learning experience for me and not afraid to be up front about it.

Tks guys
John

snapmorgan

iTrader: (2)

Here is my opinion. The more power that an engine makes N/A, the more power it should make under boost, so therefore higher compression and lower boost should be better. However, most blower pistons have a dish in them which will equal lower compression, requiring more boost.

I am going with B. I want the best pistons that I can afford for the application. True blower pistons. Thicker tops and lowered rings. Not some flat tops that weren't really designed for supercharging.

mike tkach

iTrader: (3)

what supercharger are you going to use?

getrdunn

iTrader: (7)

Hey snap. Just wondering if you have real world experience. I'm not questioning at all just real world data. Personally I think what boost etc could dictate what pistons you end up with in particular build. If your running 15 plus pounds of boost then that would change the whole picture. Now if your running a 8.5:1 uild with 5-7 pounds of boost then that would change things up. Good high comp/boost pistons weigh a ton but built for 1200 plus hp. Just asking.

getrdunn

iTrader: (7)

Unless I misunderstood Valako he said get pistons that can handle 1000 hp plus without concern. Just curious what are they using in the 900-1075 sc engines. Probably the best without a doubt but I do know Jim ran blower engines with well over 1,000 hp on blown 540's pump gas engines with your basic run of the mill 2618 pistons with no issues. Not over boosted though by any means. Evidently he doesn't like heavy pistons. Just a guess..

dunnitagain

614 Build , .060 in the hole , .060 head gasket , 22cc dish , 120cc chamber. Compression is 8.0:1

getrdunn

iTrader: (7)

871's. I'm not looking for any record breaking hp numbers but reliability etc. will be run in cold water with 850's and similar cam to 1075 sci but have another cam for back up on dyno that made over 1k hp with 540 builds but still involved raising the ports.

getrdunn

iTrader: (7)

What did smitty use for a blower?

MILD THUNDER

iTrader: (3)

You can get flat tops that are blower pistons. But, I do agree. A blower piston will have the Top ring down .300+, thicker piston, etc. Also, the wrist PIN. Most forget about the pin. I have JE blower pistons, with upgraded .180 wall , series 52 High Carbon steel through hardened pin. I believe the standard JE pin, is a series 51, low carbon steel pin.