I am looking for advice/info on pistons please.

I am having a1340 Evo built and would like some input to talk aver with my engine builder. What pistons are recommended for use with SE Heads, EV27 Cams, Crane HI4 and piton exhaust. JE pistons? SE? Or Wiseco?
Domed (10.5:1) or flat (9.5:1)? And what are the practical differences between?

Thanks.

 

I've used the EV27 and Wiseco 10.5:1 flat tops many times, That used to be the combo years ago.
Anyway....that'll work out good for ya. You may also look into an ignition upgrade while you're at it.

 

Keith Black 9.5to1 pistons, either the vthunder ev3000 or the ev5005 cams. Both work extremelywell.Wouldn't go any higher on comp.ratio due to poor quality pump gas.(unless you choose a cam with valve timing that will keep cylinder preasure down.)Find nothing wrong with the HI4 ignition, single or duel fire.

 

Thank you Extech and JB!

 

Double ditto on keeping the CR around 9.5. You can find gas that will support 10.5, but not reliably, everywhere. If you never leave town and you know where you can always get good 91 or 92 octane fuel you can probably get away with it. You'll hear a combustion rattle a lot when you accelerate, but you can work around that. Get out in Moose Nuts, Montana, though, where all you may find is a pump with 87 octane in it and you're screwed.

Pilgrim

 

I run a 10.5 to 1 motor all the time . It is fixing to be 11 to 1 CR . If you know you might be traveling where gas might not be the best just carry a small bottle of octane boost . Timing and tuning play a huge part also . I would ride any where with a 10.5 to 1 motor .

 

screaming eagle 10.5to1 piston kit is $130., cost less that the stock pistons, comes with rings and will work just fine with the EV27 cam

 

These are the results form my first 80" build with Wiseco 10:1 pistons,Sifton 143EV cam,S&S Super E,2 into 1 FAIC exhaust,and NO headwork.Max. torque 90.3,max. hp 79.8 .Tq. peak @3700,peak hp @5450.My build specs. are completely different now but this should be ballpark with what you`ve got going on.Depending on pipes,etc. Have fun,Toby