I am looking at buying a new piston for my 03 Raptor. What is the difference in different pistons? Do I want to raise my compression. I don't want to lose any durability. Will I need to buy anything besides the piston? What other mods should be done?

 

Wow, thats a lot of questions.

I would go with a wiseco 11:1 standard bore piston and gasket kit from magicracing.com. They have the lowest prices on a lot of stuff.

You would see a lot of improvement with a cam. If you dont mind upgrading your valve springs you can get a webcam or a stage two hotcam. If not, a stage 1 hotcam still gives you a couple hp and lots of throttle response and all you have to do is throw it in.

 

i would say go for the JE piston 10.75:1 which they just call the 11:1. You dont have to bore out your engine so just in case if you had any problems with the engnie cause of it or so it wouldnt cost you bank to get it fixed.

 

The JE pistons fail, just about every single one of them. They will crack and blow and you will end up doing a lot of engine work. It's just not worth the risk when a wiseco piston is just as good and doesnt cost any more money.

You will have to hone the cylinder even though a bore isnt necessary.

 

Thanks for the replies. But they raise more questions. My motor needs work right now, and I will probably have to purchase new valves.

1. Are there any valves and springs that will work properly with both the stock cam and hotcam stage 2 cam? I will run these valves with
the stock cam before I buy a hotcam.
2. Will supremium pump gas be ok with the 11:1 compression?

And what will I need with the piston. I know rings come with it, but what other motor mods do I HAVE to do with a new piston.
Thanks for all the help,

Carguy

 

You can run the stiffer valve springs with a stock cam but it will not improve performance. If you just need to run them until you get the cam, that should be fine. But its a lot easier to do this all at once.

You dont Need new valves. You can buy titianium valves if you so desire, but they are not necessary for the desired performance increases.

A wiseco 11:1 100mm stock bore piston runs fine on premium pump gas.

The Kit includes: piston, rings, circlips & wrist pin for 100 dollars. You can tack on gaskets for 35 bucks.

The valve springs are almost all made by kibblewhite. They run about 135. White bros and other companies all use kw springs, they just rename them.

 

Thanks for all the replies. That helps alot. I was just wondering, before I go buy all this stuff if it is worth the $$$. Say I get the Wiseco 11:1 piston, and Hotcam stage 2 cam, what kind of hp and speed am I looking at now?

Carguy

 

I dont have any dyno numbers and it would depend on your pipe, but you should be making at least 45-47 hp.

Plenty to take down piped banshees and piped and cam modded yfz's.

 

Thx maddog...where did you get those prices?

 

Magic Racing