Help with motor work

[steve26]

I am in the process of gathering everything to do my 06 motor now, and I have some questions concerning pistons and cams. I am having my local mechanic do the port work, the angled valves and all of the assembly as well. My questions are: What is the highest compression piston I will be able to run with pump gas? I am willing to use just about any cam in order to acheive the ability to run on pump, I know that some of it depends on cam overlap. However, I do not want to use a full top-end powered cam, I like my power to be down low and maybe in the middle, not all top. Does anyone know any kind of cam and highest compression piston combination to suit me running pump gas? I really do not want to use race fuel as this is only my practice quad, the race motor is being done by DASA and will use strictly race fuel.

thanks in advanced.

Also, what is everyone doing for valves? As far as stainless vs. titanium?

[jlm996s]

A lot of guys at trx450r.org say that you can run 13.1 with an HRC cam with fresh 93 or better octane. I'm not sure if anyone has actually done that though. C&D Racing will sell you a 13.1 piston that is coated and this is supposed to allow you to run pump gas. I haven't tried any of these, so I can say for sure. You can run pump on anything less than 13.1. VCP sells a piston called the Hammerheadz 12.25 that you can run pump fuel and it's supposed to give you the same performance as a 13.1. A lot of people had issues with these b/c they are 2 ring piston and they were getting the gaps right on the rings and they were using oil. I'm planning on getting one of these pistons anyways to try it out for myself.

[bwamos]

For a practice quad.. I'd jstu stay around 12:1 will help with reliability some too (not much difference, but it's a practice quad so every little bit helps.)

[iceracer65]

i use a wiseco 11.5 on pumpgas that will run with or beat most race gas motors.