I was thinking about getting a MrHp 12:1 light weight piston but I've been told that to run 91 octane pump gas I should stay with a 11:1. or 10:1..... [img]i/expressions/face-icon-small-confused.gif[/img]

I've decided to go with 109/110 Web cams and valve springs and need to know which piston.

So what do you motor tweakers recommend?

Also have any of you guys used octane additives to increase the rating of pump gas?

 

The closest I have come to that is. I can buy 100 octane Racing gas at the pump at a Phillips 66 station near my house for $4.39 a gallon. I mix 1.0 gals of it to 4.0 gals of the 92 octane and it eliminates pinging in my 2 strokes.

 

the mistake i made was putting my all around rider on race gas (12.5 piston) now because i have to carry fuel on long rides or octane boost (never a good place to carry that stuff) it has become my dune only machine where i can run back to the trailer fuel up instead of getting pump gas where ever. it's a trade off extra power or convience? i guess it comes down to how power hungry you are?

 

I generally run just dunes but I still don't want to have to use special gas. Having to carry a small bottle of octane additive is not that big a deal since you only need enough for the 4 gallons your tank would hold or if you really should be running 93 octane and your out riding and need gas and all you can get is 91, I don't think it would cause any motor problems, it just wouldn't run at it's optimum.

 

Octane booster is a waste of money. They claim that they will raise the octane 3 points for example. What that means is if you buy 91 octane pump fuel and add the octane booster you will then have 91.3 octane fuel.[img]i/expressions/face-icon-small-disgusted.gif[/img]

When you talk to Eric about purchasing a piston or cams, tell him what kind of ridding you do and what type of fuel you want to run and he can set you up with the right package.

 

the question is what do you want down the road? i thought i would love my 11.5, running pump 92. but i dont ride every weekend. i can go and buy 1- 55 gal drum of 110 and last me all year for 190 dollars. thats why im going to the 14.1. and when i switch to alky it gets better yet! trust me you will always want more!!!

 

Good to know. Before I go to Eric or Randall I want to have all my ducks in a row. In other words I want to have all the details worked out as to what cams and piston and valve springs I believe I need and then let them figure out what I really need.....[img]i/expressions/face-icon-small-wink.gif[/img] I just wish I could get the cams without a core charge.....I won't be ready to open it up until next month because of that.......[img]i/expressions/face-icon-small-blush.gif[/img][img]i/expressions/face-icon-small-disgusted.gif[/img][img]i/expressions/face-icon-small-frown.gif[/img]

 

[quote]
Originally posted by: shmee
?I can go and buy 1- 55 gal drum of 110 and last me all year for 190 dollars.

That's great but you have to carry it with you. I can stop anywhere and get 91 or better depending on what state your in. I think AZ even has 100 at the pumps near the river.

 

Eric also offers a thicker gasket (base or head - can't remember) that you can use with the 14:1 piston. This lowers the comp down to 11.5:1 so that you can run pump gas. Later if you want the higher compression you just swap out the gasket with the stock one and you don't have to touch the piston. Just another alternative.

 

Thats good to know.........I never heard that before.....