need race gas?????

[ridinthedunes]

I just got off the phone with LRD asking about a cam and going up to a 416 or 426 piston. He said that I have to run race fuel if I do it. He said that they can only get pistons at 11:1 and if they double the gaskets to bring it down, they blow the gaskets.....he said I have no other choice but to run race gas if I bump up the cc's........everyone agree??

[tater_kamik]

you do not have to run high octane (like 100 octane) when you bump up the cc's... you can run 93 octane with 11:1 compression, im doing it now. you can even run 93 on an 12:1 piston, though it will spark knock so it is absolutely not an good idea... but you will be fine with an 426 with an 11:1 piston on pump gas

[ridinthedunes]

wonder why the guys at LRD said I couldn't run pump gas with it????

[tater_kamik]

i have no idea, but ask anyone on here with an built 400, the better percentage of them are running 416's, 426's, 440's, and running pump gas, i know one of my buddies has an 440, 11:1 comp piston and an shaved head and it runs 93 no problem without overheating

[ridinthedunes]

thanks tater.....guess I'll ask C&D, haven't been on for a while and forgot they are sponsoring.

[z400roosteR]

Just a thought....They have a reason for saying it.......either A) it's what you need to run or B) you could run pump gas but they are saying run race gas to cover there *** and be on the safe side so in the event something does go wrong ( over heats) you can't point fingers at them.... (from what tater is saying sounds like it's more the B)

[bwamos]

Aye 11:1 is perfectly acceptable for Premium Pump on an air cooled engine.

My 330ex is 11:1. Runs pump gas w/o issue. I'll mix 25% 100ish octane with it when I go to the dunes in July to avoid any detonation. The extra drag from the sand plus 95-100 deg temps can push it over the edge and make it start to detonate occasionally.

[wilkin250r]

11:1 is right at the edge. Your MIGHT get away with running pump gas, but LRD doesn't want to risk the liability. If they say it's okay, and your blow your motor, they are responsible.

However, if they say it's NOT okay, and you run pump anyways, then YOU are taking the risks and assuming responsibility.

In the end, it's your call.

[426exThump]

I have a 99 426ex, high comp pistion, stiffer valve springs. stock cam (for now) and a k&n filter. Not sure if it 11:1 or 12:1... I run 93 and have no problems. However my Zooter realy loves it when i mix 93 pump gas with and 110 race gas at about 50/50 mix. It really peps the motor up. I'm thinking of bumpin the cam to a XR400 cam or the HRC cam. Not sure still doin some research... I mostly woods ride.

[z400roosteR]

thanks for the recap wilkin