12.5-1 vs 10.8-1 piston

[Crowdog]

What is more reliable?

12.5-1 running race gas

or

10.8-1 running premium

According to Sparks. "12.5-1 will run quite a bit better and be much more reliable. Heat is a major issue with any 400X hop up. The race gas is insurance against heat problems."

What are your thoughts?

Well the 12.5 is gonna give your thumper more power,,but here's what I looked at when I upped the bore and compression on mine...do I ALWAYS want to run race gas in this quad. If I go on a trip 4 hours away and I forget my race gas tank or simply grabbed the wrong one I'm screwed unless I know someone somewere in whatever town I'm in that sells race gas. The fact is you might get 4 years out of that piston setup,,therefor you have to run race gas for 4 years,,get the 10.8:1 and mix it 50/50 it a sure bet you'll always be able to ride your quad with the 10.8:1 piston anywere anytime any gas station.

[Crowdog]

Let's say that always having race gas isn't an issue. Now what do you think?

Crowdog

[knighttime]

Originally posted by Crowdog
Let's say that always having race gas isn't an issue. Now what do you think?

Crowdog

Well if your always gonna have race gas, go ahead and get the higher compression piston. I totally agree with Rico about gettin' the 10.8 piston. Getting race gas is a pain in the *****.

I think you need ta get the big dog,,and a set of airscoops from tinner or OMF ta help keep it even cooler. If the gas isn't an issue then go with the 12.5 without a doubt,,,the gas was the only think that stopped me,,,and it's not the money for the gas but just having to rely on race gas at all times didn't blow my skirt up,,since I also use my 416 to deer hunt with I can just get gas at the local gas station if I want too...:huh :eek: :D

[Crowdog]

But do you think it will actually be more reliable like Sparks says?

Crowdog

reliablitly I can't really say,,cuz I don't know,,,I can't see how a 12.5 compression piston,,banging even harder than a 10.8:1 would be more reliable,,but curtis sparks knows a heck of alot more than I do so if he thinks it's more reliable then I'd trust his judgement,,he does build national motors that win #1 plates.

[wyndzer]

Higher compression is going to decrease reliability. Sparks, actually suggests using a stronger connecting rod with there pistons. I have been running them for a while. The flat top design will give more power than a dome top with the same compression.

[beerock]

YES the race gas will give more longevity to the engine because of the cooler operating temperatures.(if you were running less octane and the same set up it would probably run hotter and thus wear quicker)

you can run more advance with race gas and worry less about detonation because the race gas keeps it cooler, allowing more advance then lower octane gas.

what gas are you going to be running? and what octane?

[Crowdog]

Originally posted by beerock

what gas are you going to be running? and what octane?

I run 110 Octane 76 in my sand rail.

Crowdog