race gas

[motoxxx5786]

i have heard that running race gas in my crf450 will cause damage to certain parts or burn a hole in the pistion or something like that is this true? If not which one should I use?

[zookeeper]

While I've never used race gas in my 450, there's simply no way that's true. I used to used race gas only on my last bike (2 stroke) and here's a couple facts: Race gas is much more stable during storage. If you don't ride much you don't need to worry about the gas turning to sludge and clogging up passages in the carb. Also, your engine will run cooler, I have no idea why, but it does. Race gas also contains something like 4 grams of lead per gallon. Back in the '60's gas companies used lead to up the octane (good) and as a cushion of sorts for valves (also good). But lead is extremely hazardous when you're constantly exposed, like sitting in traffic day in and day out breathing it. Race gas also smells really nice, though it's probably not a good idea to fire your bike up in the shop just for the smell! Every serious racer on the planet uses it in their car, bike or whatever and since it runs about 4 times the cost of pump gas, you gotta think they know something, right? If you've got the money to spend, your motor will thank you, but it's not necessary.

[125shifter]

By the looks of yer sig, you've gots a semi done up bike. What compression you run'n?

[2strokes_rule]

04' piston bumped up compression

12:1

I use Citgo 110 with no problem.

[125shifter]

04' piston bumped up compression

12:1

I use Citgo 110 with no problem.

12:1? I'd run pump gas (91) and not even think twice.

[2strokes_rule]

....but, as zookeeper states (and I agree), there are other reasons to use better gas.

[125shifter]

....but, as zookeeper states (and I agree), there are other reasons to use better gas.

And I can't disagree, but even he stated it's not a requirement - especially @ 12:1.

[jmart233]

I use the Wiseco 12.5:1 piston in my 03' and I run pump gas and VP U-4 at a 50/50 ratio. The bike runs great and gives me peace of mind with no detonation.

[durkot]

Also, your engine will run cooler, I have no idea why, but it does.

I am fairly certain that the higher the octane the slower the fuel burns. That's where the cooler running thought comes from. With lower octane gas the burn is faster, more like an explosion than a burn. The slower burn allows for more complete combustion - more power. I'm not sure if you would feel this in the crf though. It is necessary in high compression engines to prevent detonation or pre-ignition.

[Bryce418]

I use the Wiseco 12.5:1 piston in my 03' and I run pump gas and VP U-4 at a 50/50 ratio. The bike runs great and gives me peace of mind with no detonation.

as a note the bike will NOT run coler on u4,mr1,mr9 nutec special 4 etc. as they are oxygenated fuels some as much as %4-5 and need to be jetted properly as more fuel is needed to correct the air fuel ratio ?

[125shifter]

I use the Wiseco 12.5:1...

That's where I draw the line. 12.5:1 and less just pump gas. Anything over I'll run race gas or meth - but that's a whole other ball game.

[ReD_RiDeR_CRF450R]

Anything over I'll run race gas or meth - but that's a whole other ball game.

i can just see it now........top fuel dirbikes ? :cry:

[1dustries]

Race gas is too expensive for me and you really only need it when you have had your engine modified and then has a higher compression. Without the race gas the regular pump gas would pre detonate because the the lower of the octane. Octane rating doesnt translate into more horsepower, the octane rating only means how much the gas can resist detonating early. Race gas only burns slower and cooler and more cleaner. So without engine mods race gas is really a waste of cash unless you get the MR2 i think the gas that is oxynated which creates more horsepower. I just run pump gas cause it is cheaper and i still have plenty of power. Race gas wont make me go from last to first.

[SD]

My understanding is that in the stock, or near stock bikes, using oxygenated leaded fuel (90-92 octane) adds horsepower. When you are racing, if it is legal, use everything you can to win, including oxygenated fuel. For trail riding, pump gas is fine, but if you can afford it, run some VP gas now and then just for hoots! The lead allows VP to up the oxygen in the fuel which generates 5%-6% more hp.

If you have a higher compression, modified top end, then you have to start thinking about higher octanes, which is somewhat of a different train of thought - like dragsters and top fuel bikes.

Steve

[dirtriderwjc2000]

I use both VP U4 and race gas 110 octane. The U4 is about $9.25 gal and I use a lot more of it when riding. The 110 seems to last longer, and is only $4.40 a gal. Bike runs much better on either over pump 93 octane.

[DEGBTI]

i have been using U4 mixed 50/50 with pump gas. does anyone know if u4 can be mixed without losing the benefit of the added oxygen?

[1dustries]

When you do a blend of race gas and pump gas dont think of it as making your pump gas better because in reality the pump gas is really diluting your race gas and taking away the full performance of the race gas.

[zookeeper]

That brings up another point: because I'm also a hot-rod car guy, I read an article in Hot Rod magazine several years ago where they mixed 92 octane and 87 octane and got something like 94 octane! I have absolutely no idea if or how this works, but it seems like getting something for nothing. I think before I spent big money on race gas (Lord knows our 450's don't get wonderful mileage!) I'd spend it on a cam where you could actually feel the difference. More octane doesn't mean more oomph, but it does open the door for more compression, more timing and wilder cams without the big bug-a-boo of all racing engines...detonation.

[crf250]

i run race gas in all my bikes. i prefer sunoco. posts here in '01 and '02 felt the lead helped protect the ti valves.

[2strokes_rule]

When you do a blend of race gas and pump gas dont think of it as making your pump gas better because in reality the pump gas is really diluting your race gas and taking away the full performance of the race gas.

Is the glass half empty, or half full?? It appears yours is fully empty.

Again........good gas has benefits beyond octane.

Do you read the whole thread, or just ramble for post count??