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Discussion Starter · #1 ·
Hey guys, I said I wasn't going to do it but maybe in a year or so I may go into the engine.I've got a couple a questions about the kits. Whats thecompression on the pistons? do you have to run race gas or is it low enough to get by on pump gas? Also will a minor (clean up) port job do? I mainly woods ride so top end is not important. I'm looking for more botten end grunt.

Right now I'm waiting for my exhaust and a few more goodies to get here before i put everything on. May change my mind after the 3 mods and a 15t cog. :3question:
 

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hey man.... i just did a little engine work to my bike.... i too only ride trails, and race every once in awhile...
Which type of gas you have to run, depends on what piston you go with.... factory is like 9.75:1 (i think).... you can go with 10.75:1.... 11:1.....12:1 or 12:5..... there are a few choices....
10.75:1 you can still run regular pump gas....
11:1 (this is what i went with)- you have to mix gas... i mix 3 gallons of 91 with 2 gallons of 113....
once you go over 11:1 you will have to run strictly race gas....

you will just have to talk with ppl that do head porting.... i did the extreme porting.... but for trails and just normal riding... then YES you can just do a clean up port job.... you just have to talk with the person you are going to have do your porting... and talk with them about your personal port job... they can do whatever you want....

- - I HIGHLY recommend VELOCIRAPTOR (from this forum).... if you are looking for someone to do your head porting... he does an AMAZING job...(he did mine)....

Plattner
 

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Discussion Starter · #3 ·
thanks a bunch. when I went into the engine on my V I ran 11 to1 but with the head gasket it was like around 10.8 to 1. I ran 93 with no problems. I'll have to do a little more research when I'm ready. Thanks again.
 

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Hello Everyone,

First time poster long time reader. Has anyone ran across a good thread relating to what gas to use for what compression ratios? I used VP c12 on the raptor 350 my girl rides and im looking to start moding my 700 now. I see the big stroker kits use a 14:1. Will this c12 (108 octane leaded) be enough?
Im almost positve it will be good enough for 12.5:1 right? Thanks JIM
 

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i run 93 with 11:1 with zero problems. anything higher i would run 100 at minimum...

i ride my quad 3-4 times a week, so i wanted the most power and still be able to run pump gas. id go broke filling this thing up with race fuel 3 times a week...
 

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Its not too bad the way I do it now: get my 5 gallon jug, 2 gallons of 110/3 gallons of 93= 20 bucks a change. I have 2 local fuel distributers, one has 111 octane(Phillips 66) and the other has 110(VP fuels). I can tell the difference for sure over straight pump gas :thumbsup:
 

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so you guys that have 11:1 pistons, it is perfectly fine to run 93?

do any of use guys use those octane boosters that you can buy at autozone?
 

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i've been using some kinda octane booster from autozone in my honda watercraft that requires it.....forgot the name of it though???
 

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Look at it like this all the 450 machines, honda, yamaha, and suzuki, all come from the factory with over 11-1 compression and they run just fine with pump gas. Also race gas DOES NOT GIVE YOU HP. It only alows the engine to put out its potential hp. If you have a stock Raptor and you dyno it with race gas and then with pump gas, the pump gas will produce more hp. A engine of any type will always produce more hp with the lowest possible octane it can run on with out detination. What is higher octane = its the capability of the fuel to resist presure (compression) and the ability to resist combustion without spark (preingnition) higher octane also has the ability to be more stable under high heat. Now the burn rate. All fuels have diffrent burn rates (how fast the fuel expoldes) this is also a HUGE factor in how a fuel works for a certian engine. big engines like a slow burn rate so the longer stroke can take full advantage of the combustion. A small engine realy like a fast burn rate because of the short stroke. If you fuel burns to fast it will make a loss of hp because the combustion quits pushing down on the piston, and if it burns to slow you loose hp because it doesnt push hard enuff, and this will let the rest of the burning fuel to be pushed out your exhaust. Go look at VP fuels website and read up on fuel. Bottom line dont waste your money on something you might not need. But the choice is yours. I also think you should look up tolulyne.
 

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Yes, I understand that. I am going on the reasoning that the cam profiles and timing events from the factory on these 11:1+ machines are set up and designed to run on pump gas. Take our 9.2:1 engines and change the compression by almost 2 points without changing the timing events(and in my case cam profile) then things happen differently. Im not saying you HAVE to run better than 91-93 on 11:1, Im sayin I run it- and if anyone asks opinions then I give my opinion. You can run pump gas on 14:1 if you have the timing turned way down and the cam profile to bleed of cylinder pressure enough to do it- but then you have a turd that gets its ass handed to it everytime it turns around.
 

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Machy said:
so you guys that have 11:1 pistons, it is perfectly fine to run 93?
mine runs perfectly...
 
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