[727xx]

Ok I have the 727 kit with pp head +1 valves 290 webcams full exhaust barkers cp12.5.1 piston Can I RUN 93 octane on the motor

 

[08700xx]

No, I wouldnt...I wouldnt run pump gas on anything higher than 11:1 on a XX. Who did your PP on your head, what 727 bb kit do you have?

 

[727xx]

Thumper racing and hdd did the tb

 

[08700xx]

Cool. Where do you ride? I'm guessing from you saying 93 octane you are not from CA lol. Another member on here has the Thumper Racing BB too.

 

[727xx]

Orlando so what should I do ??? To run pump gas ???

 

[727xx]

Why do I see these 450 on a 12.??? Piston on pump gas

 

[08700xx]

Orlando so what should I do ??? To run pump gas ???

Get a lower comp piston. I dont know that they make a 11:1 for the BB though.

Why do I see these 450 on a 12.??? Piston on pump gas

Someone other than me can anwser this better for you. I asked the same question as you when I was a stock bore running 12:1 and people I trust said it wouldnt be safe.

 

[727xx]

The thing I Email the guy from thumper racing and he told me yes and some people no FUCK!!!! Then in the forms it's the same shit lol

 

[TRX700XX]

im running 93 on a cr125r i have and it is 15:1.1.... its just more sluggish and could cause a labor knock

 

[08700xx]

Yeah when I had my first build done by Alba they told me it was fine to run on pump gas (12:1) then I talked to the guys on here and they said it wouldnt be safe especially since I ride in the dunes. A lot of people talked about the weight of the XX being part of the reason why it wouldnt be safe to do it on a XX but would be on a 450...But like I said im a retard when it comes to this stuff so I pay someone else to do it so I dont have to stress over it lol.

 

[traitor08]

What's the dynamic compression of the motor.

 

[boost addict]

Hit crwh45 up he runs the Thumper 727 Piston. I am not sure what cam he runs and not sure if he has port work done.

 

[jfdanie2]

Personally I would not run under 100 octane with that high of a compression. I run an 11:1 piston and run 100 octane simply for peace of mind, and its alot better quality fuel than pump gas.

 

[TRX700XX]

i prefer to run high octanes to a point.... if you go to high of a octane your wasting your money... my CR is setup for 110 octane but it will run on 93

 

[traitor08]

I think with your cam and piston, your compression is probably in the 11:1 range. Forgot the website to the calculator I use to use.

 

[jfdanie2]

Do you have a problem finding something higher than pump gas in your area?

 

[TxAggie09]

off topic, but would it help or hurt anything to run ~100 octane in a motor with stock internals? If its that much better than "premium" pump gas i may start to look around for some out here.

 

[Brokenbones]

Mine ping sometimes under hard load with a 11:1 cp with 91, but cylinder is shaved to get 0.045 of piston to head clearance.Now I use the klotz itrate and it's gone.With 12.5 I think you play with fire,google some pics of what detonation do ... Put at least 50/50 with race gas.

 

[Brokenbones]

off topic, but would it help or hurt anything to run ~100 octane in a motor with stock internals? If its that much better than "premium" pump gas i may start to look around for some out here.

No need with stock compression ratio , too much octane is slowing combustion with low compression engine

 

[TxAggie09]

good to know. Ill keep that in mind if i ever decide to go into the motor