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Posted

hea whats up im new to the banshee world recinlty my banshee top end blew up so now im doing a std kit to the top end but while im there i would like to throw a cool head on it but i dont know which domes to buy which work for that top end kit ect

 

could you guys give me a run down of what i need to know and wat i should run ect ?

 

 

Thanks for all the help !

Posted

It really makes a HUGE difference on what elevation you are at and what your timing is set at. At sea level with +4 timing i like to run 21cc on pump gas 91 octane.At higher elevations you run smaller domes.

Posted

actually, you can run 19's and +4 on 93 @ sea level......i ran 20's on 90oct just fine......didn't bump it untill i went +5.5 timing...

 

 

Sorry but im going to disagree.. I have 19cc domes in my 350 and at sea level it kicks 180 psi on a snap on gauge that has been tested accurate. You will blow that motor up with pump at those levels. At sea level i think you are nuts to run anything smaller than a 21 for pump gas, but its your motor do what you want. Here is a link to prove im not full of shit. Look at noss' chart and you will see my motor is exactly where it should be compression wise.

 

http://www.nossmachine.com/banshee_heads.htm

Posted

actually, you can run 19's and +4 on 93 @ sea level......i ran 20's on 90oct just fine......didn't bump it untill i went +5.5 timing...

 

On a fresh brand new rebuild your telling me you would run 19's and +4 and still continue to run 93? What if the compression is 205, would you still run the 19's?

 

I see where your going with this, but I wouldnt run 90oct on +4, whats the extra say $1.00 on 5 gals. I would want it for the extra octane for the protection factor more then anything. But with that being said I did run 18cc domes on my stock motor with 91 octane, the reason was because the top end was so shot, I still was only pulling 70 lbs of compression! But thats besides the point would I do it on a fresh rebuild, absolutely not.

Posted

actually, you can run 19's and +4 on 93 @ sea level......i ran 20's on 90oct just fine......didn't bump it untill i went +5.5 timing...

 

Unless you want to personally buy someone a motor, that's bad advice.

 

What was your UCCR for that motor?

 

Compression ratio, not cranking PSI dictate the need for higher octane, along with timing.

 

You could have a 13.5:1 motor with 150 PSI is the exhaust port are raised enough, still need race fuel but not according to the "cranking compression" theory....

Posted

Unless you want to personally buy someone a motor, that's bad advice.

 

What was your UCCR for that motor?

 

Compression ratio, not cranking PSI dictate the need for higher octane, along with timing.

 

You could have a 13.5:1 motor with 150 PSI is the exhaust port are raised enough, still need race fuel but not according to the "cranking compression" theory....

 

 

Absolutely agreed, however i wasnt even going to bother going there. Depending on the bore, its in the mid 14 range on up with 19cc For reference, sunocco recomends its 110 octane for 2 strokes up to 14:1. They actually recomend their 112 for 15+ but i have had no problems with 110 on my motor. But whatever, i just dont want to see the OP blow up his new topend or grenade a crank. Bottom line sea level = bad with pump and 19cc domes.

Posted

hea whats up im new to the banshee world recinlty my banshee top end blew up so now im doing a std kit to the top end but while im there i would like to throw a cool head on it but i dont know which domes to buy which work for that top end kit ect

 

could you guys give me a run down of what i need to know and wat i should run ect ?

 

 

Thanks for all the help !

Generally 21cc is good for prem. gas. Many variables apply though, alttitude, bore size, porting (if any), etc.. Depending on your application, you may be able to go lower and make more power. Feel free to call me and i will help you.

Posted

hey i got that from either blowit, i believe........they run the setup and did all the test data with success, also ran some builds with really freakin small squish. i'm just sayin what is possible on a stock stroke/bore/porting setup......and it's not about the extra dollar for octane, that is all that is availiable.........if i wanted to push more power, i would go a little more conservative on the squish clearance and rin lower octane......i know i would be safe with 20's and +5.5 on 93, but it's easier to mix 100 and 90 50/50 and even run it a little old

Posted

hea whats up im new to the banshee world recinlty my banshee top end blew up so now im doing a std kit to the top end but while im there i would like to throw a cool head on it but i dont know which domes to buy which work for that top end kit ect

 

could you guys give me a run down of what i need to know and wat i should run ect ?

 

 

Thanks for all the help !

 

 

Just to clarify, you checked the cylinder to make sure it's still in spec? I mean what you said was that you are doing a std kit? Either you got caught up with the wrong girl...ha joke, But i take it you mean standard bore, Usually when top end lets loose its time for an overbore. Did you get it checked out?

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