how far can you push it?

[banshee1856]

Just wondering if anyone has any idea of how much power you can squeeze out of a banshee before you need to get the crank trued and welded? I will be getting mine done since I have to tear the motor apart anyways but i really only have exhaust, k&n's, and v-force reeds.

[okbeast]

It's not really a power thing. It's how much compression you have. No one has an exact answer for you, but i'd say once you get above 150-160, say when race gas is needed it's cheap insurance.

[BigRed350x]

Timing plays an important part in when to true/weld your crank as well. A lot of timing and compression will be trying to force your crank apart every time it fires. I'd do it on any crank if you have it out already and its in good shape. All my bikes have trued and welded cranks, even the stock stroke which only has 90lbs compression at this altitude with the stock head. LOL

[locogato11283]

better to be safe than sorry. just get it welded and feel better knowing its prolly not gonna come apart.

[Snopczynski]

Its not a compression thing either. The thing thats hard on them and causes them to come out of phase is dropping the clutch at high rpm. Your basically dropping one huge dead load (trans) on the motor thats spinning up in excess of 8k rpm. I run 185 psi compression on a stock crank thats not welded.

 

My cousin runs 180 psi compression on a 4mill motor thats got a really low exhaust port (172 exh. duration). He basically built it to climb holes and for torque. He is known for stopping in the middle of trails and dropping the hammer on someone behind him also. He just lost a left side crank bearing inner ball retainer, and we found his WELDED crank was twisted and out of phase. So its all about how you use it, not about whats there.

Edited June 19, 2008 by Snopczynski

[okbeast]

Right, so your compression doesn't play any part in it. 50psi is the same as 200psi load on the crank, dont weld it...

[bunboy1]

how about after market cranks? i just put a hot rods +4 crank in, does that required welding as well? thanks.

[okbeast]

how about after market cranks? i just put a hot rods +4 crank in, does that required welding as well? thanks.

 

hotrods does a tack on the pin i believe but most would recommend it being welded.

[Snopczynski]

Its worth doing it if you have it apart and are putting a crank in. In my eyes if you dont think you will neglect it, then dont tear it apart just to do it.

 

at 50 psi the motor wont run, so your safe with not having the crank welded. :biggrin: Its funny you should mention that though, cause the motor I mentioned that just twisted the crank ran 205 compression for a summer about 2 years ago before he had his domes recut. I have 3 years on my motor, still never had the crank come apart.

[Snopczynski]

Here is proof you can Push it real good!

 

Click the push it link!

[Da-shee-s-nit]

Here is proof you can Push it real good!

 

Click the push it link!

 

Salt-n-Pepa!!!!!!!!!!!!!!! :laugh: Man............you crazy as hell Snop!!!!!!!!!!!!! lol lol lol .................. .............. :yelrotflmao:

[sredish]

it's always trying to come apart, even stock. but adding in a lot of compression (165+) will add stress exponentially, then advancing the timing doesn't help. i'd say compression is the variable we add that affects it most... but it's more or less built in......

 

if it's apart or will be coming apart, get it done!