How much stress can the stock crank/ conn rods take?

[warp9.9]

The Rocket's Crank shaft is a forged one as well as the rods.

 

[BigNorm]

Thanks.

 

[Claviger]

If ever there was a member qualified to discuss the progressive weak links as power climbs, it's warp.

I recall something with an exploded clutch basket happening, the crank of course, and I think it was an output shaft or something, warp can provide more data.

Stock rotating assembly is all forged, and quite stout as delivered. Not totally sure why TTS choose to change pistons in their stage 3 setup, the stockers should hold 300 without issues on boost.

 

[BigNorm]

Not totally sure why TTS choose to change pistons in their stage 3 setup, the stockers should hold 300 without issues on boost.

Maybe they are lighter to run more rpms?

 

[Claviger]

Quite possibly, could be for added insurance I suppose as well.

 

[Neville Lush]

Compression.

 

[warp9.9]

Compression.

The winner hands down. You can only get so much out of the stock pistons which are not as good as some of the aftermarket pistons you can buy. then you have to figure things like belt slippage on smaller pulley verses running larger ones at higher rpms The smaller pulley slip creating less boost then the Rotrex unit an actually out provide. Get rid of the slippage and you will see some larger boost numbers. I am not sure how high but I have seen 18 psi on mine. at 8300 rpms and I am pretty sure there had to be some belt slippage.
Anyway about the crank I have seen three breakages over the year all from forced are engines and a few with crank nose breakage problems. putting the crank nose problem aside the others have been from detonation which can be unhealthy Two broke in number one rod journal on broke the rear flange of the crankshaft Not sure why except for massive boost at low rpms. Never really understood the need to have so much power in a area that would be just above idle except when it come to pulling something like a three or four bottom plow in the fields, be hey to each his own!!!!!
Kind of like the Dark side or any other gay, transvestite, or Queer stuff that is allowed or over looked these days to keep people from whining these days.

**** did I speak my mind or just what I was thinking at the time

 

[Neville Lush]

I have seen 21 psi boost at 6850 with NO belt slip Faaaark. That is logged electronically on my analogue module in the dyno, not peering at a gauge whilst trying to tune the bike.

 

[ruzzle]

I have seen 21 psi boost at 6850 with NO belt slip Faaaark. That is logged electronically on my analogue module in the dyno, not peering at a gauge whilst trying to tune the bike.

Sounds reasonable to me........................