2.5 six pot on bike carbs
Discussion
[/pic] I've not got any experience of bike carbs, but have a friend who runs an E30 325 on triple Webber 45's in the Kumho BMW championship. That engine was putting out around 180bhp with great throttle response. I could imagine the bike carbs might not be fueling enough at the top of the rev range. If it's possible could you change the jets to larger ones.
My mate may still have his old Webbers and manifold kicking about, I could put you in touch with him if you want.
My mate may still have his old Webbers and manifold kicking about, I could put you in touch with him if you want.
thanks for the offer could be an option however im allready running 2mm jets espicaly enlarged.
on the bike which runs up to about 13k rpm each carb is fueling 275 cc running with 1.6mm jets
on the car each is fueling 416cc with 2mm jets
an increase of 141cc however i would have thought that with much bigger jets and only around half the engine speed they should be surficent.
if your friend dose still have them around let me no if you would
on the bike which runs up to about 13k rpm each carb is fueling 275 cc running with 1.6mm jets
on the car each is fueling 416cc with 2mm jets
an increase of 141cc however i would have thought that with much bigger jets and only around half the engine speed they should be surficent.
if your friend dose still have them around let me no if you would
hoppo4.2 said:
on the bike which runs up to about 13k rpm each carb is fueling 275 cc running with 1.6mm jets
on the car each is fueling 416cc with 2mm jets
an increase of 141cc however i would have thought that with much bigger jets and only around half the engine speed they should be surficent.
It does sound like a fuelling issue more than anything, but I'm wondering if it's maybe down to something like the fuel pump or fuel pressure regulator not being able to deliver fuel at the rate the engine needs ?on the car each is fueling 416cc with 2mm jets
an increase of 141cc however i would have thought that with much bigger jets and only around half the engine speed they should be surficent.
While the maths might say the increase in jet size should supply enough fuel (I'll let someone else confirm that -I I don't *do* maths...
), it could be that the fuel just physically isn't getting into the engine.I'm also wondering (OK, guessing...) if the fundamental characteristics of how the fuel / air mixture is sucked into the cylinders is just so different between a car and bike (long stroke vs. shorter stroke, overall length of the inlet tracts, etc., etc.) means that the fuel demands of the car engine are greater than the bike, so that even with the larger jets the engine is still looking for more fuel. Or maybe more air. Or maybe both. Hard to tell until you know if the engine is running rich or weak when it starts to misfire.
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