Quote:
Originally Posted by sendler
Yes. DOHC. It looks like the gears are shrunk on with a key so only whole teeth adjustment would be possible.
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Best to build your cam teeth swap on actual timing figures.
Let me explain further :
a good candidate for this concept needs to have fairly long duration cam (peaky engine) in order to keep some overlap when teeth are swapped.
For instance GPZ have 290° cam that allow it to be delayed up to the 105° retard for closure that is used on the Prius and yet have some overlap.
Not quite sure but I think overlap is required.
Usually, singles don't have big duration cams because the engine inherently doesn't spin fast and requires help to idle properly in the first place wich is not one of the strenght of long duration cam engines.
Quote:
Originally Posted by sendler
Vacuum is already quite low. It appears to run about 5-7 inches at idle and drops away toward 0 with any throttle. Unless I was "T"ed into a restricted port that is also connected to a steady vacuum consumer.
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I don't understand, you're being too specific on your setup.
Quote:
Originally Posted by sendler
I am actually more interested in lowering the rpm of the torque peak. Possibly by increasing the length of the tuned intake runner. But even this would tend to take the mixture off of the stock map so I think any real economy gains from engine changes would require an after market fuel computer with wide band mixture logging in lieu of a dyno with a probe. They are available from Bazzaz and I will probably get one eventually if nothing more than to play with some light throttle, lean burn settings.
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Honestly, I wouldn't face the hazard of wasting a properly working engine on a valuable bike.
To me, ecomodding a valuable bike (or car) is already on the edge of reason.
Tuned intake runner is interesting but packaging constraint could get in the way quite soon.