Solid crank pulley

[petergoudie]

If anyone wants some interesting reading, Google Cadillac V16 (they made two completely different V16 engines) and Google Marmon V16. Also, about 5 to 8 years ago, Mercedes made a test V24 (12 or 14 litre) for the Maybach which was driven but opted for a turbo V12 probably because it was cheaper.

[andrew_mx83]

yeah pulley will just bolt on like a standard item, probably will need a longer bolt tho.

for timing marks i will just measure where they are in relation to the keyway on a stock one and transpose onto the new one with a scribe or similar


i think i will go and find a place that can dynamically balance the engine and speak to them about it, really they are the ones who should know about the harmonics etc yeah?

[clubagreenie]

Speak to Ross @ http://www.rosstuffbond.com.au/

Makes alloy/steel pulleys and dampners and will advise best route for your engine. Might even hve something off the shelf

[ed]

ross would refuse to make an undamped pulley... wonder why?!

and btw, balancing a crank and rotating assembly has nothing to do with a harmonic damper.

[timbosaurus]

So is that a categorical "don't do it", Ed?

I'm tossing up whether to use a machined (3rd belt rib removed) rubber-isolated steel crank pulley, or a machined solid alloy pulley too.

I can see pro's and cons of both, but can't make a decision yet.

[ed]

i wouldnt
whats the benefit of running an undamped pulley other than laziness/cost?

[timbosaurus]

I'm sure some would be interested in the lighter weight or shininess...

I got mine with an engine I bought, and it saves getting the stock one machined. So mainly cost and laziness

[ed]

the balancer i got for my 10.5k engine is damped, and the damper doesnt weigh that much. certainly doesnt add so much weight that id be worried about rotational inertia. its on a small dia, and in the field of grams, no kilos

[Rallystanza]

A friend of mine, Hen from these forums, was running his 4AGZE in RWD form with a "12 PSI" equivalent solid aluminium crank pulley on it for at least 2-3 yrs of hard hard driving bouncing off the limiter and participating in drifting, autocross etc and he eventually had a fail just driving down the freeway to Wilson's Prom. The front snout of the crank where timing gear and crank pulley mounts snapped clean off and we supsected it was due to the harmonics generated but not eliminated combined with the stresses of the larger diameter pulley. Just an example for you.

[clubagreenie]

I wasn't saying go undamped. Quite the opposite, I know what Ross would say. His new design makes them much lighter than previous and aren't they alloy/steel combination?

[timbosaurus]

I can't justify a brand new dampened custom jobbie, for me it's a choice between stock and billet alloy.

Sounds like billet alloy would be silly.

[andrew_mx83]

^^

i am sort of in the same boat. cant really justify paying $500-$1000 for a crank pulley


thats a nice bit of kit ed, mind if i ask what it cost roughly?
i also realise your point that balancing the rotating assy does not have to do with the harmonic dampener but i thought that if they have the whole short block -crank pulley included - they would balance out all the nasty harmonics for me and therefore the stress on the crank from the harmonics would no longer exist?
or am i off the mark here?

[andrew_mx83]

also, on a side note i see you have a separate attachment to run the oil pump, when setting up the dry sump system is there a guide as to what speed to spin the pump at? yours looks to be about half crank speed which is about what i was thinking.
is there a limit to how fast u can spin the pump?

[Billzilla]

also, on a side note i see you have a separate attachment to run the oil pump, when setting up the dry sump system is there a guide as to what speed to spin the pump at? yours looks to be about half crank speed which is about what i was thinking.
is there a limit to how fast u can spin the pump?

Yes, you spin the pump fast enough to it pumps about 150% to 200% of the volume of the pressure pump. This is pretty much always slower than the pressure pump so it's rarely a problem. Some gear-type pumps don't like going above about 6,000rpm or they can cavitate, if that's the case and you haven't got enough volume then you need another stage.

[ed]

er bill, the volume of the scavenge vs pressure (ratio) is determined by the size of the pump stage, not the rpm. that ratio should be fixed independent of rpm

with regards to vol output of a pump and how fast to spin, theres a certain amount of suck it and see.i think. you can test run the pump to check volume flow per rpm, but i think its all a bit ballpark till you get it on and running. that said, thats why you can buy several different pulley teeth combinations