ATI Crank Damper V-belt Pulley Size

Turn & Burn

Club Member
I've got an ATI Crank Damper to fit on my new engine build. The V-Belt pulley that would drive alternator and water pump is only 76mm dia as compared to the 150mm pulley as standard. Checking round it would appear that the Kameari pulley size is 102mm.
So the question is..
Is anyone else using an ATI damper with this small pulley (or similar) and do you notice any lack of charging or cooling?
I'm considering turning the existing 76mm pulley off and shrink fitting a larger one in its place, as I'll not spend that long in super high rpm situations that perhaps the ATI damper was intended for. Perhaps the 102mm of the Kameari unit offers reasonable compromise.
 

jonbills

Membership Secretary
Site Administrator
I have a Kameari one. The engine needs to idle above about 1200rpm or the temperature slowly starts to climb and below about 950rpm the charge light comes on in the voltmeter.
The cam needs rpms a high idle anyway so it's not a problem.
Kameari one also has room between the pulley and the timing cover for a trigger wheel!
 

jonbills

Membership Secretary
Site Administrator
Also, I think Kameari sell larger alternator and water pump pulleys if you need them.
 
I've got an ATI Crank Damper to fit on my new engine build. The V-Belt pulley that would drive alternator and water pump is only 76mm dia as compared to the 150mm pulley as standard. Checking round it would appear that the Kameari pulley size is 102mm.
So the question is..
Is anyone else using an ATI damper with this small pulley (or similar) and do you notice any lack of charging or cooling?
I'm considering turning the existing 76mm pulley off and shrink fitting a larger one in its place, as I'll not spend that long in super high rpm situations that perhaps the ATI damper was intended for. Perhaps the 102mm of the Kameari unit offers reasonable compromise.

just use smaller pulleys on the wp and alt?
 

Turn & Burn

Club Member
Thanks for the input. I’ve had a look at the smaller pulleys, my existing alt is 65mm so it’s possible to drop to maybe 55-60mm which will give an approx 10%-20% recovery, but it gives the alt a much harder time on the bearings. There’s not much more than a 10mm reduction in dia available on the water pump as you have slide the pulley past the water pump flange. Seems surprising that ATI went so far with the reduction in pulley diameter on the damper in the 1st place.
 
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