dual water pump pulley?

[tdw6974]

http://atkinsrotary.com/store/86-88-...26-15-131.html

Glen, finally got to point ordered one and got it is about 3 3/4 " in Diameter vrs the single groove water pump pulley that was on before is about 5 1/8" so if I have theory correct the smaller dual pulley will turn the pimp faster?? We run a gutted thermostat with bypass plugged. I wonder if smaller pulley cause cavitation? Hope you and family are surviving the winter!

[chuck baader]

You are slowing the water pump. With the required racing radiator for the RX7 that should not be a problem. You may, however, research the need for a thermostat.

[Greg Amy]

If the water pump pulley is smaller, then it's making the pump turn faster.

Is that a pump pulley or an eccentric shaft pulley? And how does it use dual belts if they're not both replaced?

GA

[tdw6974]

If the water pump pulley is smaller, then it's making the pump turn faster.

Is that a pump pulley or an eccentric shaft pulley? And how does it use dual belts if they're not both replaced?

GA

Greg, that is the water pump pulley. The eccentric pulley and alternator pulley are both dual groove to enable use of 2 belts as a "fail safe" also installing a Water pressure warning light.

[lawtonglenn]

I had to remember why I sent you that link ...

We use the LARGER (ie slower) single pulley ... I think
I just found a dual pulley since you wanted to belt and
suspenders yourself by using two identical belts at the same time

I didn't know then, nor does Atkins list, the diameter of their double pulley

sorry!

[chuck baader]

Went back and reread...my mistake. That is why various vendors sell a set...smaller crank, wp, and alt. BTW, pulleys are free, but it does not say you can change the number of belts

[Greg Amy]

Meh, I think they're OK. "Alternate" pulleys are allowed (with no subsequent restriction to their design) and "type" of drive (toothed, v-belt, etc) has to remain the same. It doesn't run afoul of the "prohibited function" clause...

"If it says you can..."

[chuck baader]

Greg, I disagree. It is not OEM stock and the "if it does not say you can..." rule does apply, just like not being able to change type of belt (expressly prohibited).

When I bought my RX7 I did extensive research on pulleys. The only thing I thought legal was the spherical bearing belt tension adjuster available. Remember, there is way more involved in changing the crank pulley than a simple bolt on!