dual water pump pulley?

[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!

[Greg Amy]

Greg, I disagree. It is not OEM stock and the "if it does not say you can..."

It actually does say you can. 9.1.3.D.n:

"Alternate water pump, alternator, power steering, and crankshaft pulleys of any diameter or material may be used. Type of accessory drive (e.g., V-belt, toothed belt, etc.) shall remain as stock."

There is no subsequent restriction to its "alternate" design. Ergo, the Roffe Corollary kicks in: "If it says you can, then you bloody well can!"

GA, reminding rules writers of Tip #3...


Edit: Just to clarify my point, Chuck, the following two sentences do not mean the same thing:

"Alternate water pump, alternator, power steering, and crankshaft pulleys of any diameter or material may be used."
"You may change the diameter and material of water pump, alternator, power steering, and crankshaft pulleys."

The first one allows alternate pulleys, adding (pointlessly) that the diameter and material may be changed (once you allow an alternate of something, it's open unless otherwise restricted.) The second one says you can use another pulley but you can change diameter and material only."

[chuck baader]

OK, you can change pulleys, but no where does it say you can add another belt:026:

[Greg Amy]

There is an implicit belt allowance with the pulley allowance, given that - by design - belt(s) will have to be changed with a change in diameter of pulleys. That is further clarified with the restriction that "type of accessory drive" must remain as stock.

Finally, within "Engine drive belts may be replaced with others of equivalent OEM specifications" so belts are implicitly "free" as long as they are equivalent to OEM (there's a wide open hole), and there's no subsequent restriction on the number of belts...



GA

[Dano77]

OK, you can change pulleys, but no where does it say you can add another belt:026:

And, Mazda RX7s come with multiple belts to drive multiple accesaries( Alt,AC, PS AIR Pump,) both of which pass over and drive the waterpump.

That said, if it came with two belts why cant you run two belts of a different size. Your allowed to remove AC and PS and AIR. The result is you need a shorter belt to drive the water pump that is driven by said accessary drive.

What is so confusing??????? You not adding any belts. Pretty simple if you ask me.

[chuck baader]

Dano, good point. Mine came with one belt. I have never actually seen the stock configuration so that being the case, I would have to agree its legal.