Why: spec'ing a racemate direct drive water pump and alternator.. I
> intend to order in the next week and want to select the right one.. or
> the "most right" one.
> 
> Dave
>

 

Pardon me if I fumble about a bit I have been dropping the GPM subject line posts.

 

The 200 HP from a NA 13B at 6,000 RPM will require about 175 footpounds of torque. (199.92 HP) A bit hopefull I think.

 

From an engine that prides itself on poor torque output.

 

Easy for a turbo, with just a hint of boost.

 

I note that the Chevy sized pump pulley (rather large) will require a bit larger crank pulley to maintain a Mazda similar ratio.

 

I use the Mazda comp pulley set because it uses a small belt with no idler that can fail. It slows the pump down just a bit. What the exact ratio is, I don't know. I could measure the pulleys if anyone cares.

 

This setup has been just fine for many years. As is the stock pulley set in Mazdas raced in the stock classes. Cooling is just not a problem. Even with the dinky stock radiators.

 

I use a restrictor in the water outlet, but most people use nothing at all, or an American style thermostat with the center removed, for just a bit of restriction.  

 

With a Griffin double pass aluminum radiator, it is more likely we will tape off part of the water radiator on cool days than have a overheating problem. If you can get the oil temperature under control, there will be little problem with the water temps.

 

In very cool (below 70 degrees) weather we use an American style thermostat and tape half of the radiator off.

 

Peak torque at 7,800 RPM is 154.3 foot pounds(229.4 HP).

 

Peak HP is 244.6 at 9,400 RPM. Shifts are at 9,600 RPM. 

 

This with a bridgeported 12A. Your results should be better.

 

 

Lynn E. Hanover