Underdrive?

[Guest DatsuNoob]

Does anyone know of any company out there that offers underdrive pulleys for L motor applications? Curious

[phatdave]

Like the ones for V.W.engines? All you would get would be a horse or two and a lot of extra heat.:eek:

[Guest DatsuNoob]

When I was into VW's I had underdrive pulleys on my 1.8 8v motor w/1.6 head and it seemed to rev a little higher. Never noticed any difference in heat, stayed right in the middle of hot and cold at all times, but had a low temp t-stat. was just curious if any were ever made for datsuns.

[521Lvr]

I have seen some real nice pullys for Z cars.

They would fit our trucks but I don't think they are underdrive.

You know the bottom pully is made on the damper so that would take some machining to over come if you were to find a pully.

I have thought about doing it. We have a Hot Rod Barn here and they keep all kinds of billet pullys in stock for Chevy.

The mounting holes could be drilled to fit and maybe some spacers to get the belt to line up.

If I were to do it I would get serpentine belt pullys.

also, other than looking nice I don't think you would really gain any power.

peace

tc

[ggzilla]

Yes, you could make one. Some guys make harmonic balancers for Datsun a-series, so making a different size pully should be even easier:

 

[datzenmike]

Like a lightened flywheel it might free up a fraction of a hp but the real advantage is not over revving the alternator when the engine turns 7K! Also only so much water can be sucked through the rad and pushed into the motor so again it would take some of the high RPM stress off of the pump bearings and reduce the chance of fluid cavitation in the pump itself. A slight downside might be less charging and coolant flow at idle. Easily fixed by a higher output alt. and an electric fan. In fact get rid of the clutch unit and fan blades and run an electric fan instead. Lots of spinning weight removed.

[521Lvr]

Man!... I wish I had a metal lathe.:(

[Guest DatsuNoob]

Yeah, I just figured I'd used them in my old VW, and I see underdrive pulley kits in the summit racing catalog for V8 applications all the time. Just wondered if anyone made 'em for Datsuns. Mike, you could just run a bigger alt pulley to slow the rotation so as not to fry it, and free up a little more drag on it as well, but I suppose one would have to be at a fairly constant rev to get the same output on the alternator with a larger pulley. Forget it LOL :lol:

[Bleach]

They were made for the L28 and should fit the L20b fine. (I used an L24 single groove pully on my L18)

 

I did a search and found references to PAECO and Arizona Zcar. Neither list a pulley for sale but one person mentioned they cost $150 each. Well worth it for 2 horsepower... :)

[DanielC]

Different diameter pulley did exist from Nissan. I have a Nissan Motorsports catalog from 1987 that has them. 12303-22010 L-16/L-18 101MM diameter crank pulley. 21051-22010 L-16/L-18 134MM Diameter Water pump pulley.