Plastic Fan Passes Racing Test

[FJCamper]

Race Testing Andrig's Plastic Fan

Above is one of RetroRacing's engines, a 1915cc with Weber (clone) 48IDF's on 38mm venturis, an Engle W140 cam, 42mm intake valves, 1.25 rockers, and a 1.5" tubing exhaust feeding a short Stinger with custom made low restriction baffle. The center mount aluminum fan housing hides Andrig's



Andrig's lightweight plastic fan. It is 74% lighter than a welded OEM fan, provides 7-8% more air flow, and is a single piece that will not fly apart. We've already tested the fan in a Ferrari Club event aka Ferraris vs the lone Karmann Ghia). We won because of light rain and timid Ferrari drivers. Just to be fair, we used our very HSR class legal engine, 85.5mm pistons x 74mm (Porsche 356) stroke.

Andrig says he has tested the fan to 8,000 RPM engine speed, which equates to 12,800 fan RPM, without issue. We have personally and physically tested it to 7000 RPM, slaloming around Ferraris. The fan's lack of weight boosts revving just like a lightweight flywheel.

Our only concerns -- which are provable on the track -- are does the fan rob power at high RPM by being so efficient in moving more air? We hope to see some effects at Barber Motorsports Park this 19th-22nd May 2022 near Birmingham Al. If it does rob power we'll know it by RPM loss. The fix would be a fan with fewer or trimmed blades. Just to be clear, this is an issue with racing, not street use.

The Ferrari Club event was not a good test, as our driver had little time dodging Ferraris to watch the tach on the short Talladega Gran Prix track where we hit 4th gear only once a lap with our 3.88 rear end.

https://www.andrigsaircooledtechnology.com

[John S.]

Can’t wait to hear more. The samba is all over the place on this topic. But, you know how that goes.

[FJCamper]

Andrig's fan works. We did not experience any loss of RPM or power or belt slippage/burning because of the fan being too good. We ran several 15-minute sprints at Barber with HSR (full story coming out ASAP) and engine and oil temps stayed within our normal range. This was on 91 degrees ambient, sunny days.

The obvious question is if we didn't see any disadvantages, did we see any advantage? Only mentally, because we believe the lack of weight, rotating mass, is better for everything. Belt life, alternator bearings, etc.

[Ian Godfrey]

And it is not much, but it is a bit less weight out of the heavy end of the car. Every little bit counts

[Ol'fogasaurus]

The biggest drawback to plastic fans, especially the blades is they can be damage easier than metal ones.

I wonder if a metal screen of some sort over the opening might be of some protection help, but... you never know!

Lee

[Piledriver]

The Corvair folk use a "powerdisc" centered on fan intake to restrict high rpm flow while not significantly hurting flow at idle to moderate rpms.
Their disc is under the pulley, we would need to have it as part of the fan intake venturi or such for obvious reasons.

Silicone lube on the belt to aid slippage is common as well, but probably restricted to AX.

Corvairs were to have plastic fans originally, idea was shelved when the plastic they used gave off formaldehyde when exposed to battery acid droplets from an overcharging battery... Almost gassed out a test driver.

The fellow should make them for Corvairs too, good fans are very hard to come by. (a product may exist, but its directional)

[Ol'fogasaurus]

Fan slippage was also caused by the 90° bend in the belt requiring the belt to twist coming and going between the fan on top and the drive off the crankshaft 90° away. I did get to see the belt distortion once when the driver was showing off with the hood up.

The idea was interesting, and mods were made but the idea was finally dropped for many different reasons as I remember.

Lee

[Piledriver]

Some slippage is desirable... even on a t1.
Belt tossing on racing Corvairs was considered cured 40 years ago, simply required kevlar belts and an additional belt guide in the right place.
A lightweight fan makes it even less likely.

[John S.]

I would definitely use it in a drag racing situation. If a shroud is used, which I like to do. A lot of guys that blow up fans at the track are using a serpentine belt.