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There is an interesting discussion on thesamba about a new cooling fan design.  One early adopter claims a reduction in cylinder head temperature.  The designer says because the fan is much lighter and spins up faster it is kind of like having a lightened flywheel giving better throttle response.

https://www.thesamba.com/vw/fo...ewtopic.php?t=755740

https://www.thesamba.com/vw/fo...ewtopic.php?t=755888

https://www.andrigsaircooledte...htweight-cooling-fan

1957 CMC (Speedster) in Ann Arbor, MI

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Looks interesting. Would have liked to read Jake Raby’s take on it. Also would have like to hear about it before I did my shroud. Having a Spyder, I think I’d have to pull it all apart again to replace the fan. I may buy one anyway, just to have it for next time I take it apart.

As referenced in the thread, my welded/balanced fan has a bit of runout in it when I installed it. It was a bit of a trick to keep it from rubbing the shroud.

Last edited by dlearl476
@edsnova posted:

Obviously, I'm a compleate idiot: can't see how this would pull air into the fan housing.

I wish I was smart enough to explain it. There’s some good info in the Samba thread.

My best shot: Imagine a side view with the hub portion facing us pointed down. See how it resembles a tornado? Now imagine the vortex it would create if it were spinning. Like a tornado, skinny at the bottom, widening as it goes up, eventually spreading out perpendicular to the axis of the spin.  

Also, the smaller, shallower vanes towards the center are moving slower than the larger, deeper  vanes towards the edge of the fan, which would create a suction/Venturi effect. FC135C04-4312-46A4-A11A-9C24A21EE5BA

Someone in one of the Samba threads asked the question “If this works do well, why didn’t VW do it?”  IMO, the answer is simple: safety. It’s like having a spinning propeller inside your shroud.

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Last edited by dlearl476

Fan design is an entire speciality in the mechanical engineering discipline. Fan impellers are air pumps and the fluid dynamics of it get really complicated, really fast.

That being said, the weakest argument I can think of is, "if it's such a good idea, why didn't the Sainted German Engineers do it?" Again (for the kids from Pekin smoking weed in the back of the class) - the Sainted German Engineers designed these about 80 -90 years ago to be quick and cheap to manufacture and operate. What they came up with was elegant and clever, but very, very far from perfect. There is room for improvement in every system. Not "almost every system" - every one of them.

The fan wheels are clearly one of those things. They can (and do) explode at higher RPM. The hub centers can rip out, due to the high weight and high load of the air they are moving. They're surprisingly nice, but there is room for improvement.

Does it take an enormous R&D facility to build a better fan wheel? I doubt it. I believe that the DTM works as well or better than the VW shroud, and it's a cheesy chunk of fobergass with some pieces of aluminum badly riveted somewhat randomly to the inside.

Is Adrig's fan an improvement over the VW wheel? It's intriguing, for sure, and daring. I've got zero issue with his choice of fan-wheel type - there are a lot of ways to move air, and this one is a proven radial (centrifugal) design. The lightweight plastic material is bold - I would think that it would greatly improve throttle response, much like having a lightened flywheel does. I'm most worried about the hub center ripping out of the wheel, since it's plastic with no insert - but it's not a deal-breaker for me.

All in all, I'd rather somebody else be the guinea pig, but if people buy these and they work, it moves the hobby ahead. This isn't EMPI pumping out millions of the same bad part - if the fan doesn't live up to the promise, I'd suspect  Adrig will simply stop selling them and the whole thing will die.

To me, anybody willing to spend any amount of effort trying to make a weird, archaic, obsolete, dead-end engine better is to be applauded.

Last edited by Stan Galat

Stan said “I'm most worried about the hub center ripping out of the wheel, since it's plastic with no insert - but it's not a deal-breaker for me.”

The fan on a BMW 2002 is nothing but HDPE and it’s fine. Granted, it’s held on by 3-4 bolts to the water pump flange, but still. I’m sure the people that Adrig is having manufacture these know what they’re doing, and properly torqued they should be fine.

I think the bigger problem with the speedster is the air inlet, not the fan itself. And I'm referring to the single hibachi grill opening. 

I genuinely hope the fan works better and Adrig as something worthwhile.  Kudos to him for trying.  I'd have no problem getting one, if it proves out.  the "D" key-in plastic only, does concern me a little for longevity..

I'm thinking the engine compartment lid changing to a twin-grill opening would solve more of the cooling issues.     Yeah I know its not true to the speedster.. but the SGE's  made this change on later model 356's for a reason. Style? performance? (I don't think it was cost reduction as 2 grills cost more than 1, so I bet performance)    Just my .01

@Wrenn Smith posted:

I think the bigger problem with the speedster is the air inlet, not the fan itself. And I'm referring to the single hibachi grill opening.

I'm thinking the engine compartment lid changing to a twin-grill opening would solve more of the cooling issues. 

I agree that the Adrig fan is interesting. Since my car is doing fine with the current setup I don't think I'll be trying it out, though.

Regarding the single vs twin hibachi grill opening, don't discount the addition of louvers to a single grill hood to get more airflow. I personally like the looks a lot more than the twin grills.

00000PORTRAIT_00000_BURST20200515063046134porsche-356-super-90-convertible-twinn-grille-bt5-euro-version-6 Sure, I know what you're going to say, "Speedsters never came with louvers and the picture of the red car isn't fair because it's a Super 90." I guess technically you would be right, but I'm just comparing the aesthetics. Wink, wink, nudge nudge.

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I agree that the Adrig fan is interesting. Since my car is doing fine with the current setup I don't think I'll be trying it out, though.

Regarding the single vs twin hibachi grill opening, don't discount the addition of louvers to a single grill hood to get more airflow. I personally like the looks a lot more than the twin grills.

00000PORTRAIT_00000_BURST20200515063046134porsche-356-super-90-convertible-twinn-grille-bt5-euro-version-6 Sure, I know what you're going to say, "Speedsters never came with louvers and the picture of the red car isn't fair because it's a Super 90." I guess technically you would be right, but I'm just comparing the aesthetics. Wink, wink, nudge nudge.

I couldn't agree more. They did indeed have louvers on some of those Carreras with the fancy 4-cam, right?

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