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Tue May 10, 2005 2:54 pm

I'm starting to get on my way of building my 2332 street motor. You think the Porsche fan conversion is worth it?

I haven't been able to find much info on it, but in the Euro mags, it seems all the street guys are using it. But on Massive Type IV's engine, he doesn't use one.....which makes me curious if it's just asthetics or bragging over the cost:performance/cooling gains.....

It seems like that shroud covers the entire engine, and with that ginormous fan, it seems like it'd be worth while, but you don't see many with it.....

It looks cool :lol:

Tue May 10, 2005 3:04 pm

Not worth it even if it was given to you stay with the type 1 cooling and add an oil cooler with fan

Tue May 10, 2005 3:09 pm

Do a search!

All I can say is that in my testing the absolute hardest system to beat on the TI or the TIV was the stock system and on the TI one particular 36HP system beat even stock!

The 911 kits all created huge imbalances in engine temps not forund with stock.

More air from a huge fan is not the key, the key is directing the air where it needs to be and doing so with correct pressures.

If you want a 911 system, buy a six cylinder engine. Otherwise stay stock.

Tue May 10, 2005 3:19 pm

The Porsche fan can suck alot of H/P, up to 30.

Tue May 10, 2005 3:32 pm

Bob is exactly right. I have personally seen 29 HP loss on a 239 HP engine... Stock is between 12-18 as a general rule, and my DTM typically loses 13-16 on average...

Tue May 10, 2005 5:05 pm

oicdn, Hey your right. The 911 Style Cooling kit "LOOKS' very cool,built one of my kids cars with one. {he just had to have a Bernie Bergman cooling system} He paid good money for it too. "LOOKS" bitchen with the polished fins on the alt.fan too. I can also tell you that while I havent done any airflow R&D on the shroud my knowledge of airflow in general would tend to lead me to believe the back of the shroud gets plenty of airflow and has absolutly no directional features within. Go back to Jake's site and do some more reading.If you want to purchase a cooling system, consider you'r source. I certinly feel more comfortable with all the stock cooling tin that was originally designed to use on the Type 1 back on his car. But yeah, it LOOKS cool.

Tue May 10, 2005 6:27 pm

I compare those looks to a fake blonde with implants.... Most of the time they look really good but simply can't perform!

Wed May 11, 2005 5:16 am

Jake Raby wrote: Do a search!

All I can say is that in my testing the absolute hardest system to beat on the TI or the TIV was the stock system and on the TI one particular 36HP system beat even stock!

The 911 kits all created huge imbalances in engine temps not forund with stock.

More air from a huge fan is not the key, the key is directing the air where it needs to be and doing so with correct pressures.

If you want a 911 system, buy a six cylinder engine. Otherwise stay stock.
Hey Jake. I don't suppose you want to say which 36hp system beat stock, do you?

Wed May 11, 2005 5:16 am

^^^^^Hahahaha, awesome!

Wed May 11, 2005 7:32 am

the dog house is sed to be the best type of cooling, it wouldnt of lasted so long if it wasnt.

and thinking about it wouldnt the porsche fan suk in warm air? if hot air rises up from the exhaust? then over the case/heads??

Wed May 11, 2005 7:42 am

I would have very hapily stated the 36HP shroud that kicked ass, but its Mfr refused to even pay me as little as 500 bucks for the data. I spent more than that on damn fuel... I refuse to help the jerks- They don't even know what they have and I'm sure that it was accidental that they designed something that worked so well!

Wed May 11, 2005 8:04 am

Jake Raby wrote: I would have very hapily stated the 36HP shroud that kicked ass, but its Mfr refused to even pay me as little as 500 bucks for the data. I spent more than that on damn fuel... I refuse to help the jerks- They don't even know what they have and I'm sure that it was accidental that they designed something that worked so well! Thanks anyway Jake. I can certainly understand your point. I like the DTM, but it's out of my price range for at least a year or two and doesn't provide options for the thermostat flaps. The only company I know of that makes what "sounds" like a decent 36hp doghouse shroud is SCAT, but even then I would have to fabricate my own cooling flap mounts. Just looking for a more affordable, "next to the best" cooling for the type 1 motor. Again, thanks for the response.

Wed May 11, 2005 4:22 pm

I definitly appreciate the information Jake......thanks for helping me not make a $1600 mistake.....

Wed May 11, 2005 7:58 pm

oicdn wrote: I'm starting to get on my way of building my 2332 street motor. You think the Porsche fan conversion is worth it?

I haven't been able to find much info on it, but in the Euro mags, it seems all the street guys are using it. But on Massive Type IV's engine, he doesn't use one.....which makes me curious if it's just asthetics or bragging over the cost:performance/cooling gains.....

It seems like that shroud covers the entire engine, and with that ginormous fan, it seems like it'd be worth while, but you don't see many with it.....

It looks cool :lol:

I'm very happy with mine. Kit was from Oliver Knuf at Power Tuning Parts in Germany. This shroud was designed for my 1inch wider motor (5.7 rods). It works very well. I have beaten on it, let it idle, and cruised down the highway. Temps have been very close and consistent across the board. Mind you, i used a Fluke infared thermal temp guage, but i hit everything with it, cylinders, heads, exhaust, case, and anything else i could point at. Gives me piece of mind, and i still monitor head temp with the EFI. Uses a original 911 fan, ring and alternator.

Jake, did you test any German built/designed systems? Or were they all from the US?

In Europe the 911 fan kits dominate the scene, and they run their cars hard designing the kits for roadcourses and the autobahn. Not because they look cool.

Here's a pic:

2332, drysumped, EFI 53mmTB's, ARPM superflo's

Thu May 12, 2005 1:21 am

i like mine too. haven't had a problem with it yet, or any bogus temp readings. it's a german csp kit on a type 4 motor, if that makes any difference. i've also beaten on the car wuite heavily, idled, and bombed down the freeway at 80-90mph for hours at a time. seems to do great.

lots of people like their 911 kits, and not just for aesthetics. although they do look way better than the alternatives...

Thu May 12, 2005 6:44 am

petevdub wrote: In Europe the 911 fan kits dominate the scene, and they run their cars hard designing the kits for roadcourses and the autobahn. Not because they look cool.

See I was thinking the same thing.....I was also curious if the kits tested were all german of US made...no clue if it'd make a difference, but it seems the german parts seem to be the best parts out there....

<----------VW noob

Thu May 12, 2005 9:44 am

Gotcha covered...

I tested every German made kit except the Klaus shroud which is very hard to get as Klaus will not sell to the US.. I have located one for testing and will do it later this year.

I tested every TI style kit available (or that I knew existed) including Sharpbuilt from Australia.

I have never said that the 911 shroud DID NOT work, I have stated that they lack development, they do not cool as equal as other systems and they draw HP that others do not.

For so many years the huge amount of gross airflow the fan makes even had me fooled- I NEVER anticipated that the DTM would out cool the 911 shroud until I witnessed it, especially in the high load/ high RPM tests with the TIV engine...

Now that I have my datalogger all set up look for more of these tests to be ran and the data posted simply because its much easier and faster to do the testing with the 16 channel logger that uploads info into the laptop while I drive or run the engine on the dyno.

I am replacing the passenger seat in the Plague with a full data acquisition platform that will incorporate the logger, two lap tops digital SPA gauges and back up analog instruments all in one easy to remove/install package that slides right on the seat tracks..... The systems can be read/controlled onboard from the driver's seat or from the back seat from a co-pilot since the set up will pivot 360 degrees...

You don't want to know how much this set up has cost so far.... The myths will contine to be buested and facts will be posted.

Thu May 12, 2005 1:30 pm

^^ Very nice post......

Wed Sep 30, 2020 5:36 am

So I'm interested in data, I would like to know that what I'm spending my money on is worth it. Pretty sure that goes for everybody!

Actual data or Engineering fact goes like this...

Axial Fans:
Axial fans date back to the horizontally configured windmills of Europe in the Middle Ages. The first electrically powered fans, introduced in the 1880s, were axial fans.

Axial fans are named for the direction of the airflow they create. Blades rotating around an axis draw air in parallel to that axis and force air out in the same direction.

Axial fans create airflow with a high flow rate, meaning they create a large volume of airflow. However, the airflows they create are of low pressure. They require a low power input for operation.

Radial Fans:
The centrifugal fan was invented in 1832 by military engineer Lieutenant General Alexander Sablukov of the Russian Empire’s Imperial Russian Army.

Often called blowers, centrifugal fans vary differently from axial fans. The pressure of an incoming airstream is increased by a fan wheel, a series of blades mounted on a circular hub. Centrifugal fans move air radially — the direction of the outward flowing air is changed, usually by 90°, from the direction of the incoming air.

The airflow created by centrifugal fans is directed through a system of ducts or tubes. This helps create a higher pressure airflow than axial fans. Despite a lower flow rate, centrifugal fans create a steadier flow of air than axial fans. Centrifugal fans also require a higher power input.

My thoughts on this are that upright fans are more restrictive inherently due to the unblended nature of the joins between the upright housing and the cylinder shrouds. This will increase the pressure drop across the system. This may be enough to justify the use of an axial fan due to the nature of these fans being able to create pressure. Although this does seem like a self perpetuating problem! Radial fans certainly are frugal (cheap) and package small which is good for single carbs.

Axial fans are more efficient for flow: for the same flow rate they consume less power. And its is flow rate that cools, the longer your cooling air dwells over the hot parts of an engine the higher the temperature rise. the hotter the cooling air the less ability to cool it has, temperature delta is key. If you have more flow rate the cooling air stays cooler because of the shorter dwell time, the cooler the cooling air is the more cooling it does!

It appears that on the face of it the Porsche fan has it. Axial fans are directionally correct for low pressure drop cooling systems and where power consumption is going to be a problem/noticeable/measurable.

Of course anecdotally, Porsche used these fans, and their mission statement is as ours would be: get the most power from your engine with good reliability and durability.

I'm on the cusp of building my type 4, I would love to see some actual data pertaining to application to sway me one way or the other.... Is there enough pressure drop across a Porsche shrouded engine that the flow rate drops below that of a radial fan?

Edwards Deming “Without data, you're just another person with an opinion.” :D

Wed Sep 30, 2020 5:59 am

Awesome thread ,I like the practical application of real data to prove fact.