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The 917 had cooling fins everywhere- Please don't confuse cooling capability with a cooling system's ability to cool... Two drastically different things! The 917 fan was ran from bevel gears directly from the crank.

One of the biggest mistakes that can be made is "well it worked so good for Porsche, it has to work on a VW" thats about as wrong as it gets! VW engines have much less cooling capability (fins and materials) than any Porsche engine, all the way back to before the 547 4 cam Carrera.

MASSIVE TYPE IV wrote:-----

One of the biggest mistakes that can be made is "well it worked so good
for Porsche, it has to work on a VW" thats about as wrong as it gets!
VW engines have much less cooling capability (fins and materials) than
any Porsche engine, all the way back to before the 547 4 cam Carrera.

The VW cooling system depends on pressure(pressure is built up by
turning high velocity/low pressure air flow into low velocity/high pressure
air flow), due to the short fin design of the heads. Porsche is just the opposite.

Jake, do you still have the pitot tester? I am ready to test the eletric fan
at speed, 35 mph, 55mph, 70 mph and 100 mph.

I'd like to take pressure readings at each speed to test my scoop layout,
before I glass everything in. I may have to raise the lip to grab more air.

I tried to err on the side of noise over cooling, but I doubt I'll hear the shriek over the 45 Dells.


Don

Go find a boost gauge from a big rig- it works almost the same as my rig....

I wasn't expecting pressures to be that high? 2-3PSI at the most!


What have you seen inside your DTM and the Porsche 911 style units?

Don

Be suprised... I have seen upward of 11 PSI with a DTM!

My scoop won't produce that..............until it gets up to 120mph!


That's the speed I blew the rear *glass* out the first tiem I drove it!
$175 down the drain.....


I might have to go back to the design board.


Don

Just when I thought all of the last Riechert set-ups were sold, BAS apperently has found a small new stash of them :

http://www.ahnendorp.de/angebot.html

BTW: these do NOT throw belts!

Looks like it's time to get one for testing...

The 911 fan I'm considering now will place the famn housing at a 45 degree angle, facing the cylinders.. Not a true 90 like this and not like the conventional 911 fan arrangement..

This has MANY benefits- just wait till you see how I'm gonna make it work!

Sweet, that will be interesting to see...the ~45 fan as well as the new turbo/super motors

MASSIVE TYPE IV wrote:Looks like it's time to get one for testing...

Jake,
When you do (testing one by you would be great btw), do know that the shroud of these were made for the spark plug location of the 914 2.0 Ltr engines with the 3-stud heads. Not many know this...
Also, the shroud is relatively thin and consists of two parts. The belt pulleys and its mountings are extremely heavy and the crank pulley itself is an original steel big diameter pulley. Its very cool 70's/ 80's style for a 'retro- german-looker' and the set-up has definately show potential, so you will probably sell it on testing after very easily...

The 911 fan I'm considering now will place the famn housing at a 45 degree angle, facing the cylinders.. Not a true 90 like this and not like the conventional 911 fan arrangement..

This has MANY benefits- just wait till you see how I'm gonna make it work!

That idea sounds awesome! Would be very cool if you would pursue this! I like the thought behind it

I've still yet to see anyone manage to fit a roots/screw blower to an engine using the Type1 upright fanshroud and be able to close the engine lid without mounting the blower behind the fan and run a long snout thru the fanshroud. I've seen one centrifugal blower install but it was a pile of crock and I wouldn't touch a centrifugal with a barge pole.

An Eaton M45 with no snout can just about fit in the space above the dissy to the left of the alternator (anything bigger is impossible e.g. like my Eaton M62)) but the intake is at the back which is right up against the fansroud which would mean taking the intake thru the fanshroud which could be a possibility I suppose but I wouldn't like to do it as I'm sure it would mess up the flow inside the fanshroud alot. Also the outake for the Eaton is underneath, right where the dissy is and would be difficult to design an manifold and mounting arrangement which would be practical enough to allow you to use a dissy. Possibly dissy less ignition would be a solution or turning the Eaton over but then this places the pulley on the left hand side and could cause problems when shutting the engine lid....etc... etc


IMO the options for mounting (in a bug) are:

1. Dick Landy style - i.e. go UP

2. Riechart type - i.e mount on top of (like the only supercharged motor I'm aware of that Jakes done)

3. Behind - i.e. mount the blower behind the fanshroud and take the long snout thru the shroud (requires rework of the luggage area behind the rear seats)

4 Standard Porsche fan setup - this frees up a load of room, more than enough to mount a blower to the left of the fan and even enough room for a chargecooler too. In my mind the only way to go.


HOWEVER (unless Jake can come up with a picture otherwise) there may be a possibility using the aftermarket Type1 shrouds that slope down on the left side and mounting the blower over there. I mocked this up on my buggy which uses a CSP Type1 conversion and my Eaton M62 (off my bug) and it should work. The only thing I couldn't check was whether it would fit under a beetle engine lid.

funkSoulP wrote:And how about the driveshaft of the blower? It is longer than necessary and I can't find any reason why it must be that long. Is it possible to make a new nose piece with shorter shaft?

You can make or buy shorter snouts for the Eatons from a number of places, let me know if you want the links.

cnavarro wrote:I can't answer the fan question exactly other than to say that the flat style fan is a poor solution, even worse than the 911 style shroud. If the DTM can be made to fit, Jake can do it. Cylinder wise, you'd probably want to stick to a smaller 90.5mm bore or at the largest, a 93 or 94mm bore depending on how much boost you'll be building. I would assume 5 psi on a 93 or 94 bore would be fine, especially if you step cut the heads. Any larger than that, you'll want a set of Nickies. Jake's currently working or a large displacement turbo engine that he'll be using a set of thickwalled Nickies for- we have three to choose from, including a 98, 100, and 102mm bore, all based on the registers of a STD 103 cylinder, so they are interchangeable in that respect. On the thicker 98s and 100s, you can get away even with flame ringing using 911 components for a physical interlocking seal.

Charles Navarro
LN Engineering
http://www.LNengineering.com
Aircooled Precision Performance

I sort of agree with the 'keep the bore size down' school and I don't.....

Most (if not all) of the guys I know who run blowers on Type4 motors run more than 94mm. I run 103mm for instance. The main problem I've experienced (and others) is getting the heads to seal properly with the barrels and most importantly keep it that way. I've tried doing nothing - BAD idea... and a copper sealing ring - worked for a while but not for too long. Now I'm currently going the route that Russ Fellows has found complete success with (using 103's too) which is to machine a set of ridges in the heads and an exact opposite in the tops of the barrels, use no gasket between the surfaces and lap them in well. This method has enables Russ to run very high boosts consistently and reliably on the street (with the Type4 odd bolt spacing pattern). Using larger than 90 is fine in my (and the guys I know) experience you just have to think a bit more about sealing a bit more than usual, as with any boosted setup.

Using a bigger bore and a supercharger also raises your oil temp a bit (not horrendously just noticably) easy solution - use a bigger oil cooler, now my temps are cooler than my normally aspirated Type4.

I would rather use a smaller engine/ bore and be able to make the power with added boost that stays within the confines of the cylinder/chamber..

Boosted engines make power from the boost, not the engine size like N/A

But we all have our own ways of doing things!

Jake, If you've measured 11 PSI of pressure in a DTM shouldnt it be possible to tap off some that with enough flow rate to allow the DTM (in some modified form) to double as a modest supercharger? Its difficult to see how the pressure could be that high but if you say you measured it I wouldnt doubt you.