alternatives to, engine tin Options

[jimkelly]

forgive the newbie - are there ways to remove the engine tin and cool the engine with a bank of electric fans instead? Jim

[tat2dphreak]

(IMG:http://www.914world.com/bbs2/html/emoticons/ohmy.gif)

what you can do is remove all the tin, but then you have to drive at 125 everywhere and never stop (IMG:http://www.914world.com/bbs2/html/emoticons/wink.gif)

how would you power the 100 fans it would take?

and why would you want to?

[ClayPerrine]

The engine tin also prevents the hot air under the car from recirculating back above the engine and reentering the fan. If you take it off, you will have overheating problems.. even if the car is otherwise fine.

[ArtechnikA]

sure. most of them tend to be for racing (and drag racing at that) only. AX cars that are on power at most a couple of minutes at a time might get away with it.

figure there's 3-5 HP pumping losses from moving the cooling air - and that's with a coaxial fan with no coupling losses. go have a look at how big a 5HP electric motor is. convert 5HP to amps at 12V to see the kind of current draw you'd need, and subtract that from the 90 or so your alternator can produce - don't forget to also subtract for headlights, FI computer, fuel pump, brake lights...

remind me what you are hoping to accomplish?

[redshift]

The sturgeon general has found that electric cooling fans cause cancer in lab rats with tremendous alternators.

(IMG:http://www.914world.com/bbs2/html/emoticons/unsure.gif)

Ok then..


M

[Jake Raby]

Ouch..... electric fans cannotcreate the amount of velocity needed to cool the engine correctly- period.

Every attempt I have ever seen has been a very poor one.

If it wasn't for (IMG:http://www.914world.com/bbs2/html/emoticons/stromberg.gif) the 914 DTM would be in production right now and would solve this issue.

[jimkelly]

Looks like the votes LEAN toward keeping engine tin on and there is no alternative at this time to it. I had to ask. Now I know. (IMG:http://www.914world.com/bbs2/html/emoticons/driving.gif)

[Aaron Cox]

there is a horizontal flat fan setup from porsche classics, one big 16" fan iirc.... electric.....

[URY914]

I'm going to pack my engine with ice before every a/x run.

That would work right? (IMG:http://www.914world.com/bbs2/html/emoticons/wink.gif)

Paul

[bd1308]

somebody needs to make a water cooled setup for a stock 914 engine.

[john rogers]

For a street or auto-x driven car the sheetmetal AND seals have to stay. For a road race car you can eliminate the sheetmetal, alt with the attached fan and run something like Wayne Baker did on the #22 914 in the IMSA days. That used a pair of ex-heating fans that drew air from inside the driver's compt and ducted it to the cylinder heads and cylinders only. The oil cooled the crankcase and it saved some HP but was only good for road racing.

[Mueller]

QUOTE (bd1308 @ Jul 26 2005, 10:10 AM)

somebody needs to make a water cooled setup for a stock 914 engine.

just do a suby conversion...it would be cheaper and easier...of course you could use a wasserboxer van engine, but they have thier own problems and would be a step backwards........

[Mike D.]

QUOTE (bd1308 @ Jul 26 2005, 09:10 AM)

somebody needs to make a water cooled setup for a stock 914 engine.

large fish tank around engine, few modifications, some sealant, a mount, fill it up with water and Viola! (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif) (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif) (IMG:http://www.914world.com/bbs2/html/emoticons/laugh.gif)

Of course you have to stop and fill it up with water every so often as it keeps boiling off...

[lapuwali]

Axial flow fans (like the 911 fan) are generally less efficient than centrifugal fans (like the stock 914 cooling fan). This is probably why many electric fan setups fail, as they try to use off the shelf axial flow fans.

If we assume the stock fan takes about 3hp, that's 2.2kW. If we used a 120v AC motor to power a big squirrel cage fan, that would take about 18 amps. A single car battery fully charged can do about 60 amp/hours. An inverter to change the 12vDC to 120vAC would be about 80% efficient, more or less, so figure 2-2.5 hours of run time on the fan before you totally drain the battery (no alternator). If you add an alternator, you're now looking at taking up about 7hp off the engine to generate the electrical power from the alternator (about 50% efficient), rather than only taking 3hp to directly drive the fan.

So, for a sprint road racer, or an AX car, or a drag racer, you should be able to devise an electric cooling system that will save you roughly 3hp. The electric setup would take up more space than the direct drive system, and would be a fair bit of work to put together. The electric motor would be relatively heavy.

Ultimately, I'd think you'd end up with a wash in performance.

As for water cooling, that's been discussed here from time to time. The best solution to get a water cooled flat four is, IMHO, a Subaru. You also gain OHC and four-valve heads (on most versions). There is a VW engine with water-cooled heads (the Wasserboxer), used in Vanagons. It's not much of a performance engine, though. I don't know if this engine is Type I or Type IV based.

[Mueller]

QUOTE (lapuwali @ Jul 26 2005, 10:38 AM)

I don't know if this engine is Type I or Type IV based.

Type I based, in fact the Subaru motor was based on the Type I as well, that is why it was easier for some people to use Subaru watercooled heads on VW motors.....

for my motor, I've decided to stick with the stock fan design for now, the horizontal fan idea just does not seem to be worth the trouble...... (IMG:http://www.914world.com/bbs2/html/emoticons/smash.gif)

[BMartin914]

QUOTE (bd1308 @ Jul 26 2005, 09:10 AM)

somebody needs to make a water cooled setup for a stock 914 engine.

There already is. It's called an inner tube filled with water in the trunk and a washer pump rigged up to spray water into the impeller. Cools nicely for about 15 minutes on continuous spray - so I've heard.

[tat2dphreak]

I'd be afraid squirting water over a hot head would result in a busted head... since the heads aren't made to cool like that...

[redshift]

QUOTE (lapuwali @ Jul 26 2005, 01:38 PM)

Ultimately, I'd think you'd end up with a wash in performance.

James makes many good points, but goes on to flatly ignore hydro-electric, and windmills... and since you are going to cool it with water, you may as well get your power there too.

Oh my.. a system of windmills, that cool the water, that push the turbines, that make the power, and pump the water, to cool the motor... we could use the excess power to drive aux motors to the front wheels, and you could build a dome over the whole mess, and power a 30 ton A/C!

Do you know how rare hydro-electric 914 eco-domes are?


M

[redshift]

QUOTE (tat2dphreak @ Jul 26 2005, 03:47 PM)

I'd be afraid squirting water over a hot head would result in a busted head... since the heads aren't made to cool like that...

I have seen a bug back into a lake after a nice hour plus summer drive.

(IMG:http://www.914world.com/bbs2/html/emoticons/laugh.gif)

It's as noisy as it is funny. The metal actually groans.


M

[nebreitling]

our local AX champ Andrew Blyholder (who's sometimes on the board) uses two serious looking electric fans mounted over the cylinders, and one puny looking fan over the oil cooler.

he hauls serious ass. for all of two minutes at a time.