Cooling flaps under car

[redfive]

I did a search and I cannot find a pic of the under car cooling flaps. My 914 does not have these and I need to see an example to put them in the right place. Pic anyone?

[jamcleod]

do you have a Haynes? there is a pix with dimensions in there

[Amark]

they look like this:

[redfive]

Thanks for the pic. It's a big help. I don't have the Haynes manual. I've been using the Lash book. It doesn't have any pics of the flap location.
I did find a blury pic on a google search. So after crawling under the car I easily see how they are positioned. I'm going to fab some up and put 'em on. I'm not sure if flaps where ever on my '72. I don't see previous holes or anything.

[Dave at Pelican Parts]

They added the flaps in 73, I believe. Worth adding to any 914, IMHO.

Get the Haynes book. It's less than $20 from most places (including us!) and has a "different take" on a lot of stuff from Lash (AKA Clymer). It also has the wiring diagrams, which are in B&W but have labels denoting the color. Well worth the money. It has about 85% of the words and pictures from the factory manuals--directly copied from the factory manuals, in fact!!

--DD

[lmcchesney]

Interesting. Where are those flaps? I do not have them on my 72 chasis. Are they to scoup air from the flow under the chasis into the engine compartment? If so, is that not against the impeller flow of air?
L. McC

[scbvideos]

the hayes manual lists them as "defector" guides, 1 one each side, and the tunnel area is clear. My newbie opinion is that they are there to protect the underside on the engine from rocks and stuff, as they say the oil return tubes are easliy damaged by rocks and stuff.

DH

I've been reading the hayes book while I'm on the can

[cshogen]

Actually they are used for cooling. Creates a low-pressure situation that allows the hot air to escape more easily out the top of the engine lid. Thanks for reminding me! I need to put mine on!

[lmcchesney]

Let me see. The impeller forces air over the cylinders to under the engine. But these flaps cause a reduced pressure beneath the engine so air will flow out the engine lid on top?
L McC

[Dave at Pelican Parts]

Yup. And L McC, look in your Haynes manual for a picture of where the flaps go. Leading edge of the engien bay at the bottom.

Don't have a Haynes? Get one. Seriously.

--DD

[Bruce Brown]

So how much does the rain tray effect the cooling?

[Dave at Pelican Parts]

It has an effect. Removing the engine lid altogether has a greater effect, one that you can notice if you are driving your car hard or tracking it. Hence the popularity of the "GT" lids with the second mesh panel.

--DD

[BigD9146gt]

I was told long ago that they had to be on there because they tumbled the air, creating turbulance which allowed air to reach higher into the bottom engine compartment cavitys.

Now the low pressure thing makes sence too.

[lmcchesney]

Thanks Dave. If got the 89 edition, very used. I don't see a flap on the undersurface of the uni-chasis.
That's right 914GT. My point is that cold air enters via the engine lid into impeller and out bottom directed by engine tin is my understanding. Lower pressure under the car is by way of a venturi effect.
The flaps look like they are made from 1/8" steel and point toward the rear and down. Is that correct?
Sorry guys, I don't think I have them on my 72 body and I don't remember seeing them on other 914'S. Is there a consensus on how effective they are? Do they provide a protective service as well?
L. McC

[jamcleod]

rubber or hard plastic (somewhat pliable) pg 187 in my Haynes

[BigD9146gt]

They do help. I ran my 4 motor for a month without them, and then put them back on after i was told they tumble air for better cooling. Granted as an experiment, you need the same driving conditions for the data to be accurite, but how does the fact that the second month was on average 15deg hotter than the month before, and since i keep gas/mileage records, i also drove 25% farther the second month. All during the day, not much at night, probably equal amounts both months. The engine ran on average 10-30 degrees cooler the second month.

Now the 911 doesn't have them, but its also much farther back from the firewall, so maybe the air has time to start tumbling before it reaches the engine. Plus its a better cooled engine, dry sump.

They are cheap insurance, even if you make them yourself.

[Dave at Pelican Parts]

Yup. Charlie Davis found that he had undersize ones on his 914 (installed by a PO) and when he replaced them with the full-size versions, his oil temps dropped noticeably.

I think they were added for the 73 model year.

--DD

[DDS]

http://www.syer.net/porsche_914.htm

You can see them installed here.

[lmcchesney]

Now I got it. Mine is a 72 body so no wonder they are missing. Are aftermarket replacements available? Or should we just manufacture our own? Looks to be 12 x 3 inch at a 30-45° angle down. Sheet metal should do and add little weight and replaceable. My son has designed a cold air scoup from the left rocker panel. Feeds a 3" hose into the front top of the engine compartment. The other side cools the remote oil cooler.
L. McC

[Bleyseng]

I scape the flaps when I go over a speed bump so flexible is a good thing. Check the junkyards for them.