Improving engine cooling when you already have a Porsche 911 cooling kit
 

Hi all,

I've noticed that with my porsche 911 cooling system the engine temp is perfect when the car is in motion, but when stationary the engine temp will rise quite a lot.

I think it has something to do with how the 911 fan draws the air from the rear of the engine bay.

I remember reading somewhere on the forum about an idea of cutting a vent under the license plate light.

Has anyone done this?

How well did it work in keeping the engine temp down while stationary?


Cheers,

Ian.

I see that alot with the 911......whats your drive ratio.

Re: Improving engine cooling when you already have a Porsche 911 cooling kit
 

I have done the above mod, basically drew around my licence plate, then removed it. Draw another line about an inch inside the first one, leaving more in the corners (so I can mount the plate easily).
I then drilled a hole in each corner, put the plate in position and marked where the holes were needed on the plate. Then used nuts n bolts to stand the whole number plate about 1.5 inches off. I then painted any visible bits of the bolt black.
:D

It did make a difference, and also slightly reduced air noise caused by the fan pulling the air past the decklid (which is quite close to the fan in places).

If your temp rises and rises when stationary I would say you need to check the engine bay sealing tin you are using... Is it sealing correctly? I saw a vast improvement in stationary temps when I made that seal correctly.

Cya,
Sam C

Re: Re: Improving engine cooling when you already have a Porsche 911 cooling kit
 

that is where i was going to go. check that before any radical solutions.

Question:

If you ahve a closed decklid and proper sealing tin all around the engine where does the air com from the feed the carbs/TBs and a 911 fan?

All from below the rear window?

Think about it.....

Alex

I have stand-offs on my Type 1 ( not verybody likes them), and it takes ages to warm up to 180 in the winter here in the UK, but found that the temp was ideal in the Summer. No problem with oil heating when stationary. I found that the Porsche fan conversion to be a lot more efficient than the standard type 1 fan.

Hi All,

Yes your right in that I do have sealing problems, but they are going to be very difficult to work around, as the tinware at the back of my engine bay is actually custom made aluminium, and has gaps around the turbo air intake and pressurised air outlet.

I was thinking of using an air scoop on the right hand side of the engine lid directly above the air intake, and then I could use my EFI's engine management to only turn the fan on below 2000 RPM. ie. when the car isn't in forward motion it won't need a fan.

This should hopefully help a little as a cold air intake as well, to lower my compressed air temp a little.

Thanks for the idea's everyone.

Cheers,

Ian.

hi
difficult or not get those gaps sealed!!! thats my top suggestion then do the number plate as an extra as well and you should be sorted but if you want to kill your engine theres no faster path than letting it suck on its own hot air sorry :rolleyes:

bit of fabrication never killed anybody.

911 upgrade????

Thats a DTM!

When I did my T4 install, I ran the 911 setup with no sealing tin and no cutout behind the rear licence plate. My head temps were about 395F stationary and about 420F on the highway (#4 cyl).

When I rejetted my carbs (too lean) and made up some sealing tin to seal the fan from the BAS header (fan was sucking in air preheated by header) the stationary temps dropped to about 365F and 385F on the highway.

I then made the cut to enlarge the space behind the licence plate as I thought the 911 fan was not getting enough air from the stock grill openings ... guess what .. the temps dropped again .. about 340F stationary and 365F pushing it hard on the highway.

So the 911 setup works for me ... only problem is heating the oil .. it takes about a 15min drive to get the oil up to 180F (remote cooler with thermostat).

So, make sure you seal the engine bay and make the cut behind the licence plate and offset your licence plate by about 1.5" like SamC suggested.

Sandeep

If you keep having cooling issues, a DTM and set of Nickies would be sure to clear them up :-)

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

hi
easy fit your tin properly and give yourself a cutout behind your numberplate laughing :D

Hello, when you will have nickies for 911? And what will be the biggest diameter? I have heard something about 4.0... And second question: have you something for 356?

Ian,
I have always drove my 2 liter with porsche fan, the vented rear (1303) decklid and extra opening behind the rear licence plate.
We have a square licenseplate at the rear and I made the opening a little smaller than the plate. Worked very well. Oil temperature never above 95 degr. Celcius.

I always figured the 4 vented parts in the deck-lid to be for the carbs (Alex) and the opening behind the licence plate to be for the fan. Not that those parts will listen to you, but anyway.

Yaninnya,
There was a guy here the other day some a restoration shop that wanted Nikasils for pre-A 356's to replace the Alu-chromed cylinders of those engines, about 20 sets was no problem, so I've send him to Charles. He should have enough demand by now :-)

Greetings,
Walter

Thanks for the advise everyone. I'll be re-fabricating the rear section of my porsche cooling system to seal the leaks off. I will probably cut a hole in under the license plate light as well while i'm at it.

And to solve my cold air intake issue, i'll be putting an air intake inside the right rear guard, the same as James did with his turbocharged vw. Have a look at:

http://members.shaw.ca/sharkeysgarage

CHeers everyone!

Ian