When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
For those of us who do not live in a desert - couldn't find whether these small fans are suitable in a possible wet environment. Size, value, etc. make them look interesting..
Those fans might work.
Just one thing to consider: would it be possible to design a shroud that has flaps to let more air flow through the cooler when moving?
I guess the fans would otherwise block some of the air exiting the cooler.
For those of us who do not live in a desert - couldn't find whether these small fans are suitable in a possible wet environment. Size, value, etc. make them look interesting..
Gary,
Being from over the pond you chaps may not recognise the IP (Ingress Protection) rating system which is Eurocentric. The first digit qualifies the dust protection (i.e. solids) capability and the second digit water ingress. IP44 is the minimum level of protection that might be considered acceptable. A true U boat commander would probably require IP68 which the 928 most certainly did not have in totality last time I saw one on Lake Michigan! My Spal twin fan setup is rated as IP68 for comparison purposes.
I am assuming these fans are puller type configuration but would need to confirm such
Those fans might work.
Just one thing to consider: would it be possible to design a shroud that has flaps to let more air flow through the cooler when moving?
I guess the fans would otherwise block some of the air exiting the cooler.
best regards
Tim
Tim,
Anything is possible given enough time and effort- the question is whether such is really needed. Personally I do not strictly need this cooling increment because I can avoid traffic jams [accidents not withstanding]. It would be interesting to see whether an array of such can make any difference.
When the car is idling or running at low rpms/low speeds the cooler duty is probably less than 10% of rated capacity so giving a bit of air movement is probably not going to cause any issues. Once the car gets going the natural draft will easily overwhelm any local resistance to air flow caused by the cooler. My Spal twin fan setup has rubber flaps- whether they do any good remains to be seen - Spal will tell you they do but...?
True, it might not really make a difference at speed, and while stationary it‘s definitely better to get some air moving through the cooler.
But I would argue that it does make a difference to have flaps in the shroud. The fan itself has quite a lot of resistance. Is it necessary to have flaps? - I don‘t know.
I‘ve personally never run into problems with overheating, so I don’t see a need to mod the oil cooling just now.
There were only two times I was concerned on a really hot day in traffic with the a/c running, but oil pressure always remained steady.
Michael, what's the part number for those rubber mounting bushings? They look similar to those used for mounting the electric fan on the early cars. However, Porsche appears to have made a mistake during supersession of that particular part, and the new replacements look nothing like the originals. That problem might also be contributing to vibration issues on your era of oil coolers?
Interesting observation. Can you post a picture and part number for the bushing you are referring to? Here is the electric fan assembly for 1984 and before cars. I have highlighted the potential bushings and included pictures for each below. Item #9 seems to be the closest to the Oil Cooler bushing. #2 99970330500 (M6) [img]file:////Users/MBENN3/Library/Group%20Containers/UBF8T346G9.Office/TemporaryItems/msohtmlclip/clip_image001.jpg[/img]
PET #2 99970330500 (M6) PET #2A 99970331000 (M6) PET #9 91151133200 (Bolt M6 + sleeve) PET #9 99970212550 (Bolt M6 + sleeve) #16 99970204650 (M6+sleeve) PET #22 111955641 (M6 + Sleeve)
PET lists the oil cooler bushings as 999-702-079-50 and 999-702-079-5A. The current succeeding part number is not listed as 999-702-079-5B. Here is a picture of the current bushing that I ordered and received. These bushings have a 12mm inner diameter.
Last edited by Michael Benno; 03-28-2024 at 03:49 PM.
Yes, #9 is the one I was referring to. I had not realized 16 and 22 even existed, they look much more like what #9 should look like. I'll order some of each next time.
A current issue #9 has almost no rubber thickness, and allows for almost zero movement. I *think* that a 1980 era original #9 is much thicker and compliant. At least the crumbling one I removed certainly did.
Unfortunately, none of this seems to help on your search for improved isolation of your GTS cooler, these bushings are all smaller than you need. Sorry for the derail!
My guess as to the lack of oil cooler in the 84 USA auto,
is that its not going to be used for hi speed driving or high engine speed operation ,
and the auto version wont see the higher RPMs as a 5 speed would.
I notice most of my cruising is at 3K RPM or less.
I am thinking of revising the mount to add some more cushioning and flex. I would replace the stock bushing with this setup. I figure I can add up to 8mm between the chassis and the mounting tab before I run into clearance issues. Thoughts?
Factory installation for reference
Last edited by Michael Benno; 03-28-2024 at 11:32 PM.
Forget my comment about mounting those small fans- took a look at my setup yesterday and realised that the return pipe makes that possibility impossible.
I think my thinking was influenced by the interesting Setrab setup Mr Olmann posted. That is way better than the stock setup in my opinion and the concept I raised could be tried out on that type of arrangement.
I am playing around with some different adaptations of the mounts to offer more flexibility to help minimize, pushing the flexibility into the cooler itself. This design uses 5 mm rubber elastomers stacked on a sleeve nut. See below for details
I will take that as a compliment! Thanks for the encouraging words Fred! :-)
Rebuilt oil lines will be done soon so i look forward to getting these hot-wheels back on the ground now that spring has arrived!
Michael,
Do those oil lines need a rebuild? Appreciate it is good practice to replace any hydraulic line that is 30 plus years old but I get the impression those things could withstand nuclear attack!
I have never seen or heard of an oil line failing but that does not mean it could not happen of course. Either way do post some pics of the lines and particularly the end connectors when the current hoses have been removed- I would like to see what is in there if possible/practical.
My cooler has a dink in the underside midships- been like that since I acquired the thing nigh on 20 years ago and my instincts tell me it will crap out one of these days. Thus some kind of revamp is on the cards. I have a couple of nice coolers with fans mounted on them in my "project materials bin". I am also wondering if i could make a fibre glass plenum to mount those lttle fans on if the new cooler approach looks like too much trouble. I like to explore low cost effective solutions that are easy to implement that do not corrupt the quality theme- that is difficult to say the least!
Do those oil lines need a rebuild? Appreciate it is good practice to replace any hydraulic line that is 30 plus years old but I get the impression those things could withstand nuclear attack! I have never seen or heard of an oil line failing but that does not mean it could not happen of course. Either way do post some pics of the lines and particularly the end connectors when the current hoses have been removed- I would like to see what is in there if possible/practical. My cooler has a dink in the underside midships- been like that since I acquired the thing nigh on 20 years ago and my instincts tell me it will crap out one of these days. Thus some kind of revamp is on the cards. I have a couple of nice coolers with fans mounted on them in my "project materials bin". I am also wondering if i could make a fibre glass plenum to mount those lttle fans on if the new cooler approach looks like too much trouble. I like to explore low cost effective solutions that are easy to implement that do not corrupt the quality theme- that is difficult to say the least!
Hello Fred, From a structural integrity point of view, the original GTS lines (70K miles) probably did not need to be replaced/rebuilt. The rubber was stiff and probably somewhat shrunk, but they seemed to be in decent condition, especially around the crimps. The same was true of the 87-89 oil lines (120k miles) I removed from my spare engine. However, my plan is to plumb both the external cooler below the radiator and the heat exchanger in series to help improve oil cooling in hot stop-and-go traffic.
Precision Motorwerks offers a service to make the three-line plumbing if you provide them with the source material. Here is a photo from their website illustrating the plumbing:
Since I had lines from both iterations, it was a convenient decision. Here are the hose ends and my rebuilt lines. The hose ends were re-plated. The rebuilt hoses at PTFE have stainless covers to help protect the lines from abraision. Precision Motorwerks did the work,
Aftermarket approach: Like you are expressing, I came to the conclusion that using an aftermarket solution, whether it be using a different cooler, building new lines, adding cooling fans, or building shoulds, can get complicated and expensive really fast. Then, there is the complication of space constraints, especially with fans. All these are one-off experiments with a mix of positive, neutral, or negative results from each. I felt that the leaking problem of the OEM cooler could be addressed with different mounting solutions to allow for flex. I like the two-stage cooler solution recommended by PM as a way to mitigate heat build up when stopped. This solution has been implemented several times with positive feedback.
03-28-2024, 10:29 AM
