Which single front oil cooler for 3.6 conversion?

[MuffinMan]

I will soon be joining the long list of Pelicanites that have gone down the 3.6 conversion road. I currently have a 1977 911S that has everything done except for the engine (flares, suspension, seats, Fikses, Big Reds, & spoilers). The 3.6 conversion path seems to be getting worn to a relatively clear state, which is good for the guys doing the upgrade now

Nevertheless, cooling is one question I have about the conversion. I read the archives, and it seems as though the dual cooler setup is somewhat popular. I currently have an RX7 front cooler routed by AN12 fittings/lines. Honestly, it does not cool my stock 2.7 as much as I would like on the track. I would say the average temp is ~230 , which is obviously a bit high.

I spoke to my mechanic, Powertech in Rockaway, NJ, and they recommended using a 935 factory Porsche racing cooler (I believe it is made by Behr). They said they've never seen another cooler perform as well as that one, unfortunately it's a bit over $1k just for the cooler. I assume I will need larger cooling lines, and that adds even more to the upgrade.

Why don't people use the stock 993 oil coolers, as they are sufficient to do the job. Do they simply not fit without front flared fenders? Will they not fit in the front/center location?

I do not want to have any cooling issues on the track, so your input is greatly appreciated.

Rob Fusi

[wrx paul]

Rob,
I'm sort of going through a similar issue myself. I just recently got a 3.0 into my 77 and the car had a weird cooler under the right rear fender. This was working out fine but it recently let go and I thought the cooler blew.
After removing the whole setup it turns out that the aeroquip lines cracked at the fittings and now I'm looking into doing it right. From the research that I have done on this board and talking to others I have found that the stock or any aftermarket hard lines are the way to go. The alternatives in hoses just don't dissapate the heat like a hard line will do.
I have decided to go with the carrera cooler and stock lines since this seems to be the best route, and if it isn't enough, then adding the fan to the cooler should cover it. I haven't heard of anyone with this setup complain about heat yet.

[pbs911]

the 993 coolers are difficult to fit in the fender well and air flow is limited. A single front mounted cooler would be fine for a track car. The car is moving so you get constant air flow. With a street car you are faced with sitting in traffic. A fender mounted unit with fan helps keep the temps down in such situations. The dual coolers provides the best of both worlds. It sounds like for the cost of a 935 cooler you could pick up a Elephant Racing Widemounth fender cooler w/fan and B&B/Setrab front mounted unit. What you ultimately end up with depends on the front valance. Are you willing to cut the OEM valance, going with a RS type that allows for a front mounted unit. An alternative is dual fender units. Ryan (surflver) posted an excellent install thread.

[Embs]

Tre Motorsports offer a Setrab kit with lines, fittings and mounting hardware. I installed it on an 84 carrera with no issues/very easy.

http://tremotorsports.com/

Dave Bouzaglou is the guy to talk to.

[Bill Verburg]

I've used a single valance mount B&B since '95. Only issue I ever had was at the double 50 at the Glen traffic was stopped dead going into Corning, backed up for miles, ~99&degF ambient. Solution was to take to the back roads(or stop). I suspect that even a second cooler w/ fan would have been challanged that day.

Even w/ the 3.8RS on 90&deg days temp stays ~85-90&degC


cooler is 5 1/2" X 2 1/4" X 20".

If I were driving in big city type traffic(NNJ?) a second fender mount w/ fan like the Elephant ones would be a big plus.

[MuffinMan]

Bill,

What kind of lines are you running to the cooler?

Rob

[IROC]

Hey Rob,

Is your '77 still that Continental Orange car that you had years ago? Post some pics if you get a chance.

Mike

[Bill Verburg]

Originally posted by MuffinMan
Bill,

What kind of lines are you running to the cooler?

Rob

B&B used to supply Aeroquip w/ their coolers don't know if they still do.

Other options were the I/O angles(180&deg or 45&deg), and sizes(-12 or -16)

More pics at my websites.(see sig)

[Tinker]

I'd keep it simple and like a sleeper. Run a factory cooler in each finder, like JackO does.

You won't have to change the front spoiler.

I think the RX7 coolers are too restrictive, unless you cut the end caps off an modified them???

Tinker

[Bill Verburg]

You call that simple?

You need 3 times the cooler because you have 1/3 the air flow.

If you're not wedded to the stock look a bumper cap or valance is simple and can greatly improve the appearance of stock.

Same thing for those who chose not to use flares, they are giving up a lot of handling potential.

[Chuck Moreland]

Originally posted by MuffinMan
Bill,

What kind of lines are you running to the cooler?

Rob

I now make 30mm Widemouth fittings that screw right into the Setrab coolers. These fittings allow you to use Porsche factory type 30mm hose ends and hose throughout.

You won't need AN->metric adapters. And you won't have any restrictive AN-12 fittings in the system so flow is improved.





And to answer your original question, a Setrab std172 would be a good single cooler choice for your 3.6. Combine that with the 30mm fittings and you have a clean, easily plumbed solution for the conversion.

Notching the front pan and using an RS type vent panel to give the cooler air flow a good escape route is highly recommended.

[MuffinMan]

Okay, let me answer a few questions.

1) Mike: Yes, I do still have the Continental Orange 911. I'll post pics below so you can see it in it's current state.

2) Bill: I meant to ask you what *size* hoses you have running to your B&B cooler, not what kind. I'm concerned that my AN12 hoses are not large enough.

3) As far as going for a stealth/sleeper 911 (dual cooler setup in the fenders), I think I'm already out of that game since this thing is bright orange. Kids absolutely love this color...it's like a giant toy.

4) As you can see from the posted pics below, I already ditched the front spoiler in favor of one that accommodates a front center spoiler. Unfortunately, the RX7 cooler mounted front & center is not getting the job done for my stock 2.7, thus the need for a better solution for the 3.6.

5) Chuck: You mention the Setrab std172 cooler for this application. Would you recommend tossing my AN12 SS braided lines in favor of hard lines or AN16 lines, or am I good with my current plumbing? Also, are you familiar at all with the Porsche 935 (Behr?) cooler? Powertech in NJ was explaining to me that there is a tube within a tube and special fins to aid in cooling above & beyond a typical cooler. I may be remembering/hearing incorrectly, but perhaps you can shed some light on the situation?

6) Thanks for everyone's help!

The car:

[Chuck Moreland]

Nice pictures!

I don't recommend the AN-12 stuff. The hose is adequately sized, however the ID of the fittings is not. AN-12 fittings are typically 14.5mm ID, significantly smaller than the factory stuff. Porsche stuff is at least 17mm and most of the original kit was 19mm ID.

Since flow capacity of a tube increases with the square of the radius, those few millimeters make a big difference. 17.5mm flows about 50% more than 14.5mm for a given pressure.

That said, lots of people use AN-12 stuff and their motors haven't melted down. However their scavenge pumps are working extra hard and consuming extra HP to push oil through the restrictive lines.

For anyone creating an oil system from scratch or adding new components, using the larger factory stuff seems like a no-brainer. Ripping out existing AN-12 stuff to upgrade is a judgement call.

[Bill Verburg]

Mine is -12, I agree w/ Chuck, it works fine but if I was doing it today I would try to use the -16 or his widemouth fittings.

The only down side to the bigger fittings is the room need for them. I do have some -16 aeroquip and fittings which I would have a very tough time fitting as the cooler is currently situated. There is not a lot of room behind those spoilers.

Same thing w/ the TRE RS bulkhead piece for exit clearance, it's nice but certainly not necessary.

[Antonov]

Bumping this thread back from the dead. I'm in the process of sorting out an oiling solution for a hot 3.6 in a mid year car. I have access to 2x Setrab 50-150-7612 coolers that I plan on mounting in each fender well, they should fit quite nicely.

My question; is it worth plumbing the coolers with -16 fittings given that the coolers themselves run 22mm fittings? My rationale being that you're only as good as your weakest link. Will the larger -16 fitting and lines provide any more flow vs -12 fittings given that the coolers themselves run 22mm fittings which will act as an orifice.

For reference, I plan on using the factory hard lines that run from the back of the car to the front.

Thanks in advance.

-Dino

[MuffinMan]

I'm sure there are lots of opinions on this, but I'll provide two data points. When I was installing the 3.6 in my car, I upgraded the front cooler at the same time. My car was plumbed with AN12 when I had an RX-7 oil cooler up front, and it never cooled my 2.7 all that well. For the 3.6, I knew the cooler wouldn't do the job, so I ordered a B&B 9400(?) cooler, which was much larger. I debated long and hard whether to go through the trouble and cost to change the lines to AN16, and I got a couple of opinions.

Data point 1
My mechanic is/was a very skilled driver and raced a 930 back in the day. He had AN12 plumbed to the front and everyone warned him that it was too small, and he needed to go to AN16. He decided to go through the pain and switched it out to AN16, and claims to have noticed absolutely no difference in performance or oil temperature as a result. He didn't feel it was necessary for me to change to AN16.

Data point 2
I decided to order the cooler with AN16 fittings, but bought AN16 to AN12 adapters so I could run the car with the existing lines, but would have the ability to switch to bigger lines without having a bottleneck of AN12 fittings on the cooler. The plan was to run the car for a few events, and make a decision from there. I did just that, and never had any cooling issues, so I didn't bother changing to AN16. I also had a front pan cooler duct installed, so I had a high level of efficiency from the cooler from all that wonderful air passing over it. In my case, I was OK with AN12.

All that being said, if I was doing it from the start, I would run AN16 so I would never have to worry about it. As for reworking existing plumbing or using larger hose for a cooler with a bottleneck of a smaller diameter, I'm not sure what to tell you. For reference, click the absolutely ancient thread in my signature, and hopefully it's not dead.

[Antonov]

Good to know. Out of curiosity, are you running side mount and front mount, or just front?

Originally Posted by MuffinMan

I'm sure there are lots of opinions on this, but I'll provide two data points. When I was installing the 3.6 in my car, I upgraded the front cooler at the same time. My car was plumbed with AN12 when I had an RX-7 oil cooler up front, and it never cooled my 2.7 all that well. For the 3.6, I knew the cooler wouldn't do the job, so I ordered a B&B 9400(?) cooler, which was much larger. I debated long and hard whether to go through the trouble and cost to change the lines to AN16, and I got a couple of opinions.

Data point 1
My mechanic is/was a very skilled driver and raced a 930 back in the day. He had AN12 plumbed to the front and everyone warned him that it was too small, and he needed to go to AN16. He decided to go through the pain and switched it out to AN16, and claims to have noticed absolutely no difference in performance or oil temperature as a result. He didn't feel it was necessary for me to change to AN16.

Data point 2
I decided to order the cooler with AN16 fittings, but bought AN16 to AN12 adapters so I could run the car with the existing lines, but would have the ability to switch to bigger lines without having a bottleneck of AN12 fittings on the cooler. The plan was to run the car for a few events, and make a decision from there. I did just that, and never had any cooling issues, so I didn't bother changing to AN16. I also had a front pan cooler duct installed, so I had a high level of efficiency from the cooler from all that wonderful air passing over it. In my case, I was OK with AN12.

All that being said, if I was doing it from the start, I would run AN16 so I would never have to worry about it. As for reworking existing plumbing or using larger hose for a cooler with a bottleneck of a smaller diameter, I'm not sure what to tell you. For reference, click the absolutely ancient thread in my signature, and hopefully it's not dead.

[Jaskas]

It is important to keep in mind to force all possible air through the coolers.
I have done following to help this in my dual fender cooler setup:
- Opened up the front bumper for more air in
- Made sure that no air passes the coolers
- I also made air-guides in front of the cooler, so that all air which comes in from the bumber goes through the cooler. Otherwise the air might slip out "under" the cooler under the car.

[proffighter]

Originally Posted by Chuck Moreland

Nice pictures!

However their scavenge pumps are working extra hard and consuming extra HP to push oil through the restrictive lines.

Hmm, without thinking much about your statement, oil pressure (about 4bar) is given by check valve, how can it be harder for the pump then? 4bar is 4bar regardless of the amount of oil.

[prschmn]

Chuck is referring to return side oil pressure. You don't have a gauge there. I've had
the experience in a 9K race engine that the factory filter was too restrictive causing high
return side pressure. On a very cold race morning it actually blew the filter off it's mount-inside the car-yuck. In the worst case it can break the oil pump drive or the mounts.
Not a concern though at lower Rpms. Just an example