Cooling the oil in a 3.6 . . . how did RUF cool the YB?

pbs911 · pbs911's Garage

MY 78SC is currently set up with the Yellow Bird front bumper cap, fender mounted and front mounted oil cooler. The recent 3.6 really strains the cooling system. No surprise there. Currently the front oil cooler is mounted with no more than 1/2" of space behind from air flow. In 70 degree heat I am seeing temps of 220, too hot IMHO considering there is no way the cooling system is going to withstand sustained high RPMs in the summer heat at WSIR.

I've seen posts of DIY "boxes" made by cutting into the front pan for increased air flow. I'm welding poor so a DIY fabrication job is out of hte question. I'm thinking of the TRE RE/RSR front oil cooler pan, below.

Any comments on the TRE RS/RSR set up?

But how did RUF do it? I would like to duplicate the YB.

ErVikingo · 03-06-2003, 09:23 AM

I might have photos of the underside of the YB (need to check and scan).

Anyhow, Ruf cut the nose of the car at an angle creating spce behind the front cooler and forcing the hot air to go under the car.

The lightweight YB also had a transmission oil cooler (mounted on the tail) with a trick switch to toggle the temp gauge between transmission and oil.

emcon5 · emcon5's Garage

Not much help, but here is the Ruf cooler:

An old price list I saw listed the kit at just over $1K. Not sure if it is still current.

The CTR would have still had the engine cooler as well.

Tom

Chuck Moreland · 03-06-2003, 09:25 AM

The TRE part is a nice piece that makes a big difference in airflow and cooling.

74911s · 74911s's Garage

you can fabricat the panel your self and there is no need to weld. mine is made from aluminum and rivited. let me know and you can take a close up look in person.

the extra air space will make a huge difference. my 3.0 can go for 30+ minutes on the streets of willow in 100+ temps and not break 210. before i added the ducting i could still get the car up to 240 on really hot days.

it will not really help much if you are sitting in traffic as you need airflow.

Bill Verburg · Bill Verburg's Garage

Paul, You have a fender mount and a front mount and the temps are still into the 220s? on a 70&deg day? Something is wrong somewhere. Sender, gauge, oil line, thermostat, I don't know which.

With a single B&B front mount even on high 90&deg days I am never over 190&deg F

While I agree that the TRE piece is nice. It is not necessary at all.

Tinker · 03-06-2003, 11:45 AM

Doc,

Bill is right, if you are seeing 220 on a 70 degree day around Newport something is wrong. I have the same setup as you and around town (Newport also, neighbor) my gauge stays right at 180 degrees.

Whose front cooler are you running?

Your car will not like Willow in the summer where mine generally hits 235-245 on the big track during 30 minute sessions in the 90+ degree temps. And you get a lot of air flow on that big track.

Tinker

pbs911 · pbs911's Garage

Thanks for the responses.
Bill, I am using temp sending unit C-606-112-00 and F-606-203-01 Oil Pressure sender, both Pelican parts numbers. The temp sending unit is the one listed in the catalog for the 78-89. The oil pressure give a double reading at the guage but I place the blame on the druck pressure sending unit being incompatable with the 78 guage.

Oil is reaching the front and fender mounted coolers.

The 220 temp is reached while running the motor at high revs for about 5 minutes.

Jack Olsen · 03-06-2003, 12:04 PM

Running the car at idle at high revs, or moving?

Could be a partially-blocked thermostat, or a gauge problem. Have you confirmed the temperature the thermostat is opening at, and also confirmed temperatures with a pyrometer?

I think the RS-style scoop makes sense (as well as ducting for the fender cooler, if you don't already have it), since you plan to track the car. But street driving shouldn't put you at 220 in five minutes with your system.

74911s · 74911s's Garage

Quote:

Originally posted by pbs911
Currently the front oil cooler is mounted with no more than 1/2" of space behind

i really think pauls problem is air flow. with only 1/2" behind the cooler it does not give any space for the air to exit. to cool you need air flow.

before i put in the rsr air duct i originally had my front cooler mounted with about 2-3" of space to the nose panel. it did not cool remotely close to where my car cools with the additional air flow.

anotehr buddy of mine with a 3.6 in an early car found the same thing. before he installed the rsr air duct he would hit 250 on the track no problem now with the modification he sits very cool at 210-220 on the hottest track days.

Bill Verburg · Bill Verburg's Garage

The problem is not air flow.

here is mine, yours cannot be worse and that is my only cooler

First independantly check the oil temp in the tank. I used a long lab thermometer but a meat thermometer will do.

What size front mount cooler do you have? are the return lines too hot to touch?

pbs911 · pbs911's Garage

The cooler is a Paterick Motor Sports unit, identical to the Thom is using. I only touched the bottom of the oil cooler when the temp guage showed about 190 and it was warm. I'll run it hard this weekend (it is supposed to be 75 degrees) and see how it hot bot hteh oil and cooler feels when it reads 220. I doubt there is a problem with the lines/cooler or thermostat since it was installed a few months ago with my 3.0. With that motor, oil system dropped and never reached above 200.

My air flow is more restrictive than yours Bill. My front cooler only has 1/2 core showing from the belly of the car. Your looks like it has 4-5 cores through which the air can flow. I do have the fender mounted unit with an air inlet duct where the driving light is. The oil lines from the front cooler are in the way for efficent air flow however.

Jim, I sent you an email about Sun.

obrut · 03-06-2003, 01:56 PM

Hi Paul

Do you have any gaps between the inner edges of the bumper opening and the outer edges of your oil cooler? The cooler in my 73RS replica had clearance of about an 1/2" either side and 1" on top - when I blockeded these gaps (with some hard rubber sheeting) my oil temps dropped dramatically.

The air will always go around the cooler unless you force it through the cooler. This setup was tested at a 1 hour race in the middle of a Sydney's summers day with an ambient temp of high 30degC with no problems.

Cheers from Oz - Ryan