Wipperman

Hi,

In have a 911-73 (RS-replica) with a 2.7 engine.
The only modification is that I have installed a MSD system and cam covers from a 3.6 engine.
The engine was renovated 4 years ago and the result from the dyno test was 220 hp (last year) on the flywheel.
I will take part in some club races with this year and will enter at the Eifel Klassik (http://www.eifelklassik.com/) at the Nürburgring next year.
The problem I’m having is the oil temp.
The oil temp when driving on a normal road is 90C (194F) but the problem starts on the track, 125C- 130C (257F-266F).
My first reaction was to install a second oil cooler, but I’m not sure if that will solve my problem.
With my limited knowledge I have found three areas that has to be checked:
1. The internal oil cooler is damaged or needs to be cleaned
2. The thermostat doesn’t open and needs to be tested.
3. Something that looks like a thermostat, or at least a housing is located on the oil lines close the torsion bar. I have been thinking if that’s another thermostat for the trombone.
I will install an external cooler due the nature of the Nürburgring but I want to have everything in perfect order before doing the installation.

I’m verry grateful for all the help I could get.

Best regards

Anders

ebsalem

Anders that sounds pretty normal for a 2.7 with just the internal cooler. I can only track my car on cooler days.

An external cooler will solve the problem.

regards,
e

RoninLB

I have no experience with a 2.7 210hp, so I can't confirm a front fender oil cooler will be good enough. If you can borrow one ? it'll be a quick install.
I can only guess that you'll need a front cooler.
On my stock 2.7, driving thru 110deg desert at 3.8k rpm, my temp is about 210degF.

PS... that's 210 with a fender cooler

MAS

Too hot, I think.

BTW, it's not normal for a 2.7 to run any hotter than a 3 or 3.2, as long as the troublesome thermal reactors have been removed (which I'm sure they were decades ago).

There is a grid/grating/mesh I believe at the bottom of the oil tank. Make sure that this is not clogged. My local Porsche mechanic had a heck of a time with an SC last year that was overheating. After trying many different things, it turned out to be the above problem.

Also, if you are going to be racing, you should definitely have a secondary oil cooler. This would apply to any size 911 engine.

mducharme

Have you checked the timing ,first thing I would check. then the sump screen. Been a while since I had a 2.7 I remember something about up grading my oil pump when I had the engine rebuilt.
Mducharme 86 930 turbo
84 carrera cabrio (for sale)

Lefty's Deceiver

I have the same engine. 2.7 MFI. You MUST have an external oil cooler to run it on the track. Either a front mount (what i have) or fender mount. Mine runs 110F on road and about 180F on track.

Lefty's Deceiver

PS: You don't need a bigger oil pump as mducharme suggests. Your pump is fine. You might have issues with low oil pressure under braking because the oil can move away from the pickup in the oil tank. The fix is a mod to the oil tank which involves a baffle.

mducharme

Lefty thanks for correcting me ,You are probably right . I should have said , something up graded with the oil pump . Sorry.
Mducharme.

markwemple

Bruce Anderson has said that once Porsche started making 911s with more than 165 bhp they added a front cooler, hence the trombone on an SC. I think it make sense, although my notion would be that any enhanced 911 should run one. Besides, all that extra oil has to help. Make sure that your timing is dead on first. 911s hate timing mods and my 2.7 was once about a degree out and it uped my temp more than 10 degrees F. SO just double check.

GrantG

I have a front air-dam oil cooler (and 930 oil pump) on my 2.7RS clone (240hp) and it runs at 195F max at the track even on hot days. It makes a huge difference

Wipperman

Hello,

Thank you all for your help.
I’m not fond due to aesthetic reasons to install a cooler in the front, a fender mounted is more appealing.
The front cooler has a larger cooling capacity so I guess that it’s the path I will take.
I will also check the timing and the sump.

Thanks!

Best regards

Anders

ebsalem

another option would be to cut the back out of the headlight bucket and when you're on the track replace the headlight with an open wire mesh to get the airflow. Easy & cheap.

e