SC running hot

[glewis80SC]

Had my SC get real hot last time at the track. Drive there everything good when i starting pushing it around track temp went up lost power. Cooled down drive home ok.
Change oil next day, took it to my mech. had a valve adjustment done.exhaust vavles were tight. Car runs great but when i push it hard for a bit temp still begins to rise. Have never had heating problem till that day. Any suggestions?
greg

[Ferrariguyma]

My 78 had the original loop cooler and would run hot. I went with a Elephant Racing Wide Mouth Carrera Oil cooler,electric fan, and ER finned oil cooler lines, new thermostat and added a oil cooler scoop. No more hot temps. The car barely gets to 100 on the temp gauge.

[FenderGuy]

cooler like Ferrariguyma suggested i plan on this doing this for extra protection in the Az heat

[boyt911sc]

Greg,

I had similar experience last year with my '78SC at the track. Lost power and felt like running with 5 cylinders! The culprit was the auxiliary thermostat. Later installed new thermostat and a Carrera cooler and over heating was never experienced again.

TD

[fastfredracing]

you could also check for restricted oil lines, they sometimes get damaged while jacking/lifting, best of luck
Fred

[rs6er]

Also, pull off the engine shrouds and make sure your cylinder fins are not full of junk or nests.

[dan79brooklyn]

My1979 SC with the stock cooling system gets HOT in warm temperatures when pushed hard (sustained high RPMs) it also gets hot in traffic in high ambient temps. I asume this is normal with stock system and that the SC loop cooler is not up to the job. In my expereince anyway...

[qcwang]

Hi Greg,

I had the same problem with my first time out at Streets of Willow last year in May. The temp got up to just about halfway between the last white line and the Red!

I found that my problem was a crushed oil line under the passenger side near both the front and rear wheels. Must have occurred when I got new tires and the tire shop put my car on the lift and crushed the lines.

Luckily, my mechanic was able to manually bend some of it back to allow better flow. I am told it is under low pressure at about 28-30 psi, so a little compromise is ok. That with install of a Carrera oil cooler w/fan and oil cooler scoop has helped. My next two trips to SOW, the hottest it got was halfway between the 9 o'clock white line and and the one above it ( I guess it is about 230 degrees? I don't have numbers on my guage.). This is the same as the hottest it got when I am stuck in traffic before all of this happened so for now I am happy and will replace the oil lines later.

Hope this helps!!

[gold911]

Something you might want to check into is early SC's have an update to the sump screen and oil pressure relief spring that has an effect on cooling during hard cornering which results in power loss. You can find details on this site by searching using "sump screen"

Good luck

[Grady Clay]

Greg,

Good advice above. It is worthwhile to look at all of the above potential causes and solutions.

Not said (yet) is ’78-‘79 911SC has a smaller diameter engine fan than other period 911s. You would be wise to change the fan and fan housing from the original 226 mm to the later 245 mm diameter 11-blade fan. You already have the desirable 134 mm crank pulley. This combination turns the larger fan 1.82:1 of the crank speed.

This cools the hottest and most important parts – heads and cylinders at the source of the heat.

For track use, ”Water vapor cooled 911 - the Rubbermaid Solution“ will solve the heat dissipation issue. This is only suitable for track use.

That said, you need to insure there isn’t some other problem. As noted above, that might include failed thermostat, crushed pipes, clogged cooling fins or even an internal engine problem.

A Pelican search on this issue will yield a huge amount of information and opinion. Most is pretty accurate. It is worth the effort to sift through all of it and compile your set of priorities.

Best,
Grady

[Tim Hancock]

Originally posted by dan79brooklyn
My1979 SC with the stock cooling system gets HOT in warm temperatures when pushed hard (sustained high RPMs) it also gets hot in traffic in high ambient temps. I asume this is normal with stock system and that the SC loop cooler is not up to the job. In my expereince anyway...

+1

I do not track my '79 SC, but last year towards the end of two parade laps at MidOhio on a mid 90's day, I experienced a power loss and the temp gauge was way up there.

A few weeks ago I finally got around to installing a 28 row brass cooler and fixed my partially crushed oil lines at the same time. While I have not driven it yet on 90 deg+ days, it ran much cooler than before on an 80 degree day while flogging the heck out of it.

Here is a link to my recent oil cooler and crushed oil line post, in case you are interested in doing the same.
DIY crushed oil line repair and oil cooler upgrade

[shbop]

Grady, Does installing a 134mm crank pulley, with the 245mm fan, always produce the 1.82:1? Where does one find the 134mm crank pulley? Thanks in advance.

[glewis80SC]

Thanks to all for their info. The oil line are good had them all replaced and new thermostat about 4 months ago. No crushed lines either. It has the standard trombone cooler which i know is not the best. Until that day it never ran hot, i will take all your suggestions and get to work. keep you posted.
thanks,
greg

Turn 1 Big Willow

[ChrisBennet]

Originally posted by Tim Hancock
+1

I do not track my '79 SC, but last year towards the end of two parade laps at MidOhio on a mid 90's day, I experienced a power loss and the temp gauge was way up there.

A few weeks ago I finally got around to installing a 28 row brass cooler and fixed my partially crushed oil lines at the same time. While I have not driven it yet on 90 deg+ days, it ran much cooler than before on an 80 degree day while flogging the heck out of it.

Here is a link to my recent oil cooler and crushed oil line post, in case you are interested in doing the same.
DIY crushed oil line repair and oil cooler upgrade

Tim,
The power loss is not a function of higher temps if I recall.

As alluded to earlier, early SC's had a problem where they would fail to scavenge the oil out of the crankcase under track conditions which would lead to power loss and higher temps. The fix was something to do with the sump screen (venturi?).
That said, I thought "early SC's referred to the 1978 models. My memory is really fuzzy on this whole topic though.

My point is, don't assume you've solved the problem because you've increased the cooling capacity.
-Chris

[Bill Verburg]

Here is a link to a previous discussion on early SC trackday heat issues

[chrisp]

When I first tracked my SC in high heat (90+ degrees) with stock oil cooling system the oil temp was 250 degrees.

I went to a Carrera type fender radiator and it dropped to about 230, again on really high temp days

I added a fender air scoop (replaces one of the bumper lights) and it dropped to about 220

I've since upgraded to a not-so-large front bumper mount cooler that fits tightly against the valance (no leaking airflow...the key to the success of the system) and now even on the hottest, hardest track days it won't work it's way past 190-200 degrees.

[ja78911sc]

I experienced high temps on the track only. I changed over to a Carrera cooler, sump screen update, 11 blade fan & marker light scoop. I still experienced high temps during my last few laps.

Solution--I cut my horn trumpets off & cut a hole in my front valance. I welded three pieces of metal on the back of the valance which directed the air flow toward the cooler. I also attached a screen to the valance. You can also use a Carrera valance which has a hole in the valance for the fog lights. Then design something that will divert the air through the cooler.

Additional info:

Front valance modification to increase air flow to oil cooler

Good luck!

[304065]

Originally posted by shbop
Grady, Does installing a 134mm crank pulley, with the 245mm fan, always produce the 1.82:1? Where does one find the 134mm crank pulley? Thanks in advance.

Very, very hard to find used. I bought a new one, $200! I'll post a picture when it arrives.

[hytem]

Originally posted by dan79brooklyn
My1979 SC with the stock cooling system gets HOT in warm temperatures when pushed hard (sustained high RPMs) it also gets hot in traffic in high ambient temps. I asume this is normal with stock system and that the SC loop cooler is not up to the job. In my expereince anyway...

Gets hot in traffic sounds about right. And hotter in the summer.
Last summer, the temp gauge might reach 9 o'clock in heavy traffic (horizontal). Last Sunday, I got behind a walking marathon on a country road with a cop car in front--and the gauge crept up to about 8 oclock (190 C) from its usual 7:30 or so (180 C) where it's been all winter.

I don't like air cooling. Gases simply aren't as heat conductive as liquids, and don't cool efficiently. I don't know if my oil cooler is working, either. When you get back up to cruising speed, you don't see much of a cooling affect after heating up in traffic--as you would see with water/glycol cooling.

[ChrisBennet]

Originally posted by hytem
Gets hot in traffic sounds about right. And hotter in the summer.
Last summer, the temp gauge might reach 9 o'clock in heavy traffic (horizontal). Last Sunday, I got behind a walking marathon on a country road with a cop car in front--and the gauge crept up to about 8 oclock (190 C) from its usual 7:30 or so (180 C) where it's been all winter.

I don't like air cooling. Gases simply aren't as heat conductive as liquids, and don't cool efficiently. I don't know if my oil cooler is working, either. When you get back up to cruising speed, you don't see much of a cooling affect after heating up in traffic--as you would see with water/glycol cooling.

No question that water is a superior coolant but take away the radiator fan on a water cooled car and you're in the same boat as the SC. I think the SC's lack of a fan across it's radiator (the front oil cooler) is the real culprit.

-Chris