Running Really Hot on the Track, I don't necessarily mean fast Options

[ww914]

Yesterday at Buttonwillow for our DE, the temperature was not all that hot, but I could only get in 2 laps at race speed before my CHT gauge started hollering at me. Here are the maximum values from yesterday:
Cyl #1 384 degrees
Cyl #2 357 degrees
Cyl #3 433 degrees
Cyl #4 402 degrees

I have the alarm set at 400 degrees, so each time it reached that temp, I backed off and let it cool down and finished each session with just a Sunday drive. Here's what I have:
My engine is a 2270 built by Original Customs
2 40 DLRAs:
150 main jets
180 air correction jets
34 venturis
9164.2 emulsion tubes
75 idle jets
50 pump jets

Both carbs are accurately sync'd and the a/f gauge shows between 13 - 14 all through the progression to WOT
The timing is set to about 30 degrees

I am running a stock cooling system with the thermostat and flaps working properly. I pulled engine tin to look for obstructions. None.

I am running a Sebtrab 8 x 10 oil cooler but my temps are over 220 when pushing it hard. No fans.

I am not sure where to go from here: alternate cooling, larger oil cooler, fans? Any suggestions would be appreciated.

[brant]

13 to 14 is way too lean.
Especially the 14 number

Ignore how rich it gets below redline and shot for around 13.1 maximum lean at redline. Ignore the 11's and 12's you see on the way to 13.1

[ww914]

13 to 14 is way too lean.
Especially the 14 number

Ignore how rich it gets below redline and shot for around 13.1 maximum lean at redline. Ignore the 11's and 12's you see on the way to 13.1

OK, I will shoot for 13.1. Any idea why 3 & 4 are so much higher? Is it just the way the engine was designed or do you think something else is going on there?

[brant]

3 will run hotter.
However I wonder what is going on in that bank. Sometimes you need to adjust the linkage at rpm and not just idle.

Fans can be an abstruction at speed. Oil cooler exit is more important than fans on a track car.

The timing should be fine but sometimes I've found different readings between different timing guns. So worth double checking as too much timing will create heat





Your oil catch tank is also an obstruction to your cooling fan pathway. I like to mount my catch bottle on the rear of the engine bay and put nothing on the front firewall in the path of the air for the fan

[Randal]

Where is your external oil cooler? And how is the air currently extracted?

[ww914]

3 will run hotter.
However I wonder what is going on in that bank. Sometimes you need to adjust the linkage at rpm and not just idle.

Fans can be an abstruction at speed. Oil cooler exit is more important than fans on a track car.

The timing should be fine but sometimes I've found different readings between different timing guns. So worth double checking as too much timing will create heat





Your oil catch tank is also an obstruction to your cooling fan pathway. I like to mount my catch bottle on the rear of the engine bay and put nothing on the front firewall in the path of the air for the fan

My can is right over the fan. Maybe I will move it.

[ww914]

Where is your external oil cooler? And how is the air currently extracted?

It is on the passenger side rear, as low as a dare to go. There is quite a bit of space behind it.

[Jetsetsurfshop]

Our cars are set-up really similar. Here's a pick of my oil cooler set up. I have ran up to 255-260f. There's some new ducting to try to "solve" my oil temps.
Even with that crazy oil temp I didn't run past 375F on the head temp. I had something make a nest in the engine tin before my last rebuild. Tons of leaves in there also. Over 400f + then. I wondered too if your catch can is blocking air too.

Whats your max oil temp and did you still have oil pressure?

[Randal]

Where is your external oil cooler? And how is the air currently extracted?

It is on the passenger side rear, as low as a dare to go. There is quite a bit of space behind it.

I can't tell if the cooler is just hanging there or do you have a front shroud to direct funnel the air through the cooler?

Plenty of space in back, but without capturing the air and forcing it through the cooler you are likely losing a bunch of cfm's that would help to cool the oil.

Can you run a (big) tube from the front of the car to to the engine firewall in front of the fan? All the old guys used to do that and it works.

I think Foley's car has one of those tubes. He could tell you how much it helped.

[ww914]

I can't tell if the cooler is just hanging there or do you have a front shroud to direct funnel the air through the cooler?

Plenty of space in back, but without capturing the air and forcing it through the cooler you are likely losing a bunch of cfm's that would help to cool the oil.

Can you run a (big) tube from the front of the car to to the engine firewall in front of the fan? All the old guys used to do that and it works.

I think Foley's car has one of those tubes. He could tell you how much it helped.

I did some further checking of a/f and cyl temps yesterday. With the original setup I ran the car pretty hard on a remote stretch of road to try to simulate the track. The first run showed this:
13.5 at redline
#1 336
#2 291
#3 368
#4 339
This was with 150 mains and 180 a/c jets

After changing the 180s to 170s, I got a better a/f reading, but temps were higher. Maybe because everything was just hotter by then.
Second run showed:
12.6 at redline
#1 343
#2 311
#3 384
#4 357

At cruise on the way home, after resetting the CHT, I got the following max CHT readings at 60 mph in 4th gear:
#1 332
#2 300
#3 381
#4 341

Today, I am going to move my oil catch can and move my oil cooler down a couple of inches and rework the air scoop. My oil temps were running just a bit over 220 and my oil pressure was good. Tomorrow I will pick up some larger jets to play with and see what happens.

As I think about other fixes, I have come up with these ideas:

Installing Foley's remote oil cooler set up that eliminates the stock cooler and adds a deflector to get more air to 3 & 4.

Adding a GT all screen deck lid.

Installing a FAT fan setup with a 911 blower.

Installing NACA air ducts on the side of the car to get more air to the blower.

Comments welcomed.

[r_towle]

3 will run hotter.
However I wonder what is going on in that bank. Sometimes you need to adjust the linkage at rpm and not just idle.

Fans can be an abstruction at speed. Oil cooler exit is more important than fans on a track car.

The timing should be fine but sometimes I've found different readings between different timing guns. So worth double checking as too much timing will create heat





Your oil catch tank is also an obstruction to your cooling fan pathway. I like to mount my catch bottle on the rear of the engine bay and put nothing on the front firewall in the path of the air for the fan

My can is right over the fan. Maybe I will move it.

Yup, I would move that box to the other side.

[ww914]

I moved it to where the original air pump was and just a bit higher. I also moved my oil cooler up. I felt it was picking up warm air from the engine. Everything ran cooler yesterday with 14 runs at the AX at Marina. I still may duct some cool air to it with a NACA duct.

[ww914]

Update on heating issue. Bottom line, everything was still very hot, even after I installed the NACA duct and hose to the cooler. Hard freeway driving 70 -80 caused the temps to show very hot like before:

#1 max 334
#2 max 307
#3 max 437
#4 max 347

My gauge shows a max temp that can be reset.

Oil temp ran between 230 - 250

So, with this I decided to drop the engine and take a look around. First thing I found was an alternator cover inside the impeller. That had to be blocking a lot of needed air. The second thing I found were two broken blades. Probably OK for a stock motor, but not for this one, not the way I drive it. So I have a new impeller coming as well as Chris Foley's external oil cooler setup that eliminates the stock oil cooler and sends all the air to # 3 & 4, none to where the stock cooler was as it will be blocked off. There are a couple others things I will check, valve clearance and timing, but that is it for now.

[J P Stein]

I've read a lot of BS over the years about oil cooler locations.

It all boils down to BIG and in the nose if you're serious.....some classes make it tougher. Finger something out if you're in that position.

[ww914]

I've read a lot of BS over the years about oil cooler locations.

It all boils down to BIG and in the nose if you're serious.....some classes make it tougher. Finger something out if you're in that position.

Believe me, that thought has occurred to me.

[Jetsetsurfshop]

Oil temp ran between 230 - 250

Do you come in once the oil temp hits 250 or did it max out there?

I think the cooler up front is going to happen on my car too.
Shane

[ChrisFoley]

Warren,
would you like to be the guinea pig for my new oil pressure relief device?
I have a prototype ready for testing, just need a car with oil pressure gauge for monitoring.

[ww914]

Oil temp ran between 230 - 250

Do you come in once the oil temp hits 250 or did it max out there?
Only if I back off.

I think the cooler up front is going to happen on my car too.
Shane

[ww914]

Warren,
would you like to be the guinea pig for my new oil pressure relief device?
I have a prototype ready for testing, just need a car with oil pressure gauge for monitoring.

Sure Chris, but like we talked about, only after I get this heating thing resolved.

[Jetsetsurfshop]

Warren,
would you like to be the guinea pig for my new oil pressure relief device?
I have a prototype ready for testing, just need a car with oil pressure gauge for monitoring.

Whats the intent of this device?
Is it something you can swap out without draining the oil?
I stay up at night worrying about oil temps, will this help me sleep?
Shane