Engine cooling questions, Pictures added Options

[GaroldShaffer]

I have 73 with a 2.7 /4 engine. I use this car mainly for just autocrossing and I want to do some track day stuff, but I need to get the oil temps down before I do that. Let me start by saying I bought this car setup like this and I do not know who built the engine. I have a oil cooler mount up front with a electric fan that is pulling air through the cooler, covered with shroud and vent through the floor. The floor vents are just the BIG floor plugs removed.

Engine is full of oil, cooling fan for oil cooler on, running temps can hit 230+. Yesterday at an autocross temps hit 250+ (I would say 280) and this is with a just and 80 degree day. I do have a co driver and the event was fasted pace so there was no real time to shut down between runs so the car ran for over and hour. When the oil temps went above 250 I did shut it down and did not run anymore runs for the day. I know that is too hot and do not want to damage the heads.

I will post pictures of my oil cooler setup later today. I know I need to get the temps down and was thinking adding a electric fan in the engine bay to help push air more air over the engine may help, yes? Maybe need a bigger cooler up front also?

To be honest I would really like to pull this engine and drop a /6 in there, but is not in the budget right now.

Your thoughts? (IMG:style_emoticons/default/confused24.gif)

[Jetsetsurfshop]

We need to see some pictures of the from oil cooler. I was running similar temps (in Florida) until I installed the front cooler. Solved my problems. Surprised your having such a spike doing an autoX. (IMG:style_emoticons/default/driving.gif)
Questions...
Is the exit bigger then the entry?
What kind of cooler are you running? Is there something blocking the airflow?
What size lines?
Post the pictures. The usual suspects will chime in.
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[ThePaintedMan]

The fan in the engine bay won't do much, if anything, IMHO. Just FYI - if the head temps are still okay, then running 250+ oil temps won't cause them harm directly. It's the thermal breakdown of the oil itself you're worried about, and thus, mechanical wear on bearings, etc. Would definitely change it before you take it out again.

As Shane said, the idea behind and oil cooler, radiator, etc is that the exit should be ideally 2x the surface area of the entrance. Unfortunately that usually means cutting. How does the car run when just driving it around town?

[GaroldShaffer]

Looks like I need to clean the underside of the engine, lots of oil down there. Anyway the oil cooler is a Earl's. I count 35 ribs and is 7 3/4 tall. I ran the fan and it does pull air through, enough to hold a paper towel to the grill and I feel good air flow through the holes in the front pan.

I did PM with Jake and he said I need Nickies. $$$ and maybe I do, but I can't imagine that the past owner ran this car on the track with these temp issues. I would ask him, but he has passed. (IMG:style_emoticons/default/sad.gif)

[GaroldShaffer]

The fan in the engine bay won't do much, if anything, IMHO. Just FYI - if the head temps are still okay, then running 250+ oil temps won't cause them harm directly. It's the thermal breakdown of the oil itself you're worried about, and thus, mechanical wear on bearings, etc. Would definitely change it before you take it out again.

As Shane said, the idea behind and oil cooler, radiator, etc is that the exit should be ideally 2x the surface area of the entrance. Unfortunately that usually means cutting. How does the car run when just driving it around town?

I have no issues cutting the front pan if it will help keep the temps down. I haven't really taken it out on the street much to give you a good answer. While it is plated for street use I really don't like driving a cage car on the street without a helmet on.

I do plan to change the oil before my next event in two weeks

[ChrisFoley]

-10 oil lines are too small for a front mounted cooler.
The cooler you have may be inadequate for a 2.7L, even in that location.
Cutting the trunk floor to increase outlet area is a good idea. One more hole of equal diameter would do.

Depending on the way the oil system is assembled, some of the oil may be bypassing the external cooler.
I would probably ditch the stock cooler entirely and apply that cooling air to the cylinders.

Do you have an oil pressure gauge? How about CHT?

[GaroldShaffer]

Chris yes I have a oil pressure gauge, right now can't remember the pressure reading from yesterday. Was focusing on the oil temp. No CHT will add that to the list of things needed. What size lines would you run?

[ChrisFoley]

I've always used dash 12 oil lines for front mounted coolers.

[Jetsetsurfshop]

This is the box I made for my cooler. Its a 60 row cooler.
I checked my notes from my last track event. The temp at the track was about 95 degrees.
oil temp 200-205
oil pressure 40 lbs
CHT 350
I agree with Chris on increasing the air exit size. Thats where I'd start. (IMG:style_emoticons/default/beerchug.gif)
Maybe change your oil before your next event too.
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[Jetsetsurfshop]

Air exit.

[GaroldShaffer]

OK Looks like I will be doing a little (IMG:style_emoticons/default/sawzall-smiley.gif) (IMG:style_emoticons/default/smash.gif) work before my next event in two weeks. Also will be changing the oil for sure.

Thanks for the input guys (IMG:style_emoticons/default/beerchug.gif)

[porschetub]

OK Looks like I will be doing a little (IMG:style_emoticons/default/sawzall-smiley.gif) (IMG:style_emoticons/default/smash.gif) work before my next event in two weeks. Also will be changing the oil for sure.

Thanks for the input guys (IMG:style_emoticons/default/beerchug.gif)

I would think the outlet would have the same size as inlet to get full flow.
Have you calibrated your gauge to a known temp?
Hope you get it sorted,cheers

[brant]

OK Looks like I will be doing a little (IMG:style_emoticons/default/sawzall-smiley.gif) (IMG:style_emoticons/default/smash.gif) work before my next event in two weeks. Also will be changing the oil for sure.

Thanks for the input guys (IMG:style_emoticons/default/beerchug.gif)

I would think the outlet would have the same size as inlet to get full flow.
Have you calibrated your gauge to a known temp?
Hope you get it sorted,cheers

Oil cooler exits needs to be larger than intakes.
I did three different exits on the same race car with the same motor and same cooler but dropped temps each time I increased the exit. (About 25 degrees total)


Also check your gauge wiring. And if the voltage regulator is consistent output at high rpm?

You have something going on. The oil bypass that Chris sells is a given at this point
You might need a bigger cooler. Maybe a fluidyne double pass
At track speeds the fan becomes a hinderance and would be better removed
But I would think for ax it shouldn't be a problem really.

[mgp4591]

It looks like you have adequate sealing around your shroud from the pics, but make absolutely sure that you have all edges sealed snugly so no air is escaping your ductwork. Just my 2 cents.... (IMG:style_emoticons/default/shades.gif)

[ChrisFoley]

The oil bypass that Chris sells is a given at this point
...

I'm more concerned with the possibility that the oil filter bypass could be opening due to increased pressure drop across the filter circuit due to the long oil lines to the front of the car.

[stugray]

The oil bypass that Chris sells is a given at this point
...

I'm more concerned with the possibility that the oil filter bypass could be opening due to increased pressure drop across the filter circuit due to the long oil lines to the front of the car.

Exactly!

I used 12AN lines to the front for my coolers.
ANd running above 230 degrees means that your oil pressure is probably dropping off a LOT.
And with the small oil lines, that is causing excessive pressure drop.

How is the cooler plumbed into the system?
If it is from the oil cooler location, then the oil probably IS being bypassed from going through the cooler.
If you are using a sandwich adapter at the oil filter, then it probably is not being bypassed (at least by the stock pressure regulator).
However - when using the sandwich adapter at the oil filter location the oil CAN still bypass the cooler because of the oil filter bypass circuit in the filter adapter (stock bracket).
If the pressure drop is too great due to the small line diameter, then high pressure at the oil filter can cause the filter bypass circuit to open and all the will go around the filter and the cooler.

[stownsen914]

It looks like you have adequate sealing around your shroud from the pics, but make absolutely sure that you have all edges sealed snugly so no air is escaping your ductwork.

What he said! Plus, I think I see from your pictures in the first post that there may be a path for air to get around the shroud after it enters the duct opening in your spoiler but before it enters the cooler? If so, it's critical to seal all that off. If you give air another patch to follow other than going through the cooler, it will take the other path. The cooler is high resistance for air to pass through, so everything needs to be sealed off, or your you'll hardly get any airflow through your cooler.

Good point as well about the exit being bigger than the inlet. The exit should be bigger than the cooler (double if you can swing it).

[SirAndy]

I prefer the hot air going out the top instead of under the car.
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