Pictures from weekend @ Willow Springs, too hot - questions... Options

[campbellcj]

Hey, what the heck is Jack "Mr. 911" Olsen doing over here. Thinking about a turn to the dark side of mid-engined mania?

Steve - your cooler setup looks quite similar to mine and assuming it is getting proper flow and the t-stat is opening correctly, etc, I doubt you'll be able to improve on it much. The shrouding on mine might be angled more (i.e. ram effect) and I do have a huge 32"x7" opening in the front bumper area for intake; the outlet is a large opening in the trunk floor under the cooler. The degree of metal cutting is not for the timid.

I had forgotten however that the 3.6's don't have an engine mounted cooler, so maybe an auxiliary cooler as Jack mentioned is worth exploring. Clearly there are lots of 911 racecars who've figured out a viable solution and can even run long enduros. You might want to check with Chuck Moreland @ Elephant Racing as he's done quite a bit of research into oiling systems and cooling solutions.

I am currently running 15-50W Mobil1 but might switch back to 20-50W dino to keep the costs and leaks under control.

Also BTW you should have a quick chance to glance down at the gauges in the 7-8 area (back straight) before turning into the almost top-speed turn 8 section.

[campbellcj]

Actually in looking at your pic, I realized my cooler is mounted at an approx 45° angle (top end tilted back) as opposed to bolted vertically to the front of the tub. I'm not sure how much of a difference that makes, if any.

I have some pics at home but am on the road for a few days.

Anyways...when is the next event at Big Willow or another local track that the SoCal crowd is planning to run?

[Jack Olsen]

...when is the next event at Big Willow or another local track that the SoCal crowd is planning to run?

I'm thinking of doing the Streets of Willow event that Speedventures has going on July 25th. $110 for the day seems like a pretty good deal. (They're running on the 24th, as well, but I'm karting that day for the first time in 28 years.)

Some of you mid-engine guys should come and school me at the Streets. Isn't that a 914 track? (IMG:style_emoticons/default/cool_shades.gif)

[ChrisFoley]

siverson,
Do you have a pic of the front of the car that shows the inlet?
I like Chris C.'s idea of tilting the cooler back. It creates a plenum ahead of the cooler to build positive pressure, and it might be easier to seal the edges to the shroud.
I also like -16 lines for an engine that size. Not only will they reduce drag on the oil, they will give you a greater volume and radiate some more heat as well.

[0396]

Steve,

Your '6' looks great. I only wish my car looked that good.
I'm currently inthe process of builing one myself.
Years ago, I thought of building a 3.6 too. But after talking to Andial regarding the extra cooling needed for the 3.6, I ended
up building a 3.4 instead.
As for your oil line concerns,if you do need to upgrade to -16, I need some too.
Maybe we can purchase together so we can lower the price.
Does anyone have any suggestions on where I can purchase 36'
of Aeroquip -16 at a good rate?
The current rate is approx $12-16.00 / foot.
Last weekend while installing my hot lead from the battery,I ended up drilling into my -16 line. So being that they are about 20 years old anyway, I thought of replacing the whole lot.

Steve, see you at Willow (IMG:style_emoticons/default/rolleyes.gif)

[rick 918-S]

(IMG:style_emoticons/default/wavey.gif) Hi Jack Olsen, Welcome! (IMG:style_emoticons/default/monkeydance.gif)

[siverson]

> Jack Olsen
> did you cut outlets for the cooler airflow down below the shroud?

Yes, there is a big hole in the trunk floor that is about equal in area to the intake hole.

> What kind of times were you running?

I have no idea, but I'm sure they weren't impressive. I could smash the throttle pretty well on the front and back straight and have a lot of fun and get to a good speed, but I'm sure I could have been a lot faster on the rest of the track.

> Saw a 3.6 track-only car that had 2 coolers that size back to back in the front with a splitter/flow-restrictor to make sure the oil moved through slow enough to get proper cooling.

That's an interesting arrangement. I was wondering about that - if I could use another cooler behind the current one getting the hot air, because I'm guessing the the exhaust hot air is still well cooler than the oil.

> Streets of Willow event that Speedventures has going on July 25th

Hmmm... That sounds like fun. I've never run that course either, and if I can get a new test cooler system installed by then, maybe I'll see you there.

> But after talking to Andial regarding the extra cooling needed for the 3.6

That's funny, Andial built my engine for me... :/

-Steve

[siverson]

Here's a picture of the inlet. Currently no front valence installed, as the fiberglass one I got was total crap, and I've been modifying my stock steel one into a GT valence.

-Steve

[siverson]

Maybe I should get a mesh with bigger holes too... ?

-Steve

[Martin Baker]

Who's did you buy that was total crap. I am not happy with mine either.

[J P Stein]

Does anyone have any suggestions on where I can purchase 36'
of Aeroquip -16 at a good rate?
The current rate is approx $12-16.00 / foot.

Summit racing or Racers Warehouse (wholesale?)

Bout 9 bucks a foot at www.Summitracing.com.
Great guys to do biddenss with.

[maf914]

Maybe I should get a mesh with bigger holes too... ?

-Steve

Screen, grill bars, etc. can restrict air flow. You might try a larger mesh.

Another thing to consider is the valence. I wonder if its abscence might make a difference. Its rounded shape may smooth the airflow under the front of the car. Smooth fast airflow results in lower pressure which might help draw air out of the oil cooler exhaust opening. If the airflow is not smooth it tumbles around and pressure builds.

A spoiler or air dam would probably help by restricting the flow under the front and creating a low pressure area for better exhaust air flow. Might help the handling too.

Adding an flap angled toward the rear at the front edge of the exhaust opening is another way of reducing the pressure at the discharge, increasing airflow. Sort of like the flaps added to the engine fire wall on later 914's.

Just some crazy ideas... (IMG:style_emoticons/default/laugh.gif)

[john rogers]

When Chris Burns was racing his RSR motored 914 several years ago he had lots of trouble with high temps. They did several things to get them down, including an air deflector at the rear edge of the targa top to force air into the grill openings which were GT style. I ran a deflector on my big four as it had the same trouble and would lower temps by 20 degrees. Additionally, they made sure all the engine sheetmetal and rubber seals were there since even at speed if they are missing the fan can still suck hot air from under the car. When I did my six conversion I took great pains to make sure I had the cool top side well sealed from the bottom. Lastly, I would install some sort of air deflector in front of the cooler exit as Chris has noted there needs to be a low pressure there to help suck out the hot air. Good luck

[ChrisFoley]

The lack of an air dam definitely hurts you, big time. An air dam will increase the pressure at the inlet and decrease the pressure at the outlet. A stock type valence will not be enough, you need a real air dam that drops straight down. You won't even notice the increased drag, but may actually notice improved high speed handling.
You won't need any bigger mesh screen if you are managing the air better.

[TimT]

fwiw heres how I mounted the cooler in my 911

[TimT]

phthit

[siverson]

Thanks for all the good tips. My to do list is growing quite long and I think I'll be able to solve this problem. I just stopped by Deiters here locally and they had some other good ideas.

For one, they said my thermostat is probably too small and I should confirm it is -12 all the way through or get the Troutman thermostat. Anyone have Troutman contact info? Couldn't find them on the web.

Plus, they mentioned that I needed to make sure that the oil was flowing through the cooler going in on the bottom. I'm honestly not sure which way this is going now, but they said this can make a big difference (otherwise air gets trapped in the cooler, not oil).

My current to do list:

- confirm car isn't running too lean (dyno this weekend)

- confirm oil cooler and thermostat are being filled from the bottom

- finish building front valence, seal inlet air to cooler too

- confirm/replace thermostat size

- add "flap" to create low pressure on oil cooler exhaust air. My plan here is to cut further cut the trunk a little more on the sides, but not the front, then just fold it down at 45 degrees.

- add underside engine flaps (good reminder, I've been meaning to put these back on!)

- use 20/50 oil, not 10/30 oil

later if that hasn't worked:

- add fans behind cooler

- try less restrictive mesh

- add second cooler somewhere

- go to -16

[siverson]

Yeah, I'm sure it's better to vent the air up and over for a number of reasons, but I didn't want to do that for cosmetic reasons. It's still 70%+ a street car.

-Steve

[TimT]

- try less restrictive mesh

I doubt that mesh has anything to do with the problem....


Here is some interesting reading about aerodynamics splitters etc...

-16 line is good for the return to the engine... like Chris says more volume... make sure you get the "support" for the -16 line though, its a spring that keep the line from collapsing

The oil line going to the cooler can be -12 since its the pressure side of the system...

I'm honestly not sure which way this is going now, but they said this can make a big difference (otherwise air gets trapped in the cooler, not oil).

Yes this makes a big difference... you could have a whole oil cooler full of air, the oil will find the path of least resitance...... like only go through one row of the cooler..

[seanery]

Troutman