So, we have been running a rear cooler hanging down near the aft of the transmission. It has been doing an OK job of keeping us cool. This weekend we ran at Laguna Seca (where it was supposed to be 74 degrees, but was actually 87) at a charity event. I was taking 3 people out for 3 laps each (about 20 minutes) and then would come in when the temp reached 250. Interestingly, we found that shutting down the engine cooled it off faster than letting it idle (I thought the fan was supposed to cool these things). On Sunday, the temperature was more like 78 degrees. The engine temp, even with 6 people on 3 lap runs each (about 45 minutes) only got the car up to 240 degrees.
As we are still breaking in the engine it makes sense that the temps would come down as teh cylinders have less friction once teh rings are worked in. We are also running regular dino oil, so synthetic should bring down the temp as well (10 degrees or so).
However, even though it looks like we will be able to keep our temps at around 230-240, we have to deal with Buttowillow and Thunderhill at 100 degree temps. I think it is time for a front cooler.
So, I know Brad has spoken about some types that he uses that keep the cars at 190 degrees (which sounds to low to me BTW). What brand are these and where is the best/cheapest place to get them? Also, what is teh best place to get teh AN fittings and oil hose? Do you think that steel braided is a requirement or just looks nice?

Thanks for the feedback...

Chris

Summit Racing or Racers Warehouse (Wholesale?) for
braided lines & fittings.
Fluidyne for the cooler.
Troutman for thermostat.
BTDT.

Debates on the various hoses & stuff can go on
forever. The set-up above will run about 900 bucks and you won't have to worry about it again.

Here's a couple places for oil lines/coolers:

http://www.batinc.net/files/kits.pdf

http://www.pegasusautoracing.com/

Do you really need a thermostat for a racing application? Also, what is the size of your cooler (4"x13")? Do you use -8 or -10 line? Any recollection as to how much line you used?

Thanks,
Chris

think of a cold, november morning at Laguna. You NEED a thermostat.

I know, its not COLD, but just cold.

[QUOTE]

If you are running a 6 it's recommended you use -12 lines. I have a 8X16 front mounted cooler with -12 braided lines. Keeps the car under 200 deg. so far. I bought 32 ftl of line and had a 4ft. piece left, but you may run your lines different so don't cut it too close or you could waste a piece.

yes and yes.

- use the dash 12 lines. always. even on a /4. if you ever "upgrade" your engine or cooler, you won't have to run new lines. (which is a PITA).

- you'll need a thermostat. you'll add quite a bit of additional oil and you want to be able to get the engine to operating temperature before you get on the track.

that should get your temps down to between 195 - 210, which is perfect ...
Andy

We are using an oil cooler from a 1978 Mercedes 300SD.

Good quality and cheap if you can find a used one.

BL

Hmmm... always thought that for a /6 at least one of the lines had to be -16
Stoopid imperial sizes. Why can't you guys just use the metric system

cheers,

Jeroen

they do! officially since (gosh, when was that? late 70ies?)

they just don't know it yet ...
get the word out.

Andy

The feed line "should" be AN 16.......the stock line is about that size. It's gravity or suction feed.The scavenge side has hella pressure on it (or the potential for same). Anderson recommends 12AN minimum. 16 would be easier on the oil pump.

I haven't said anything controversial all week so here goes....

I know a number of very fast (and reliable, long-lifed) 4 cylinder and 6 cylinder RACE ONLY cars that do not use a thermostat.

The builder claims that the restriction was worse for the cooling system than the cooler is good.
Thus I ran my 4 motors with the thermo pinned open, and my new 6 race car will not have a thermo in it, (This is at desert climate.)

I also know that these same cars are religiously warmed up FULLY before they are pushed.

there.. said it.. Now time to sit back and watch the fireworks..
brant

Brant,
Given our California weather and the fact that this is a track-only car, I was trying to get around the thermostat. The coolest temps we ever operate in at the track are probably around high 50s to low 60s in early March.
The other issue is cost.. A thermostat runs about $90 and the 4 AN fittings if you use -12 are $8.50 to $12.50 each depending on which hose you use. This adds around another $130 to the cooling setup. If it is something I only need in cool climates, I would rather not spend the money. If someone wants to put one in later, it is easy because the lines would be there and you would just cut and add connectors and the thermostat...

Chris

I'm not sure I have the cajones to run w/o a thermostat. It could/would be a very expensive "experiment" if the cooler catastrophically failed. Ambient temps at our local tracks range from low 30's to 115F. About the same at my house and the local canyons, too. I do warm up my engine and trans on jackstands at the track, after unloading the trailer, but couldn't even this relatively gentle warmup put a "shock" to the cooler if it got slammed with cold Mobil1 on a brisk morning?

What are your thoughts about the sandwich-type thermostat versus the in-line variety?

http://www.racerpartswholesale.com/mocal.htm

Seems plumbing would be a lot easier and cheaper with the sandwich-type.

Chris

My last car (2.0 four) had the sandwich plate type (Mocal), with an Earls cooler. They seem to work fine and are definitely cheaper/easier. The main issue from what I recall is that the oil filter becomes a really tight squeeze. Take a look at how little extra room there is now around the filter, and then imagine knocking off another 1.5" or so.

We have never had a thermostat in the race car since it was built up with the four and a dry sump system 12 years ago or so. You just have to let the oil warm up some before you go full throttle down turns 8 and 9 at Willow Springs (usually a pace lap is okay). I use a cooler from Earl's and they made up the lines with the fittings for no extra cost os I was sure they did not leak. The cooler is the largest I could fit in the front of the car and air ducts out the bottom. The nicest off the shelf setup I feel, is Patrick's with the cooler and fiberglass ducting but like most of things you pay for what you get.

As Milt noted, on a 6 the suction line has to be a dash 16 or even better a dash-24 (we used) for hooking the suction pump to the oil tank. Dash -12 is okay for the cooler lines for either a 4 or a 6. I have seen several car with the oil tank up front and that makes a long line back to the pump suction but it works.

Chris,

Its kind of a gamble that you have to decide on your own.

I did it on recommendation of my builder..
I did it not to save money, but rather to improve cooling and ultimately performance.

I had a thermo installed in the begginging... it was the mocal plate, and I think that is fine.

On my 4 cylinder I had a back up plan. I installed an pressure release valve in an accusump.

ONCE, on a very cold morning "frosty and wet" I did blow the valve. dumped a couple of quarts in the trunk floor in the pits. Did not blow the cooler apart.

The purpose of the thermostat is twofold:
first to save your cooler from too much pressure
second to reduce wear on your engine - cold start/poor lubrication wear.

you can go with a safety valve if you want.
You can monitor the ambient temp (ie: don't start the motor if you feel it is too cold for the oil to provide good lubrication) and monitor the pressure.

When I cold start I won't rev- the motor to the point of bring the pressure too high. If this means driving around the pits for 20 minutes and missing a session, then I make that decision.

Our summer temps are 80 degrees in the morning and 110 through out the day. We barely ever see 50's or 60's.

Also, I theorize that we loose a little cooling efficiency at altitude due to the air being less dense.

The mocal type uses a little space but is still very doable. Re-route the clutch cable slighly and it will work fine.

good luck either way.

John,
Where did you get your cooler and who was it that built the lines? I have been looking for the Earl's coole, but have not been able to find it. Also, it would be nice to just tell whoever you are buying from the lengths and connectors and have them do it all. Did it cost any more, or did they do it because you bought a bunch of stuff?

Thanks,
Chris

John:
I was talkin' to a race car guy (internet) that put a pressure gauge on the scavenge side of a 9eleben motor......cold pressure up to 165 psi. I don't remember all the details....other than he had an external cooler......but the 911 oil pump is a different animal than the T-4 jobbie. It'll make short work out of one of them overpriced Fluidyne coolers... when you screw the pooch, BTDT. The gud news is that they will send you a new one for nuthin'.