New 2.8 Liter Six for the Racecar, I'll be asking a bunch of Conversion Questions Options

[infraredcalvin]

You should also consider the stock location and style for the oil tank. I have run in the front as well on a conversion car I owned in the past.

(IMG:style_emoticons/default/agree.gif) Both my cars use stock -6 oil tank. Even though I’m already plumbed to the front for cooling, the stock location is already engineered and keep things neat and clean.

[motorvated]

You should also consider the stock location and style for the oil tank. I have run in the front as well on a conversion car I owned in the past.

(IMG:style_emoticons/default/agree.gif) Both my cars use stock -6 oil tank. Even though I’m already plumbed to the front for cooling, the stock location is already engineered and keep things neat and clean.

So if running a front oil cooler, the stock 914-6 oil tank has enough capacity to feed a 2.8 liter motor, or should I go for a larger capacity tank. I would like to mount the tank in the engine bay and not up front, and actually I'd like to run the stock oil cooler and maybe an additional cooler out back and not cut holes up front and run long oil lines up front and back. But I'm thinking that there may be no way around installing a front mounted oil cooler on a race motor.

[Krieger]

On my 3.0 track car I run the stock tank with a cooler up front and the stock engine oil cooler. No issue with oil capacity.

[brant]

The motors create a lot of heat
Your about to double your HP. So you’ll need a lot more cooler than your old motor

Additionally the cooling at our altitude and humidity is not so great
I run 3 oil coolers on mine with two of them up front
(A 4th cooler on the transmission)

Rpm also contributes to the equation

I’d be very surprised if you didn’t need a front cooler cooler on an air cooled racecar

[motorvated]

The motors create a lot of heat
Your about to double your HP. So you’ll need a lot more cooler than your old motor

Additionally the cooling at our altitude and humidity is not so great
I run 3 oil coolers on mine with two of them up front
(A 4th cooler on the transmission)

Rpm also contributes to the equation

I’d be very surprised if you didn’t need a front cooler cooler on an air cooled racecar

So what size front oil coolers are people using and what size oil lines, and running lines through the longs? Also what size for the 915 transaxle cooler? Any additional protection on the front of a front oil cooler to eliminate the possibility of damage on the track, like a screen?

[campbellcj]

I kept the shelf and tin in mine, and also the trunk floor, partly because I mainly drive on desert tracks with tons of dust and rocks, and partly because I've kept the car street-registered so I can occasionally take it to C&C's and shows. So far no issues but obviously it adds some weight and prevents the easier access. I do have a gutted out GT-style lid so the whole engine cover is just mesh and is removable.

Re twin-plug - I have the JB Racing dizzy and dual MSD boxes.

Totally agree re. keeping the oil cool and I have the stock engine cooler plus a large shrouded cooler up front with (IIRC) AN-12 lines in the tunnels. It's a Mazda Competition part from a long time ago with a screened front intake and it dumps out under the car. I've had the car on track at Willow Springs in >110F ambient with no issues. Oil tank and console setup is factory -6.

The recent PMS build sold on BaT vented the cooler into each wheel well which I thought was interesting and maybe not optimal re brake temps (?)

[brant]

I dump my 2 front coolers through the wheel wells also
I wondered in the beginning if it would impact brake temps...


my mechanic told me no...
said that 200 degree air from the cooler was not going to hurt 600 degree brake temps...

turns out he was correct.
I've never had brake temp problems.
in fact if anything I have too low of a brake temp problem

I started measuring my rotors temps..
had to remove all of my brake cooling to get them to come up to a higher temp... operating range...

in fact had to lower my pad compound to a lower operating range just to get the temps up

had to lower 2 designations on pad material as the first step still didn't bring my brake temps into operating range....

so at least on my car... getting enough temp into the brakes was my problem and not overheating them....

I know I'm running a smaller motor (2.0) than a lot of others do...
I realize that with a much bigger motor, my top speeds would increase that that would also bring my brake temperatures up...

but at least in my application, the oil cooling air... does not negatively impact brake temps

[motorvated]

I dump my 2 front coolers through the wheel wells also
I wondered in the beginning if it would impact brake temps...


my mechanic told me no...
said that 200 degree air from the cooler was not going to hurt 600 degree brake temps...

turns out he was correct.
I've never had brake temp problems.
in fact if anything I have too low of a brake temp problem

I started measuring my rotors temps..
had to remove all of my brake cooling to get them to come up to a higher temp... operating range...

in fact had to lower my pad compound to a lower operating range just to get the temps up

had to lower 2 designations on pad material as the first step still didn't bring my brake temps into operating range....

so at least on my car... getting enough temp into the brakes was my problem and not overheating them....

I know I'm running ma smaller motor (2.0) than a lot of others do...
I realize that with a much bigger motor, my top speeds would increase that that would also bring my brake temperatures up...

but at least in my application, the oil cooling air... does not negatively impact brake temps

Ok next question. The 915 transaxle that was in the prior 914 was equipped with an external Tilton pump and cooler with fan. Unfortunately that cooler remained in the car and I only have the AN fittings remaining on the case. So I need to reconstruct a cooling system for this transaxle. I am thinking that I can use the same type of Tilton positive displacement pump that was used in the prior system. I would like to use one of the Summit racing aluminum "heat sink" dual pass coolers with no fan for cooling as it keeps things simple and the cooler is more compact and more robust than a finned cooler. The heat sink cooler should do the job as long as air is flowing over it, and since the transaxle only gets hot when the car is moving at speed, air will be flowing. I really shouldn't need a fan for when the car is not moving, and the heat sink cooler still removes some heat in stagnant air conditions, although the rate of heat transfer will be much slower.

Is anyone using a "dual pass heat sink" type cooler with no fan for their transaxle, and if so is it doing the job? Summit Racing has them but they do not have a Btu heat transfer rating for them, so it's kind of a crap shoot as yo how well they will work.

[mlindner]

I have both the engine shelf and tin. But for better engine access I had the top angle portion of the trunk wall removed when rear suspension support was added. Mark

[brant]

I run a 901 instead of the 915

I ran my trans cooler with three different ducting (intake air) set ups all measured with a trans oil temp gauge

The small electric fan out performed 2 different ram air set ups.

Air flow under the rear trunk is restricted the lower the car is
We put our trans cooler into the rear trunk

I would want to actually measure the effectiveness of any set up

Oiil coolers are all about intake and exits
That’s why radiators are shrouded on production cars
I ran the same front cooler on my old race car with 3 different exit designs and lowered the oil temp15 degrees each time I improved the exit

You may benefit from copying effective race set ups of others
Look at the fastest set ups. Frank beck for example

there is a lot of ambient temp under the trunk... those exhaust headers are really hot and heating the whole area... heat tends to get trapped in that area too....

[stownsen914]

my mechanic told me no...
said that 200 degree air from the cooler was not going to hurt 600 degree brake temps...

Agree with this. I have my front cooler dumping to the wheel wells on my 914 racecar and have never had an issue. I have a 260 hp and Wilwood large brakes on the front. I do duct the brakes separately.

On the trans cooler, it's a little tough on a 914, but anything you can do to get the cooler away from ambient heat and provide it a source of fresh air ducting will go a long way. Remember a cooler is a heat exchanger - if it's sitting near the exhaust, etc., it's going to have a hard time shedding heat from the trans oil.

(I put mine in the passenger right rear fender and ducted air to it, but I have flexibility due to full fiberglass widebody.)

[Charles Freeborn]

My front coolers and ducting for brakes. Don't have any good pics of the plumbing - I'll take some next time I have it out and in the air. Concentrating on the other end of the car at the moment..