Combined rad/oil cooler - Page 2

BruceLambo · 03-09-07, 09:21 PM

Quote:

Originally Posted by toy264

Lynn-

On another thread, someone suggested a thermostat in the transaxle cooling circuit, and I assume the same considerations would apply to that application as well. Any thoughts on that? Or is this the wrong forum

For the transaxle you couldnt use a thermostat without having the oil constantly circulating. It would be better to use a temperature sender in the oil, inside the gearbox linked to the appropriate electrical actuating system to circulate the pump until a lower temperature is reached then the pump switched off.

John Fitzpatrick · 03-09-07, 11:25 PM

My transaxle, an early ZF, has a mechanical pump, so a thermostat was suggested to bypass the cooler until the oil came up to operating temp.
John

Russ Noble · 03-10-07, 02:16 AM

John, for road application, and since you've got that pump in the ZF, I would think heat exchanger/s in the top hose with a remote thermostat in the waterline after the exchanger would work well. That will keep the oil/s close to engine operating temp.

Lets face it with a GT40 (or your V8 Lotus 47) on the road you can only maintain full throttle for short bursts at a time. Nothing is likely to get excessively hot as prolonged full throttle driving is not likely to occur. The car is just too fast for that!

For most road going GT40's though I think Lynns KISS principle applies, forget the complication. Quite frankly on the road, with a decent and properly ducted and plumbed radiator, I can't see heat build up anywhere being a problem at all. Rather the opposite in fact.

For racing, oil and water temps often run uncomfortably high and I would tend to put the exchanger/s in the bottom hose. When you run the motor up to temp before racing an exchanger would have the excellent side effect of also warming up the trans.

Just my thoughts.

BTW, do you know what your 47 weighs?

Cheers

John Fitzpatrick · 03-10-07, 11:08 AM

Quote:

Originally Posted by Russ Noble

BTW, do you know what your 47 weighs?

Cheers

As I remember, the article Motoring News wrote on the car listed it as 1800 Lbs.
John

TudorMiron · 03-31-07, 05:41 PM

Hi All,
Here's my 2 cents:

Oil/water heat exchanger is used in racing for decades with great success. Here's a link to most effective unit to date. Produced by Laminova of Sweden (Part of Opcon corp.)
On our formula cars we tryed every existing solution starting with oil/air than oil/water mocal, setrab and some others. Laminova provided best results.
www.laminova.com

They also have one combined - engine/gearbox oil/water heat exchanger in one unit.

Cheers
Ted

Julian West · 03-02-08, 08:05 PM

Using this type of exchanger for cooling engine oil, is the exchanger fitted in the coolant pipe that flows *to* the radiator or *from* the radiator??

regds,

Jac Mac · 03-02-08, 08:50 PM

I use it in the one *from*. But being an old * Geezer * from an island in the middle of nowhere and therefore making my own I am probably doing it wrong, eh Francis!

Jac Mac

Fran Hall RCR · 03-02-08, 09:17 PM

Eureka....

ragrod · 03-31-08, 07:15 PM

How about the little ones that ford puts on cobra mustangs that fit between block and oil filter, looks simple and compact, no oil lines to run.just water lines They are approx 1.5 inches thick that will require a angle adapter for oil filter clearance. I am wondering how well it would work on a track day car?
Randy

Mike Drew · 04-01-08, 05:34 AM

Panteras have similar cooling systems, and any Pantera that is run hard on a race track suffers from oil temperature problems, even when engine temperature is well under control. Many Pantera guys are in the 'no news is good news' camp and don't instrument their cars; one friend who has, has fought oil temp problems on the track for years, trying a series of air-to-oil coolers mounted in various places, all with no success. He can get the oil to 300 degrees in just a few laps.

I drove a 1985 Pantera GT5-S from Spain to France to Italy a few years ago, and it was equipped with an oil temperature gauge. At triple-digit speeds, the oil temp would climb up to 300 degrees, which is devastating. We would have to slow down and finally drove the car using the oil temp gauge as a speedometer!

Laminova water to oil coolers seem like the optimal solution for cars that don't have good airflow to cool things naturally. GT40s historically used air-to-oil coolers and are equipped with various scoops etc. to facilitate that. But water-to-oil coolers are generally more efficient, and have the secondary benefit of allowing the water to warm the oil. Ultimately the oil adds heat to the water, which in turn impacts the cooling system, but a proper radiator should be able to deal with it. Friends who have done before-and-after tests found that the oil temperature and water temperatures stabilized, with the water temperature about ten degrees hotter than before, and the oil temperature being the same as the water temperature, instead of skyrocketing off the gauge. That seems like a good trade-off.

Here's a direct link to the type of coolers I've seen employed with success:

Laminova

These suckers are expensive!

However, Ford Crown Victoria police cars (only the police cars) were equipped from the factory with similar units (built by Laminova), and they can be had fairly cheaply if one scours E-bay etc.

One early adopter of this concept found out the hard way that Fluidyne quality isn't always the best. He bought a Fluidyne water-to-oil cooler:

FLUIDYNE - High Performance - Radiators and Oil Coolers

And fairly shortly, his unit turned into a water-to-oil MIXER. It broke internally and flooded the coolant with oil (since the oil pressure was higher than the water pressure). Then, after engine shutdown when the oil pressure dropped to zero and the radiator cap was holding 16 psi, it went the other way and pumped coolant into the oil, turning it into latté.

They stood behind their product and gave him a new one for free, but he still had to pull the engine to change the bearings, pump all the passageways clean, and he also had a heck of a time flushing the oil out of his cooling system. So there *are* potential drawbacks to this plan....

Jac Mac · 04-01-08, 06:22 AM

Or if you have access to a small mill & lathe, make your own----

Jac Mac

Julian West · 04-02-08, 05:59 AM

FWIW,

Following my recent engine failure I decided on a laminova cooler. I guess it's very hard to quantify exactly what type of cooler is 'best',... I'm sure oil/air works fine but I decided on oil/water heat exchanger.

Personally I felt the only decent cooling airflow thru the car is thru the nose & therefore this is the best place to get rid of heat. My water radiator works really well & I'm confident It can easily handle the extra 'load' placed on it by the exchanger.

Secondly, packaging..... fitting the exchanger in the engine bay (it's getting pretty busy in there!) the largest laminova C43 series is a nice fit against the bulkhead in the GTD. I'm part way thru fitting it, but will post more picture in my build thread GTD Restoration completed! when it's finished.

The exchanger is fitted in the water return pipe. I guess the water running thru the exchanger will have been cooled by the radiator. Altho the water will then carry the heat back into the engine I guess at the end of the cooling cycle the rad disperses the heat to air.

I managed to reduce the high cost of parts by using a s/h exchanger. The laminovas are easy to strip an clean as you can see form the pictures. Also I found it's well worth hunting around for prices on the oil pipe fittings. EG I was quoted 28+VAT for a -10 elbow in the UK (over 60 dollars!), whereas at Summit an Aeroquip -10 elbow is just 17 dollars!! Rip off Britain I guess!

Once it's all complete I'm really not sure how I'm going to guage the efficiency of the cooler/exchanger. I'm not keen on going to the extent of data logging or even where on the dash I would be able to fit an oil temp guage. Will cross that bridge when I come to it!

The pictures progress to date....