951mat

I'm looking to replace my stock oil cooler with a Mocal or equiv unit mounted in front of the radiator/condensor. My oil pressure tends to drop drastically during DE's as the motor gets hotter, especially in corners. (I live in Houston). Pressure seems fine during everyday driving, so I don't think anythings wrong. Question is, what size do people recommend. I believe the typical sizes are 235mm x 19 or 25(passages I think)The 19 are +/- 6 inches tall and the 25 are 7-3/4" tall. I don't do anything other than DE's now, so I'm assuming 19 would be fine and a big improvement over stock. Any opinions?

Konstantin

I have a setrab one from sweden I think it is the one tha Porsche use in the 962
it is 26x 15x 5 and has 20 rows
I wnat to install it with a Mocal oilfilter adapter in the oilfilter housing. from there the tow lines goes to the oil cooler and back. The mocal adapter has a thermostat in it.
I still didn't install it as I am not sure where to install it but many told me in fornt of teh radiator it should be ok.
I expect at 20 degree Celsius oil temp drop from this as my oil temp goes up to 150 degree on the tarck or 140 degree at WOT at the Autobahn.

Konstantin

951carter

I have the big mocal in front of the radiator. I don't think that this will solve your paticular problem though. It sounds like you need an Accusump system if you are loosing pressure in the turns. I put the Mocal and the Accusump along with the updated oil pan baffle in my car. My temps stay on the first white mark and oil pressure is 3 even before i start the engine =)
The oil pressure does not drop even in high speed spins.............don't ask how i know.

951mat

Does anyone else see their pressure drop with time on the track? I was told that it is somewhat common. Two other people I talked with said they don't see any pressure drop, but they have larger oil coolers. Its not so much the corners as it is track time. The longer I drive (the hotter it gets) and the less pressure I have. The pressure does dip some in corners but only after I see the large drop with the track time/heat. The last time I drove a DE it was in the 90's, which doesn't help. I should say the temp gauge doesn't get too hot, it runs around the second mark, or a little lower, under these conditions I mentioned.

Danno

Yeah, mine drops down to 4-bar on the gauge on hot days during and after a track sessions. There's no drop of oil-pressure in the corners. I'd like to install an oil-temp gauge to keep an eye on this. Most likely it's due to thinning of the oil from high heat.

My next plan is to get an RX-7 oil-cooler off a 12a or 13b motor. It's wide and low and is shaped similarly to the air-conditioning condensor on our cars. That way, it won't block too much air going to the radiator...

951carter

It is normal for the pressure to drop when the engine gets hot. The pressure dropping in corners is what concerns me, that is not normal. According to the Porsche manual it is OK for the pressure to drop to .5 bar at idle when hot. It should be at 3 or above when driving, if it were under 3 i might get a little worried.

"At 5,000 rpm, with the engine at normal operating temperature (approx. 90C / 194F), the pressure should be approx. 4 bar. A slight drop in oil pressure is normal under certain operating conditions such as prolonged highway driving in hot weather.
At idle speed, with the engine oil hot, the oil pressure can sink to 0.5 bar - this does not indicate any loss of engine performance.
However, if the oil pressure drops suddenly while you are driving, or if the warning light comes on, pull off the road, stop the engine and wait for it to cool down. Check the engine oil level. If the level is normal, contact the nearest dealer."

Konstantin

my water temp ALWAYS show 83 degree. Guess what. I have an oil temp gauge and it goes from 90 degree up to 150 Degree or 260 F and tzhe water is always cool. RThat means the water try to cool up the oil but the oil is still hot!!
Do not trust your water gauge.

Konstantin
PS both gauges are calibrated and checked and show ok. I have a lower temp sensor. befor this my water went up to 100 degree especially with slow driving in the city