Front oil cooler tubing size?

mtnbikepoacher · Post by **mtnbikepoacher** » Thu Sep 20, 2007 6:31 am

Hey all,
I'm planning on moving the oil cooler to the front on the race car as it's not getting cool enough in the back.
What size tubes are recommended to run to the front? I suspect it's a 20 foot run there and back. I'm planning on using 5/8" tubing for the long sections. Is there a engineering formula for flow/pressure loss and length I shoulf be refered to?

BTW... Coolant temps are 180 at race speeds, and oil temps are 210. I'd like to get them closer to 190.

Thanks,
Al

benwick3 · Post by **benwick3** » Thu Sep 20, 2007 9:29 am

Al,

When I discussed this with Ian Carter many years ago he reckoned that the pipe size would need to go to at least 3/4" to maintain flow. I decided not to due to the considerable weight of the extra pipes and oil.

I presume your temps are in fahrenheit. If so I wouldn't worry too much. I regularly see 110 degrees oil temperature and it used to be 120+ before my new ducting to the cooler. With current oils 110 is not a problem particularly if you are using a synthetic.

Pete Richards

ImpManiac · Post by **ImpManiac** » Thu Sep 20, 2007 9:42 am

Al,

Have you considered an oil-to-water heat exchanger? THIS is an example of one that is available commercially in the UK. Val's (Impudence126's) set up is shown HERE. It's extremely neat and it would save a lot of weight, I'd think. It effectively uses the engine coolant to dump the heat to the presumably front radiator, in your case, anyway.

(Val's car uses a rear radiator with an auxiliary front heater matrix in the air flow.)

Just a thought.

IM

SimonBenoy · Post by **SimonBenoy** » Thu Sep 20, 2007 1:58 pm

We're not permitted to cut holes in the front for oil coolers in the HSCC, so all run rear coolers. I believe keeping the oil cool in an Imp is essential so I run 2 coolers, 1 is water cooled (my water runs 75-85 on a hot day) and the other is air cooled but with a fan as I cannot get enough air flow through it otherwise. I still see close to 120 on the oil (Valvoline VR1) with the sender in the sump plug but this drops back quickly on the in lap to around 90 and I haven't measured anywhere near 100 with my IR temp reader thingie (so maybe the gauge is overreading?).

And I change the oil frequently.

Cheers - Simon

mtnbikepoacher · Post by **mtnbikepoacher** » Thu Sep 20, 2007 4:14 pm

Perhaps I'll just run some ducting afterall.

Another question: Where to put the oil temp sender for the best accuracy? I put mine into the main galley in the timing cover. I figured that it was taking a reading off the oil right after it was sucked into the pump.

benwick3 · Post by **benwick3** » Thu Sep 20, 2007 6:12 pm

Al,

My temp sensor is in the line from the separate oil filter to the engine via the port from the original filter assembly. i.e. from the tank - oil pump - engine. Previous to the dry sump system I had the sensor in the original sump plug, i.e. above the sump extension. Figures appear to be very similar from both of these locations.

Pete Richards