Oil cooler and line questions - Lateral-g Forums

wmhjr · #1 07-24-2011, 11:35 AM

OK guys, as mentioned in a couple other threads I've concluded I need to immediately put an oil cooler in the poncho. At Motor state I was easily getting my oil temp into hte 260 range at Gingerman. At Heidts any doubt was immediately eliminated when I hit 300, and had to back way off and baby the car for the road course element. The cause of this is that my block is bottom filled to the freeze plugs in order to get the power from that pontiac standard block safely.

Currently I have an adapter plate mounted to the block with 2 1/2" NPT ports, which I installed 1/2" NPT to -10AN fittings. These currently go to a frame rail mounted Canton oil filter setup. My plan is to re-engineer that and have the lines instead go forward, to an oil filter somewhere in the vicinity of the engine bay, and then to a front mounted oil cooler in front of my radiator.

I have several questions.

1) Any recommendations on the most effective cooler? Frank has a pretty nifty looking unit that I'm interested in - it's in the Bull run racer, and can be had either with or without fans. I don't know that the fans would be helpful (pusher fans) considering the rad fans will be pulling through anyway, and I don't have much power available, so I'd probably have to run a new power line directly from the battery.

2) Even though the ports on the block will be 1/2" NPT, is -10AN enough for the lines? Pretty much anything they attach to will be 1/2" line connections. Would -12 in the lines themselves really help?

3) Engine temps have been relatively manageable. Normally I'm at 180-190. When the oil heats way up, the water temps also get up to 210-215, sometimes 220. However, it's briefly and I think it's possible that between the oil temp and heating up the hard block that reducing the oil temp may also result in a little drop in peak water temp when I'm really hammering. But that's just a theory. Thoughts?

4) At present, before the oil REALLY heats up, my oil pressure is about 75psi at start, and around 50-60 after warm-up. I'm concerned about pressure drops after adding all the volume/lines/cooler, but plan to run it as is and watch it. If pressure drops much at all, during the off season I'm pulling the engine and putting a higher pressure Melling pump in the motor. Thoughts?

I need to start this change quick, so any and all advice is very very welcome!

BTTBSS · #2 07-25-2011, 07:11 PM

Do you have a stock oil pump? HV pumps will bypass a lot of oil and the cooler may not help much. I have -10AN on my LT1-383 and a huge EARLS cooler. Oil still hits 285-300 after twenty minutes of open track running. Good synth oil
helps. German Castrol 0W-30 has stood up well confirmed by Blackstone labs. Mobile has a new track use oil with twice the zinc of regular oil supposed to be good up to 400 degrees but its about $ 15.00 a qt. Somebody try it and let me know how it works.

wmhjr · #3 07-25-2011, 09:29 PM

I do not have a stock pump. I'm running a worked over Melling M54D. I don't think it's going to bypass enough - frankly if it did that would also mean that the filter itself would be totally ineffective.

I'm running Brad Penn partial synthetic 20-50. I change oil after every track event.

ccracin · #4 07-26-2011, 05:25 AM

Bill,

I have never been a fan of putting the oil cooler in front of or combining it with the radiator. First, if you use an internal heat exchanger in the rad for either oil or trans fluid,(not that you suggested this) you still only have the surface area of the rad fins to transfer the heat out of the water. Therefore unless you increase the rad size accordingly you can only remove so much heat. This is a pitfall I saw a lot in racing. Guys would swap a standard rad for one with a built in oil heat exchanger of the same core dimensions and continue to have problems. In the end, they still didn't have enough heat exchanger area to remove the heat. This all leads to my next comment. If you put the oil cooler in front of the radiator, then the heated air will now be moving through the radiator and will now not be able to remove as much heat from the cooling system. My recommendation would be to run and external cooler mounter somewhere other than in front of the radiator. The one in the Bull Run car was recommended by Wegner. We will probably look into that one as well. The fan gives you more versatility in mounting if you can't mount it somewhere you are able to get a duct to it. If the only place you have to mount it is in front of the rad, then so be it. That is not as bad as building it into the rad. You are at least adding heat exchanger area. I would not put the pusher fan on it then. If you didn't have it running all the time, all it would do is block the natural air flow from it and the radiator since it would be in front. (This is why I don't like pusher radiator fans as well)

As for pressure drop, you are going to have to give it a shot and go from there. Obviously the more elbows the more pressure drop down stream. The bigger the line the better as well. We'll be talking.

wmhjr · #5 07-26-2011, 06:33 AM

Chad, thanks. I'm concerned about the same issues. I really don't have another area to stick a cooler that I can think of. Space is an issue to say the least. I could probably stick it in the engine compartment behind one of hte headlight buckets "maybe" but there is no air flow and the effectiveness of the cooler would be suspect to say the least. The Bull run car has that PRC cooler (I think) but it is mounted in front of the radiator without the fan. I agree that assuming that the unit is mounted at the correct spacement (maybe an inch or less) in front of the rad I'm better off using the integrated shroud/fan on the back of the rad to pull air through than anything else. I think I could have two results from it.

I think it's possible that during track time, I'd see reduced overall temps as airflow and lowered oil temps would reduce overall operating temps. However it's also possible that in "street" traffic kind of driving, I could end up with higher water temps due to the loss of heat exchange in the radiator but not enough airflow.

ccracin · #6 07-26-2011, 06:44 AM

We were looking at this cooler since we have a PRC rad and the quality is top notch.

http://www.prchotrod.com/products/pr...ccessories.php

wmhjr · #7 07-26-2011, 06:55 AM

That is exactly the PRC cooler I'm looking at. I would like to see it unshrouded (without the fans). I'm a little concerned about how it will block the radiator.

ccracin · #8 07-26-2011, 07:01 AM

Have you looked at mounting it horizontal in front of and at the base of the rad? You would have to run fans unless you put some type of dam or splitter on the car to direct air up through it. Thinking out of the box a bit.

wmhjr · #9 07-26-2011, 07:33 AM

I have but don't think there is enough room in front of the rad/core support to fit it. I would be very surprised if there were. The other issue would be that it would be right up against the bumper if that could even happen, so you'd risk catastrophic failure of the oiling system even if you just bumped the bumper. There really isn't any room other than n front of hte rad/core support due to the (low) height of the car.

ccracin · #10 07-26-2011, 07:47 AM

Fine then, I say jack the engine up and build a new car around it!