Oil Cooler Question
 

Guys,

So, there's an oil cooler in the SwapShop (actually, there's a pair of them), that has my interest if I can make it work. It's a Champ Inline unit, model # Cs312-6-d. I can't find out anything about them, but the pics (in the SwapShop) lead me to believe I can use it. I would like to add it to the oil cooling circuit that is already in place on my Merc 496HO. I don't have an oil temp gage installed, but I have to think the ProCharger is adding heat, and I know the closed coolant temp elevates for a while after a cruise of any real duration. I'd guess it could be added into the oil plumbing in series with the existing cooler, which should be easy enough. But I'm unsure how to do the water. My thinking is to use the outgoing intercooler water.

Anybody have any thoughts, advice or guidance?

Thanks. Brad.

You're intercooler hose is probably only 1/2" or 5/8" ?

I'd convert the factory oil cooler over to a power steering cooler, then remove the PS cooler from the back of the engine and install the larger oil cooler there. I've done that on a few 496 whipple builds.

87Mirage,

Without peeling the cover back and lifting the hatch, I'd say that's probably right. That's about what the overboard stream is. Keep in mind, though, that the engine already has a stock Merc oil cooler. I'm just trying to give it a little help.

Thanks. Brad.

FYI the part number for the fittings needed to convert the factory oil cooler to be a PS cooler on the return line are made by Vibrant. Part # 12027

87Mirage,

Is the Merc PS cooler bigger than the oil cooler? I'm trying to wrap my head around the purpose of what you're proposing.

Thanks. Brad.

The factory PS cooler is long, it goes across the rear of the engine. It's mostly a straight pipe, with a small bulge in the center for the cooler portion. Typically the rear is where most performance engines locate the large oil cooler like you want to install. You've got 1.25" water lines heading up there perfect for what you want to do. The 496 water routing is kinda complex over by the factory oil cooler, so it's easier to leave all that alone, and just use the factory oil cooler as the new power steering cooler.

Use a IR temp gun and measure the oil temps at the remote filter head. Measure the head and the filter to see what temps your getting

Adding/changing the oil cooler can be anything from simple to complex but depends on what temps your seeing

I installed a temp sensor on my filter head and found I was way above 300* F and replaced the cooler twice, head and line sizes before I got the temps down

Buying a used oil cooler is a crap shoot unless your know who your dealing with. The cooler may have been used on a blown motor and was cleaned but was it actually cleaned enough to get everything. It could be used and found not large enough like me (but you don't know me) .

You dont have oil temp gauges but you feel the need to add an additional or larger cooler because you have a hunch the hair dryer might be adding heat, got it makes sense

First thing is to determine if the oil is getting too hot. Does the oil pressure drop after a hard run??
What do you mean by coolant temp is elevated after a long cruise?? How elevated??

Griff,

I am running a 165° stat, and the temp holds at that as long as I run, no matter how hard. After a mild cruise, say 20min @3500RPM, if I settle in, down to an idle, the temp will climb to ~180° or so for 5-10min, then gradually come back down. The oil pressure does drop during this time, but usually only after I've run it harder than about 4K. These observations leads me to believe the oil is getting hotter than I'd think it should be. I had a 140° stat, that I got from Whipple when I had them do the stage 2 ECM tune, but, like a dumbass, I had it sitting on the swim deck, forgot about it, and donated it to the highway somewhere between my shop and our local lake :rolleyes:. It is my intention to acquire another, but have yet to do so. I can't imagine this will have any other affect, other than to lower the range in which these temperature swings take place. How much effect does coolant temp have on oil temp?

Thanks. Brad.

F2,

Very insightful....

We know that any power adder puts additional pressure on the bearings and heat into the block, which inevitably leads to increased oil temps. I am seeing indicators that would support that suspicion. Being that it is an otherwise mechanically stock Merc 496HO, with a ProCharger, my layman's assumption is that the OEM oil cooler is just not quite getting the job done, and I'm exploring options to rectify it.

For the record, I have been known to stare at my dash, trying to figure out where I'd place an oil temp gage. I don't dismiss the potential need for one.

Thanks. Brad.

What you have going on sounds pretty normal.

Griff,

While I agree that there’s nothing really alarming, I just can’t get comfortable with 20lbs of oil pressure. 🤷‍♀️

Thanks. Brad.

I had a 100% stock 496. I drove it easy most of the time. The longest I had it wot was about 2 minutes. Oil temp was climbing to 240 plus. That's when I backed out down. Water temp was around 70*.

If you drive the engine hard, the oil will definitely be hotter with the blower.

Larger oil cooler depends on your driving habits.

I would never buy a used oil cooler, you just never know what has been through it. You really need to figure out what your oil temp is, basing it off oil pressure isn't very accurate. For reference, my water temp is around 160 and oil is 190

When people post oil temps I think it is necessary to state weather the temp is pre or post cooler.

I've built a few 496s with whipple superchargers. I've done some experimentation on oil coolers. I went through 5 different sizes just testing etc. So, I did try it with just the factory oil cooler as a baseline. The oil temp shot up to 250+ faster than Biden's deficit. (measured before the cooler) The rate of climb was scary. At the 600-650hp level a 3x16 CP Performance cooler worked just fine. On an 800hp 496HO it's looking like a 13 plate box cooler is the trick. Hope that helps.

The stock oil cooler is a wee little feller!

Rule of thumb is 10psi per 1000rpm so 20 at an idle is not out of the ordinary for hot oil. My engine once warm has 25 at 800rpm and 65 at 6000rpm. Any more than that you'll start to have distributor gear fatigue. I understand you have coil packs on a 496, but its just a big block rule to keep in mind.

I 10000% agree on never ever ever buy a used oil cooler. They aren't that expensive. If the $200 you're going to save makes it feasible, a less expensive hobby is in order.

You may very well need better oil control. But a used cooler isnt the route I would take.

Johnny,

I guess the thing that caught my attention is that it stays at ~40lbs at idle, even after coming up to temp (water), so long as I stay at idle, but, then, after cruising is when it drops off when back at idle. Maybe I'm overthinking it. I've been accused before....

Loud and clear on the used oil cooler. I was a bit concerned about the potential implications of it. I won't.

My real concern with dropping oil pressure is the correlation with oil temp. I know that hot oil is oil breaking down. I just don't know what that threshold is or how hot it's actually getting.

Thanks. Brad.