Do I really need an oil cooler?

[white79bu]

My 79 Malibu is mainly a street car but I am planning on running it a local track day this spring for the first time. It's nothing real radical but I don't want to hurt the motor. I am getting an oil temp. gauge for it so I know what it will be doing. So my question is with me being a newbie will I really run the car hard enough to get the oil hot? I'm running a 450 hp 406 sbc with a t56, c5 front brakes, Lt1 rear dics, 12 bolt w/ 4:10 gears, tubular upper control arms, 36mm Iroc front sway bar, 7/8 rear sway bar, kyb shocks, power steering cooler, 17x8 wheels w/ Falken rubber and Mobil 1 15w-50 oil. So it's pretty basic stuff. What do you guys think? Should I buy one to be safe, because that's what I am leaning towards. Thanks Andy

[SStrokerAce]

Depends on the oil temps that you see, and the quality of the oil.

Oil temps really depend on the block work and machine work on your internal parts, the better that is the less problems you will have, and less heat in the oil.

Bret

[ProdigyCustoms]

Yeah, what stroker said. Basically high performance motors are often built "loose' to extract extra power by reducing frictions which in return, beats the oil and heats the oil. It is doubtfull you motor was built loose as you are no wheres near any ragged edge. I would pass on the cooler. I would probably pass on the gauge unless you really feel the need.

[Blown353]

Oil temps are definately a concern (and a $50 gauge may save your engine, so why not?) but I would be more concerned about your oil pan. What kind of pan are you running?

Most "street" pans are woefully inadequate for track use and will often starve the engine under sustained braking and/or sustained hard turns which you often don't encounter on the street.

For example, my Moroso "claimer" pan, (which was the best-baffled stock-profile oil pan I could find) makes my oil pressure flutter a bit during a max-effort stop from 150mph as all the oil sloshes to the front of the pan; if I'm on the brakes real hard and then go into a real hard turn the needle will flutter a bit too. This is the reason I haven't tracked my car-- because if I can make the oil pressure needle dip on the street I know it will happen even worse on the track (CarlC had this problem with this same pan on his Camaro.)

For the first time on the track I would highly recommend taking along a passenger and ask them to keep their eyes glued to the oil pressure gauge for the first couple laps so they can scream and flail their arms at you if your oil pressure dips. Again... it may save your motor!

Another thing you may want to do is overfill your engine by a quart. During the sustained high-rpm use it will see on the track there will be a good amount of oil trapped up in the valvecovers; overfilling the pan a bit will help to cut down on the chance of starving the oil pump without killing power from excessive windage.

Troy

[SStrokerAce]

Troy,

Good adivce, even better is a accusump.

I'm a fan of tight clearances, a motor doesn't have to be lose to lower friction.

Bret

[Blown353]

Troy,

Good adivce, even better is a accusump.


I forgot to touch on that. An accusump is definately a good idea but I would not use one as a "crutch" for a crappy oilpan and to have to rely on the accusump during every turn-- much better to have a good oil pan that works in 95% of the situations and have the accusump make up for the other 5% than use a junk pan that starves the oil pump in every corner and rely on the accusump in every turn to keep the engine intact.

Troy

[CarlC]

The pan is the most important component for wet sump oil control. Accusumps, coolers, remote filters, etc. are secondary components that compliment the pan.

This definately does not mean that a car with a stock pan cannot go to the track. It only means that there are limitations to what it can do. Stay below the threshold, and all is good. However, an oil pressure and temperature gauge is an inexpensive insurance policy. I've seen two other 406's, along with my own, that have had oil temperature problems when pushed. If appearance is an issue, use electrical gauges and make the pod removeable using a quick-connect plug for the electrical.

[white79bu]

Thanks for the great advice guys. I am running a moroso 7 quart (kick out) pan. So it's probably not that great but it has to be better than a stock GM pan. And I plan on adding an extra quart when get to the track. I will probably wait till this spring for the cooler. So I can drive the car with the temp gauge to see how it acts. There are some nice twisty roads not far from my house that are never traveled I can experiment on. Thanks for the help Andy

[SStrokerAce]

Very good advice on all of Carl and Troy added.

Bret

[white79bu]

Ok guys I have another quick question. I just bought an Autometer electric oil temp gauge and I am trying to figure out were to install the sensor. The instructions say to install it in the oil pan but there has to be an easier place to put it. Because I don't want to have to pull the pan off. Thanks Andy

[Blown353]

The best place to install the oil temp sender is down in the pan where it will be immersed in oil. You can do this by welding a bung to the side of the pan or you can make an adapter to thread it in the drain plug-- although it may hang a bit low.

Another acceptable location is in the lines going to and from a remote filter (if you have one) as the sender will see a continuous flow of oil. If you block has a tapped port above the oil filter boss, you can put one there too.

I have seen (at least for imports) a little spacer block that goes between the oil filter and the block specifically for oil pressure and temp sender installations. I haven't seen any of these adapters for domestics but they may exist and if so this would be the cheapest/easiest way to correctly install the temp sender short of removing the pan and welding a bung in it.

I've also seen senders installed using T-fittings at the back of the intake but in that location they usually don't read correctly because of heat-sinking and since they're on a dead-head line they're not bathed or in line with the flow of oil and typically read lower than actual temps.

Troy

[Zee]

Oil temps are dependent on a lot more than simple clearances. For example, my Pontiac 455 has 3.25" mains which have a significantly longer circumference than you do with a 2.45" mains. Assuming similar RPMs (or same time to cover the longer distance), the larger mains will place a lot more stress on the oil. The 455 uses a 4.21 Stroke which also requires an even higher oil operating psi to maintain sufficient pressure within the bearing at the same RPM. Again more stress on the oil resulting in higher temps.

I use a Canton Pontiac road race pan which has full baffling and several trap doors. It also comes with a handy bung in the sump for an oil temp sensor. I believe this is the only correct place to measure the temperature of engine oil. My recommendation would be to go with a better pan which has provisions for a sending unit. Run it and if temps exceed 220-230 after break in of the motor, you will need to add a cooler. If you need a cooler, it appears the Earls unit is about the best out there.

[SStrokerAce]

What I'm talking about is not comparing a 3.25" main to a 2.45" main, but comparing the same setup (SBC for example) and how good your maching is on the block and crank. If things are out of round then you are going to get some high oil temps from the added friction. The larger your bearing size the more clearance you need. A SBC that works fine at .0025" clearance is similar to a Poncho with .0035"

Bret

[Zee]

Agreed. Oddly enough, most Pontiac enthusiasts do not run those kind of bearing clearances. My point was that some makes of engines are going to run higher oil temps than others regardless of clearances.