Me and my new track buddy Jim have been discussing adding an oil cooler to our LT4's. After some disscussion, and thinking about various GM cars that have factory coolers, we have found the solution. :D

Jim noted the 9C1 cop car had a factory oil to air cooler on the LT1 motor, so I closely inspected my 96 impala SS which has a cooler in the radiator. this afternoon I crawled under both my cars and here is what I have found.

The LT4 has an offset oil filter adaptor to clear the cat, and so does the Impala. In fact both oil filter adaptors are identical except the Impala has the bulk head connector for the oil cooler lines. here are the measurments.
the corvette filter hangs 6 1/4" below the block. the impala filter hangs 7 1/8" below the block. so where talking under an inch (7/8") of additional filter hang.... which just about brings the filter level with the bottom of the cat, or lowest part of the ZF. While I don't think this will pose a problem, a shorter filter must be available. so worst case using a shorter filter won't harm anything.

The nice part is the impala oil lines run snug against the block and bring the lines right into the radiator. so I might get the 9C1 oil lines... and then adapt their cooler somewhere by the power steering cooler, which is nicely tucked up over the lower entension arms of the C4.

Definately a winter project, and definately some enginnering and design will be going on to do this. I believe all factory parts can be used.

The only thing holding me back is I would like to see a 9C1 factory oil cooler, and see how the lines mate up. Also I think a 9C1 must have a thermostat in there whereas the oil heats up during the winter. I am a member of the Imppy club, so I just need to track down a 9C1 somewhere.

I think this will turn out very :cool:


[Modified by larryfs, 9:42 PM 9/7/2003]


[Modified by larryfs, 2:18 AM 9/8/2003]

 

Excellent!

:)

 

I should add the oil pan in the impala is different than the LT4 C4. but all else looks like it'll bolt up. It'll have to be done on my trailer, that is the only way I'll have the ground clearance, so that means I can't do it in the garage.

If the 9C1 oil lines are flexible enough, they should be routable to a new location. I'm thinking this is even easier than the fancy aftermarket kits.. and you don't have to relocate the filter.

 

are you sure those aren't coolant lines? i think maybe your impala has a system where coolant is circulated through the oil filter base, rather than taking oil to the radiator.



[Modified by MSR, 8:12 AM 9/8/2003]

 

GM never installed a oil cooler system that circulated coolant through the oil filter base. There oil coolers route oil trhrough the radiator or an exterior oil cooler.

 

I seem to remember reading of a GM oil cooler setup that used coolant flowing to the filter to cool the oil.

Don't attempt to use a cooler in the radiator that was designed for the automatic transmission fluid. These coolers are designed to be on the return line of the transmission where there is very little pressure -- 80 psi of oil pressure could rupture that cooler in the radiator.

Tom Piper

 

I know they had that setup on Camaros from the factory as an option. I have heard but have no proof that they came on some L98's as an option.

 

I stand corrected. I work for GM and have never heard of this setup. Doesn't seem like it would be too effective to me.

 

My first thought was why do you need an oil cooler? Are your oil temps too high? I guess auto-X guys might need some help here, but you're adding another system that could spring a leak from debris on the track. Remember, you don't want your oil temp too low. There was a reason GM did away with the oil coolers in 92 and on. Just a thought. :chevy

 

I doubt a pure auto-x car has oil temp problems. Even with back to back to back 60 second runs I've never seen over 230* oil temp and that was on a HOT day.

However, at 307* during my last track session, I think my oil temps are too high. 4000-6500rpm on average with blasts to 6800rpm over the course of a 25 minute session will do that :D

For L98s, the RPO code for the engine oil cooler was KC4. My '90 L98 had this cooler. It was part of the Z51 package. It was an oil to coolant style cooler. While it may be fine for the street (someone in this post or another mentioned it lowered their oil temps by 10*), it's no where near adequate for track use.

 

I called the mobil1 800-askmobil question and answer line.

flash point is 491, and they don't see a problem in running 300 oil temps......

 

3 questions:
1) Why not simplify the job by using an oil to water cooler within the radiator, much like on the Impala? Ron Davis and others make a HD radiator with built in oil cooler (not trans cooler) fittings.

2) Considering the space available after a HD radiator is installed (which you probably want anyway for racing), can you still put an oil to air cooler between the radiator and AC evaporator, or do you need to put in front or near the power steering cooler?

3) Is there that much increased efficiency with an oil to air cooler rather than a oil to water cooler in the radiator?

Thanks. A lot of LT1/4 owners are watching your engineering efforts.

 

In response to your questions :)

1) A radiator of this type exists for the C5, but I have yet to find someone who makes one for the C4. I just double checked Ron's website and only found a radiator of this type for the C5. The C4 radiator only had a cooler for the transmission. I just sent an IM to "Jeff M". In another thread he mentions getting one of these. None the less, I'm not sure I can expect a 40*+ oil temp drop if I go this route. If someone has road course experience with this on a '92-'96 LT1 or '96 LT4, I'm certainly interested.

2) I plan to install a Fluidyne radiator. I'll install the oil cooler in front of the ps cooler for simplicity.

3) In this case, I believe the answer is yes.

:cheers:


[Modified by 96GS#007, 8:51 PM 9/8/2003]