ZR1 Oil Cooler

[8upZR1]

Hello everyone,
I was wondering about the oil cooler on our cars. It looks relatively large but how good is it?? Is the pressure drop large? Also does it clean/flush nicely? My ZR1 is a 1990 and I am about to fire a new motor so I dont want any issues from the original oil cooler. Are replacements available?? Does anyone have any experience with aftermarket units? I dont think there is that much trash/gunk is mine but Id like to be safe.

[A26B]

Hello everyone,
I was wondering about the oil cooler on our cars.

It looks relatively large but how good is it??

I think the ZR-1 cooler is as good as any other.


Is the pressure drop large?

Never measured it but seems very un-restricted when I "tried" to blow the oil out with air once. Design & tube size indicates negligable pressure drop to me.


Also does it clean/flush nicely?

Not particularly, because it's not a single tube. There are several large (0.5" i.d.?) tubes with a tube plate on each end, much like a radiator. Good from the standpoint if 1 tube plugs, the rest are open. Makes it difficult to flush & insure all tubes are open, but I can't imagine what would plug a tube. I don't even try to get the old oil out when changing anymore.


My ZR1 is a 1990 and I am about to fire a new motor so I dont want any issues from the original oil cooler. Are replacements available??

No direct aftermarket replacement to my knowledge, but have never looked for one.


I dont think there is that much trash/gunk is mine but Id like to be safe.

Considering the design, I would recommend removing the cooler & drain the oil by tipping the inlet/outlet to the lowest point. Then rinse with solvent by shaking the cooler with it oriented horizontal to slosh solvent from one side to the other through the tubes, repeating until clean. Then drain thoroughly, put new oil in the cooler & slosh like before, then drain again.

Obviously I don't have any aftermarket knowledge, but unless your oil cooler is damaged, I doubt the lines will be plugged, but may have some gunk similar to the engine, if any.

[tccrab]

So, tell us more about this new motor.
What did you finally put in?

TomC
"Crabs"

[Jeffvette]

What you will find is the aftermarket cooler is more compact, weighs less, and offers more mounting configurations than the factory piece. Since you are not running the LT5 anymore, I don't think you are worried about using factory components.

[Tyler Townsley]

Hello everyone,
I was wondering about the oil cooler on our cars. It looks relatively large but how good is it?? Is the pressure drop large? Also does it clean/flush nicely? My ZR1 is a 1990 and I am about to fire a new motor so I dont want any issues from the original oil cooler. Are replacements available?? Does anyone have any experience with aftermarket units? I dont think there is that much trash/gunk is mine but Id like to be safe.

Oil coolers are next to useless in a LT 5. If you look in the manual you will see that there is a thermostat in the front housing that controls oil flow through the cooler, this little gem does not open until the oil temps approach 240 deg which is a little to late for any real help in keeping the oil cool. I believe there was a lengthy discussion covering cooling issues some time ago that explained this and other shortcomings in cooling the LT 5. Do a search on my name and it should come up.

Tyler

[jonszr1]

is there a way to change the opening temp?

[Jeffvette]

Oil coolers are next to useless in a LT 5. If you look in the manual you will see that there is a thermostat in the front housing that controls oil flow through the cooler, this little gem does not open until the oil temps approach 240 deg which is a little to late for any real help in keeping the oil cool. I believe there was a lengthy discussion covering cooling issues some time ago that explained this and other shortcomings in cooling the LT 5. Do a search on my name and it should come up.

Tyler


Tyler, he no longer has a LT5.

[Tyler Townsley]

is there a way to change the opening temp?

Short of taking it out I have not found one with a lower opening point. Not to say there is not one but I have not seen one.

Tyler

[8upZR1]

Where is this thermostat located? Is it in the actual cooler? It sounds like something I would remove but I dont remember seeing anything "funny."

I'm probably just being paranoid, but I like everything to be as perfect as possible. Nothing to worry about when I sleep. For the sake of an easy life I sold the BBC and used that $$ + the $$ from the LT5 stuff to build a SBC. Not just a SBC, but a nice one. Dart lil M, 406" SCAT rot as, MAHLE pistons, AFR 227 Elim, LUNATI solid roller, CROWER SS shaft rockers & lifters, MANTON pushrods (yes pushrods, but not just any, 7/16" to 3/8" single taper .120 wall), Super VIC, QFT 950.

Im not exactly thinking of it as a step down from the LT5 in performance or durability. It should put a smile on my face. I still have some details to work out but Im hoping that by the end of the year the car will be done.

One of the big ?s Im struggling with is what to do about the thingy thats gonna be sticking out of my hood. Scoop? Open? Cowl? just no time to think about somkething like that.

[Jeffvette]

Where is this thermostat located? Is it in the actual cooler? It sounds like something I would remove but I dont remember seeing anything "funny."


It's in the oil filter housing.

[8upZR1]

Well then, I guess I have nothing to worry about. I got rid of the housing ages ago. Thankyou everyone for the info. Now I plan on just cleaning mine out before use. It seems like the easiest thing to do. Custom install of an aftermarket unit will probably take the same amount of time & hassle.

[xlr8nflorida]

Well then, I guess I have nothing to worry about. I got rid of the housing ages ago. Thankyou everyone for the info. Now I plan on just cleaning mine out before use. It seems like the easiest thing to do. Custom install of an aftermarket unit will probably take the same amount of time & hassle.

Not sure how much cooling occurs but I know the oil trickles out of the cooler.
If you idle for about 30 mins, the oil cooler dumps the old oil and fills up with new oil. As a result, the system has more oil in it, reducing temp of oil.

Lt-1s see 228-240 all the time and they don't even have an oil cooler so those temps must be safe.