Hello all. I've got a 1991 Chev. Camaro Z28 with a stock tuned port injected 350 motor. I currently have a dual exhaust setup from the factory. I like to someday replace them and have also read on these posts that many owners have to remove the engine oil cooler to accomodate their headers. Has anyone installed a set of smog-legal headers that didn't require oil cooler removal?

 

So, does this mean I have to remove the engine oil cooler no matter what brand headers I buy?

 

Well, first off, you honestly don't have "dual exhuast" from the factory, you just have dual tips coming out of the back. If you had dual exhuast, you'd have one pipe for each side of the engine, whereas the factory z28 exhuast has an I-pipe.

Anyways, to answer your question, I am sure any shorty-style headers, from various companies (i.e. hooker, hedman, slp, etc.) would work without removing the oil cooler since the collector doesn't hang down very low. However, if you want any type of LT header, the oil cooler has to be either gotten rid of, or modified in some way. Do a search for hedman header install and you should find out about that. Hope this helps.

 

Sorry, 305RSlc, but you are incorrect (at least, you misunderstood what he was saying).

The factory put dual cats on many models, with the exhaust pipe from each manifold each going to its own cat. After the cats, the exhaust is merged, but until that point, it is "factory dual exhaust".

I do not know if headers cause interference problems with the oil cooler, though. Only SLP, Edelbrock, and Hedman make headers for dual cats, so I'd say call each of them up and ask. If you get a definate answer from any of them, I'd say they are the ones to go with. If they hesitate at all, reconsider.

FWIW, I do not recall anyone saying they had to delete the oil cooler in order to install headers (of course, they'll come out of the woodwork now...).

 

Well owning a 91 Z now, I know exactly what you are talking about. Personally, I would not consider putting two cats in the y-pipe a "dual exhuast" setup, but I suppose that is how the factory wanted it to appear to be. My definition of dual exhuast is having a single pipe for each side of the car, not merging into a single pipe for both sides, ever.Thanks for spotting, and clearing that up, for those who may have misunderstood.

 

Conventional terms:

"Dual exhaust" - as you described, separate exhaust pipes & mufflers for each cylinder bank, or, at least, each half of the engine. Using an "H" or "X" pipe doesn't "un-dual" the system.

"Dual cats" - what the factory did, and what I described. It was worth about 10 HP over their single cat system. Whether that still applies with currently available high-flow 3" cats is the subject of debate - all too often, I'm afraid.

"Factory exhaust" - something that needs to be replaced in its entirety...

 

Amen.

 

FWIW - I had to remove the measly factory oil cooler when I installed my SLP Tri-Y headers. But it doesn't seem to have much effect on engine temp. That factory cooler is so small and such a hokey setup I don't see how it could have made much difference.... YMMV of course.

 

i have the Hooker 2055's with the factory oil cooler setup. no issues whatsoever.

 

That's what I am wondering. I am getting ready to install my hedman longtubes, and I am debating whether or not to get rid of the entire oil cooler assembly. I do live in a relatively hot climate, but I can't see how if hot engine coolant is supposed to be cooling the oil, how it would help that much. Maybe it's just a good idea to get rid of it period....weight savings...

 

Engine oil temp > engine coolant temp at operating temp.

 

I'd consider the factory oil cooler more of an oil temperature stabilizer (as I think I've heard around here before)...