Hi everyone I just bought my first 3rd gen Camaro and it’s a 350tpi and I was wondering what cam I should buy. My car is more or less stock aside from headers and a 3 inch exhaust. I’m not primarily searching for power but more a nice cammed sound but of course a bit more power is always fun. And I’m also wondering if I have to put in a roller or if a regular flat tappet will do

 

Flat tappet cam in a roller cam block? Easy. Shove the cam in, leave off the factory retaining plate, use a standard flat tappet cam timing chain, drop the flat tappet lifters in the bores, get the right length pushrods and away you go. But the high overlap cam will not work nice with the TPI ECM tuning and the IROC's transmission torque converter will drag on the engine at idle and you won't get the sound you're looking for without a new high stall (loose) converter.

Put on a carburetor and a loose torque converter along with the flat tappet old school hot rod cam and enjoy it.

 

Okay so if I throw in a real lumpy cam it will just sound normal?

 

no, it'll run terribly. It comes down to the ecm doesn't play nice with cams that are "lumpy".

 

Aliceempire is correct. A lumpy cam will not work well with the ECM. It will also be hard to tune. It used to be that the old Crane 2032 roller cam was a good upgrade for stock-ish L98 roller motors. But Crane is no longer around. If your motor is roller, you did not specify year, I would stay roller. If your motor is flat tappet, I would stay flat tappet. Not worth the expense to change a flat tappet setup to roller, even though it can be done, but expensive.

Hope this helps,
Fred

 

Research the ZZ4 and LT4 hot cam. Start reading.

 

GM# 9446

 

All 87+ 350 TPI engines come with roller cams, so you're light years ahead to stay with a roller cam. However, a cam swap is not one of the first mods you should do, because of everything you have to remove to get to it, and everything you should change while you're in there. Things like the timing chain, valve stem seals, screw-in rocker studs, etc.

 

What year? Do you want to get into tuning? Would you want to change the valve springs?

The reason I ask is the 87-89 MAF cars can get away with running a decent sized cam and it run pretty good without HAVING to change the stock programming.

It’s also advised to change the valve springs with a performance cam. Although if it doesn’t have a lot of miles on the car you could go with one of the lower lift, less aggressive roller cams. Changing the springs is a bit of a pain, but isn’t all that hard to do still in the car.

As Kevin said, unless it’s a low mileage car, you’ll need to replace the timing chain. Actually it’s not a bad idea to do it regardless of miles - I would. Same with the valve seals, definitely replace them if you swap springs.

 

The main thing is don't buy a cam over 212° @.050, with no less than 112 LSA. You want something that's not going to get into it's power band when the TPI starts having trouble breathing.

As has been said already, anything that gives you a "cammed sound" is going run terribly with a TPI manifold and stock heads... it's just a set of mismatched parts.

Plus something like a ZZ4 cam (208°@.050) can probably allow you to get away without tuning. It won't be optimized, but with a MAF system it can probably adapt to a large extent.

 

A zz4 before and after tuning at 5280 elevation.

 

That's^ a 350??

 

yes a zz4 is a 350 cid

 

I know. Those numbers seem pretty low, unless they're uncorrected. IDK why someone would do uncorrected pulls though. Or pulls in 1st and 2nd gear.

 

What’s your elevation and dyno numbers for your L98 ?

 

4500' or so.

 

I would have expected close to the same hp and tq at that elevation. Just a comparison of how tuning affected this engine. I’m expecting to loose up to 50hp on a 412 build I just had put together and dynod at close to sea level.

 

412*.85=350.2...so a little more than 50, even.

But your other engine, that ZZ4, that'd gain ~3% coming to SLC from Denver, so 217*1.03=223hp. Or so.

Elevation is rough for us.