Hey guys,

If you've seen my other post, you know i just put a freshly rebuilt '79 Camaro Z28 engine into my '83 Camaro Z28 (originally HO motor) which i beleive is an L48. (but has the former 305 HO's air cleaner (dual snorkel), carb, intake (alum.) and exhaust manifolds/pipes)

Does anyone know any of the L48's orginal performance numbers (ie, horsepower, torque, compression ratio, etc) because i would really like to know.

And if anyone could take a shot at what it may have with the 305 parts mentioned above, that would be greatly appreciated.

Thanks,

-Adam

 

You don't need numbers. "L48 performance" is an oxymoron, that's all you really need to know.

Torque is the only thing that was half-way respectable with that engine. But, it came at such a low RPM that HP was kept down in the 150-range. The heads were large chamber (76cc), the pistons dished, so compression was in the 8:1 range.

Those were sad days to be a Bow Tie fan. If you retained stock-type pistons, and used the original heads, compression will still be low. The cam was of the peanut-variety, so keeping it or a factory-like piece is a big performance no-no.

The good news is that the L69 parts are healthy enough for a nice 350. Get a real performance cam in it with decent heads (like ported L98's at least), and it has some performance potential. Only part of the L69 system that would hold you back at all is the exhaust, and even it isn't as bad as it could have been. Headers will still help, though.

 

IIRC the rating was something like 170 HP and about 240 ft-lbs of torque.

I traded in a 79 4-speed Z28 at the dealer for the 83 L69 car I drive now... the 83 was so much faster than the 79 it wasn't funny, it was embarrassing actually. And the 79 had a Comp HE268 cam, a Holley 650 replacement carb (9895? I'm not sure about the list #, I've slept since then after all), and 4.10s out back which I got in a junk rear after the stock 3.73 rear took a dump one day. In fact, I think I even let a set of 186 double-hump head castings go along with it when I did that, I was in such a hurry to get rid of it, That L48 motor was the same as all the other mid-late 70s 350s: a joke. There's just something desperataly wrong with a "Z28" that has a 170 HP 350. The OE cam was the 929, same as all the other 70s 350s; the heads had been 882s, which I put in the trash; it had dished pistons of course. I had a 78 Z28 at the same time as all this, same identical motor except it was an auto, it was just dog-slow. I used it as my work truck at the time so I didn't have to put miles on the 83.

 

Well.. i got the '79 350 into my car and everything (including computer) hooked up, and it seems quite a bit faster than the 305 HO did.. sounds better too IMO.