thomaswat

I reciently had my '65 engine rebuilt ( 327ci 350hp) and it has a very strong lope. Noticably more than before, and the rebuilder says it is the same as the 30-30 cams that was originally in it. It won't run smooth until aroung 1800- 2000rpm and he says thats normal for these high performance engines. I admit it sounds good when idling, but I have to stay in 3rd gear under 35mph because of the "bucking" I get. If I slightly give it gas, it smooths out, but trying to maintain a low speed at low rpm is next to impossiable. I'm even thinking about scrapping this cam and replacing it with something more low rpm friendly. Any thoughts and comments will be appreciated.

ctjackster

I can't answer the question in your title, but I have to point out that your L79 / 350 hp engine (if that's what you have) did not come with a 30-30 solid lifter cam, and should not have a "big cam" lope. PErhaps you have a 356 hp - L76 engine? Or perhaps you have an L79 that has since had a 30-30 cam and solids swapped in?

In any event, if you DO have solids in there now witht he 30-30 cam and want to address your low end issue and keep solids, you might consider the LT1 cam, as many have done. Another alternative would be to put the L79 cam and hydr. lifters in there, much better in the low rpm range.

aaronz28

the 30-30 is being referred to becasue of the factory valve lash settings...

the original part number is 3849346 and the cam has 254 degrees of duration at .050 onthe intake and exhaust lobe, with .485 lift on a 114 LSA...

it is a much larger cam than the l79 327-350 cam...

and the 30-30 has solid tappets vs hydraulic tappets with the L79 cam.

i'm not sure if anyone grinds a Hydraulic version of the 30-30 but i can't imagine that it would be any good. The hydraulics would collapse before the cam even reached peak power LOL.

you could put a dial indicator on the intake and exhaust pushrods on the number 1 cylerder and find what the max lobe lift is... it will give you a realistic idea on what cam you actually have in it.

thanks

aaron

clem zahrobsky

the orignal valve lash for the 346 "30-30" cam was .025 but with this lash setting there was not enought vacuum for the GM FI unit to operate properly so GM changed it to .030

Olustee bus

I also have a mild cam (Hydraulic comp cam) in my 63. It has a very noticeable lope. I am having trouble with the bucking and I thought it was due to the cam but now I think I have an intermittent miss and am trying to trace that down.

My acceleration is great, however, when the load is low, I get this bucking and it is a miss, not due to the cam lope. See my thread about a intermittent miss. Olescarb has given my a good suggestion thus far.

Olustee bus

Oh yeah, as I said, my cam gives a very noticeable lope at idle. I also considered changing back to a milder cam. One thing I did was change the stock mufflers with MagnaFlows. Now, I would not change a thing. It sounds to sweet!

Grey Ghost

Maybe your builder used the wrong cam...I had an L-79, totally rebuilt a few years ago. It would idle like a sewing machine at 600 rpm. Nice little lope, but not too aggressive. It was rebuilt to factory specs, but bored out .30 over.

Kinda sounds like the builder thought it should get a 30-30 ?