I believe I have a LT-1, solid lifters, not sure which though. Engine needs pushrods and rockers. No vacuum at idle, probably lots of valve overlap. It was supposed to be from a 1/4 mile car, bought it many many years ago so the info on the engine is lacking (no numbers) Don't think its a stock cam though.

I was thinking if I can't/don't replace just the pr and rr, maybe I should get a new cam , pr, lifters, rockers.

I want to put in a decent cam, without pulling the heads, how big can I go. Should I go Hydraulic or stay with Solid?

do I have to pull the existing cam to get it's durations? Will a shop tell me the cams design so I can match it's duration or go lower?
Do I need to know it's base circle? ( saw some questions on a custom cam form)

I was thinking something in the 240 range, .525 lift, 112 LSA with 1.5 RR

TIA

 

Your vacuum issue could be misadjusted valve lash.
As for a cam, that is tough question since you do not know anything about this engine. You won't need to worry about base circle diameter unless you are building a stroker engine and need the clearance between the rods and the cam. You really need to know what the head CCs are, the piston and deck height or you may find yourself right back where you are at.

Also the durations for a solid cam can not be directly compared to a hydraulic cam. For example a 242 duration at .050" for a solid cam, roughly equates to a 230 duration at .050" for a hydraulic cam. With that kind of lift in a mechanical flat tappet solid you are into the "racing only" type of cams UNLESS you are looking at a roller cam. You may also need to have one custom ground to get the LSA and ICL that you want since those are typically on a tighter LSA of 106 or 108.

A couple street cams assuming that you have a 10:1+ compression to support the durations might be something like the stock LT1 cam 242/254 .459"/.485" on a 116 LSA, the Crower 00321 242/248 .482/.504" on a 115 LSA, Engle 1025 244/244 .507/.507" on a 108 LSA. An Isky Oval track cam p/n 201524 244/248 .524.534" on a 106 LSA gets you about where you are asking about.

 

I believe it a high compression engine and I think my vacuum problem is caused by the cam itself, I was told I should get a more milder cam for the street, years ago from a Tuner at Baldwin Performance, ( the famous Camaro building tuners of yesteryear).

I think I may have found parts to hobble it together till I decide what to do. Thanks for your input!

 

What are the cam specs for in your sig?

 

IM working on my C3, I don't know what the cam specs are. All I know, its a solid lifter cam, the engine is supposed to be a LT-1 .060 over,
High lift cam from a 1/4 mile car.

 

My bad!!! I got confused when I saw only one car listed in your profile.