I will be swapping a LT1 cam into my L03 this spring, and am currently setting my self up for it (getting parts and info and such...). Now, I have heard that you can change your vavle springs with your heads on, just by filling heads with compressed air. Is this true???? Also, should I change my distributers' gear? And do I need to use assemblly lube, or could I just smear some oil on the cam and such since its a roller??? Thanks!

 

Buck,

What LT1 cam are you using? There were only about six camshafts made for that family of engines. If your lift is around or over 0.480", you should probably change springs.



The springs can be changed without removing the heads, provided you use springs that are 1.260" diameter or smaller (stock size). This can be accomplished by using compressed air. The air pressure will hold the valves in place while you remove the retainers and springs. This can also be done by inserting a length of braided nylon rope into the cylinder through the spark plug hole, then cranking the engine by hand to compress the rope against the valves.

The dowel pin at the front of the camshaft will have to be tapped deeper into the hole so that it protrudes only about 0.300". Most factory cams were drilled deeper to allow for this. If the dowel cannot be tapped back into the hole, it should be cut to provide that length.

The distributor gear does not need to be changed it you are already using a roller cam in the engine, but a new gear never hurts, either.

The lobes and journals on a roller cam should be coated only with clean engine oil, no greases or cam break-in lubes.

 

Thank you! I am not sure which year it is from, but I believe its off of an f-body...well, for $35 SHIPPED, including cam, springs, valve locks, and retainers - I figured, hey, why not?

 

One thing to check when you have one of the sets of springs pulled is the retainer to seal clearance. I know of one member on here who put a .480 lift LT4 cam on a new set of Vortec's without checking and ate up the seal's. My set of Vortec's hit at .465 so this was a no-no. There are ways to correct this without machining if it is a problem.

Good luck

 

DM91RS, could you please clarify? Also, would it be worth it fer new valve seals? The motors got about 50K on it (lot more one car though...).
EDIT: nm about the clarifing, i get it - I think - to much lift, and retainer hits seal . Can you get shorter seals, or what? I heard that there arent any real problems with dropping a stock LT1 cam in the L03...but I havent done it, so I dunno fer sure

 

I'm down with the air pressure method of keeping the valves up, but I don't get this rope thing. I'm generally pretty careful about keeping any debris out of my combustion chambers -- even those nylon ropes leave some fibers behind sometimes. Isn't this bad (stuck in your cat) or potentially disasterous (abrades piston head or valve openings) to leave behing a couple nylon fibers when pulling the rope out? Vader, can you explain why this is safe?

 

Take a match to a piece of nylon rope sometime and see what happens... I'm sure after you see, you won't be too concerned.

 

I had the LT4 stock cam with the stock 1.5 rocker arms on my LO3 heads without any problems

The max lift with the 1.5 rockers was .450

 

well, thats good news. I have heard about the dowel pin in the distributer gear (??) needing to be pushed in. Does anyone have any details of this?

 

The pin on the front of the cam is the one that needs to be tapped in or cut off. I used a brass hammer to tap mine in. You just don't want to "mushroom" the head of the pin as you press it in.

 

Alright. Thanx fer clearin it up!