So looking forward to this Christmas break in order to install my Doug's headers/Sidepipes and my Competition CAM on my 1980 C3 L48 automatic.
I plan to do the side pipes first, making sure the engine is running/starting perfectly then break into the top end and do the CAM replacement.
QUESTION: With those who have done it, what would the expectations be around new timing settings? Since it is critical to get the engine running immediately instead of cranking and putzing, I want to ensure that the engine is timed as perfectly close to expectation as possible in order to ensure a quick start and then to ensure the motor timing is optimal.
TIA,
Ken

 

Set it up with the timing advanced a LOT. It will start easier, run cooler during break in etc. It's a low compression setup..so the more timing the better.

Once it's broken in and running, you can work on the whole distributor setup...but I typically use a lot of initial and limit total as needed. It helps response everywhere.

JIM

 

I learned how to set the timing "statically" on motorcycles and that works well enough on an automobile. If you mark the distributor and watch the balancer you should be able get it close enough to a starting point without too much trouble.

Are you using a "Roller" camshaft or just a "Standard" Hydraulic cam with hydraulic lifters? If you are going to replace the cam I might be inclined to do that first and install the new exhaust afterwards. The cam is the bigger challenge and might take a bit longer.

Before starting the engine I like to run the Oil Pump using an electric drill long enough that I see oil at all points and pressure on the gauge. Having everything well lubricated makes the startup easier on the parts in the engine.

After your engine is all "buttoned up" after the new cam is installed you need to break in the new camshaft. Be sure that you have enough Zinc in the oil being used and have everything wired up and the timing light connected. Using a small funnel pour some gasoline down each of the two vent tubes that stick up on the carburetor. This gets the carburetor "primed and ready for action". When I hit the key I want an immediate start and then I adjust the idle to the faster speed allowing the crank a time to "bed-in".

I used a Comp Cams 275 Dual-Energy cam in my BB 427 and it was a very nice cam albeit "small" by today's standards using roller camshafts. When installing the cam, be sure to soak it in assembly lube to get it through the first half-hour of running. I have a very powerful Filter Magnet that wraps around 2/3's of the oil filter and holds on "tight". The magnet picks up most of anything ferrous in the oil system. The cam break in should have very little metal come off unless the lobes are being ground down inside the engine. For the first few oil changes, I cut open the filters and inspect the pleats for any unusual material.

Being careful after the cam was broken in I went and drove the car for a while around the neighborhood. Then I changed the oil and filter after it had a few miles and less than an hour running time.

Since you live in the Richmond area then you are very lucky to have ZIP products and A.E.D. Carburetors. Zip has so many parts available and AED is ONE of the very best carburetor "builders". They take Holley raw castings and finish machine them in house. They can make you one of the nicest carburetors designed for your engine! I have one of their 850 HO carburetors and it made my 427 purr from the moment I installed it.

Good luck with your Christmas presents for your Corvette!

Best regards,
Chris

 

Standing on the passengers side, remove four plug wires from the distributor cap so the cap can be laid on its side.
Jog the IGN key and note when the rotor is pointing to # 1 terminal post.
Verify TDC #1 on the vibration dampener. You can crank a little beyond such as 10 -14 degrees BTDC, won't hurt a thing.

Now take a black Sharpie and put a reference mark on the Intake and the base of the dizzy. Continue marking the dizzy also.
Now you know where to stab and clamp the dizzy later on.
If it ran good at those marks, it will run good again at those marks.

 

I learned how to set up timing statically. So it will fire right up, instantly.
It does not even matter if you remember where the distrib was.

You can get it within 2* without a timing light!

• Find the compression stroke for #1, thumb pressure, whistle, etc
• Line up the tab on the balancer to say 15* for initial start-up. You could do it exactly, but more advanced is better than the opposite on initial start-up.
• Stab the distributor a couple times, til #1 terminal is where you want it. And the advance can is where you want it. You will need to play with the oil pump rod.
• Here is the "trick" Open the cap and look at the HEI "star" twist the cap very slightly, until the tips of the center star, and the outer star tips, line up exactly.
• Tighten it down . You are at exactly 15* initial.
• Do not worry about the timing being "correct" or 36* total, etc etc. until after the cam is broke in..
• Maybe do a fast timing check at first start to be sure you are somewhere around 15*.
• Set the distrib vacuum advance on manifold for intial start-up, or quickly after timing check. A cooler engine is better, and you are not going to "load" it.
• Reset timing before you drive it.

You can do this with points also, it is just slightly trickier. It happens when they 1st open.

 

As said above, take the time to set up the timing before pulling it apart. It will fire right off.

 

If you have the distrib marked for it's original location,
it is even easier to set the timing, WITHOUT a timing light, and get it within 2 *.

• Set the timing at the crank by eye to 15-20* for initial cam break-in. Tab and balancer.
• Line up the two "star" shapes in the HEI. (reluctor & stator ?) One is attached to the shaft, the other to the housing.
• Done.