Ignition timing questions

I have my initial timing set at 20 degrees btdc. The valve cover sticker
says 10 degrees btdc. I do not have a factory cam anymore and the
instructions on the cam did not say anything about ignition timing. It
does run smooth where it is at and has good vaccum at idle.

I can not get the timing closer to 10 degress without pulling the
distributor. So I took it out and tried to put the dizzy back in where
the vacuum advance would not hit anything. Not really much luck there.

Before
you ask why am I messing with my timing if it is running good....


I wondered if this would be the correct initial timing for my motor with
its current set up, or if I still needed to go by the sticker on the
valve cover. I was told that I can move the pug wires around one spot
and then watch a vaccum gauge while I move the initial timing around.
Set the timing so the vaccum reading is a half inch less then the max
vacuum reading. I want the timing set at the optimum point for my motor.

I want the timing set at the optimum point for my motor. With the different cam and today's gas, give it what it wants! You can ignore the stock timing settings and make them what it needs. Watch your total!

Why do you say to watch my total timing?

I called Summit. They made the cam. They said my initial timing should be between 10-12 degrees. Im at 26.

Could my timing chain be off a tooth?

You should verify that your timing marks indicate true TDC. Gotta determine that the balancer hasn't slipped.
Are you saying that ya cant get it to run good under 20 initial?
I said to watch your total cause when ya give it more initial (by turning the distributor), you are adding total to it too. 12 initial and 36 total should be good.

Correct. i can not get it to run good under 20.

Can I verify by using a plastic straw in the spark plug hole and watching its travel while looking at when the straw is at its highest point and seeing where the pointer is at on the balencer?

http://www.summitracing.com/search/Brand/Proform-Parts/Product-Line/Proform-Piston-Stop-Tools/?autoview=sku or you can make one.
Stick that sucker in #1 spark-plug hole.
Roll the engine till it hits the stop, make a mark at your pointer
Roll the engine in the opposite direction till it hits the stop, make a mark at your pointer.
EXACT TDC will be in the center of those 2 marks. You will not be able to roll the engine there until removing the stop.
The reason you have to stop the piston before TDC is that the crank rotates a few degrees while the piston is stationary at TDC. So you cant just run the piston up top and set it.

I have not had a chance to get back to this yet.

It is one of those times where I wish I had somebody around that knew how to build a motor to look things over.

How can I make a piston stop?

Sometimes stopping the piston to check TDC with the engine all together can be tough. What I've done is remove the rockers on number one then take a piece of 3/16 aluminum welding wire and stick it into the spark plug hole, bend it and push it all the way over till it touches the cylinder wall on the opposite side. Then bar the engine around by hand until the piston comes up and pinches the wire between it and the cylinder head. Mark the balancer. Then turn the engine the other direction until you again pinch the wire, till it stops you from turning the engine, mark the balancer. Then split the difference between your marks for an accurate TDC.

OldRedFord wrote:Why do you say to watch my total timing?

A long time friend and drag racer friend of mine once said, set intial timing a couple of degrees retarded from where motor bumps the starter,bring the timing in as fast as the motor can take it without spark knock.Have full timing in by 2000 rpm's.Just watch for total timing,spark knock is tough on the pistons.My 460 is some crispy using this method as are all my motors.