champer

* * * So I was working on the super bee last night and was reading the manifold vacuum while adjusting my air fuel mixture, idle and timing. And my vacuum gauge was reading 15-18 in/hg but it was vibrating so fast I never got a steady reading. I've been told it has a mild cam and I think that may be why but I'm not sure. Anyone ever had this issue? Also, my harmonic balancer is aftermarket and whoever reassembled it left the timing marks indicator off. (Little metal thingie with degrees stamped on it) Subsequently, I have no way to check my timing other than vacuum and sound. Any tips? The car has a 383 with edelbrock performer intake manifold, holley 750, headers and cam. I was thinking it should have at least 350 hp but feels so sluggish that my 4cly Honda accord could outrun it.*

Coronet 500

That type of reading can be a sticking intake valve.

440roadrunner

Set timing with vacuum off, lowest idle you can get, and adjust for max RPM / vacuum

You can MAKE a timing pointer. Buy or make yourself a piston stop

Summit:

http://www.summitracing.com/parts/pr...FUJqfgod0gwAKA

The only problem with this type is that there is no lock nut for the stud, so it can wiggle and move. You want it RIGID

Remove the ground for safety, remove the no1 plug and make sure the piston is "down a ways" You will probably have to play with the length the first time. You are NOT trying to find TDC but rather stop the piston "down in the bore" at some arbitrary amount

First, use a pencil, etc to estimate TDC and make a pointer / tab that will be "in the range" of the timing mark. Get this made, if not temporarily and bolted firmly in place

Carefully wrench the engine around until it stops against the stop device. Because you are making a timing tab, we'll do this "different"

Make a mark on your "new" tab accurately next to the factory mark on the balancer.

Now rotate the engine CCW until it once again stops. Make a second mark next to the TDC on the balancer

This will generate TWO marks on your new timing tab. True TDC is halfway in between

In your case, probably the easiest way to deal with advance marks is to do one of two things

Either measure around the balancer and buy some stick on "timing tape"

Or figure the 'degrees per inch' around your balancer and mark it out with a small, flexible tape.

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The way I mark a balancer is with a small flex tape, a scribe, and small 3 corner file, and a small square

Measure carefully around the balancer. Recheck this carefully. Figure math, how far something convenient is, say, 40 degrees or 60 degrees. Carefully mark this distance from TDC USING YOUR TAPE

So now you have TDC and "say" 60 degrees

Now take your dividers. "Play" until you find exactly 1/2 way between TDC and 60, of course 30. You can check this each way, same distance from each

Now do same thing, to get 15 degree marks

You can take this as far as you want.

TVLynn

So many things said !! START OVER verify Top Dead center for timing marks. Do a compression test !!! Plug routing/ firing order

Coronet 500

Compression test is a good idea and could give an answer before wasting time trying to tune.