Your on the right track now, it's time to tune your timing.

First a question, do you have either a back to zero timing light or good timing marks that are easy to see and go at least to 40?

 

it goes in increments of 2 degrees.
ATDC 10,8,6,4,2,TDC,2,4,6,8,10,12,14,16,18,20,22,24,26, 28,30 BTDC
currently have it at 8 btdc
and i have a timing light

 

OK the next thing to look for is when the mechanical timing starts to advance.

Sart by unplugging the vacuum line from the distributor, and hooking up your timing light. Look at the timing marks with the engine running. While doing this make small changes in the RPM by either moving the throttle lever or turning the idle speed screw.

The goal here is to find two things, at what RPM the timing starts to advance, and make sure that RPM is higher then the idle speed. If it's an automatic, the idle speed in gear.

The timing needs to be stable at idle, before we can go any further.

 

ok im going to give this a shot tomorrow thanks man

 

A couple questions for you, I should have asked earlier.

Stock distributor? Duraspark correct?

Are you using the vacuum advance? Where is it hooked up?

What's the compression ratio of your new motor?

What's the cam?

 

dura spark dis.

vac advance is hooked up to the carb(edelbrock 1406 ,the passengers side port and the drivers side is capped).

and as for the comp ratio, i dont know just used stock pistons i am assuming the trucks got the orig. compression ratio which i dont know what that would be. doesnt have car compression pistons if thats what you are hinting at. although i wish it did!!!

and its got a stock cam unfortunately

 

Have you had a chance to look at the idle timing stabilty yet?

 

yeah it idles a 8 just fine it does skip around much at all.

 

<TABLE style="FLOAT: left; MARGIN: 5px; WIDTH: 164px; HEIGHT: 168px" cellSpacing=0 cellPadding=0 border=0><TBODY><TR><TD class=smallfont vAlign=center align=middle> </TD></TR></TBODY></TABLE><!-- END TEMPLATE: album_picturebit --><!-- BEGIN TEMPLATE: album_picturebit --><TABLE style="FLOAT: left; MARGIN: 5px; WIDTH: 164px; HEIGHT: 168px" cellSpacing=0 cellPadding=0 border=0><TBODY><TR><TD class=smallfont vAlign=center align=middle> </TD></TR></TBODY></TABLE><!-- END TEMPLATE: album_picturebit --><!-- BEGIN TEMPLATE: album_picturebit --><TABLE style="FLOAT: left; MARGIN: 5px; WIDTH: 164px; HEIGHT: 168px" cellSpacing=0 cellPadding=0 border=0><TBODY><TR><TD class=smallfont vAlign=center align=middle></TD></TR></TBODY></TABLE>well min ran until i pulled the motor. lifter and cam wiped out.

 

You mean it just sits there at 8 and stays put, even with small RPM changes?

If so good, the timing being advanced at idle is a common problem that needs to be adressed first if you got it.

Next thing to look at is the total mechanical advance. With the vacuum line off rev the engine and look at timing. It should start advancing just a few hundred RPM off idle and keep going till it reaches a max. We need to find that max and at what RPM it gets there.

I suspect that your knock is because this max is way to high and way to soon. It shouldn't go over say about 32 (with your intial at 8) at about 3000 RPM, any more or sooner and we most likely have found your problem.

One thing you may want to try if you haven't, as a little experiment is to drive it without the vacuum line plugged in and see if the noise goes away. It shouldn't but if it does it could indicate another less common problem.

Once we know about your max/total timing we can get you set up right, you may be suprised how much power you can gain with some good tunning on the timing.

When you brought the timing down to 8 you had to adjust the idle speed cause the motor slowed down right?