When the weather got too cold to drive the SS I decided to install some new valve covers and since I was pulling the valve covers I might as well pull the intake because I had a little coolant leak at the front passenger side. Of course since I was doing all that I thought I would retard the camshaft to help bleed off some of the mid range cylinder pressure. It seems that with a 10.3:1 compression 408 and the fast ramps of the Voodoo cam (262/268, 219/227@.050) my engine did not like much timing at all (in the 60-90 kpa range) even though I was running 93 octane. I wanted to change camshafts but thought the cheaper thing to do is retard the cam and see if the situation improves. So I installed the bottom crank gear with the rectangle (for 4* retard) at the 12 o'clock position and the timing gear had the dot at 6 o'clock. The #1 cylinder was at TDC verified by the position of the piston and the #1 exhaust and intake valves were closed. After things were buttoned up I dropped in the dist. and rotated the engine slightly so that the timing mark was at 8* BTDC and the rotor was pointing at the #1 terminal. Now when I went to fire the engine it kicked over but did not fire. For some reason it sounded like the spark was happening too late. What it sounded like was the spark was happening when the exhaust valve was open as the exhaust was popping. So I stopped and reverified that the engine was at TDC and the rotor was pointing at the #1 terminal. I tried again and got the same results. I even rotated the dist. to advance it and the situation did not improve. I just ended up soaking the plugs with fuel. So now I am thinking that I potentially have the timing gear a tooth off if. Even though I swear the marks were at 6 and 12 o'clock. Unless someone sees a flaw in how I timed the engine. Any suggestions? I want to get the SS running now that the weather is turning nice.

 

So I take it your getting some detonation at that range? What are your plugs gapped at? Have you tried a colder spark plug?
Once you have an engine with really high compression and/or big cams, then fine tuning heat ranges and gaps become more critical.

 

I haven't tried a colder plug. I was using the standard plug suggested by AFR which crosses to an Autolite 3923. I did just install a set of 3922s. The issue I think I have is my dynamic compression is too high. With a static of 10.3:1 my dynamic compression ratio was 8.67:1 with the Voodoo cam installed at the recommended centerline (the cam is ground with 4* advance and the installed centerline is 108). I've read that anything over 8.3:1 or so is too high and anything over 8.6:1 is for race cars (leanred this after the engine was built). So I thought that I would retard the cam 4* which brought the dynamic comp. to 8.3:1. I thought that with the 3922 plugs would take care of the situation. Just can't get the engine to fire now. I use .035 gap as I've read the closer gap is better for higher compression. I'm about to pull the timing cover to confirm that I got things lined up.

 

Hold on there...
Dot to dot is #6 fire position.
Both dots up (12 o'clock) is #1 fire position.

That said your 180 out.
Pick the dissy up till you can spin the rotor and
spin it 180, drop it back in...GOOD TO GO..

 

Thanks Zipfast. I did not know that. That's an easy fix.

 

I agree, looks like you might have set it for TDC on the exhaust stroke or you have the dizzy 180 out.