56chevtruck

I am maybe a little better than a shady treer, but this is not a living. I have built several little hot rod motors for my 56 chev truck. I just dropped a 350 4-bolt in it and it started right up so I know the distributor is where it needs to be. However, when I go to fine tune the timing, it is backwards. By saying backwards, when I turn the dist counter clockwise, it advances the timing, speeds up the idle and dies. When I move it clockwise, it slows idle down and I can get it to about 24 to 26 degrees and starts pinging awful. It seems to run the strongest at about 30-32.
Any suggestions why it will not retard timing counterclockwise.
I have standard timing sprockets.

Hope I am doing this right, never been on a forum.

Thanks

maxwedge

Welcome to AF, can I assume you have the dist vacuum hose disconnected? Proper balancer /timing cover match up?

56chevtruck

yes, I have pugged off the vacuum line. After messing with it a little more, I found that I can rotate the distributor clockwise, way advanced and the pinging goes away but loses power. It so advanced in fact that the timing marks on the balancer are under the water pump. It's crazy. I am going to try a snap-on digital timing light tonight, maybe that old chrome craftsman is seen its day. Also going to check the advanced levers on the dist to make sure thay are not hanging up. If you have any other suggestions, I am open.
Thanks for the response.

Blue Bowtie

If you installed a later design balancer, the timing groove on the outer damper ring may not be where you expect it. I think that's what MaxWedge was trying to communicate. Aftermarket timing covers and their bolt-on tabs are also notoriously innaccurate.

56chevtruck

I installed speed pro pistons, around 11:1 compression and my heads are 64 CC. Does this require different timing settings? I have replaced the timing gears and double checked correct timing mark alignment. It was good but the motor is running the same. Making alot of racket when taking off, quitens after around 2,500. But, going about 40 mph and getting into it, it is nearly powerless. Again, the timing line advances when I move the distributor counter clock wise and thats crazy. I installed a spare distributor in and the same result.

Help

777stickman

Actually it's not crazy at all. If you pull the cap and crank the motor you'll see that the rotor is spinning clockwise. So, when you turn the dist CCW you are advancing the timing. Initial timing should be around 8 degs BTDC at idle with the vacumm hose off and pluged. SBC motors like 30-34 degs total advance. That would be around 2500 rpm with the vacumm hose hooked up and the mechanical advance weights in full advance due to the high rpm.

Another issue is the vacumm. If you're running a Chevy HEI dist, or any aftermarket one with vacumm advance, the hose need to be plugged onto a "ported" vacumm port on the carb. This port has no vacumm present at idle. When the trottle is opened a small amount is when the vacumm is then sent to the dist advance. This gives great throttle response off idle and good driveability...........Steve

__________________
"R57 3CAR" 210 2dr post. 420HP 355 F/I 4sp 3:42 posi. (Dale Earnhardt tribute done by me.)
75 GMC Vandura 3/4 Ton
78 Chevy K5 Blazer
98 Chevy K2500 Suburban LT/7.4
05 Dodge Ram 3500/Cummins (Wifes horse hauler)

56chevtruck

Thanks for the advice. I went ahead and tore it down and found that the #4 intake lobe was wiped and the #7 intake was starting to grind down. Wow, I marked them and they were a matched set so I kinda eliminated that as a possibility. I only had about 400-500 miles on that cam and lifters. I placed them in a different block, maybe that was the problem. To your knowledge, what would cause this? oil pressure was 65-70 and the lifters SEEMED to spin freely during installation.

bobss396

So the lifters were put back on the same cam lobes they started with? That's always a good thing. But you wiped out a cam in real short order, what shape were the bottom of the lifters in? That will be a big help for us to help you.

Other things could be lack of cam lube when it was put back together, maybe a lifter too tight so the lifters were bottomed out which would cause fast cam wear.

Bob