351 ENGINE INITIAL TIMING???

76'SN wrote: am i going to need a puller to remove the harmonic balancer? i am picking up a cloye gear set and chain with all gaskets tomorrow.

Yes, you're going to need a puller to get the harmonic balancer off. If you don't have one or can't borrow one from a neighbor, try the rental section at your local auto parts store.

Just throwing this out as one more thing to check before you go tearing into it- Check the distributor shaft end play with a feeler gauge. Compare it specs for that dist (don't have the spec handy). If there is too much play, then the timing will vary as the shaft rides up and down on the tapered drive gear.

Good luck
-Brad

this is what i have so far. i pulled cover and saw that i had a some play in the chain. the first pic is just as it sits and the second is showing the amount of play in the chain which seems to be quiet a bit. probably a 1/2in or so.

Unfortunately I tend to agree although hard to tell from the picts. In my experience you typically have serious teeth wear before it effects timing enough to cause running issues. Here is where I would put the balancer bolt back in and then turn the engine over and look for any lag in movement between the cam and the crank. In my experience you typically have serious teeth wear before it effects timing enough to cause running issues.

i have put a timing light on it and watched. the timing advances and returns to initial with no load. it seems after i run it with a load, it runs fine long enough to plane then runs sluggish. i havent paid attention to my oil pressure because i think my guage is broke. ever since i got it, it stays around 75-80lbs under any condition (idle-WOT).

well I would say you need to look at the advance weights again and pay close attention to the springs and how freely the weights move?

are you setting the timing when the engine is at 600-700 rpm?

well I would suggest that you spin it around untill the dots on the two gears are lined up vertically. Once that is done then unbolt and slide both off at the same time, then align the dots on the new gears with the chain on them and slide it onto the crank and cam.

usually you can start the bottom gear a little then slide the chain over it while you are holding the top gear in the proper alignment then slide them on the rest of the way, too hard but make sure you get them lined up properly. There should be an instruction sheet in with the new gear and chain so review that as a reference for detailed info.

I am sorry, but I was too lazy to read all the posts. I think the original chain was fine, but since you opened it up, no harm in changing it. How many years/hours on the engine? My quess is that you need to pull the distributor and replace it. Save the gear.

if you can check all bolts on the intake and maybe put a vacuum guage on it, with this you should see a miniumum of 18 inches of vacuum, it was good that you did take the time to do the chain and your on the right track and converting over to electronic will also help. a good way besides spraying starter fluid around the intake to check for leaks is a paint stick soaked in charcoal fluid, you light the stick and then blow it out and it gives off real good white smoke and if leaking will pull the smoke in by the leak. these are simple tests and if problem continues a compression test wouldnt be a bad idea either if all other attempts to repair dont cure the problem

When you set the timing ,double check it AFTER the distributor is tightened down.The timing WILL change several degrees after the distributor is snuged down! It drives the 2 gears into a tighter mesh.

Double post

Andy,
Yes I always double check the timing after tightening down the distributor.

"Ride up" is different than "tighter mesh". Ride up is the normal backlash (clearance between the gear teeth) built into the gearing with the machining tolerances.

"Tighter mesh" would be like shimming the pinion gear depth for backlash on the spiral bevel gearing in a differential.