Ignition Timing

[Charles Talbert]

WOW!! Nice looking rig. That settles it for me, a truck this nice just deserves to be RIGHT. I couldn't rest til I slipped that oil pump out and reinstalled in time with the cam; that would also be faster and easier than fabbing a new base plate for your distributor.

[Charles Talbert]

Sometimes things get a little sideways

Sorry, I guess I misunderstood.

Nah, I really can't say you misunderstood. I think it's more like my attempt at explaining may have gotten a little sideways. I'm not the greatest at getting exactly what my mind is thinking on paper. Takes more than a single attempt to get everything to line up sometimes.

[MontanaWDX]

Oil pump

WOW!! Nice looking rig. That settles it for me, a truck this nice just deserves to be RIGHT. I couldn't rest til I slipped that oil pump out and reinstalled in time with the cam; that would also be faster and easier than fabbing a new base plate for your distributor.

So, I take it the pump can be removed while the engine is still installed in the truck?

If I go that route, are there marks or reference points or is it just cut and try?

Do you agree that the ignition timing might still be too far advanced, if the pulley marks are still way off?

Any comments on the plugs?

Thanks.

MTWDX

[Charles Talbert]

So, I take it the pump can be removed while the engine is still installed in the truck?

If I go that route, are there marks or reference points or is it just cut and try?

Do you agree that the ignition timing might still be too far advanced, if the pulley marks are still way off?

Any comments on the plugs?

Thanks.

MTWDX

No problem to pull the pump, it comes straight out with room to spare.

No reference marks expressly for that purpose, however I can take some pictures of a new pump we have to go in an engine we are currently building that will show the installtion procedure we use here. I can do that tomorrow.

Once again, I can't actually see what you have; based solely on the info you have provided, I would say it is still advanced too high. Per your information, retarding it to the point you were able to achieve before reaching the end of the rope, sounds like the change made a significant difference in the engines performance level, so yes I would bring it on into line at 4* BEFORE TDC. Elevations, gasoline types available, etc in your specific area could demand a little different setting to be the best it can be for you there, but that's something you'll have to work out under conditions in which the truck will be operating. I would most definitely use 4* BEFORE as my base line setting and work from there if you feel a better adjustment is possible.

In my opinion, the plugs aren't telling a perfectly true story until you achieve the proper set up. Once you get timed correctly, and are happy with performance; then you can further investigate plug conditions and work on any fine tuning you feel may be necessary at that point.

[MontanaWDX]

Labor Day !

Thanks Charles for the info on removing, then re installing the oil pump so I can re clock the distributor.

I got out the 9/16th wrench to begin, then hesitated..."why couldn't I simply replicate the oil pump re set by unbolting the distributor base plate completely, so I could move it all the way to get the timing marks where they need to go at 4 deg BTDC?"

Remember, I had run out of adjustability and set the distributor as far as I could get it, bringing the timing to within 24 deg advance. I have a nice timing light which shows rpm and advance.

As I said before, the truck ran great on the road at this setting but I knew that after determining TDC and the accuracy of the pointer and pulley marks, there was still something wrong. Why does the PW run so well at 24 degrees worth of advance?

So, I took this experimental route and traded the 9/16th wrench for the 7/16th, removed the plate bolt and freed up the distributor.

Since the base plate bolt was now out, I had to secure the distributor in place with a small spring clamp. I started the engine and let her warm up then shot the pulley with the strobe.

At the previous distributor body setting, at max base plate slot travel, I still had 24 deg of advance as proved by the advance button on the timing light.

But now, since there was no base plate retaining bolt, I could remove the temporary clamp and continue moving the distributor by hand, clock wise. As I did so, I set the timing light and watched the prime TDC mark move closer and closer toward the pointer.

At the suggested 4 deg BTDC, I reset the spring clamp. Now the engine was running very badly and I had to readjust the idle mixture and speed but finally the engine coughed and quit!

Now my confidence is shot so I am going to re visit my prior work to check the exact TDC on #1 at the compression stroke, where the pointer lines up with the pulley and where the distributor rotor is at this event. The first go around proved that the pointer is positioned correctly.

At least I didn't go to the trouble of re clocking the oil pump only to find that the truck wouldn't run at this setting.

[Charles Talbert]

Obviously something is out of kilter that you have yet to discover exactly what.

Anyway, I took pictures of a new pump today to show how we install ours. Once you figure out what is going on, let me know if you still need them, if you aren't going to pull your pump, no sense in posting pictures.

[Gordon Maney]

Obviously something is out of kilter that you have yet to discover exactly what.

Anyway, I took pictures of a new pump today to show how we install ours. Once you figure out what is going on, let me know if you still need them, if you aren't going to pull your pump, no sense in posting pictures.

Even if he has solved his problem, others can learn from your photos, so please post them!

[Charles Talbert]

Even if he has solved his problem, others can learn from your photos, so please post them!

OK, I'll get it done as soon as time permits.

[Gordon Maney]

OK, I'll get it done as soon as time permits.

Great!

[MontanaWDX]

All done!

Pulled the horn for more space, spark plugs, small 1/8th plug over #6, set the dial indicator back up to TDC, got the pulley into line with the pointer, then made sure #1 was on compression.

Everything checked out like before.

This time around I decided to measure exactly where the piston was at the 24 degrees advance my truck seems to run well, versus where the piston should be, 4 degrees BTDC, at correct ignition timing.

I'm sure there is a mathematical formula that I could apply but I don't know it. Anyway, I found that there is about .25" difference in piston travel between where my distributor fires and where it should fire a fraction later (out of a total of 4.6" of stroke).

So, I'm done. The truck is running great and I'm gong to live with the 24 degrees worth of advance, or 20 degrees over where it should be.

Maybe it's our altitude (3450'msl) or fuel, or...? If I ever find the problem, I'll post the reply to this thread.

Thanks to all for the help and encouragement. (I'm with Gordon, I'd still like to see Charles' oil pump photos)

[Gordon Maney]

What were your intended units of measure on those numerical values? Something occurred with regard to formatting....

[Charles Talbert]

Pulled the horn for more space, spark plugs, small 1/8th plug over #6, set the dial indicator back up to TDC, got the pulley into line with the pointer, then made sure #1 was on compression.

Everything checked out like before.

This time around I decided to measure exactly where the piston was at the 24 degrees advance my truck seems to run well, versus where the piston should be, 4 degrees BTDC, at correct ignition timing.

I'm sure there is a mathematical formula that I could apply but I don't know it. Anyway, I found that there is about .25" difference in piston travel between where my distributor fires and where it should fire a fraction later (out of a total of 4.6" of stroke).

So, I'm done. The truck is running great and I'm gong to live with the 24 degrees worth of advance, or 20 degrees over where it should be.

Maybe it's our altitude (3450'msl) or fuel, or...? If I ever find the problem, I'll post the reply to this thread.

Thanks to all for the help and encouragement. (I'm with Gordon, I'd still like to see Charles' oil pump photos)

Altitude and fuel can make a definite difference in things. You'll have to reach the bottom of that theory at your location.

[MontanaWDX]

I did not notice....

I did not notice the weird formatting of the numerical values I posted. When I put the post up it looked OK.

Here it is again, but I changed to the word "inches" to avoid formatting issues:


This time around I decided to measure exactly where the piston was, at the 24 degrees advance where my truck seems to run well, versus where the piston should be, 4 degrees BTDC, at correct ignition timing.

I'm sure there is a mathematical formula that I could apply but I don't know it. Anyway, I found that there is about .25 inches difference in piston travel between where my distributor fires and where it should fire a fraction later (out of a total of 4.6 inches of stroke).

So, I'm done. The truck is running great and I'm gong to live with the 24 degrees worth of advance, or 20 degrees over where it should be.

[Steve Pellock]

Charles I would be interested in your oil pump pictures. Mine has had a timing issue since day one and it needs a little choke to get her to idle. Tom Petroff said to move the oil pump but I have never had the time to do it.

[Gordon Maney]

Charles I would be interested in your oil pump pictures. Mine has had a timing issue since day one and it needs a little choke to get her to idle. Tom Petroff said to move the oil pump but I have never had the time to do it.

I suspect Charles is goofing off. He is likely sitting in a lawn chair out behind his shop, drinking Pepsi and eating potato chips; playing the radio....