When i set it to 10 BTDC is will tap when i rev the engine but not at idle. when i set it to 0 TDC to reduce tapping for driving it will tap when i cruse at 45, plus it has horrible power and acceleration. not to mention i get gas twice a week.

A couple months ago i put in lifters because they were sounding like a sewing machine at idle. they were all frozen solid. so i know those aren't the sound.

Using a mechanics stethoscope, The tapping sound comes from the middle of the block behind piston 2 mostly but as you increase rpms it spreads to other cylinders.

 

The initial timing should be 10 BTDC.
Looks like something is not right with the mechanical advance.

 

Well i verified that the damper is not off, it is correct. It will still need to be replaced.

If i change the timing it changes the noise substantially. So a re-curve kit will most likely be my next step. Heavier the spring the less mechanical advance correct?

 

A heavier spring delays the advance so that full advance occurs at a higher rpm.
It doesn't change the amount of mechanical advance.

 

Any recommendation for a kit with a variety of springs?

Mr gasket 925D is what most people segust but how many springs does it come with?

 

2 springs. A light and medium iirc. It isn't just the springs, you'll have to get inside the distributor and see exactly what you have, distributor tuning is a total package deal. If you disconnect and plug the vacuum advance can run it up and kind of sniff out what it has in terms of total. Usually people replace the heavy spring with a medium or light, and maybe bend the spring arms in a little looser so timing comes in faster. But limiting or reducing the total degrees of advance the distributor can provide is maybe the main thing. Depending on the application, a distributor might provide 20°, 26°, 30° or 36° of timing at the crankshaft. 20° is maybe what you want for a more performance oriented tune.

Keep in mind if you use your truck as a truck hauling gravel, towing etc, there's a limit to what you can get away with. The link provided above shows what's inside a typical Ford distributor. It's a pain because it has to be disassembled to get at it. Read as much as you can, so as to minimize how many iterations you gotta go through to get it right. It's pretty simple, but there is a learning curve. Here's another good primer:

Distributor Tuning

 

From what I have read online puting the stoppers in different slots changes the total timing and the springs change the rate you get that timing. So.... With that said I have to figure out what this engine likes for total timing, I know it needs 10 at idle and I need to replace a spring with a heavier one to delay my timing advance. I'm going to do some research to see if anyone else has specifics on what they did to their distributer with the same set up as me

 

Ok so here in my old dist. I have a 13 and 18 slot, I assume this discribes the distance that the mechanism can travel before it hits the stopper. Now changing the slot piece will change my total advance, the springs determine how fast it gets there.

So... I notice the side with the 18R slot has no stopper and the 13R does. I also noticed that the 18 side has alot of slack in the spring which is the thicker one. Now I assume that the light weight spring controls the advance until the slack is taken out of the larger spring which then kicks in to make sure that there isn't too much advance in the high end.
So I am going to try to replace the small spring in the dist with the larger one out of the old distributer just as a test. This should severely retard the low end mechanical advance. And maybe give me an idea of what I need to replace it with. Or maybe with luck fix my problem temporarily.

 

Man, you work fast! Don't lose that spring clip that's inside the shaft across the garage. I haven't yet, but I saw the usual suspects want $12 for a replacement. I'm sure they'd want to mail it out in a big *** box, too. You'd have to remove that to change to the 18 slot. I really doubt you'd want to do that, but.

Right, the light spring is taken up first, then the stiff spring adds to it. The heavy spring is looser too, by design. The two together make up the curve. That distributor has 26° of timing internal to the distributor the way it's setup now. "13R" slot distributor degrees is doubled at the crankshaft, since it turns half speed of the crank. This 26° limits how much initial can be dialed in, to about 10°, since somewhere around 36° Total is basically all she wrote for many engines. Can experiment a bit, brazing up the slot to shorten it or, installing a bushing around the peg or stop to limit it. A short piece of vacuum tubing works. Some people like to dial in lots of initial - close to 20°, whatever it will take without starter kickback, and limit the distributor internal quite a bit, still end up with that same 36°. Don't forget you can bend the spring arms too, making the springs tighter or looser, to adjust when the timing comes in. The shop manual doesn't mention installing lighter or heavier springs, but it does discuss bending the arms to make sure the timing is at spec at any given engine RPM.

What you'll probably find is you don't need a heavier spring, if anything you might want a lighter spring, or loosen them up. It's important to verify true TDC before anything else, if the damper or balancer is off, the keyway slots, the numbers will be off. Even a new balancer, accuracy should be checked. I bet your 10° indicated is actually more than that, since balancer outer ring has slipped.

It could even simply be a matter of too much vacuum advance, after removing EGR. Be sure to disconnect and plug vacuum advance while setting up your distributor. Setup the springs and weights and initial timing first. This may take a few test drives. Then when satisfied it's running good, smoking tires, etc, then re-connect vacuum advance and tune the canister only.

 

I thought I had lost the clip at first but turns out it was stuck to my magnetized screwdriver. 😂
Of course it is my old distributer so I didn't mind as much.

Anyways after some research I have learned that it very much depends on your vehicle weight, compression ratio, performance needs, and type of fuel to run. many other variables go into it.

I just wonder if I need less total or a slower mechanical.

I of course will do all of my adjusting without the vacuum advance hooked up. Have it plugged off to the side.

So... Back to what that engine needs.
Further back in the thread someone had mentioned that the timing curve of the 300 was very aggressive due to the egr system needing it. That being said... Can I reduce the speed that the mechanical comes in my replacing the small spring with a larger one. Won't that make for a smoother timing curve over the rpm range?

 

Yes, it will do that. But you may find it very sluggish and feel "heavy", and you'll wonder if maybe the parking brake was left on. Are you certain TDC is located accurately right now? I thought you had a defective balancer iirc.

The basic objective with any engine, street or strip, is pretty much as much timing and as fast as it will stand, at all times under all conditions, just short of engine knock or ping. That's what all the springs and weights and vacuum diaphragms is fer. Emissions considerations changed that, and not for the better. Improved catalysts (I guess) meant engines in later years no longer had to be detuned.

I would say give the engine whatever it wants, not what you think it should want. Experiment, find out where it starts to ping or knock and then back off just short of that point. Maybe your engine will only accept 32° total, but then don't limit it to 28°. Maybe your engine likes 38° total, so then don't set it to 32°. Maybe you can bring in all the timing by 2800 RPM, if you can, that's what you want. If 2400, that's even better. EGR wasn't the only modification, they may have changed the combustion chamber design too, in the heads and pistons, making it more prone to engine knock without EGR, I don't know. This may factor. Then they may have also retarded the camshaft or valve timing. This is not desirable in a street driven engine, especially a truck.

 

Yes I need to replace the balancer because it wobbles,but I verified that it is correct. Probley still a good idea to replace it anyways to save my engine some damage. Right now it makes a low frequency tone that gives you headaches.

Well I guess I'll pick up a kit and start experimenting

i read this and it has a great explanation behind how a lighter initial spring will kick in the second heavier spring faster. is the mr gasket 925d kit lighter springs than the original light spring?
http://www.gofastforless.com/ignition/advance.htm

 

Yesterday i ordered my re-curve kit from summit, until that gets here i decided to see what i could do to temporarily get it close to the correct timing.

This morning bright and early at 4:30 i moved my distributor a notch over so that the vac adv wasn't against the block and set it to 10 deg BTDC. Started it up and drove it with vac adv plugged. the truck wouldn't tap off of take of but would in the mid rpm range so 15-1800 i simply took some slack out of the large spring and went for another test drive. This fixed my tapping immediately. Now... i am going to replace the small spring with a lighter one, and fine adjust the large spring until i get my timing in as fast as possible without tapping. It is a little sluggish right now but at least there is no detonation going on. Starts easy and doesn't turn slow. idles smooth and temp was good this morning. We will see what it does on a 95 plus degree day like it will be this afternoon.

FYI- my aftermarket "stock" distributor has a Phillips head bolt in place of the little retainer clip for the reluctor. I of course didn't have to take it out because i could just bend the tab through the hole in the breaker plate.

Kit should be here tomorrow afternoon and might get put in by Saturday night.

 

A good place to start, maybe, is look in the manual, in the ignition specifications. It will list the amount of mechanical advance (in distributor degrees, not crank degrees) at different RPM, idle, 500, 100, etc. Same thing with the vacuum advance. If you add it all up, initial, mechanical, and vacuum, you'll see about what it should be at cruising down the highway at say 60 mph on flat ground - maybe 45° BTDC, maybe more. It's useful to know what the RPM is in high gear at 60, as well as the manifold vacuum. The numbers in the manual are normally used when setting up using a distributor machine, but you can do the same thing pretty much using your engine. The only thing is figuring out what you might have to pull out or modify due to EGR. BE CAREFUL around the radiator fan, it isn't one of my favorite things to do, revving an engine up close to a spinning fan. Old metal fatigues, and have been known to lose a blade. Use caution.

 

Ok so I got the springs, I installed the spring in place of the small spring and put it all back together. She started with a turn of the key. I made sure it was at 10 btdc still to ensure that the small spring was tight enough to return it to it's base timing position. I drove it (vac adv disconnected for this whole procedure) drove great no tapping, seems a little sluggish in the mid throttle rpms so 1300 to 2000 are kinda slow advancing. Now here's where I ha e an issue

It will start idle and run fine, engine temp is fine.

I drive it and engine temp is fine. But as soon as I come to a stop it increases temp rapidly, not over heating but just getting warm really fast.

This would be a base timing issue correct?

Other than that it runs 1000 times better and I havnt burned too much gas in the test runs so I'm going to check mileage this week.

Thank you much for the advise