Hey everyone,

I'm new to actually posting on a thread. I've been gleaning knowledge off of these for years but am now becoming a part. I recently received a 1974 Ford F100 with a 360 engine in it from my dad. I just switched out the points distributor with a new HEI one. My big question is regarding the timing. When i set my total timing to be 34-36 degrees BTDC it results in my initial timing being right around 24 BTDC. Everything I read leads me to believe the initial timing should be closer to 12-14 degrees for these engines. It definitely runs better the more I advance the initial timing yet I've restricted the initial in order to prevent exceeding the total timing of 36 degrees. It runs pretty smoothly at all RPMs, however I do wonder if it would run better if I advanced it more but don't want to exceed 36 degrees total timing. Also, this seems to be right around where the old points distributor ran too, not to say that was correct though. Anyway, curious if any of the many experts here have some thoughts/insight on this or if I should even be concerned? Also, please forgive me if this topic is actually discussed somewhere else on here. Being new I just haven't been able to dial in on that thread if it exists.

Thanks so much!

 

First off , when you say total is that with or without the vacuum advance in ? and how many rpm are you checking it at ?

If you're checking everything correctly you may have to work on your curve. 24 initial means your mechanical is only kicking it 10 degrees or so and that's unacceptable.

You initial can be whatever it needs to be, it doesn't matter. the problem is you're probably going to get detonation on that curve and I'd think it would be kicking the starter.

 

Thanks for the reply. To answer your question when I say "total timing" I mean with the vacuum advance disconnected. I'm checking it around 3000-3500 RPM, basically wherever it stops advancing is what I take the RPM up to which is right around 3000-3500. Curious what the symptoms of "kicking the starter" would be? I haven't noticed any odd feelings/sounds out of the truck. It seems to run smoothly overall but just feels like it doesn't have quite the power that it could. Also, could this be a cause of being off a tooth when I put my distributor in? And another question... from my understanding, the only way to adjust the mechanical advance is to adjust the springs in the distributor?

Thanks so much.

 

You're doing it right then. kicking the starter means the starter has to fight the engine as it tries to turn it. you can feel and hear it as it tried to get over TDC. if it starts smooth and easy this is not a problem then.

Being off a tooth with the distributor won't matter. you are adjusting it out.

Yes the mechanical is set with the weights and springs. in your case the mechanical isn't allowed to travel far enough, . you may have to look it over good and see if something is binding , if not maybe your springs are so heavy it won't allow full travel. sometimes there is a stop on it, see what's limiting it's travel and if you can alter it. your mechanical should easily have 20 degrees built into it if not more. the HEI's have some distinct advantages but in the end they're a chinese product and you can't take anything for granted.

You should check it with the vac advance in too. hopefully you'll be in at 50-55 or so . if it starts good, runs good and doesn't ping under load and you're getting in the 50's all together you initial isn't a problem. your curve is less than optimum though even if it works and you should stay on it until you fix it. .

 

Thanks so much for your help. I went and checked it all again a few hours ago and came up with the following: initial (vacuum advance disconnected) = 18 deg BTDC, total (vacuum advance disconnected) = 36 deg BTDC, total (vacuum advanced connected) = 58 deg BTDC. Not quite as big a difference as my initial numbers but still only 18 deg mechanical advance. I'll still do what you suggested and take a look to see if there are any limiting factors or what the springs are at and see what's expected with those springs from the distributor manufacturer. One weird thing while I was taking my initial timing this time though was my timing light was jumping off of my mark and then coming right back every once in awhile. Right at that exact same time it sounded like the engine had a slight change. Would that be a symptom of a misfire? If so, I'm guessing I just need to check my wires to make sure they're tight? All my plugs are pretty new. I also recently re-gapped them from .034 to .045 due to the electronic distributor now. Not sure if that would be contributing.

Again, can't thank you enough for all the great information/suggestions.

 

The first thing I'd do is drive it a bit and see how it runs. you could actually turn it back 2-4 degrees and still be in a good spot if you need to.

The most important thing is to get it out and get on it pretty good and see if you can hear any pinging under load , this is detonation and you can't have any of that. either turn it back until it stops or run a higher grade gas . if you aren't pinging and it starts good the last thing is do you notice any surging or odd feeling at a cruise speed. most likely this would be excessive advance. as long as it starts good forget about your initial.

If this all runs out good I'd just leave it for now. if you want to check your mechanical look for whatever is stopping it as you turn the rotor to full advance by hand. this may or may not be adjustable , most likely with a different block or bushing. I'd stay on that before I worried about springs and weights.

 

Sounds good! We took it out this evening and i didn't notice any pinging or surging and it feels great at cruising speed. I'll keep driving it, maybe turn it back a couple degrees and see how that feels, and just keep taking it out and seeing how it drives. I'll be sure to post back with any updates but thanks so much for all your help!

 

What shape is the harmonic damper in? Is it original and could be worn enough that the outer ring has slipped?

 

Honestly I'm not 100% sure on the harmonic balancer. I'm guessing it's the original one. I'll take a look in the next few days and get back to you on that. I do however seem to remember seeing it have a very slight wobble when it was running. I'm guessing it shouldn't have any play at all?

 

Good point! I had one on my f100 fly apart on me, and it was one of the old ones that the pulley was on the outside of the ring that flew off.. I ended up limping it home, thankfully it was cold out, as I didn't have a water pump

 

I went and fired up the truck and watched it and it was pretty dang smooth. Hardly any movement. I also am not hearing any weird noises nor seeing any excessive engine vibration. I did my best to take a close look at it and struggled to actually see the rubber portion but everything I did see looked to be in good shape with nothing standing out as looking worn or cracked or anything.

 

If it runs good and isn't pinging or knocking, don't back off on the timing. If anything, bring your 1/2" wrench with you and increase the timing very slightly till it does. Back off from that point just a degree or two. That's the optimum point.

If you mark the distributor housing with a pencil line you can see how much you twist the distributor. About the width of a pencil line is 2 degrees at the crankshaft.. Starter kickback is when the initial timing is advanced far enough to overwhelm the torque of the engine starter. This might only show up when the engine is hot, esp. with headers. Temporarily disable the ignition and crank the starter to see if the problem goes away.

When the distributor timing is satisfactory, then re-connect the vacuum advance and go for another drive. Don't mess with the initial timing anymore, just adjust the vacuum advance canister. This time again juuust short of any knock or ping, excessive advance here will reveal itself when running at part throttle or steady cruising on flat ground. In this situation it will actually diminish when accelerating. A slight vacuum advance caused rattle is acceptable now and then.

 

Thanks for the great advice! I took it out today and did some minor adjustments with everything everyone has posted in mind. I've now got the initial (vacuum advance disconneced and plugged) timing set at 20 degrees, total (vacuum advance disconnected and plugged) at 36 degrees, and total (with vacuum advance connected) at 60 degrees. The total was all in by 3000 RPM. It seems to be running really well across the board (up hills, accelerating, coasting, etc.) when I drive it. My big two questions are #1: 60 degrees total seems really high with my vacuum advance connected. I was told in the 50's was ideal. I'd adjust it down but don't really know how. I thought that putting my allen wrench in the vacuum advance port and turning it clockwise was supposed to retard the timing but it didn't make any difference in regards to the 60 degrees at 3000 RPM. I was also reading that's not really what that allen key adjustment is for. It's more for how quickly the advance kicks in (i.e. the amount of pressure on the diaphragm) vs. the total vacuum advance adjustment. Anyway, wanted to get some expert advice on this. Thanks again so much!