1967 Mustang 302 without timing marks

OK, I know the 302 didn’t come with the 67, the 289 did. But it has the 302 now and we just bought it.



The car is running but badly. The engine has no timing marks to set the timing to.



What do you do in a case like that? Can I figure out where the timing marks should be or should I go to a mechanic to have a timing mark plate installed?



It’d be nice to get this thing working properly. I would appreciate any assistance any of you can give.



Thanks,



mspart

Yes, it should have a timing plate and the timing should be around 6 degrees BTDC with the distributor vacuum lines disconnected. The timing figure is a general one because we do not know what year engine (most are 6 degrees except the Boss 302 if I remember correctly), type of distributor, any engine modifications that may exist, etc.

Hopefully it is just a matter of ignition timing and not a sign of something more serious.
If the timing is a problem you should be able to rotate the distributor back and forth to get a happy medium until a timing plate can be added and the timing set properly.

Since too much timing advance can ruin an engine I would suggest no lengthy or highway driving until this matter is resolved. Hope that helps.

The easy and probably most accurate way to find Top Dead Center is to thread a bolt into the #1 plug hole. Turn the engine BY HAND (DO NOT use the starter for this !) until the piston contacts the bolt. Mark the damper. Then turn the engine the other way around until the piston hits again. Mark the damper again.

Top dead center is precisely halfway between the two marks.

My dad often used to simply set the timing by ear as OK4450 suggests. It wasn’t that he didn’t have a timing gun or didn’t know how to use it. It was just that half a century ago, timing wasn’t that critical. Inelegant, and probably not optimal from a pollution or fuel efficiency POV, but better than having the engine run rough I should think.

Before you set the timing you need to figure out what kind of ignition system is on this motor. If it was a vintage 289 it would have points and condensor. Is that the case here? Or, has someone installed some sort of electronic ignition? Some early electronic ignition systems still used the points, but ran a lot lower current through them.

If you have points in the distributor the points need to be set either with a feeler guage or a dwell meter. The setting of the points changes the ignition timing. So, when tuning up one of these motors you set the points first, then set the timing.

If the motor was known to be good you could set the points. Then if you had an accurate tach on the motor you could move the distributor until you had the proper idle speed. That would usually have you in the “ballpark” and close to the correct timing.

Your rough running could be so many things. Poor carburator, weak compression, burnt valves, etc. If it were mine, I’d first check the points. Then I’d mark the distributor so I could return it to the current position. Timing didn’t really change that much so it could be close where it is. Then I’d move the distributor a bit one way and then the other and see how the idle speed is affected. If the motor smooths out you’ll know timing was an issue. If it stays rough you have something else going on. If it stays rough I’d set the distributor at a point where the idle is just a bit too slow. This way your timing won’t be perfect but good enough for you to continue to trouble shoot your problems.

All this is assuming the plugs, plug wires, distributor cap, and rotor are all in new condition. It wasn’t too hard to get the plug wires crossed up on these cars. So, find the firing order (should be stamped on the manifold somewhere) and make sure you’ve got the right wire going from the distributor to each plug.

Absolutely set the points before setting the timing. In the absence of a dwell meter (When was the last time you saw one of those?) they can be set fairly close with a .015" feeler gauge at their widest.

A vacuum gauge can be used to set the timing. The factory specification is not a scientific calculation. Timing is correct when it is set to run the best. With a vacuum gauge the distributor can be moved to get the highest vacuum and then load the engine to ensure that it doesn’t detonate and if it doesn’t, kill and re-start then engine repeatedly to ensure that the engine doesn’t kick back on the starter.

I had a 1965 Rambler where the timing marks were off. A skilled mechanic timed it by feel and put a mark so it could be timed with the strobe light. This mechanic told me what you just said–the factory specification was a place to begin and then fine tune from there.

There will be timing marks, a groove on the harmonic balancer and a tab on the timing chain cover close to the surface of the balancer. If yours is lacking these things, then the engine was assembled from a basket of parts someone had lying around comprised of MANY different engines of various vintages…

What vintage is the ignition system? Does it have points? Or the pointless Motorcraft electronic used 1975 - 1985…

Thanks everyone for responding. I’ll try to answer and give more detail here.

The ignition is points and condensor, very simple, no electronic gizmos. New points and condensor and the points were set with a dwell meter. New rotor. All of that looks good. Plugs and wires came with the car. The plugs are gapped but look like timing was an issue. The wires are metallic and the sheathing on one is worn through. We’ll tape that up or get new wires, I don’t think that is a huge concern right now.

We ran the car a little and I explained to my son (he’s 18 and it is his new baby) about timing and how the position of the distributor affects that. So then we rotated the distributor and got it running as smooth as possible. Actually, going further made it run a little smoother at idle but hitting the throttle made the engine bog quite a bit so we backed it off until we had a happy medium. I think we are about there.

I really like the suggestion of making my own zero point. There is a tab or arrow from the block that appears like it could point out TDC but there is no mark on the flywheel.

As far as if it is a Boss 302 or not, I have no idea. I don’t know how to tell the difference.

Well, from everything that you guys have said here, it appears that we will probably have to time it by ear and play with it a little. I don’t mind that but I’d rather use my timing gun. I’ll think about making my own marks and see where that takes us.

Thanks again and I’m open to anything else anyone has on the subject.

Thank you,

mspart

Remove #1 plug and using a bright light and a dental mirror, I THINK you can see the piston come up. With a breaker-bar and socket on the nose of the crank, rock the engine back and forth watching the piston as it comes up to TDC and movement stops. Put your finger over the spark-plug hole and verify compression as you bring the piston up. If you feel no compression, rotate the crank one full turn and check again. That will be VERY close to Top Dead Center on the compression stroke. Now carefully look at the surface of that balancer for a line across its surface…maybe it’s full of paint or grease…Now carefully look under the water pump for that stationary timing plate…

OR, on the surface of the balancer, a timing SCALE is etched. These can be very hard to find after 40 years…Paint will cover it right up. This scale will have 0 through 30 degrees. There will be a pointer on the timing cover close to the surface of the balancer. Make a chalk mark at 8 degrees BTDC then use a timing light to set the timing, vacuum line disconnected…Connect the vacuum line and slowly rev the engine to say 3000 RPM while observing the timing marks…You should see the advance kick in and pull the timing up to 30 degrees or a little more…Trust me, clean up that balancer, use sandpaper if necessary, and you WILL find that timing mark or scale…

with the engine running check the rubber hose attached to the distributor advance pot. If there is vacuum on that hose at idle it is connect to the wrong port on the carburetor. The correct port is at the front near the bottom. It is “ported” vacuum, there is virtually no vacuum at idle but as the throttle is opened a progressive vacuum is delivered.

Hey Rod Knox, do you know FOR A FACT that this engine used ported distributor vacuum?? Many Fords used manifold vacuum. This retarded the timing under heavy acceleration to prevent detonation, but provided full advance at high vacuum to give good mileage…

The 302 does have timing marks but they are very hard to see (if I am thinking of the right car), I was surprised about 5 years ago redoing a 65 hp boat engine that they no longer had dwell meters at the NAPA store I went to. Keep your eyes open for one at garage sales.
As far as timing I believe from my cougar and ranchero with a 302 you have to disconnect and plug the vacuum advance. Make sure the points are set correctly before checking the timing. The timing marks were barely discernible notches, and a metal shall I say fin to line it for for timing. Clean it up, they have to be there. I used a dab of white out for the right mark to make checking the timing easily.

The odds of this engine being a Boss is probably near zero so I wouldn’t get too wound up over that. I was just pointing out that a Boss engine (looks the same but is vastly different) uses far more advance in the timing than other small block Fords. The Boss also uses a dual point distributor. (not to say that could not have been changed over the years.)

If this engine has the dual advance mechanism (which is likely) the vacuum port on the advance that is closest to the dist. cap connects to intake vacuum; the other vacuum fitting goes to ported vacuum.

The bogging on acceleration could be incorrect vacuum lines, stuck advance mechanism, too much retard on the timing, or a faulty accelerator pump circuit in the carburetor. I’m leaning towards too much retard at this point.

If the engine is missing its timing pointer a local salvage may simply give you one of these for free or a couple of dollars at most. They’re easy to install.

You might, still, be able to get a timing plate from a performance shop, or JC Whitney (www.jcwhitney.com). You attach the timing plate to the front of the harmonic balancer, I think.

I’m not certain, Caddy. And if the distributor is from the mid 70s it surely could have that nightmare of ported/modulated manifold vacuum. If it is ???

Thank you all. This is great information. We have it running but now I think the emergency brake cable is seized. The car won’t budge. So we have lots of time to play with this thing.

Again, thank you and I’ll report back what I have found.

mspart