Timing Issue

[Mark B]

Hello All-

I have a fun one that challenged me all summer. I was having trouble starting the car, and after the usual list of fuel, spark, etc.. I decided to really look at the timing, as it seemed off. I pulled the valve cover, pulled plug one, and confirmed TDC and the set the distributor. Started right up and ran like a top. Drove it and got gas and when I went to restart it would not start. After a quick assessment, I thought the issue was the distributor "popping" out of place, and causing the dog to not connect and rotate the arm correctly. I rotated it and it plunked back, and secured it better with the cinch bracket and it did start, but ran poorly. Long story short, I have figured out that the timing on this car can wander, and it is not the distributor but rather appears to be the timing chain possibly hopping a tooth or two. It happens whenever a bit more stress is put on the engine, meaning I can reset everything to TDC, and then rock the car in gear and watch the distributor timing start to differ from the timing marks on the pulley, as if the timing chain was jumping or the crank pulley was spinning a bit without the crank moving as much. Is that even possible?!?
I know I am not saying this as well as others might, but I will start by taking apart the front and the timing case and see if things are stretched, worn etc.

I ran this by this group to see if someone else has experienced this tricky one and if I am on the right track. The car is a 1967 Series V running dual Stroms. The engine is old, tired but generally up for the task. I am already seeing that scope creep and such might just compel me to do a full rebuild and really get back to a good baseline on this car.

For those who were there, this is the same engine I blew and replaced a head gasket on at Ians during the Invasion a thousand years ago. Same one where we put an engine in Todd's car.

Thanks in advance for any and all comments and advice.

Mark B

 

[Gordon Holsinger]

Hello All-

I have a fun one that challenged me all summer. I was having trouble starting the car, and after the usual list of fuel, spark, etc.. I decided to really look at the timing, as it seemed off. I pulled the valve cover, pulled plug one, and confirmed TDC and the set the distributor. Started right up and ran like a top. Drove it and got gas and when I went to restart it would not start. After a quick assessment, I thought the issue was the distributor "popping" out of place, and causing the dog to not connect and rotate the arm correctly. I rotated it and it plunked back, and secured it better with the cinch bracket and it did start, but ran poorly. Long story short, I have figured out that the timing on this car can wander, and it is not the distributor but rather appears to be the timing chain possibly hopping a tooth or two. It happens whenever a bit more stress is put on the engine, meaning I can reset everything to TDC, and then rock the car in gear and watch the distributor timing start to differ from the timing marks on the pulley, as if the timing chain was jumping or the crank pulley was spinning a bit without the crank moving as much. Is that even possible?!?
I know I am not saying this as well as others might, but I will start by taking apart the front and the timing case and see if things are stretched, worn etc.

I ran this by this group to see if someone else has experienced this tricky one and if I am on the right track. The car is a 1967 Series V running dual Stroms. The engine is old, tired but generally up for the task. I am already seeing that scope creep and such might just compel me to do a full rebuild and really get back to a good baseline on this car.

For those who were there, this is the same engine I blew and replaced a head gasket on at Ians during the Invasion a thousand years ago. Same one where we put an engine in Todd's car.

Thanks in advance for any and all comments and advice.

Mark B

Mark I think you are on the rite track . I have seen cars where one or both sprockets were very worn in the Sunbeam’s the chain tensioner is a hard rubber that wears and sometimes turns into a gooey mess from the additives in modern oils. If you find the sprockets are badly worn replace them and the chain and tensioner. Check your balancer as well sometimes they Dr bond and the timing marks move

 

[beamdream]

Well I'll just throw this into the ring, if the timing chain jumps it won't just be the igntion timing thats out but the valve timing will be out as well and thats not something you're going to reset without major mechanical work, and, you can be sure if it's out you won't be able to get it running right by shifting the distributor.

As to timing marks being out I would suspect that the rubber has perished in the crank pulley, this'll cause the marks to keep shifting , in this scenario you would be better setting the timing with the aid of a vacuum gauge.

 

[pruyter]

About a year ago I overhauled the engine of my brothers engine and by dismantling I noticed that the marks on the sprockets were not exactly in line with cylinder 1 or 4 in TDC although the engine was running very well. By putting everything together I made the stupid mistake to correct the lining of the sprockets with the result that the engine did not start at all no matter what I tried. It took me a long time to figure out that perhaps the wrong lining was after all not wrong at all because of the fact that the TDC mark in the pulley was not at the place where it should have been.
So the moral of this experience is: don't change anything at the adjustment of the lining of the sprockets when the engine is running fine and secondly: One teeth out of line has severe consequenses as for example no starting on the engine.
I agree with beamdream: use a vacuum gauge in order to set the timing!

Regards,

Peter

 

[Tim R]

I think that Beamdream is probably correct and the outer part of the pulley is moving around the perished rubber on the crank pulley this is why the marks appear to be moving. I had one disintegrate once and the inner and outer separated, it caused a LOT of damage. I would check this out urgently if I were you.

Tim R

 

[Tom H]

"or the crank pulley was spinning a bit without the crank moving as much. Is that even possible?!?"

As you can see from the above replies this is absolutely possible due to the elastic material holding the outer rim of the pulley. But if this is what is causing your timing marks to shift - BUT NOT THE ACTUAL TIMING - then we are left to ponder why the car would not start. I have often experienced hard starting / slow cranking on Alpine,s after brief stops, like a refueling. I have great doubt about the timing chain slipping a tooth or two.

Tom

 

[Mark B]

Thanks much for all the advice and guidance. I need to really understand and get my head around what is possible as it relates to what I am seeing. It does seem that potentially the pin that holds the cog or slot gear on the distributor may have sheared which was suggested by a local Alpine guy. I do have another distributor I could put together and swap to see if that might be happening and I should have time this week to really figure out what is moving independently and out of the usual order. Will certainly let everyone know what I find.

Thanks again,

Mark B

 

[jumpinjan]

I have figured out that the timing on this car can wander, and it is not the distributor but rather appears to be the timing chain

If you are using a timing light to see the timing jitter, it's probably the rubber tensioner is gone, the chain is worn out, just flopping around. I have seen this before.
Jan

 

[beamdream]

Thanks much for all the advice and guidance. I need to really understand and get my head around what is possible as it relates to what I am seeing. It does seem that potentially the pin that holds the cog or slot gear on the distributor may have sheared which was suggested by a local Alpine guy. I do have another distributor I could put together and swap to see if that might be happening and I should have time this week to really figure out what is moving independently and out of the usual order. Will certainly let everyone know what I find.

Thanks again,

Mark B

If the drive pin has sheared (feasible, but well down my list of probabilities), the distributor wont be turning. Easy enough to check, take the distributor cap off and see if you can turn the rotor button beyond the normal few degrees of advance/retard freeplay, or, simply spin the motor over with the cap off and see if the rotor spins.

If you cant get your head around the timing marks, perhaps I can try and explain (forgive me if I`m too presumptuous here).

Imagine the crank pulley, with timing marks, hard fixed to the crankshaft, as the crank spins so do the pulley and timing marks. Now imagine the pulley being fixed to the crankshaft with a ring of rubber around the end of it and an outer ring (with timing marks) being fixed to the rubber so that the whole assembly revolves with the crankshaft. Now imagine the rubber perishing and the outer ring (with timing marks) flexing about on the end of the crankshaft; what you have is the crank turning with the distributor/camshaft drive train all turning around in the correct order, but, the piece of pulley carrying the timing marks on perished rubber is not necessarily turning at the same rate (this piece of pulley has the resistance of turning the fan/waterpump/generator etc.)

So long story short, while the crank turns the timing marks aren't rigidly connected to the crank and cant be relied upon for accurate assessment of the timing.

Clear as mud ??

And yes beyond this, is Jans suggestion (one of many other probabilities) that the timing chain tensioner is worn enough to cause some slack in the timing chain.

 

[Mark B]

So I did get the car running, and as might be typical, it appears that it was more death by a thousand cuts. Basically I went to square one and started with as fresh a mindset as possible. I pulled the valve cover, the distributor and made certain the first cylinder was at TDC. (static timing at about 7 degrees). I removed the fan and belt and then did my best to see if there was any play in the pulley or any way to tell if the rubber had perished, and came away with nothing. The distributor "slot" is at the 1 to 2 position if that make sense, and did not seem inclined to wiggle or jump when I put pressure on it using a slotted screw driver. In placing the distributor back into place is seated solidly and I noticed that when at TDC the rotor was almost at a position where it pointed directly at the block. If you were standing at the fender looking at the engine, the rotor was just off the 12 pm position, slightly to the right. I fiddled with the timing wheel and placed the cap and it seemed that this would barely catch the number one lead, and that the position of the cap placed the number one lead at about that spot but the vacuum advance was pinned to the block. This struck me as odd, and so I grabbed a second distributor to compare and there was a definite difference. I think the distributor is old, worn and has a lot of slop, though the pin holding the slot dog was solid. I took the whole thing apart and cleaned it up and found the wheel advance seemed to be a big issue. When I would slide the plate in the distributor along its range it would often bind and push the advance diaphragm thing out of its seating. It would sort of bind and was not allowing the vacuum advance to seat correctly and basically pinned in an extreme retarded position. Even though I could scroll the nut, it was really no doing anything for the position of the plate and I could see how I could idle all day and never cause and issue, but if I hit higher revs, and got into the advance it would stick. Over time I had compensated by moving everything to extremes such as the distributor plate and wheel to try to get the points to open at the right time. Once I cleaned it up and twisted the "cable" a bit it seemed to stop binding, and then I readjusted the plate in the distributor to make it more centered, I set the points, etc.. and the car could now be set up without the advance hitting the block. It was close but still had about a half inch. During this process, I did notice there were about 4 different style of rotor in my parts bin, and one had a significantly longer sweep, if that makes any sense. The one I was using seemed in decent shape, but I put a red one of similar shape and dimensions in, and the when I started the car it fired up fairly readily, and as it warmed up, it liked having the distributor rotated away from the block and ran best at higher RPM with about an inch or so between the block and the advance. Overall, there was way too much play in the distributor. I did try the longer sweep rotor and it ran poorly with that in, and oddly would not start with the original rotor in place! So concluded I was fighting too many variables at once and just had to dial it in methodically to get back to where thing made sense. I still have some tweaking to do and will likely get new distributor and get this back to normal operation.

Thanks all for your help and input. Sorry for the long post but I hope it can help someone in the future.

Mark B

 

[hartmandm]

Mark,

I was still using my original Lucas 25D distributor on my Series V. I noticed the timing was quite erratic. I sent my distributor to Jeff at Advanced Distributors in Shakopee, MN for rebuild. The timing has been steady since the distributor was rebuilt. A rebuild is one option.

Mike

 

[Mark B]

Great suggestion. I would prefer to stick with my original. Thanks!

Mark B

 

[Paul A]

Mark,

I was still using my original Lucas 25D distributor on my Series V. I noticed the timing was quite erratic. I sent my distributor to Jeff at Advanced Distributors in Shakopee, MN for rebuild. The timing has been steady since the distributor was rebuilt. A rebuild is one option.

Advanced Distributors does excellent work and comes highly recommended by many Brit car enthusiasts.

 

[puff4]

Advanced Distributors does excellent work and comes highly recommended by many Brit car enthusiasts.

Ditto. Jeff did mine too, and it greatly improved the performance of my newly rebuilt motor. It is now the first thing I do when I get a car - I pop the dizzy off and send it to Jeff - totally eliminates any concerns about the ignition right from the start.

 

[beamdream]

So I did get the car running, and as might be typical, it appears that it was more death by a thousand cuts. Basically I went to square one and started with as fresh a mindset as possible. I pulled the valve cover, the distributor and made certain the first cylinder was at TDC. (static timing at about 7 degrees). I removed the fan and belt and then did my best to see if there was any play in the pulley or any way to tell if the rubber had perished, and came away with nothing. The distributor "slot" is at the 1 to 2 position if that make sense, and did not seem inclined to wiggle or jump when I put pressure on it using a slotted screw driver. In placing the distributor back into place is seated solidly and I noticed that when at TDC the rotor was almost at a position where it pointed directly at the block. If you were standing at the fender looking at the engine, the rotor was just off the 12 pm position, slightly to the right. I fiddled with the timing wheel and placed the cap and it seemed that this would barely catch the number one lead, and that the position of the cap placed the number one lead at about that spot but the vacuum advance was pinned to the block. This struck me as odd, and so I grabbed a second distributor to compare and there was a definite difference. I think the distributor is old, worn and has a lot of slop, though the pin holding the slot dog was solid. I took the whole thing apart and cleaned it up and found the wheel advance seemed to be a big issue. When I would slide the plate in the distributor along its range it would often bind and push the advance diaphragm thing out of its seating. It would sort of bind and was not allowing the vacuum advance to seat correctly and basically pinned in an extreme retarded position. Even though I could scroll the nut, it was really no doing anything for the position of the plate and I could see how I could idle all day and never cause and issue, but if I hit higher revs, and got into the advance it would stick. Over time I had compensated by moving everything to extremes such as the distributor plate and wheel to try to get the points to open at the right time. Once I cleaned it up and twisted the "cable" a bit it seemed to stop binding, and then I readjusted the plate in the distributor to make it more centered, I set the points, etc.. and the car could now be set up without the advance hitting the block. It was close but still had about a half inch. During this process, I did notice there were about 4 different style of rotor in my parts bin, and one had a significantly longer sweep, if that makes any sense. The one I was using seemed in decent shape, but I put a red one of similar shape and dimensions in, and the when I started the car it fired up fairly readily, and as it warmed up, it liked having the distributor rotated away from the block and ran best at higher RPM with about an inch or so between the block and the advance. Overall, there was way too much play in the distributor. I did try the longer sweep rotor and it ran poorly with that in, and oddly would not start with the original rotor in place! So concluded I was fighting too many variables at once and just had to dial it in methodically to get back to where thing made sense. I still have some tweaking to do and will likely get new distributor and get this back to normal operation.

Thanks all for your help and input. Sorry for the long post but I hope it can help someone in the future.

Mark B

OK, without wanting to bash this to death, you're probably not going to feel by hand any slop in the pulley with perished rubber. The real issue is that you cant rely on the timing marks, hence the suggestion to do your timing with a vacuum guage.

 

[Gordon Holsinger]

OK, without wanting to bash this to death, you're probably not going to feel by hand any slop in the pulley with perished rubber. The real issue is that you cant rely on the timing marks, hence the suggestion to do at idleyour timing with a vacuum guage.

My old shop teacher told me adjust to factory specs and adjust for highest vacuum

 

[beamdream]

My old shop teacher told me adjust to factory specs and adjust for highest vacuum

Yes, but a word of caution with setting the highest vacuum; you are likely to get into the detonation zone depending on fuel used and other variables.

Best to road test and listen for pinging after this exercise, you may find there`s a need to back off the timing a degree or two.

 

[puff4]

Yes, and Alpines tend to silently detonate in #4 cylinder, because it gets the hottest, and that’s what causes the horrid pitting we often see in the heads. IMHO, I’d err on the side of retarding it a wee bit to prevent this.

 

[pruyter]

When using a vacuum gauge the procedure is: adjust the distributor to the highest vacuum and then....retard 1/2 inch!

Regards,

Peter

 

[Mark B]

I wanted to update on this as things were not as good I a thought in my last post. I thought I had fixed it when I managed to get the car running. It ran for 10 minutes and then back to the old tricks. I kept setting TDC and then the distributor, and switched rotors, caps, distributors, plugs, wires, etc.. trying to get this car to run. Occasionally it would cough and sputter, but generally not. The long story short is this. Its was literally jumping multiple teeth on the crank sprocket every few starts or under any aggressive load, at which point it would not run. I would occasionally get lucky every 20 attempts at starting it, and I think I set the engine to TDC 40 times. Started to see things like the rotor being in such a different location and then noticing the valves not being in the right position, or the engine would fire but have no compression or backfire through the manifold and carbs. Then I would reset to TDC and try again. I rotated that engine 100 miles I think. When I finally dug into the timing case it was sooooo painfully obvious. Even trying to loosen the cam gear caused the chain to slip. The chain was stretched just a bit, but the crank gear was completely shot.

Still don't get how the tensioners look and feel brand new after 50+ years. I had ordered a bunch of stuff from Rick not quite knowing what I might find when I got into it, and other than the new chain and crank sprocket, I used all the old stuff as it looked great. With the new chain and gear in place, the car literally fired up and ran like it should first crank, and has continued to do so. Even took it for a short spin when the weather cleared.

Just wanted to get this here for others so they don't stupidly torment themselves for as long as I did.

Thanks again for all the great advice and support. Heres a picture of "toothless" my old gear next to the fresh one. Quite a difference.

Mark B