3500S Timing issue

R

Roverfan

New Member
Hello All,

My 3500S is running pretty well these days after a couple of years tinkering here and there. I have always found the ignition timing difficult to set with a strobe because the marks seem to wander all over the place. I would say around 5 degrees.
Would I be correct in assuming this is likely to be a loose timing chain? I cannot think it would be anything in the distributor itself.

How much of a job is a replacement chain and gears? There looks to be alot of stuff to come off in order gto get to it.

Any advice would be appreciated

Thanks

Richard
 
Hello Richard,

Yes indeed the most likely cause is the timing set. The nylon covered timing wheel teeth wear away and break off while the chain becomes very loose indeed which in turn effects engine performance and fuel consumption, both negatively.

It is quite a bit of work to replace, so if you are intending on doing it you may as well do the full top end too,...rocker shafts, lifters, camshaft, the lot,...else it is just false economy, especially if you intend on keeping the car. How many miles has it covered?

Ron.
 
Thanks Ron,

Difficult to say exactly what mileage it is! On the clock it shows 90,000 but I am pretty sure it is not the original engine. The mileage looks about right for the car based on the history I have but there was a 10 year period where I have very little information. It has HIF6 Carbs and I am told these were not fitted on a 1971 car.

Is it much more work to do the top end aswell?

Richard
 
Hello Richard,

Once the timing cover is off, the essentially the hardest part is over, however.....(isn't there always) when withdrawing the camshaft,..the lifters may well not lift out so they will need to come out from below,..which means that they will likely fall through once the camshaft is on its way out. If you are lucky they will end up in the sump which will need to come off if you have not already removed it. If you are unlucky they will get stuck on the way down and you will need to fish them out.

Changing the rocker shafts is not overly difficult nor is removing the inlet manifold in order to do the above. At least once you have done it all (new head gaskets too) then you won't have to worry for another 20 years or more.

Ron.
 
Hi Vaultsman,

Thanks for that. It may be useful when I tackle the job!

I treat estimates of time and money on cars pretty much the way I treat the weather forecast!!

If I get stuck, I may be in touch.

Thanks again.

Riochard
 
Roverfan said:
I have always found the ignition timing difficult to set with a strobe because the marks seem to wander all over the place. I would say around 5 degrees.
Would I be correct in assuming this is likely to be a loose timing chain? I cannot think it would be anything in the distributor itself.
Click to expand...

Hi all,
excuse my ignorance here, I'm probably wrong, but is this not likely to be a distributer issue? One of the causes discovered for the running problem on my white V8 was a stripped screw on the vernier adjuster on the distributer. This could cause the timing to jump around? Just a thought.
Regards,
Dave
 
The V8 hasn't got a vernier adjuster - are you referring to the points adjusting screw ? I can't see that making the timing fluctuate although it may alter as the points close up
 
dmcsweeney said:
Roverfan said:
I have always found the ignition timing difficult to set with a strobe because the marks seem to wander all over the place. I would say around 5 degrees.
Would I be correct in assuming this is likely to be a loose timing chain? I cannot think it would be anything in the distributor itself.
Click to expand...

Hi all,
excuse my ignorance here, I'm probably wrong, but is this not likely to be a distributer issue? One of the causes discovered for the running problem on my white V8 was a stripped screw on the vernier adjuster on the distributer. This could cause the timing to jump around? Just a thought.
Regards,
Dave
Click to expand...

More likely to cause the dwell angle to fluctuate rather than the timing.
 
Dave3066 said:
More likely to cause the dwell angle to fluctuate rather than the timing.
Click to expand...

Altering the dwell does alter the timing, that's why the dwell must be set before doing the timing, but if the points adjuster has stripped the thread in the nylon then the points will just close up. The erratic timing could be either a fault with the mechanical advance in the distributor, or excessive wear in the timing chain.
 
harveyp6 said:
Dave3066 wrote:
More likely to cause the dwell angle to fluctuate rather than the timing.


Altering the dwell does alter the timing, that's why the dwell must be set before doing the timing, but if the points adjuster has stripped the thread in the nylon then the points will just close up. The erratic timing could be either a fault with the mechanical advance in the distributor, or excessive wear in the timing chain.
Click to expand...

Hi all,
apologies, this is actually what was happening mine. The RO discovered the problem when he noticed the dwell angle changing. He told me it was caused by a stripped adjuster, I assumed it was a vernier on the distributer. I still have a lot a lot to learn! Should have stuck with diesels!
Regards,
Dave
 
I had this once on a three litre Capri, there was so much play in the distributor shaft it affected it all :)
Much easier than doing the chain if it is the dizzy :wink:
 
Hello Richard,

Does your distributor still run points? The Lucas 35D8 distributor shaft does tend to develop rather more than a reasonable amount of free play, and if you are still using points, then this will certainly result in less than satisfactory running. If this is the case, then there a few options,....remove the points and capacitor and fit an electronic ignition system. Remove the distributor and have it refurbished. Purchase a new replacement distributor. Personally I would opt for the first option.

Ron.
 
Hi all,

It's great to find an active forum like this! Only trouble is if I don't look for a day!!

I probably should have said right at the start, the reason I didn't think it was particularly distributor related is that i checked for wear and free play and tightness etc and of course it is fitted with the Lumenition electronic ignition kit. To be honest, when I first noticed it, It puzzled me but the car seemed to run OK and at the time, there were other priorities like overheating, paintwork, brake fluid leaks, sticking carb linkages, suspension bushes, engine mounts etc etc, you know the story I am sure.

I had heard about the wear issues on the timing gears and chain and guessed that could be why. Now I have seen some pictures of worn gears, I am amazed that Rover didn't do something sooner!!!!! As a matter of interest, are the newer engines still like this??

Thanks again

Richard
 
Roverfan wrote,..
I had heard about the wear issues on the timing gears and chain and guessed that could be why. Now I have seen some pictures of worn gears, I am amazed that Rover didn't do something sooner!!!!! As a matter of interest, are the newer engines still like this??
Click to expand...

Hello Richard,

It is my understanding that the 4.0 and 4.6 litre engines had all metal timing wheels as standard but the morse type timing chain remained, so premature wear was still a problem.

In my case the original timing wheel from my 3.5 only had two teeth left when the engine was stripped, so needless to say I was very lucky to have not been left stranded had a piston and valve collided.... :shock:

Ron.
 
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