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TR2/3/3A Setting the timing on TR3

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Don,

Good idea, but two problems:

(1) I wouldn't have the slightest idea how to remove the old distributor. A mechanic friend of mine said there are several types, and each is removed in a different way. Knowing my usual luck, I'd get it half way out and wouldn't be able to remove it..... Or, just as bad, I probably wouldn't be able to get it back in. Mechanic friend (not the shop guys who would do the work for me) said that depending on the model, I might have to adjust it in come complicated way. I think I would get into real trouble if I tried it myself. (I'm definitely a "beginner" at mechanical work).

(2) I wouldn't know where to buy a used one, and I would be a poor judge of the quality of the used one. Might just be substituting one bad one for another.

With a new spring, my mechanic friend said that my current distributor should be good for another 5000-6000 miles before absolutely having to be rebuilt. He is going to install the spring (or show me how) and will check the condition of the bushings while he is at it.

So, despite your excellent idea, I think I'll keep the old one going until winter arives, and then I'll take the car to the shop and let them fuss with it.
 
LexTR3 said:
Don,


With a new spring, my mechanic friend said that my current distributor should be good for another 5000-6000 miles before absolutely having to be rebuilt. He is going to install the spring (or show me how) and will check the condition of the bushings while he is at it.
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When you do have the dizzy rebuilt, just have your friend take it off and then SEND IT TO JEFF AT ADVANCED DISTRIBUTORS... He has the experience and equipment to set it up correctly.... Particularly since fuel has changed in the last 50+ years, the engine has probably been modified etc etc.... he will set the dizzy up to match the current conditions, not what may have been correct in 1950.
 
Hi Don,

Thanks for the advice. The shop I deal with has done a lot of work for me, and a lot of good work. I have already talked to them about rebuilding the differential this winter and other projects. I feel obligated to take the distributor to them as well, and I feel certain that they have someone they contract with to do these rebuilds. The shop specializes in British sports cars, but has worked on many others as well for about 25 years, and has an excellent reputation. So I don't think I'll be sending the dizzy to Jeff, although I know that he comes highly recommended. Thanks, anyway, for the recommendation.

Fuel has changed, indeed, but we are lucky down here, at least for the time being, to have non-ethanol gas readily available.
 
TR3driver said:
Sorry, my bad. We do have 91, just not 93 and up.

But practically any car made in the past 20 years will have a knock sensor, allowing it to run on lower octane fuel without damage. They just burn less if you use premium.
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Randall,

My mistake here as well as the Premiums here are 93 and not 91 which you would think would be inline with the 95 RON of the 60's.

And you are correct on any modern car being able to retard the timing in response to detonation. I was thinking more about older muscle cars which wouldn't have that benefit.

Scott
 
HerronScott said:
I was thinking more about older muscle cars which wouldn't have that benefit.
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Which brings us back full circle; to having to set the timing based on what the engine responds to best with the available fuel.

Another alternative, which I've wanted to try for many years but haven't, is water injection. Supposedly water is very beneficial to the combustion process, especially when trying to run a high compression (or supercharged) motor on lower octane fuel. Maybe someday ...
 
And talking about bringing us back full circle. I mentioned earlier that the trouble I was having setting the timing on my car might have been due to a poor advance return spring in my distributor. (I subsequently found out that there are two springs in the distributor, not one.)

Today I received a small package from Moss containing five advbance return springs, none of which matched. I called Moss technician for instructions and learned:

(a) these springs almost never, ever break

(b) there are two springs in the distributor, one weaker than the other

(c) five springs give me some choice of performance, but no one could explain how the performance would vary

(d) problem is probably goop build-up in the distributor inhibiting the return.


Has anyone had experience with these springs? Of the five, which two are best to use (Or probably just try to match the ones presently in the car).

This is all stop-gap, because I intend to have the distributor rebuilt this winter.
 
If the problem is not the advance springs, then why not just keep the old ones?

Clean and lubricate the advance mechanism, then don't forget the drop or two of oil every 6000 miles (or year, whichever comes first).

The springs are not really "return" springs at all, but rather they determine the amount of centrifugal advance by resisting the force exerted by the weights. The heavier spring is supposed to be loose "as installed", since it only comes into play at higher rpm (giving slower advance above a certain rpm).

So it's not important that the springs pull the point cam all the way back against the stop (it will be pulled there by friction from the point rubbing block even without the springs).

Moss should be able to tell you which springs are suitable for which distributor.

Here's a little chart I made some time ago, showing some of the different factory advance curves
 

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You would be risking the destruction of your pistons by trying to select the springs yourself. Selecting the wrong spring could result in over advancing the ignition timing. "Preignition" or "Detonation" .Look that up on the net.
You should not drive the car without proper advance.
Bring the dizzy to your mechanic or cut out the middle man and send it directly to Advanced Disrtibutors.
Unless you think you or your mechanic can figure all this out.
https://www.jcna.com/library/tech/tech0015.html
 
Randall and Poolboy,

Thanks very much for the caution and information.

I am no mechanic, so I wouldn't try to do any of this myself. I am being helped by a friend here in town who had a shop for about 30 years where he worked on foreign cars. He has repaired and rebuilt these distributors many times, so I feel confident he will know what to do.

He checked out the timing and the distributor and determined that something was wrong -- possibly a problem with the springs. But he did nothing more at that time.

Tomorrow he will come by and remove the plate in the distributor and check the springs and other elements to see if he can see a problem. Then he will decide either to fix it, or if it is beyond easy repair, he will recommend sending the distributor off to be rebuilt.

I'll let you know what we find.
 
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