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MG TD TF 1500 - Vibration Gone
|Thanks to the combined wisdom of this BBS and the Archives, I have managed to solve a vibration that was driving me nuts. |
I rebuilt the engine and transmission over the Winter and when the car went back on the road this Spring it ran fairly well but I had some issues to address. Stupidly, I addressed them all at once (carbs, valves and ignition) and then had a problem. With the help of various individuals on this BBS I managed to solve them and get the car running reasonably well again but still had an issue that really bugged me. At idle I had a miss that I couldn't track down as the spark was strong on all plugs. It seemed to go away at highway speeds and we have used the car a lot lately. I couldn't rest though until the miss was "fixed" (I have a number of old rotors and they were changed out, distributor cap changed, new plug wires, new points and condensor and new plugs but it remained) I also noticed that the gear shift was rattling like crazy and it had never done that before. Reading through the archives I decided that the timing had to be off.
I had initially set the static timing at top dead center but once it was running I had changed it the same way I have done many other LBC's, I turned the distributor clock-wise to maximum rpm and then backed off about 100 rpm. So this time I tried backing it off a bit more and using a timing light I moved it to approx 10 degrees.........smoother idle. Took the car for a long run yesterday and the engine is smooth and has lots of power (?) and no more gear shift rattle. My wife commented that the car was running the best it has ever run so it was very noticable.
THANKS TO ALL WHO HAVE DISCUSSED THIS TOPIC IN THE PAST< YOU REALLY HAVE HELPED!
Would you say the car has the same powered performance it did before you re-set the timing?
Are you considering changing the octane rating of the fuel you use, now you have somehwat retarded the ignition?
|One of the things that had concerned me was that it would be down on power but it actually wasn't noticable, if at all. I am still using good old regular and it runs better and smoother than ever. |
I have owned this car for 10 years, the first five in restoration, and I have to say that for the last four I have been very disappointed in how it ran. I had it up for sale last year until my son wanted to have it in his wedding using wedding cars tonbridge and I then decided that I would keep the car and see if I could get it running properly. This year has been great!
|There is a contributor to this list, I think his name is Denis Baggi, who is a great devotee of retarding ignition to get rid of a buzzing gear lever. I also think he has made up an arrangement whereby he can alter the timing by rotating the distributor from the cockpit.|
If he is reading this, perhaps he would like to run over his ideas again.
I used to find a manual advance and retard lever on my 1928 Lagonda's steering column a great advantage. I would not mind having one on my blown TD.
I'll consider the problem but I have always thought that to, possibly, reduce the performance of an engine IF it is running well, by retarding the ignition just to cure a rattling gear lever, is taking a sledge hammer to crack a walnut. I would rather jam my leg against it. However, I note you are well satisfied with how the car is now running, which is good news. Any signs of it getting a little hotter?
I wonder if they rattled when the cars were new and, if so, how they cured the problem?
|If we don't get an answer about "adjustable advance" I know I have the paper/instructions on a backup hard drive (my power supply died for the external drive so can't get to it right now ..but have new wall-wart on order) |
This has been one of my "planned mods" for the TF. It always made sense to me as it was something I remember from my old "Pan head Harley" days (having easy adjustment) and makes even more sense after having my car sit unused for a couple of years while fuel companies changed the gas formulas.
(This was covered recently on another post to this BBS). I think Dave hit it on the head with his explanation of how this affected the running of my car after her long rest!
David 55 TF1500 #7427
|It was very hot yesterday and the car ran at 185 all day and the oil pressure remained at 50 lbs at everything but idle.|
Brian, I'm glad your car is now running smoothly - it must have previously been very advanced to run so roughly! As a matter of interest, do you know what the static timing now is? I'm sure you checked the distributor weights were free as well!
The first thing to check with a rattling gear lever is the fit of the rod in the aluminium gearbox extension. No bushes were fitted originally but any good shop can line ream and fit some. This usually cures the rattle which is of course also made worse by a rough vibrating engine! Retarding a correctly set up engine will increase fuel usage,and lead to overheating and some loss of power.
|J C Mitchell|
When you indicated that you turned the dist. cap clockwise, you were advancing the timing. After turning it back slightly, did you establish where the timing was set relative to TDC? This would be important to know for future adjustments. I think there shoud be a better way to correct a rattle, then by adjusting the timing. I can advise that the gear lever did not rattle when they were new. The rattle is the result of wear.
Denis Baggi has designed a device that will allow a driver to adjust the timing from the drivers seat and it is probably in the achives as he discussed it on this BBS several months ago.
|G. L. Raham|
|Found the post in archives ..but link no longer works:|
From: Denis L. Baggi firstname.lastname@example.org on 26 August 1998 at 08:09:45 (UK time)
At the risk of repeating myself, I have solved the problem of ignition advance and different fuels by constructing a remote advance control from the dashboard. If interested, look at
|The archives had many comments on the benefits and drawbacks of advancing and retarding the timing and also gear shift rattle.|
I started this process by setting the timing statically at TDC using a small light to ensure the correct opening of the points. Prior to the work I performed on the car, the gearshift did not rattle, it is a good fit in the extension. After many years of working on MGA's and MGB's I used the static method as a starting point and then turned the distributor to get max RPM and then back off about 100 RPM. On the TD it resulted in very poor idle and a very bad rattle from the shifter, not one that would stop with a knee against it. By turning the distributor back anti-clockwise the engine idled better and the shifter rattle is gone. I have no noticable lack of power and the car is now great to drive.
I have marked the pulley in 10 degree increments and I would guess that it is now at approx 8 degrees dynamic. I must stress that this is the experience on my engine and I tried it after doing an exhaustive search of the archives. Some of your comments above echo what you have said in the past and I value all of the opinions. I believe that, unless you have a lot of wear in the shifter mechanism you shouldn't have any rattle if everything is set up properly and if it didn't rattle before then it shouldn't rattle now.
Anyway, it is now really enjoyable to hop in and drive and it doesn't even mark where its been as much as it used to. This is a plus plus.
Once again, thanks for all of the input, that is why it is so great to belong to a group such as this.
|My shifter rattled a lot, unless the timing was retarded to the point the car was really sluggish. At restoration, John Twist rebushed my badly worn shifter housing and checked or replaced all of the springs, dampers, etc. Guess what? The rattle is less, but still there unless the timing is retarded so far it is a total slug! So there seems to be some variation car to car. Of course ingnition timing is dependent on camshaft, compression ratio, gas octane, etc. George|
|Mt TF (prior to engine re-build) always had gearshift rattle in 4th and sluggish on hills unless timing was "on". |
Honestly I haven't driven the car enough since the rebuild for a fair comparison, but that has been pretty much the same since she has lived with me.
I haven't checked with gun since my last adjustment but car was running roughly so adjusted by ear, (on the road) rattle went away and power returned on last outing.
Haven't pulled plugs yet to have a look at them.
David 55 TF1500 #7427
This thread was discussed between 18/07/2009 and 19/07/2009
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