Distributor sealing

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jddevel
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Joined: Wed Jun 20, 2018 11:48 pm

Distributor sealing

Post by jddevel » Mon Jan 21, 2019 6:27 am

On removing the distributor from my TF1500 I notice there is no seal. Is this normal or should there be a gasket. Looking at Moss replacements it certainly appears that they have a 'O' ring on the shaft.

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Steve Simmons
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Re: Distributor sealing

Post by Steve Simmons » Mon Jan 21, 2019 9:30 am

There is no o-ring that I'm aware of, but I'm not sure about replacement distributors.
1949 TC8975 / XPAG 9609
1949 TC9849 EXU / XPAG 10507
http://www.mgnuts.com

jddevel
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Re: Distributor sealing

Post by jddevel » Mon Jan 21, 2019 9:36 am

Thanks Steve. Other enquiries suggest no "seal".

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ian theobald
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Re: Distributor sealing

Post by ian theobald » Mon Jan 21, 2019 6:38 pm

I just had my distributor rebuilt and came back with an O ring but try as I might could not get the locating bolt through ,even pressing down hard.
With the O ring removed I shone a torch at locating hole and is much like a Cotter pin hole in that distributor sits firm on machines surface and locating hole a near perfect fit.
I would think just a neat interference fit of shaft on bush
Mine was all wobbly and oil was leaking up severe.and shorting out at high revs such as over 50 mph.
Now has been bench tested to 10,000 crank shaft revs.
Not many places here in Oz repair these now.
Interestingly a place in Qld specialising in VW lever arm shocks happy to do the rear on my TC but want both to balance although one is only leaking but quoted something like 250 dollars I think which is ok
It's a shame there wasn't an exchange service as with my distributor took nearly 2 months

Tom Lange, MGT Repair
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Re: Distributor sealing

Post by Tom Lange, MGT Repair » Tue Jan 22, 2019 4:49 am

Ian - there are so many individual identifiers on a distributor that an exchange would not work. The first is the date of mfg.- many people want their original, dated distributor back. Also, there are many cars using similar distributors, so many cars have replacements from Morris cars, small vans or "fasctgory" replacements from the 60's, with differeing body coinfigurations. While they work, a replacement probably has a different advance curve, and is less appropriate than an original.

In the US we have the excellent Jeff Schlemmer at Advanced Distributors, who probably takes less than 2 months. Most importantly, he will contour your advance curve, dependent on the modifications to or demands of your engine, driving style, and needs. A thorough rebuild involves testing on a Sun distributor machine, checking for looseness of the body on the tube (only sometimes fixable), complete dismantling, renewal of the bush(es), checking for wear on the weights and body, broken clips, etc., polishing of the shaft if necessary, replacement of the springs and/or weights, thorough lubrication, replacement of the points plate and a new red rotor, another visit or two to the Sun machine and appropriate tweaking of advance curve to a max full-advance of 32 degrees. A VERY finicky process!

Of course, if originality is not a concern there are excellent alternatives - a modern, modified distributor with vacuum advance, or a 123 unit with a programmable advance curve. For innovation I always look to the racers
for the latest and best.

Tom Lange
MGT Repair

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