Thread size in timing cover -points plate studs ?

[Douglass Harroun]

Could I get some help on thread size in timing cover for points plate mounting studs? Need to helicoil there
Thanks
Doug

 

[seattle##gs]

#2 BA

 

[Ron L]

I have had a lot of difficulty with helicoils in the timing cover. Those little 2BA's seem to easily strip out (31.4 tpi). I usually make an aluminum insert with a coarse external thread and a 2 BA internal thread. With a little JB weld on the external threads I have not had an issue with the pillar bolts pulling out.

 

[Bob Z.]

Very non-correct but possible solution if the threads are damaged already:

Use a 10-32 tap and die on the timing cover holes and pillar bolts male threads.
Use the tap on the pillar bolt female threads and use nice stainless steel 10-32 Allen screws to now secure the points cover.

10-32 is very close to 2BA thread size.
These fasteners are low torque and the the re-threading will hold without using inserts. This solution can also be used on damaged Amal carb top and float bowl threads. Also the gearbox inspection cover threads.

Again my apologies to those that would go to the effort to retain the factory correct 2BA fasteners used in damaged parts.

 

[swooshdave]

I put 10-32 on mine. If those strip out I’ll see if I can Timesert them.

 

[Ron L]

10-32 = 32 tpi
2BA =31.4 tpi

Both are really too fine for any strength in aluminum. I believe my problem was the stainless steel coil of the Re-Coil (~helicoil) did not have enough aluminum for a strong thread. The Re-coil pulled out of the casting with minimal torque on the pillar stud. Maybe due to weak metal in the cast aluminum? Something caused the original pillar stud to strip as well. In any event, turning an insert from a bar of aluminum worked fine and a larger diameter and coarse thread pattern seems to hold it in place. I probably would have chosen brass rather than aluminum, but I had the aluminum rod on hand and no suitable brass.

Timesert is a good idea if the OD is not too large for this application.

 

[B+Bogus]

At risk of committing heresy, I’ve used M3 Timeserts on Amal Concentrics with very good results in the past, and they’re also 2BA.

If I get a ban I’ll understand

 

[RoadScholar]

British Tools & Fasteners in New York state:

https://britishfasteners.com/index.php/

Carries 2BA fasteners and has taps and dies for same. I did take a look and saw that the 2BA tap/die sets are, currently, not in stock, but worth a call for an update.

In the case of the specialized, part number, fasteners that retain the points/EI plate, they also present a 2BA female thread for the cover screws, which I'm sure you know. Unless the later Triumphs went to a 10-32 threaded part, or jumped straight into metric you are better off repairing the 2BA threads that are buggered. I did find this, do scroll down:

https://www.recoilshop.net/shop-recoil/thread-repair-kits/pro-xl-series-kit-ba/ba-2ba-kit.html

My quick search turned up more than a few options.

Your last resort, of course, is to buy another timing cover. PM me if are thinking along these lines, I'm pretty sure I have one, pre-mk3.

Best