MTFCA Forum

On my friend's English (righthand drive) Model T the advance and retard lever will not retard enough for starting. Checking the timing shows that it fires at about TDC instead of about 20 degrees after. I tried adjusting the commutator pullrod but there is not enough thread to unscrew it. We need to make a sllghtly longer one but we can't identify the thread. Does anyone know what it is?

You should be able to adjust timing by bending or straightening the rod that connects the 'commutator' with the rod on the steering tube.

Colin

the thread is 7/32-32
it is an obsolete thread for manufacturing, though taps/dies are available...what is not easily available is the diameter rod you'd need

the fact that you even have a threaded commutator rod indicates that you likely have an original and as stated above, it is a simple thing to bend the rod for the majority of your needs.

Also, 20 degree ATDC is quite a bit too much retard for starting

Thanks. Scott.
This is a righthand drive car and the pull rod is only 6 inches long. We will use 6mm diameter rod and turn the end down to 7.32 inch.
Colin

Colin

you're welcome...and you did note that it was RHD and I completely blew past that when I offered my opinion. Sounds like you have a workable plan

let me add that the correct thread is only about .003" larger than a 12-32 thread (if a 12-32 die is more readily available to you, you should be able to successfully use that). If it were a split die, then you could in fact make the correct thread with no trouble...I just don't know how easily either of these things can be had in UK. In the US, they are just a keyboard and 5 days away! Probably the same for you...

I have found that the thread matches that on wire wheel spokes of the same diameter. These have a rolled thread. I have a small collection of odd spokes from which to choose. One of my cars even has a locknut for the threaded end, made from portion of a spoke nipple. I really have no idea of the thread count. A motorcycle restorer may be able to help.
All from down under.

Don't know if this will be of any help.
My RHD T's don't have adjustable screw ends they are bent rods.
with the spark lever fully retarded the small lever on the bottom of the rod ( below the steering bracket) it vertical at 12o'clock.
The commutator (RHD) connection is at 6 o'clock. the right angle bends on each end of the commutator pull rod are 7 inches apart.
If you have the ends bent at 90 degree you should be able to put them into place at each end by bending the rod slightly mid way and twisting one end
to get it into position so it slides in and allows the movement to move the commutator to advance and retard.
Having the pull rod already I would just lengthen it by welding or sleeving it so more thread was available for adjustment.

If it fires at TDC, you could leave it alone.