How deep is a manifold bolt hole on a Super A?

Tue May 01, 2007 7:26 pm

How deep does a manifold bolt hole go on a Super A? Bolt hole is the one closest to the drivers seat. Yep, I broke one off and want to know how far in I need to drill before I get into the head. Also need to know where to get a manifold for a Super A! Thanks

Tue May 01, 2007 9:37 pm

If the engine on the A is designed like a Cub, and I do not know if this is the case, but the bolt hole should open into a water passage. I know this for fact on the Cub with the manifold bolt closest to the seat. Don't ask.

I would try a counter clockwise drill bit. Typically the heat and friction will start to back out the broken bolt way before you ever drill through it.

JPs should have an A manifold:

Good Luck,

Tue May 01, 2007 9:43 pm

I would also recommend a good used manifold over a new reproduction. The repos just don't fit quite right.

Wed May 02, 2007 11:18 pm

Thanks for the left handed drill idea, I had forgot that one. It didnt work but thanks. Now I have a broken starter tap in there. Broke off about 3/8 of an inch deep and i guess there is 3/8 of an inch left in there. Any ideas on that one? Other than that the work is going fairly well, and better than expected.

Thu May 03, 2007 7:51 am

Sorry to hear about your progress. Unfortunately you are in a real pickle now. The tap is hardened steel, and nearly impossible to drill, especially that deep into the hole. I would recommend a LH thread drill bit again, to try to get the tap out, but understand that it will be a sacrificial drill bit, as the hardened steel will really wear it down fast.

It sounds like the bolt is in the head too deep to try to weld something to it. I'm assuming that you don't want to pull the head and take it to a shop. Under this assumption, I may suggest one last thing. If you have 3/8" or more of threads left in the head, I would find a grade 8 bolt with the right threads, with a lock washer and nut. Put the nut on the bolt and run it up to the bolt head. Then put the lock washer on (yes it will fall off at this point). Put some lock tite on the tip of the bolt and thread in the bolt so that the lock washer is going against the manifold, and thread the bolt in until it stops/bottoms out against the stuck bolt (don't try to force it tight as you don't want to strip out the threads in the head). Then tighten the nut and lock washer against the manifold. At this point you could cut off the head of the bolt, or just leave it on there . The nut and lock washer should hold the manifold on like the original setup.

I know that this is not a "perfect" fix, but if all of your other manifold bolts are ok, and you're not planning to take the head off, then this is not a bad solution.

Good luck,

Sat May 05, 2007 4:06 pm

You" will not" drill that extracter out , there to hard . In a shop we have them burned out [EDM] . All you can do is try and pick it out a little at a time . Put a punch on whats left of the extracter and hit it with a hammer , there so hard they will shatter . Ware eye protection and use a air nozzle and keep blowing it out .

It will come out but it will take time , and you will end up replacing that thread with a keen-sert , heli-coil or next size bigger bolt.

I would also get the motor hot on the tractor , the added heat can't hurt .