Hi all. I have an Austin Seven crankcase which has damage to one of the threaded stud holes that bolt up to the block ( a crack in the casting along the depth of the hole. This stops the stud being tightened as the crack opens up.) In its present state it is pretty useless but I am loathed to throw anything away that is Austin Seven because as time goes on parts become harder to find. Does anybody know of ways to make a reasonable repair to make is usable or should I send it to the scrap man.

Location: Nottinghamshire

John, The only repair that I can think of is to get the hole welded up and to drill & retap. The mating face of the block will need to be filed back to flat,but the job should last.

Location: Piddle valley, Dorchester.

Depending on which stud it is, I believe it is theoretically possible to replace the stud with a bolt fitted from inside the crankcase.

I should add I have never done this myself, but have heard of it. I guess ensuring that the head does not foul the crankshaft or big ends has to be a factor.

Rick

Location: Deepest Norfolk

Yes, I've done this on the front left stud looking from the front of the engine. So far so good. I did post about this yesterday, but thought the better of it and deleted the post in view of the crack.

Dave

Location: Galloway

One solution could be to spot face the area inside the crankcase where the stud comes through and fit an Unbrako (socket head) screw from the inside. This is a popular way of replacing suspect studs. Success will depend on how much the crack has weakened this area.
Ron Hayhurst

Location: Thornbury

I would have it TIG welded.You can A7 weld crankcases on the extremities, Welding down the sides you seem to just chase the crack for some reason.

I have also successfully drilled through a crankcase and fitted a bolt from the inside although the job was on a single cylinder air cooled engine (Isetta 300) not an A7. With a cracked stud hole like you describe I might try filling it with 'Lumiweld' then drilling and tapping a new thread. Of course you would need to be careful to get the hole back in precisely the same place.

Location: Derby

In my previous message I omitted to say that on the crankcases I have modified I have kept the existing thread and cleaned it through to the inside. The socket head screw was fully threaded so as to sit on the spot face. I can see that a bolt with a diameter the same as the stud would be fine, although maybe an extra bit of a fiddle when assembling the cylinder block.
Ron

Location: Thornbury