Ricardo head broken stud repair/removal.

I Just arrived back home from my trip but it is after one in the morning so I will crawl into bed soon.

The question is;

Has anyone else had broken studs on top of the head on a "D" ?

It's a silly question because I know some of you must have had.

I have a few ideas as to how to deal with this problem, and I will try to salvage the threads as I go about it.

I have 4 broken studs of which the remains are below the machined edge in which the stud holes are drilled and tapped.
Can any of you relate to me how you have dealt with your particular engine's broken studs, and what you did that was successful?

My first thought is to use a small end mill to machine the broken end of the recessed stud flat, and able to be drilled, and then heat and soak in penetrating oil and let it sit and free up somewhat.
Then I could eventually attempt to remove the stud end with a quality "easy out".

(That may actually produce a lot more work than I originally wanted if the engine does not need to be disassembled.)

The second idea suits only for the studs which are nearly flush with the edge, that is to TIG weld and build up an extention to the stud end, and with that, make the attempt to carefully weasel the broken stud out of the hole.

The last idea would be the desperate attempt to drill and tap for a helicoil and re-finish the hole that way, although that goes against the grain with me as I want to keep things as original as I can.

Thoughts?

Regards, John.

if you can drill a centre hole down the stud infill bottoms out on a bottom of the hole and fill with some derv it should cheap it's way under the stud, leave it for a few weeks and plenty of heat and welds nut to the top with welder wound up high leave to cool before attempting to turn with spanner.

failing that drill out and helicoil it but that last resort.

Matt

Hi Matt,

There is one stud I can do that with and I will.

I'll drill the hole, and do the soaking thing, and then I will wld the nut on and try to move the stud back and forth.
it may well work.

So much for going to bed, I just can't seem to relax and put this engine out of mind.

Thanks for the advice,
John.

I would say to try and drill down the center of each stud getting bigger and bigger then try a stud extractor. If you fail doing that you still have the choice of fitting a helicoil, or maybe getting a stepped stud but I don't think you'll get the same thread so you may have to tap the block metric/AF and try to get some brass nuts to suit.

Stu.

Thanks stu,

I will get my chance to have a better look at it hopefully today.

My first aim is of course to keep the original thread pattern alive if I can, so I'll have to be careful to not damage whats left of them, as because of the age, they may have become so brittle that they are not salvageable in the first place, but I have to try, and that's where the fun is for me.

Thanks for the reply,

John.

Good luck John and remember one of the best things to posses when restoring old engines is patients.

Stu.

Hi I have just drilled a couple of broken studs out of my D head, I drilled a piece of 5/8" plate to act as a guide (if you have a pillar drill big enough to get the head in you won't need the guide) I then clamped the guide over the broken stud and drilled it out to 6mm making sure it's central. I then remove the guide and tap the hole to the original 5/16th bsw, all being well you'll end up with a usable thread.
Hope this helps Dan

Thanks Dan, for the comment,

I have just managed to get the engine out of the truck and inside, it is still -18*C out here, and I have taken some more pics of the D.

I had to think for a bit as to how to not get myself killed moving this large bookend!

I took an aluminium ladder and used that for a slide to reach from the truck bed to the ground.
the truck is quite high and I could not lift the engine, so I did what I did and surprisingly it all worked well and I was able to put the engine on a wheeled platform and got it inside.

After taking the pics I saw that this engine is a little different than some, and now I will wait untill I get the books in to see just exactly what the differences are.

It is definitely a "shafty" and right off I noticed that the main crank bearing is rough, so that will need replacing.

The studs are a minor problem from what I can see, and I should be able to re-do them easily.

On the carb, I do not see an air intake plunger to push nor a primer pot, and the camshaft has no Stauffer grease pot to twist.

The carb does have a screw inserted in the hole where the air push plunger is supposed to be, but at this point I will wait for the books so I can have a better understanding of what goes where and why.

I'll try some pics in the next post so folks can have a better idea of what I have.
please comment away, as I need the exchange to learn from.

Encouragement and friendly advice are priceless for something like this, don't forget that I am new at old engines and eventhough I understand the technology, I will need guidance for sure to make things complete.

Cheers, Smitty.

Hello folks,

I am going to quit this thread. The studs are out and that job is done, so it will be easier to continue on the "first Lister" thread.

See you there, John.

Great news you managed to get the studs out did it take much work?

Stu.

PS might as well tell us here about the studs and then finish the thread not leave us dangling.

Smitty wrote:Hello folks,

I am going to quit this thread. The studs are out and that job is done, so it will be easier to continue on the "first Lister" thread.

See you there, John.

i have a broken stud on my lister head and have not atempted to try to remove it yet - i was thinking of the easy way out if it wont remove by putting a dummy bolt on the cover,

how did you get the stud out in the end?

I've got a broken one on mine as well (well, my nephews'). Fortunately I think there was still a bit sticking out proud of the casting, so hopefully it won't present too much of a problem.

It's a common one though, snapped bolts & studs. Years ago you'd send them off for spark erosion (or is that just for broken taps & drills?). Does anyone do that any more?

If you drop the parts you need the studs removed from into Smitty's he'll take them out for you

Or pay for me to take them over and I'll wait till there done.

Stu.

stationary stu wrote:If you drop the parts you need the studs removed from into Smitty's he'll take them out for you

Or pay for me to take them over and I'll wait till there done.

Stu.

Iiiiimmm Baaaack!

Hi Stu, just popped back in the house after a hellish trip in the cold.

Laughing at your joke and letting you know that you're always welcome to visit and bring parts with you lol.

I removed my studs with easy outs and a small drill to get them started, worked ok for me, but in doing that, I realised that they could be a royal pain in the buttocks if they are stubborn.

I had one, (the last one to come out of course,) that would not move for anything, I ended up drilling that one a few times going bigger each time so I would stay in the center of the existing treads (if they were still viable,) and thus got to the point where I had to re-thread the hole so that the leftover pieces of stud which were nastily stuck in the threads, could finally let go and allow a fresh thread in the original hole.

The thing that was disturbing was that the original thread was an SAE type rather than the British Whit.

One of very few explanations I can think of is that my particular engine has the original brass Canadian Ident plate on it, and that it may well have been tapped SAE as a Canadian destined engine?

When I get the chance I will upload the pic with that plate on it.

If that was not the way it was shipped, then somewhere along the line something was changed, although I could not determine that the original WW threads had been re-tapped SAE.
I am reasonably sure the threads are the first ones tapped.

The size is 5/16 @ 18TPI

Would the original holes and threads have been 1/4 WW maybe?

Thanks for the replies, John.

steve w wrote:

Smitty wrote:Hello folks,

I am going to quit this thread. The studs are out and that job is done, so it will be easier to continue on the "first Lister" thread.

See you there, John.

i have a broken stud on my lister head and have not atempted to try to remove it yet - i was thinking of the easy way out if it wont remove by putting a dummy bolt on the cover,

how did you get the stud out in the end?

I guess I can continue this thread lol,

I had two studs with some of it sticking out Steve.

I carefully heated them a bit.
Then I added some very thin oil I had sitting around (high speed spindle oil from cotton spinning machinery) and let that soak in as much as it could, and then I clamped on a pair of Vicegrips (wondeful tool that! if you're careful.)
I very gingerly tweaked the stud back and forth until it showed some movement.
then I let it be and soak some more.
After heating the casting around it this time (but not a scorching heat, just hot,) the next attempt was easy as it came loose just as easy as you please.

The hardest one I explained in a post up one or two.
Regards and good luck Steve, John.

stationary stu wrote:Great news you managed to get the studs out did it take much work?


PS might as well tell us here about the studs and then finish the thread not leave us dangling.

Stu, Consider this thread live as it seems not to want to go away lol.

Yes I did get them out, but I was lucky with it, could have been a disaster very easily.

Check out the posts here, they'll explain what I did.

Regards, John.

With regard to the threads, (I assume SAE is what I/we call UNF & UNC threads?) perhaps these engines were shipped over in bits & assembled in Canada. If this was so then they may well have been shipped with blind holes, ready to be tapped.

Although 5/16" sounds a little bit too big for those studs, I thought they were 1/4"? Of course, not forgetting, this is a pretty early example of Lister's D type, so it may well have been restored in the past, these studs are usually trouble (which is why I always grease every thread on reassembly when I restore an engine).

Sounds to me like they have been re-tapped in the past to SAE but I could be wrong. Could it not be a BSF/BSW thread rather then SAE.

BSW / UNC - ?
BSW is usually compatible with UNC, the only different one is 1/2", the rest are interchangeable. The only noticable difference between them is that the BSW have a slightly larger head size, (for the purist there is 5 degree difference in the pitch angle), which is not really significant.
The threads per inch are the same (except for 1/2").
Generally BSW and BSF was used on English cars and motorcycles until the 1960s, after that and on American cars and motorcycles UNC (coarse) tended to be used, in conjunction with UNF (fine).

Stu.

nutgone wrote:With regard to the threads, (I assume SAE is what I/we call UNF & UNC threads?) perhaps these engines were shipped over in bits & assembled in Canada. If this was so then they may well have been shipped with blind holes, ready to be tapped.

Although 5/16" sounds a little bit too big for those studs, I thought they were 1/4"? Of course, not forgetting, this is a pretty early example of Lister's D type, so it may well have been restored in the past, these studs are usually trouble (which is why I always grease every thread on reassembly when I restore an engine).

I had wondered the same thing Nut,

1/4" sounds more reasonable seeing the job it has to do, of course I can only assume what they were in the first place, but now that I also have read Stu's answers, I need to go and find out what really happened with the threads. IE the size of the original threads as shipped or from the original distributor.(If they were processed in Canada here.)

I put an anti seize compound on most of my rework as I hate to see the same thing happen again to some other poor bloke in the future when he needs to take things apart to restore.

Thanks, Regards, John.

stationary stu wrote:Sounds to me like they have been re-tapped in the past to SAE but I could be wrong. Could it not be a BSF/BSW thread rather then SAE.

BSW / UNC - ?
BSW is usually compatible with UNC, the only different one is 1/2", the rest are interchangeable. The only noticable difference between them is that the BSW have a slightly larger head size, (for the purist there is 5 degree difference in the pitch angle), which is not really significant.
The threads per inch are the same (except for 1/2").
Generally BSW and BSF was used on English cars and motorcycles until the 1960s, after that and on American cars and motorcycles UNC (coarse) tended to be used, in conjunction with UNF (fine).

Stu.

Hello Stu,

I of course only assumed that the threads are SAE even though I fitted the tap in the only hole which was left with thread before I started on this, but what you've explained sounds very possible to me.
I am not so aware of British standards and quite ignorant of anything else than WW, because as a kid I only learned about that in school and missed the rest, day-dreaming of aeroplanes, bikes, engines and submarines, while looking out of the windows and not paying the attention I should have lol.

What you said about the threads matching up quite as if they could be British or BSW, makes more sense than me guessing at it.
The one stud that came out with preserved threads (wheather they are the correct ones or not,) matched the 5/16 tap I have (5/16- 18TPI)seemingly perfect, so I assumed that that was the size as produced as I could not see any cross or double threading as in a re-tap.

I find all of this very satisfying and it makes me happy to do the research, I will find out sooner or later what was used originally.

I also thank you for stating the thread angle at 5 degrees different (wider or more pointy?), that is a tidbit I had to have a tea over to celebrate as new information like this is a bonus for me and makes me remember a few more things about threads I learned in school.

So...., as it sits, The holes are now compatible to two kinds of hardware it looks like, and that is just fine by me, nothing I can do to change it back if indeed it was 1/4 inch BSW to start with.
I am happy just to have something workable and that I am not stuck with any damage.

Cheers and Regards, John.

Smitty wrote:The size is 5/16 @ 18TPI

Would the original holes and threads have been 1/4 WW maybe?

nope
5/16 18tpi is 5/16 BSW
it is very close though to 5/16 UNC (also 18 tpi) although the 2 seem to fit together well the actual thread pitch is very slightly different
Andy

Most old British cars, bikes & stationary engines didn't just use BSW & BSF threads, just my little Tarpen has 4 different thread types on it. There are BSW (Whitworth), there are also BSF threads, but the smaller stuff is BA thread & there are also a few BSCY (Cycle thread, also known as BSC) which can be found on quite a few engines (which surprised me when I found out).

Then there's the motorbikes, even as far back as the 1940s (that I know of, possibly even earlier) some were using a combination of BSF, BSW, BSCY & the American thread sizes (UNF & UNC) started sneaking in! Some of these machines really require a well stocked tool box to work on them, I'm always finding stuff which needs BA spanners, when I thought they were just a mis-shapen 1/8" Whit.

Also, the largest BA spanner size is larger than the smallest BSF & BSW size, so there's a cross over there somewhere as well!

Is it any wonder we were over taken by countries using much simpler tooling methods.

I'm still trying to work out, in my mind, how you keep the same TPI when there's a 5 degree difference in the thread angle? Maybe one didn't cut as deep??? (Maybe I should stop trying to think about it! )

I've got some UNC taps in the workshop, & a good set of BSW & BSF taps & dies, I'm going to have to test out Stu's info. I'm not doubting it for one minute, but I always like to test out new information when I hear it. Perhaps I can also find out which one doesn't cross over? (I've also got a big tin of various nuts & bolts to play with as well).

So I'm off to play with my nuts!

All the crankcase related threads on a Lister D are BSW, UNC (or SAE) and BSW are virtually interchageable up to 1/2 inch as Stu has said. Hopper cover studs/bolts are 5/16 BSW as are the flywheel housing and the carb/ exhaust fixings. The timing case studs are 1/4 BSW.
Lister made great of the fact that the piston could be removed with just a 1/4, 5/16th and 3/8th spanner, box spanner or socket.

Pete.

Foden wrote:All the crankcase related threads on a Lister D are BSW, UNC (or SAE) and BSW are virtually interchageable up to 1/2 inch as Stu has said. Hopper cover studs/bolts are 5/16 BSW as are the flywheel housing and the carb/ exhaust fixings. The timing case studs are 1/4 BSW.
Lister made great of the fact that the piston could be removed with just a 1/4, 5/16th and 3/8th spanner, box spanner or socket.

Pete.

There we are then, I must have threads that fit but are flatter, fatter or higher lol.

Though I am not fooled to think that I have SAE or UNC at this point.
I believe now that I have the BSW threads that accomodate my tap and studs, so I am happy.

Next step will be the removal of the crank and all of the rest as well, but only as soon as I have read the books when they come in.
I am home for just today and off to Salt Lake City tomorrow, so I am just eying up a beer and having fun on here.

Thanks for the info Pete, John.

See John all this info you would have missed if you'd put this post the bed. And all the headaches it's given people thinking about threads

Stu.