Perkins 4108- Heat exchanger stud sheered off

[danielefua]

Hello Daniel hope all well with you and your enjoying your retirement, remember me you helped me install a Simrad autopilot with a Neco drive motor, in a Nic 38. I even got a mention on the 'how to' sheet posted on the net. I was in Sardinia at the time, now moved to Greece. Best wishe . Mike

Hi Mike, of course I remember you although I did not recognize your nickname. Your contribution is still acknowledged in the new versions of the note! I am fine and having fun also; we may happen to meet sometime in Greece as I plan to sail to Lefkas sooner or later, I have a mooring waiting for me there and I love that place.
Do you still have the Neco drive doing is faithful job? Best wishes to you too.

Daniel

 

[Sarnia]

Sorry about this thread drift everyone...
Hi Daniel, I am also at Lefkas, but not in Lefkas itself, but based further South at Vlikho yacht club, last year was my first season in Greece which convinced me to move there from Sardinia, love the islands to.
Yes the drive is working perfectly, click the pilot on and it takes over seamlessly, it understands the Simrad signals perfectly, only had two occassions in very bad weather when I have had to helm myself, be good if we do manage to enjoy a beer somewhere next year.

 

[huldah]

I am about to remove my heat exchanger from my 4108 as it has blown a gasket. Hopefully, I will not have a similar problem!

However, I know how difficult it is to punch and drill accurate holes. You have three good studs, so you can calculate the accurate position of the broken stud. I suggest you get a thick flat steel bar, drill it to be a tight fit on the remaining three studs, and drill a small pilot hole over the broken stud to take a small drill. After drilling the first pilot hole in the stud, enlarge the pivot hole in the bar, ready for the next drill. Drill the bar with a pillar drill so the holes are dead upright. This way you should get an accurate hole, even if using a hand held drill.

The bar may also be useful to support and guide the tap.

If the heat exchanger is a tight fit, you may be able to use that to mark out the position of the holes in the guide bar. Use a drill that is a tight fit in the holes to mark the centre of each hole, then enlarge to the correct size.

With the pilot hole drilled, you could try a stud extractor, before further drilling. (Don't break the extractor!)

 

[Sarnia]

Making a template of the heat exchanger bolt positions, to accuratly redrill the stud is always a good idea, a piece of "0.125 (1/8th.) mild steel plate just big enough to cover the four holes will suffice, as you point out the holes in the template need to be a good fit but pass comfortably over the remaining three studs. The fourth position just having a pilot hole through which using the same drill you can find the centre of the stud. Mild steel be fine, you are only drilling through it once.
Extractors in inexperienced hands can create more problems than they solve, if it breaks, getting a hardened one out in a confined space not something to look forward to, tapping has its challenges to, but slowly slowly and good tallow or cutting oil works, remove the tap regularly and clean the flutes and more lube, you will (i am assuming it is not something you have done much of) get the feel of it as the tap cuts the new thread.

 

[daviddb]

Easyouts by name but not by nature in my experience! And if one snaps off flush within your already snapped off bolt then you will be entitled to let slip a Cpt Haddockesque oath.

Being of an Eeyore-ish disposition I'd probably 'pop' the head off and see if I couldn't weld a short bolt on to the recalcitrant stud and then worry away at it. Got to be a calmer process all round doing it at a bench/kitchen table rather than in situ. Anyway fingers crossed and all that and let us know.

yrs

David B

 

[huldah]

An update to my post.

I did once manage to accurately drill out a stud, leaving the stud thread in the hole. I was able to hook out this thread. It came out as a helical coil - no tapping required.

 

[Sarnia]

An update to my post.

I

 

[Sarnia]

An update to my post.

I did once manage to accurately drill out a stud, leaving the stud thread in the hole. I was able to hook out this thread. It came out as a helical coil - no tapping required.

That can happen, but needs the clearance hole to be accurate leaving the coil as you said, but it does depend on what was the cause of the break, if just overtightening or bottoming in the hole then there is a good chance it will happen, but when it breaks as a result of either corrosion either from water ingress or action between disimilar metals plus many cycles of getting hot and cooling, the chances are less likely, which is why in this case I suggested what I did.
It is entirely possible that when tapping begins he may 'find the thread' as I put it earlier, a little tongue in cheek without getting his hopes up it would happen as it did for you.

 

[Norman_E]

My experience of easy outs is that most are too brittle and will snap off with much less torque applied to them than the amount required to shift a rusted in stud. I agree with the posters who say use a welder to heat the stud and weld something to it. I once welded a nut to a broken stud, using a nut one size smaller than the stud itself and welding through the hole in the nut after thoroughly heating the stud by depositing some weld onto it. It then came out fairly easily, after giving it small movements in both directions. From memory it was a 3/8ths inch UNC stud to which I welded a 5/16th inch nut. The job is much easier if you can weld vertically downwards and pretty well fill the nut with weld. The job is probably best done with the head off.

 

[RichardS]

My experience of easy outs is that most are too brittle and will snap off with much less torque applied to them than the amount required to shift a rusted in stud. I agree with the posters who say use a welder to heat the stud and weld something to it.

The problem is that you have to have welding gear and the knowledge of how to use it. Stud extractors do work providing you can drill a big enough hole in the stud to use an extractor which is say 75% of the stud diameter or more. Use cobalt drills in stages. Even stainless steel will drill relatively easily. But you defintitely need to use heat as the final stage in most cases. The differential expansion between the stud and the block is what enables the extractor to work in difficult cases.

Richard

 

[blackdogsailing]

thanks for all the advice. Sorry about the delay in replying. took a short break away from boating ! Head is going to have to come off as we snapped off the easy out. Going to give it to a workshop to save any more hassles. Will get the valves done at the same time. Anything else I can/should do with the head off ?

Chris

 

[daviddb]

thanks for all the advice. Sorry about the delay in replying. took a short break away from boating ! Head is going to have to come off as we snapped off the easy out. Going to give it to a workshop to save any more hassles.

Chris

Ahem! snipping<<Easyouts by name but not by nature in my experience! And if one snaps off flush within your already snapped off bolt then you will be entitled to let slip a Cpt Haddockesque oath. >> snipped

*stands by for a darn good & merited flaming on the basis nobody likes a smart a r s e or an I told you so merchant*

Bad luck! I'm sure the shop will have it done in no time.

 

[parbuckle]

Ahem! snipping<<Easyouts by name but not by nature in my experience! And if one snaps off flush within your already snapped off bolt then you will be entitled to let slip a Cpt Haddockesque oath. >> snipped

*stands by for a darn good & merited flaming on the basis nobody likes a smart a r s e or an I told you so merchant*

Bad luck! I'm sure the shop will have it done in no time.

Its a shame your advice proved to be spot on but there is always an element of luck in these things.

 

[Sarnia]

thanks for all the advice. Sorry about the delay in replying. took a short break away from boating ! Head is going to have to come off as we snapped off the easy out. Going to give it to a workshop to save any more hassles. Will get the valves done at the same time. Anything else I can/should do with the head off ?

Chris

Should never have had to come off, a simple drill procedure would have done, easy out a bad option in the circumstances, maybe ok in different ones, but as suspected the stud is well set in its threads which caused the stud to shear in the first place, but thats now down to experience, which is usually a costly way to learn.
My 4108 hasn't had its head off in 12 years, no need unless I hear a tappet clacking.

 

[Sarnia]

Ahem! snipping<<Easyouts by name but not by nature in my experience! And if one snaps off flush within your already snapped off bolt then you will be entitled to let slip a Cpt Haddockesque oath. >> snipped

*stands by for a darn good & merited flaming on the basis nobody likes a smart a r s e or an I told you so merchant*

Bad luck! I'm sure the shop will have it done in no time.

Thats true, told you so is not helpful, other than maybe next time choose a different and proven option, so feel free with the oaths...