Topic: TRIBSA

[martin99]

Don't worry about it Martin, it probably came out of the factory like that!

Nobody could accuse you of being predictable mate 

I used plasticine to make a "dam" around several repairs I've done with epoxy, it just allows you to fill the repair area, and you can just file down the excess material sitting "proud" of the repaired area.

Been a long time since I played with plasticine!

And lastly, remember that one day when you eventually sell it, someone's gonna start a thread somewhere telling the world what a butcher the PO was! Talk about cruel irony............

That does it! I'm going to see if I can get it tigged. 

Thanks for all the comments and advice so far gentleman, been in touch with my tig welding buddy who said he'll have a look at it for me, in preparation I'll Dremel a vee into it tonight, I think this is probably a good idea even if it ends up getting filled with epoxy, we'll see what happens.

[martin99]

And also, should I grind a vee into that crack a little to present a larger surface area for the epoxy to take hold?

The one thing that would concern me when it comes to using epoxy on an old Triumph engine, is the porosity of the aluminium, there would be plenty of oil and contaminants soaked into it, if it were me,  I would be getting that block tigged up properly... You shouldn't have too much trouble finding someone to do it for you..

That's a good point well made mate, I'm on the case.

[martin99]

http://www.alumiweld.com/index.html

Stupid me, it's alumiweld. I wish I could I could remember where I saw the write up on this stuff, I was impressed. That link should get you in the door.

Hey jgger, thanks for all your input. I'm looking at welding at the moment, but if my mate doesn't think it's do-able I'll be looking at these alternatives again.

[simon#42]

i dont like the epoxy methods of repair to be honest , i have used alumiweld on radiators plenty of times with good success but it is a low temp process and am not sure it
would be the best solution for this .  if it was mine i would remove the tappet block [ even if it destroyed it ] and would then weld the crack on the inside and outside . the hole
could then bored to the correct size [ for a change ] , the base of the cylinder can be trued up on a mill . if done properly you wont be putting enough heat into it to do much damage

[martin99]

Cheers Simon. Yes I agree that would be the ultimate solution, but I took it over to my friend Chris tonight and he has welded it with the block in situ after taking a fair bit of time preparing it by vee-ing as much as possible to permit decent penetration. He's quite the perfectionist and I trust in his ability, I'm far more satisfied with this than I would have been with an epoxy repair. Mick was on the money with the whole 'old porous metal' observation, Chris remarked that it proved to be a dirtier job than he first assumed. He's told me to take it back to him if, after cleaning it up, there are any spots that need re-visiting.

Next time (if there is a next time) I'll take the lessons I've learned from this little episode and farm out tappet block replacement to someone with the knowledge and equipment to do the job properly. I'll try and post some pics tomorrow.

[Retro Rocket]

i dont like the epoxy methods of repair to be honest , i have used alumiweld on radiators plenty of times with good success but it is a low temp process and am not sure it
would be the best solution for this .  if it was mine i would remove the tappet block [ even if it destroyed it ] and would then weld the crack on the inside and outside . the hole
could then bored to the correct size [ for a change ] , the base of the cylinder can be trued up on a mill . if done properly you wont be putting enough heat into it to do much damage

My thoughts exactly, Do it once, do it right....

[754]

I am not sure they even tig cast iron, that is with cast iron rod...I mean it would be as strong as dry pasta.. The rod that is..
 I have had some nightmare machining jobs, where someone tried fixing cracks on cast iron.....a lot of welding methods, unless pre and post heated..end up extemely hard, and wrecks cutting tools .
The last thing I would do to that functioning. Useable part..is to put heat localized heat into it, and have worse problems.
 If just filling the crack , I would drill a teeny hole at the end of the crack.

[martin99]

This is an alloy block Frank, tbh it's a pity it's not cast iron, I may not have stuffed it in the first place.

[Terry in Australia]

This is an alloy block Frank, tbh it's a pity it's not cast iron, I may not have stuffed it in the first place.

I don't know mate, it looks like you tried pretty hard..........

[martin99]

This is an alloy block Frank, tbh it's a pity it's not cast iron, I may not have stuffed it in the first place.

I don't know mate, it looks like you tried pretty hard..........

Yeah, I know Terry I can't blame anyone else. I think I'll soon be able to move on from this shattering experience and will no doubt find another vital component or two to fck up before this is done

I don't have a problem holding my hand up when I make a cock-up, I'm sure others make some monumental ones that they choose not to share on here for fear of embarrassment, or maybe no-one else does make mistakes, and it's just me?

[simon#42]

yes martin it is just you !

[martin99]

yes martin it is just you !

 

 

[754]

Next time, check parts with a micrometer..  Lots of hand fitting probably went on there..

[Terry in Australia]

yes martin it is just you !

+1, if you're hoping that I'm gonna admit to stuffing anything up, you'll be waiting awhile Martin, I'm an expert, just ask me.....

[martin99]

Next time, check parts with a micrometer..  Lots of hand fitting probably went on there..

I did check it Frank, the block was .003" larger than the narrowest dimension of the hole. I thought heating up the block would have expanded it that much at least, but I was obviously too optimistic.

Never mind, never too old to learn something new! 

[Terry in Australia]

Was it a Pommy micrometer Martin? They're usually around 1/2" out..... (and they leak oil and can't play cricket)

[ken65]

hahahaha. love it.

[martin99]

hahahaha. love it.

Please don't encourage him. I think I can see why his missus doesn't mind him working 400 miles from home. 

[ken65]

A mate of mine makes fun of my 72 bonneville  (stephanie) mercilessly .
It's pretty funny.

[martin99]

Your mate is called Stephanie? Does he like Johnny Cash?

 

[ken65]

haha. thats the bikes name.

[martin99]

Like I said, I took the block to my good friend Chris to get the crack sorted. He opened it up, sat on his comfy stool, and did his thing....



After cleaning up....





The evidence of porosity is clear to see, but he's done a good job I reckon.

Now, I've been troubled, cut to the quick even, by the implication from certain commentators on this thread that I don't know a measuring instrument from a musical instrument, so I conducted a little experiment. I mounted the barrels (after which I placed the barrels  ) on to the crankcase to see if the material removed during the clean-up would potentially cause a leak at the joint....



Using a non-Pommy (Starrett) set of feeler gauges, I ascertained that there is less than .02mm gap at the joint. Moving the gauges around the base, this is no more than anywhere else, which as far as I'm concerned proves two things; 1), I haven't removed too much material from the sealing surface, and 2), they never sealed properly in the first place. To quote a certain Aussie gentleman, this is probably how it came out of the factory!





So then the next logical step is to work out if it will actually seal with a gasket. The base gasket
 that came with the gasket set measures twice(ish) the width of the gap....



So I'm thinking it's going to be ok. (Especially if the gasket gets a liberal slavering of Hondabond both sides  ). Next job is fitting the new pistons.

As an aside, followers of this sordid tale (yes, both of you  ) will undoubtedly have been awed and bewildered by my engineering and tool-making prowess. As a special offer to SOHC forum members, I am making available my bespoke tappet block insertion jig, complete with NASA approved insertion tool. If it generates enough interest, I may expand the range to include Hardly Davidsons. Get your orders in quick, I don't expect these fine examples of British engineering to be hanging around for long. Princess Kate is already getting grumpy that I may have to focus my attention elsewhere, but as I tried to explain to her, at 63 she'd be a lost cause, whilst an old British engine is worth fighting for....



 

[Retro Rocket]

That looks much better.....    Just remember, its an old triumph, if it don't leak, its probably a fake....

[Terry in Australia]

Ha ha, beautiful work Martin, I'm proud of you mate. As much as I'm impressed with your bespoke tool making prowess, my magnificent Harley  is backed by enormous world wide resources of every possible tool required at quite reasonable prices, so, with the greatest of respect, my advice is not to give up your day job mate, and anyway, your current paid employment will probably come in handy with future pommy sh1tbox restoration projects............

[jgger]

That looks much better.....    Just remember, its an old triumph, if it don't leak, its probably a fake....

For Brit bikes I think the saying is "If it doesn't leak- it's out of oil"

Harvie Davis is a different deal because the build process is different. The Harley's are fully assembled then dipped into a vat of oil......so it can leak IN.