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john.r.davies

Cracked block repair - A US technique

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This is a new thread over on The Triumph Experience about a TR2 block crack:   https://www.triumphexp.com/forum/tr2-and-tr3-forum.6/tr2-block-cracked-use-as-is-or-repair.1673977/

It leads via another link to a thread on The British Car Forum, describing in vivid, illustrated detail the repair of a similar crack on, I think a TR3: https://www.britishcarforum.com/bcf/showthread.php?97470-Block-Crack-Repair

The discussion on TE urges a weld or braze to prevent crack extension.       Owners and our resident engineers may be interested!

John

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But similarly the possible block warp or hardening ramifications of a welded repair on the block is discussed also and the "Lock and stitch" insert used instead (very nice too).

Mick Richards 

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Do we not also follow the factory advise of placing a wrap of lead linger around each head stud under each head nut washer to seal the stud to the head. Thus limiting the passage any water to the oil areas?

Peter W

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52 minutes ago, BlueTR3A-5EKT said:

Do we not also follow the factory advise of placing a wrap of lead linger around each head stud under each head nut washer to seal the stud to the head. Thus limiting the passage any water to the oil areas?

Peter W

Do Moss sell it Peter ? I can't see it on the site.

Mick Richards

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No Mick part number  30123 was deleted a while back.   I still have about 3/4 lb left of the original lead linger which is basically lead wire.
You can substitute non cored solder as that is the same sort of thing.

Cheers

Peter W

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19 hours ago, BlueTR3A-5EKT said:

No Mick part number  30123 was deleted a while back.   I still have about 3/4 lb left of the original lead linger which is basically lead wire.
You can substitute non cored solder as that is the same sort of thing.

Cheers

Peter W

Additional info but slightly off topic

I guess 2 feet of lead linger per TR engine would do.  On the assumption you need enough linger to single wrap 10 head studs (Pi x 0.5") which is 18".  Plus another wrap for the oil pressure relief valve lock nut, say another 2"

Possible source, but too large a diameter - Offered in USA by roto metals at 1$ per foot.  The original lead linger is 1/16" diameter (1.8mm)  and the smallest diameter this company offer is 1/8".  (3.2mm)

https://www.rotometals.com/lead-wire-by-the-foot/

 

Or you could just triple the wraps with this stuff at 0.6mm diameter  https://www.sportfish.co.uk/veniards-lead-wire.html

Cheers

Peter W

 

Edited by BlueTR3A-5EKT

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1 hour ago, stuart said:

Source here in various sizes http://www.goodfellow.com/E/Lead-Wire.html

Stuart.

At £200 per metre I'd be able to pay someone else to rebuild my engine, if only I could sell my roll of the stuff at that price!

Peter W

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2 minutes ago, BlueTR3A-5EKT said:

At £200 per metre I'd be able to pay someone else to rebuild my engine, if only I could sell my roll of the stuff at that price!

Peter W

I know Im not quite sure how they arrived at that price as thats well over the top!

Stuart.

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Just now, stuart said:

I know Im not quite sure how they arrived at that price as thats well over the top!

Stuart.

It is aimed at the scientific world.   They probably expect the scientists to be spending someone else's budget.

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Having got around to looking at the repair process, I don’t understand how a crack like that can lead to overheating - unless it’s because it becomes impossible to achieve the right clamping force in the relevant stud with a resultant head gasket blow. 

Happy to be educated. 

Rgds Ian

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I've checked the posting Ian and I can't see any reference to overheating (unless missed) or is that your inference ? In my opinion that's a good engineering fix...but a sledgehammer to crack a nut.

There are many blocks being used that I've seen (and rebuilt) that have that crack at the rear and none showed overheating problems, the water occasionally found it's way out and fizzed itself to dry on a run but not even a teaspoon amount lost I'd guess. I've fitted studs with PTFE wrapped on the bottom threads which has stopped it, it makes the stud too stiff to fit by hand but just wind the stud in until it reaches the end of the thread and don't overtighten into the block. All the studs take a full torque with no problem.

Mick Richards 

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