Cracked valve guide bore head repair - is it for real?

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jseng1

jseng1

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LASER WELDING

Anyone else have any experience with this? Can it be done in the US?

"EMP in Havant Hampshire can laser weld inside a valve guide bore... an elongated and cracked valve guide bore was successfully welded and remachined."

http://www.e-m-p.biz/laser-welding/classic-cars/

If this really works it'd be a great way to save all those cracked heads.
 
Have read mention of this repair process on this forum , a month or two ago , from what was said I think the talk was positive and worth trying to save the head .... can’t remember what thread I read it in though ...
 
Jim, Ive just sent tham an email to see if they can repair a gouge I have in a set of barrels off my Roadster that has a gouge from an errant circlip tip that let go recently.
I would rather get it repaired like that instead of boring and installing a new liner
Regards Mike
 
Brooking 850 said:
Jim, Ive just sent tham an email to see if they can repair a gouge I have in a set of barrels off my Roadster that has a gouge from an errant circlip tip that let go recently.
I would rather get it repaired like that instead of boring and installing a new liner
Regards Mike
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Assuming they can "patch it", do you think the difference in hardness between the weld and barrel matrix will be problematic with ring wear and sealing?

I am really keen to hear who has used this for the repair of the intake port cracking in by the guide support.
 
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jseng1 said:
LASER WELDING

Anyone else have any experience with this? Can it be done in the US?

"EMP in Havant Hampshire can laser weld inside a valve guide bore... an elongated and cracked valve guide bore was successfully welded and remachined."

http://www.e-m-p.biz/laser-welding/classic-cars/

If this really works it'd be a great way to save all those cracked heads.
Click to expand...

I have Seager engineering on my Facebook feed. I have some of their stainless Norton Rose nuts and seem to do quality work.

They posted this week pictures of a similar repair to a Triumph T120 head in the valve guide bore, followed by machining and guide fitting.

Seems to be coming technology. I have an RH4 head so have contemplated asking for an opinion.
 
I wonder if they could close up a sparkplug hole enough to be re-drilled and tapped, including filling in the combustion chamber dome around the spark plug hole. I have a lightly used Combat head that an idiot cross threaded and then tried to fix back in the late 70s. He drilled it through with too large a bit. There's nothing else wrong with the head.
 
It was Norman White who first started to use EMO to fix cracked heads, so I don't doubt they can do the repair. What % they can do and how long the repair lasts is unknown.
 
It was me who put Norman onto them, the success is looking good, so far only one has a concern that it may have failed. The beauty of this system is that it causes no distortion, if fact as soon as the laser is off you can touch the weld! The laser can lay a seam of weld as narrow as 0.2mm wide, so ideal to get into cracks and circlip grooves etc. Because the size of weld applied can be carefully controlled, the resulting re-machining if needed is minimal. It can be used to build up material prior to machining.

I would not try a cylinder bore, but if needs must you may get away with it. I think the hardest to weld is stainless using a welder, but most other metals including some plastics can be lasered.

If they can focus the laser they should be able to do it, when I was there a vintage 4 cylinder engine with a combined block and head was having hard weld seats built up by laser at a depth of around 7 inch.

I don't think that for one moment there is not someone available in the US who will provide laser welding, it is the land of plenty apparently. There a lots of laser welders in the UK, though only a few will do public jobs. Australia I believe there are very laser welders. The equipment looks most suited to a Dentist surgery, as you can imagine you need microscope googles when welding 0.2mm
 
I recall the first time I saw 2 pieces of 1/8" alloy sheet butt-welded together by laser. Looked like one piece with a wide scratch on the surface.
 


We should see laser welders become more common shortly. Won't be long before they are on sale at Harbor Freight.
 
Brooking 850 said:
Jim, Ive just sent tham an email to see if they can repair a gouge I have in a set of barrels off my Roadster that has a gouge from an errant circlip tip that let go recently.
I would rather get it repaired like that instead of boring and installing a new liner
Regards Mike
Click to expand...

I would have thought that welding cast iron would result in a failure. However I am just now reading a book about racing Hondas. One of their motors had cast iron rings, and the top ring was hard chromed. So perhaps these days more answers have been found.
 
Emailing them now about this... wonder if it's beyond even their capabilities

Cracked valve guide bore head repair - is it for real?
 
acadian said:
Emailing them now about this... wonder if it's beyond even their capabilities

View attachment 13939
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That’s not the right question, as I’m sure it is within their capabilities.

The real question is: is it economically viable? A very firm NO would be my assumption.

I also think the head might be severely softened by the amount of welding required.
 
It's a shame, really, it's a splayed port T140 head that's otherwise in pristine condition. Maybe I'll just turn it into a desk lamp
 
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