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Discussion Starter #1
Hello all,
I am about to have some work done on my 1954 Thunderbird engine. Both exhaust spigots on the head are damaged (pictures attached). What is the best solution? I think I am correct in believing that these spigots are not threaded or pressed in but rather a part of the iron head.. The company I am going to for the repairs said that if that is the case it would be better to cut them off and bore out the exhaust ports to press in new spigots as welding them could result in them being out of round. What are your opinions?

IMG_1996.JPG

IMG_1997.JPG
 

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There’s enough left there to hold the pipes.

The one with the long crack looks like it needs the piece removed so it doesn’t drop off in use.
 

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Is that a crack in the head at 8 o'clock??? If so then pressed in versions won't work either. The crack will only get bigger with pressure plus heating and cooling.

Personally, I would take the work to somebody that can weld cast and get the spigots/exhaust stubs repaired. Don't get them removed or replaced, just repair them. I reckon they could be welded up so that they are as good as new.
 

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I agree - it must be easier to repair the spigots rather than remove / replace them ( your pockets will retain more money too)
 

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What TT say or scrap the head...Weldling cast iron ,especially thinner stuff, is a bit of magic....Building it up with spray welding or rod is possible and then the time spend making it all round and nice might be a bit expensive..Maybe a replacement is best...
 

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Discussion Starter #8
No cracks in the head itself.. I did discuss welding but was told that getting the spigots round again when grinding back would be extremely difficult. if there is enough material there to hold the exhausts, I might consider just cutting off the damage
 

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Discussion Starter #10
That is actually the edge of the flaked paint. However on second inspection I did realise that the crack in one of the spigots goes more or less right down to the head, so in light of this new revelation... what are my options??

Apologies for the qaulity of the photo, I know it isn't perfectly clear but you can see the crack running in towards the head

1.jpg
 

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I say weld it, still. Its not a big job tbh. Grind out and fillet weld the cracks and build up the missing section. Preparation is the key. Use a TIG or an Oxy torch with filler rods for cast iron.
https://www.ebay.com.au/itm/ERNI55-1-16-nickel-cast-iron-TIG-welding-rod-Blue-Demon-1lb-tube/302707248015?epid=882640344&hash=item467ac20b8f:g:-Z0AAMXQMmJRWgpq

If you can't do that find somebody who can. You can probably do the finishing yourself, buy some 1/4" drive shaft carbide tungsten deburring tips and use your electric drill. You can also get some neat flapper wheel tools for the drill that would linish the outside and also small enough to fit inside the stubs. If you have a die grinder it would be easier, but an electric drill will still work OK, just take your time.

https://www.ebay.com.au/itm/10x-Tungsten-Head-Carbide-Burrs-For-Rotary-Drill-Die-Grinder-Carving-Bit/123775314714?hash=item1cd1956b1a:g:xbYAAOSw7aZc49NY
I bought and use these and they are fine...thought they would be junk and go blunt in a minute but several years later and they are still like new.

https://www.ebay.com.au/itm/15-80mm-Sanding-Flap-Wheel-Disc-Abrasive-Grinding-1-4-Shank-For-Drill-Grit-80/323417993485?hash=item4b4d36f10d:m:m_gdeJCkNM1dXv8OHOaUsdQ
And get something like these to finish off.

Up to you really, is the rest of the head worth saving? Are they readily available and not too expensive? Do you want original? Is time an issue? These are all the questions you need to ask yourself, but IMO its not a big job, its just fiddly.
 

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That is actually the edge of the flaked paint. However on second inspection I did realise that the crack in one of the spigots goes more or less right down to the head, so in light of this new revelation... what are my options??

Apologies for the qaulity of the photo, I know it isn't perfectly clear but you can see the crack running in towards the head

View attachment 652776
The Trident guy is right. That has to be fixed or another head used.

It’s not strong enough for the pipe to be clamped onto. A weld should work.
 

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Just like everyone says, if you can get a new head then that is the best option. Welding old thin cast iron especially European iron is iffy. A press in sleeve would be best if keeping the head. Welding an engine block is one thing but welding thin iron could distort. I’m more do it once do it right. That long crack will crack again due to rust and different material expansion especially exhaust.
 

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Pre-heat well and braze it.

Bob
Bob I thought of brazing, but those exhaust stubs can glow red hot sometimes {I've seen it at night on a run where we were doing 60-70mph for 20 minutes}. I'm not sure if brazing would stay strong enough under those conditions. You also need to groove out the cracks with a tungsten carbide deburrer or a Dremel and then fillet weld. But either way it is very important to get to 'new' metal on the edges. You want the weld area cleared of any rust or contaminants.
 

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Discussion Starter #16
Thanks for all the advice. I'm going to try and weld them.. failing that I'll be digging in to my wallet again
 

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I always drill a hole just beyond the end of the crack to reduce the chance of the crack continuing. I think you should try to weld it. It’s the easiest and cheapest and doesn’t preclude trying another way if it doesn’t work. I think you can use a die grinder to get it round again. Just keep sliding a pipe on it as you work
 
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