Mugello Spigot Buggered! Suggestions?

[Donnie]

Yes

[lozmondo]

Pics remind me of dear Lozmondo. It was one of the first parts fairs at Kettering after it moved from Mkt Harborough. Mr Dalton was looking for a donor TS1 barrel for an engine MB were going to build for him. In his defence it was a bit dark in the hall but Loz found a barrel and bought it over. "Did you notice half the spigot is missing?" said Broady?
It was welded up and bored out and replated and is still going strong as far as I know.

It is indeed

[Steve J]

I have seen exactly this sort of damage before (not on a Mugello, fortunately) - and it was all my fault I was persuading a heavily seized piston to leave a barrel, after soaking it in WD40 for about a week - the piston eventually came out, but the spigot had cracked in exactly the same way as the photos. I then discovered the reason the engine had seized was that the top ring peg had worn away, and the ring had rotated over the peg. I reckon this created extra pressure against the cylinder wall, and when the ring reached the thinner spigot, the pressure was too great for the spigot, and the inevitable happened.

I see from the Mugello photo that the crack in the spigot has allowed the broken part to move outwards, indicating that the pressure creating the crack came from the inside. It's possible that it may have been done earlier by removing a seized piston, but as the guy had never built an engine before, my guess is that the ring gap was not over the peg, and he tried to force it all together, with the same result. Don't let him put the repaired kit together......

[Ian Hepworth]

Pics remind me of dear Lozmondo. It was one of the first parts fairs at Kettering after it moved from Mkt Harborough. Mr Dalton was looking for a donor TS1 barrel for an engine MB were going to build for him. In his defence it was a bit dark in the hall but Loz found a barrel and bought it over. "Did you notice half the spigot is missing?" said Broady?
It was welded up and bored out and replated and is still going strong as far as I know.

It is indeed

I'll never forget the look on your face. You went from pleased as punch to gutted in about 1/100th of a second.

[lozmondo]

...youthfull exuberance !..or plain stupidity

[Lamaddict]

There seems to be more general problems reported on Mugello's on this site and others yet people still keep buying them . I can't imagine that happening very easily to a SIL spigot. Good luck anyway

[grimspeed]

http://www.pjme.co.uk/acatalog/Cylinder ... eving.html
these guys are pretty good ! could rebore aswell after.

[Ian Hepworth]

...youthfull exuberance !..or plain stupidity

It was bloody dark in that bit of the hall.

[carlos fandango]

http://www.pjme.co.uk/acatalog/Cylinder ... eving.html
these guys are pretty good ! could rebore aswell after.

I Beg to differ They iron sleeve an rb 250 barrel for me to 71mm f@@ked up the first time, by cutting the boost ports to high when i pointed this out, he said it was like that before when i produced a port map from my pocket he agreed to do it again unfortunately the second time, the bored it off center
They also f@@ked a barrel up for CSPE/Diablo moto

[Donnie]

There seems to be more general problems reported on Mugello's on this site and others yet people still keep buying them . I can't imagine that happening very easily to a SIL spigot. Good luck anyway

eh? nothing wrong with muggy's Ive never seen any reports of production type problems, ie where its a problem with the design and construction, most probs Ive seen are user error just like this is.

Frankly, if he cracked it through "gentle tapping" then yes, it may not have happened with a sil barrel, however, he may have carried on "gently" tapping until he cracked the crankcase instead (which Ive seen someone do!)