welbike Posted April 5, 2021 Share Posted April 5, 2021 G3L, has less fins on the top l/h side, and the pipe pushes in, so it's not that, but what and why, I don't know, is it not G80? larger bore, but same bolt pattern. Cheers, Lex Quote Link to comment Share on other sites More sharing options...
Ron Posted April 5, 2021 Share Posted April 5, 2021 (edited) I've just been reminding myself. The G3 has an exhaust spout. G3L doesn't. Ron Edited April 5, 2021 by Ron Quote Link to comment Share on other sites More sharing options...
welbike Posted April 5, 2021 Share Posted April 5, 2021 Yes, they had to loose weight!! and a lot of it too! Lex Quote Link to comment Share on other sites More sharing options...
flyingfleasteve Posted April 9, 2021 Author Share Posted April 9, 2021 It’s certainly a strange head. I cannot seem to find any information about it, most other Matchless heads do no appear to have the exhaust spigot. Small steps this week, the barrel has gone to the blasters, I have decided to have a go myself at repairing the broken fins.....😬 Now that the crank breather pipe has arrived and fitted I can start building up the drive side of the engine. Quote Link to comment Share on other sites More sharing options...
flyingfleasteve Posted April 11, 2021 Author Share Posted April 11, 2021 (edited) The barrel is now back from the blasters and there are several cooling fins to be repaired. I have started the process but it’s much harder than I anticipated....... I shall keep plodding on....here’s hoping. Edited April 11, 2021 by flyingfleasteve Quote Link to comment Share on other sites More sharing options...
Chris Hall Posted April 11, 2021 Share Posted April 11, 2021 I tried welding cast iron once and gave up. I think it’s a very specialised art form, controlled heating and cooling of your work and using the correct filler material is key. When I tried, I pre heated it the Gas BBQ and very slowly cooled in the BBQ, but it didn’t really work to well and I had little hair line cracks around the fin, radiating beyond the original damage. Quote Link to comment Share on other sites More sharing options...
Ron Posted April 11, 2021 Share Posted April 11, 2021 The two specialist guys I've used for cast iron fin repairs always braze the new piece on. However these two guys involve a lot of traveling, so I've had a couple repaired by an excellent local fabrication guy (Phil) who simply TIG welded mild steel to the cast iron and defied me to snap them off without using serious force. What is it with such heavy handed people who can't remove a head or barrel without breaking fins off. I managed to drop this NOS M20 head about 10 years ago, which broke about 5 fins. Phil repaired it with TIG. I've just replaced it with another recently acquired NOS head, during my big bore piston fit. Ron 1 Quote Link to comment Share on other sites More sharing options...
flyingfleasteve Posted April 11, 2021 Author Share Posted April 11, 2021 I am going down the brazing route. But it takes a knack to get the heat into the metal and brazing rod. Once the braze is grinder back if it’s not adhered 100% it leaves a weak area and the job starts again. I have to say this barrel is abnormally damaged, but I will keep plodding away..... Quote Link to comment Share on other sites More sharing options...
welbike Posted April 12, 2021 Share Posted April 12, 2021 I have an old cylinder, that I use for knocking the fins off of, and then grind the pieces to size and MIG weld them just on the edges, still holding out after all these years, but the damage wasn't so severe as on Steve's barrel, I don't think it affects the cooling much, as the OHV design runs a lot cooler than a sidevalve. Cheers, Lex Quote Link to comment Share on other sites More sharing options...
flyingfleasteve Posted April 12, 2021 Author Share Posted April 12, 2021 I have given it a good go, in the end after buying an expensive brazing touch I ended up welding the repairs, heating both the barrel and new section of metal both before and after. A few imperfections but pretty solid 🤞........time will tell but never again! 2 Quote Link to comment Share on other sites More sharing options...
Chris Hall Posted April 12, 2021 Share Posted April 12, 2021 Looks a good job! Better than mine ended up.....let’s just say it was down to better iron! Quote Link to comment Share on other sites More sharing options...
Leggy90 Posted April 12, 2021 Share Posted April 12, 2021 Wow! Excellent work Steve, you would never think it had been repaired. Quote Link to comment Share on other sites More sharing options...
flyingfleasteve Posted April 13, 2021 Author Share Posted April 13, 2021 Thanks gents! The job is no way perfect but a vast improvement, it was in a bit of a mess before hand, I am glad I have tackled the job, I just need to have the barrel bored out now then it can be fitted! 1 Quote Link to comment Share on other sites More sharing options...
Rootes75 Posted April 13, 2021 Share Posted April 13, 2021 That is a very nice and neat repair. Quote Link to comment Share on other sites More sharing options...
flyingfleasteve Posted April 13, 2021 Author Share Posted April 13, 2021 3 hours ago, Rootes75 said: That is a very nice and neat repair. Thank you for your kind comments! Quote Link to comment Share on other sites More sharing options...
flyingfleasteve Posted April 20, 2021 Author Share Posted April 20, 2021 Progress was a little slow last week but a few more jobs ticked off...I am hoping the repair to the exhaust flange is the last bit of welding....... 1 Quote Link to comment Share on other sites More sharing options...
Ron Posted April 20, 2021 Share Posted April 20, 2021 Well done Steve. A bit more practice and we'll all have someone to send our broken barrels to😏 Is the metal ring inside the exhaust port a permanent fixture now? Ron Quote Link to comment Share on other sites More sharing options...
flyingfleasteve Posted April 20, 2021 Author Share Posted April 20, 2021 Thanks Ron yes it is. I thought long and hard about including it as I did not want to impede the exit of the gases but the repair is now belt and braces with hopefully 0 chance of leaking/ recurrence of damage. I polished back the inner section of the sleeved tube and took the step away which I hope will help 🤞 I was feeling creative yesterday, I also made this...... Quote Link to comment Share on other sites More sharing options...
Ron Posted April 20, 2021 Share Posted April 20, 2021 I will have to refresh my memory about the battery carriers and fixings, as we learnt last year that there are differences between the G3 and G3L and I think I might need to swap mine as I think both mine arrived to me with each others carrier. ........ Purely by coincidence as the bikes came from totally different sources. Ron Quote Link to comment Share on other sites More sharing options...
Ron Posted April 20, 2021 Share Posted April 20, 2021 Well it only took me 1/2 hour to gather tools, move the bikes and remove the battery trays. The difference can easily be seen at the tops. The G3L is reduced in width. Both will now have to be re-painted in their respective colours. Matchless didn't bother to change the part number for the modification? Ron Quote Link to comment Share on other sites More sharing options...
Chris Hall Posted April 20, 2021 Share Posted April 20, 2021 Were the carriers produced by Matchless or are they Lucas items specifically for Matchless? Quote Link to comment Share on other sites More sharing options...
welbike Posted April 20, 2021 Share Posted April 20, 2021 I actually don't know, but suspect AMC themselves, Norton BSA and RE had Lucas parts, but that came from a universal prewar system, they are stamped with Lucas, and a date code, albeit very faint. Lex Quote Link to comment Share on other sites More sharing options...
flyingfleasteve Posted April 20, 2021 Author Share Posted April 20, 2021 9 hours ago, Ron said: Well it only took me 1/2 hour to gather tools, move the bikes and remove the battery trays. The difference can easily be seen at the tops. The G3L is reduced in width. Both will now have to be re-painted in their respective colours. Matchless didn't bother to change the part number for the modification? Ron Different in height to Ron? I assume they accepted the same battery? Quote Link to comment Share on other sites More sharing options...
flyingfleasteve Posted April 20, 2021 Author Share Posted April 20, 2021 A bit of advice folks..... I have stripped the rocker cover down and noticed there one of the rocker arms had excess lateral movement. On closer inspection it appears the outer bush is worn and the arm has started rubbing the inner casing. How easy are the bushes to remove and replace? I cannot see how to get any type of tool inside the bush to remove it? Quote Link to comment Share on other sites More sharing options...
Chris Hall Posted April 20, 2021 Share Posted April 20, 2021 I can’t see from the photo the size and shape of the cover, but when a bush is fitted in a blind hole, the process is normally as follows. Heat the area around the bush and then bang the cover on a hard, flat surface so that inertia will force the bush out of the expanded aluminium. it only needs to come out a little to know that it will come out. If you get it moving, you can re-heat and go firm but gentle. No need to belt the crap out of it, it’s all in the technique. Quote Link to comment Share on other sites More sharing options...
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