pat slinn Posted January 3, 2010 Report Share Posted January 3, 2010 Hi Charlie & Alan, I saw a C15 barrel during the 60's that had the pushrod tunnel cast in. It was from the states. Cant remember if it had a liner or a chromel bore. The 441cc Victor GP had a Nikasil bore and that was in the early 60's. The F1 & F2 Ducati engines that I built for Tony Rutter in the 80's had NiKasil bores and were trouble free. I never had to change a barrel on the 600 or 750 in 3 years, and that they were used in the TT and all the F1 & F2 championship races in the UK & Europe. There is something really satisfiying about making your own patterns, and casting something. Go for it Charlie. Pat. Quote Link to comment Share on other sites More sharing options...
alan Posted January 3, 2010 Report Share Posted January 3, 2010 hi Pat, were the Ducati bores plated localy.. somewhere like Stalybridge for instance.. or were they shipped from Italy? Charlie, At the risk of nearly going back on thread.. When i had my Serco ally barrel rebored, the liner had gone oval. The ovality was blamed on the uneven shrink due to the irregular shape of the barrel especially in the region of the push rod tube cut out.. nikasil bores might kill two birds with one stone...... and maybe open up a commercial opportunity... this time next year, me, you and Pat could all be millionaires........... Quote Link to comment Share on other sites More sharing options...
pat slinn Posted January 3, 2010 Report Share Posted January 3, 2010 Alan, Ducati had there barrels plated in Italy. I believe that there is a company called Motrac from Ellesmere Port that are specialists in Nikosiling cylinder barrels. Remember the early air cooled 250 TD Yamaha racers, they had a piston siezure problem because of cylinder distortion, water cooling sloved the problems. PS. Just looked up Motrac on the internet, I Googled Niksil plating. Pat. Quote Link to comment Share on other sites More sharing options...
charlie prescott Posted January 3, 2010 Author Report Share Posted January 3, 2010 Hi Guy's , Alan Pat, Thanks guy's for the encouragement, yes I will go for it, get the castings done and then decide ,Liner, Nikisil ,Or even Ceramic bore as I have a company in cheltenham that will process the latter. Pat, have you heard of a foundry with the name SIRMAL, as I have a B44 barrel with that name on it in front of me,bore is 85mm, Is it from the USA? as it was one used by Arthur Lampkin,I am told, and has a cast liner built in,Not the norm hey, as you guys say they were Nikisil plated. Do you think we may be on to a gap filler then? Regards Charlie. Quote Link to comment Share on other sites More sharing options...
totalshell Posted January 3, 2010 Report Share Posted January 3, 2010 jump into a fantic forum where nikasilling is common, as i remember when i had mine done only two places in the uk any good with the best being in the south west.. Quote Link to comment Share on other sites More sharing options...
charlie prescott Posted January 5, 2010 Author Report Share Posted January 5, 2010 Hi Guy's OK, Got a lump of Jelutong,( Wood from Malaysia) and have sourced some 3mm Birch ply too model the fins on the wooden pattern. And have been in touch with the "Monkey on my shoulder"! (sorry Paulie) and he has told me he has an old book in his extensive library, on casting practices, he also said I need a Pattern Makers Rule, or a "Shrink rule" as they are called. He has an old Rabone catalog with one in but said it was 2 shillings and 6d. so the price was well out of date. The only one I can find, is in the States, but it would be wouldn't it, as them boys are into every thing. Paulie said, don't forget if you intend to fit a dry sand core into the mould you will have to incorporate prints into the pattern to hold this. Yea OK Boy, I said. Looks like I am getting into a whole new world of "Foundry Speak". Looking like fun though. Regards Charlie. Quote Link to comment Share on other sites More sharing options...
b40rt Posted January 5, 2010 Report Share Posted January 5, 2010 Hi Guy's OK, Got a lump of Jelutong,( Wood from Malaysia) and have sourced some 3mm Birch ply too model the fins on the wooden pattern. And have been in touch with the "Monkey on my shoulder"! (sorry Paulie) and he has told me he has an old book in his extensive library, on casting practices, he also said I need a Pattern Makers Rule, or a "Shrink rule" as they are called. He has an old Rabone catalog with one in but said it was 2 shillings and 6d. so the price was well out of date. The only one I can find, is in the States, but it would be wouldn't it, as them boys are into every thing. Paulie said, don't forget if you intend to fit a dry sand core into the mould you will have to incorporate prints into the pattern to hold this. Yea OK Boy, I said. Looks like I am getting into a whole new world of "Foundry Speak". Looking like fun though. Regards Charlie. Love to see some pictures as you progress. Ross Quote Link to comment Share on other sites More sharing options...
charlie prescott Posted January 6, 2010 Author Report Share Posted January 6, 2010 Hi Guy's, Pat Slinn, Just e-mailed me with this information, I'm sure he won't mind me re publishing it on here. He also said,did I think the Scottish Pre65 committee, would allow cast in push rod tunnels on A C15? You tell me. Here is Pats e-mail. Hi Charlie, Part of my "general" engineering training whilst a apprentice at BSA was spending time in the pattern making shop and casting prototype castings. BSA management in their infinite wisdom decided to close down the pattern shop and have all casting out sourced. another lost skill. Apart from sending young apprentices for "long waits" and "left handed screwdrivers" some of us were tricked into using "shrink" rules for general use!!!!. Causing great fun amongst the older craftsmen. If anybody tried that to day it would probably be a violation of something or other. As you progress with the patterns perhaps you could post them on trials central, that would make a very interesting post. Funny you should mention Jelutong a friend of mine only showed me a piece that he had in his garage, his father was a pattern maker. Pat. Yes Pat I will post some photos as I progress. Regards Charlie. Quote Link to comment Share on other sites More sharing options...
kev99 Posted January 12, 2010 Report Share Posted January 12, 2010 hi charlie, how did you widen the cub swing arm without cutting it was thinking of doing one myself. cheers kev Quote Link to comment Share on other sites More sharing options...
charlie prescott Posted January 12, 2010 Author Report Share Posted January 12, 2010 (edited) Hi Guy's. Hi Kev. Right, first you need a surface table, or a flat surface of some kind. And also the use of a set of gas bottles. Now, as you look at the swinging arm from the back, the right hand leg is straight? Yes? now this is the side you modify. you really want two angle brackets with holes in to be able to bolt the pivot spindle to these brackets , and then clamp them to the table, if you see where I am coming from. Now, If you look at the casting the tubes are brazed into, you will see that the left one (from the Back) points out at a slight angle, this is the profile you need for the other side. So you really need some one with gentle hands to put outward pressure on the right hand leg,while you heat the casting diagonally across the corner until it is about cherry red, your other pair of hands should then feel the leg moving slightly, now just play the heat gently on to the casting until it resembles the other side, (DO NOT) Apply to much heat or the casting will crack. The right hand leg should now be out at an angle. Let the casting cool. Now measure and mark up where you need to bend the leg tube to match the other. Again apply heat to the leg tube at the point where it needs to be bent. gently pull this back when hot, too the profile of the left one, and until the back dropouts are parallel.If you string a center line from the front you should now have a measurement from this center line on both side of the center of about 3. 7/16" . When cool you can cold set and true on the face table. After some time I also decided to lengthen the back spindle plates by 1", then filling in the same amount of spindle hole at the front. Should I have made or bought a newly manufactered one? But it was fun. This is something like it should look, Picture Greystone. Edited January 12, 2010 by charlie prescott Quote Link to comment Share on other sites More sharing options...
kev99 Posted January 12, 2010 Report Share Posted January 12, 2010 hi charlie,thankyou for your reply but now i am confused!!!! the 2 swing arms that i have both look like the pic and measure 150mm across the inside back edge. was this a factory part or would someone have kindly widened them for me. will have to dig in the garage and see if i have a striat one. but it looks like i have saved some gas,just slipped it over a 400 back wheel and it looks to have good clearance.. thank you again for your help ... kev Quote Link to comment Share on other sites More sharing options...
charlie prescott Posted January 12, 2010 Author Report Share Posted January 12, 2010 Hi Guy's. Hi Kev. Good news then, all you need do is lengthen the plates at the wheel spindle end by 1" to be a good job. The arms you have could be BSA Bantam D7 I think. Do they measure 6 3/4" ish, between plates? I'm here to be corrected as I have never used them, perhaps I should have? To any one who carries out similar mods ,Don't forget you need to widen the top damper mounts to the same width as the swinging arm, or use Trikshocks, or any units with Rose joints. Regards Charlie. Quote Link to comment Share on other sites More sharing options...
b40rt Posted January 12, 2010 Report Share Posted January 12, 2010 Hi Guy's.Hi Kev. Good news then, all you need do is lengthen the plates at the wheel spindle end by 1" to be a good job. The arms you have could be BSA Bantam D7 I think. Do they measure 6 3/4" ish, between plates? I'm here to be corrected as I have never used them, perhaps I should have? To any one who carries out similar mods ,Don't forget you need to widen the top damper mounts to the same width as the swinging arm, or use Trikshocks, or any units with Rose joints. Regards Charlie. Hi Charlie I take it that your background is engineering, interesting getting the hands on experience/info that you obviously have. (and Wayne) Quote Link to comment Share on other sites More sharing options...
charlie prescott Posted January 14, 2010 Author Report Share Posted January 14, 2010 Hi Guy's, Just been doing a bit more research on BSA and came up with this GEM http://www.babelgum.com/3002075/champions-jeff-smith.html. Now sit back and enjoy a piece of history,filled with information.Brilliant. Bruce Cox ! Is it the Bruce Cox I used to know way back,from Banbury? Regards Charlie. Quote Link to comment Share on other sites More sharing options...
2fargone Posted January 14, 2010 Report Share Posted January 14, 2010 Thanks for that link Charlie, very interesting. Quote Link to comment Share on other sites More sharing options...
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