Engine blown - Cylinder spigot fractured

[kiwipom]

hi guys/olev, i have done, that i was onto that one, sometimes people do not seem to know what they have i have seen Norton cases advertised as B.S.A.cheers

[kiwipom]

hi guys, a couple of pics of barrels that i got from U.S.A. in damaged state,you can see the top finn has been welded. Just bought some fron nz site Trade-Me advertised as A7 but Olev assures me that they are A10. I wonder if they have cast marks A7 on the thick flange as i have only just noticed on my damaged set, does anyone know why they are marked this way,cheers,Bob

[1660bob]

Yeah Good Call MG- the barrell situation is  dire, and A10 cases/pistons rods are going to continue to get damaged as weary worn out barrels are desperately sleeved and fail like above . Recently I paid a visit to Molnar Engineering in Preston and on the shop floor there was a batch of lovely new alloy Commando barrels awaiting machining, yummy!. I asked Mr. Molnar if there was any chance of some A10 barrels being made by him..... NO came the rather short answer. Ah well.... I told him the barrel situation was desperate for A10`s, so I`ve sown the seed at least. C`mon SRM!, have another look at barrels for us, we`re all gonna have to convert (back) to Commando`s at this rate!!!!! Bob `C`

[RichardL]

Interesting. I had a run-in with his wife by email and did not know, at the time, that both of them were a-h8&%$. Trust me, I am being so reserved in not completely flying off the handle right now. Here is part of a previous thread. http://www.a7a10.net/forum/index.php/topic,881.msg5819.html#msg5819  Apparently, these two have made a career of making enemies.

Richard L.

[1660bob]

Hi Richard,I have to say none of the comments on your link to the earlier post surprise me much.
I have been buying stuff from Molnar`s all of my classic bike life, (20+years) and it never gets easy. I have consequently bought less and less from them to the point where i avoid at all if possible simply because I like to visit in person, and see what I am paying out for whenever possible! (I live just 1 mile away, and I once ordered some bits which took a month+ to come!!!)But its plain callers like me are not really welcome.
I can understand this to some extent as Mr.Molnar is best described as "feverishly busy" making a lot of good components for the classic bike scene, and hasn`t much time to deal with customers face to face or on the phone etc etc,.But this of course is ridiculous when your income comes from those very customers.It seems he is much more into the Manx racing engine parts/Vincent crankcases etc these days and of course customers for such items are generally well financed and spend much more per transaction than the likes of Me who just want a more modest order of shiny nuts/bolts.His business seems in the main,to have moved on to such major components/full engines/spares. I really wonder whether he should consider selling off the nuts/bolts/small components side to someone who can devote the time and proper courtesy to more modest customers, whose stainless timing case screw set means just as much to them as a Race Team Manager buying a full Manx engine.It`s a shame, but I shop elsewhere as a result.Best Regards, Bob `C`

[Mark Parker]

If anyone was going to cast some cyls I think alloy would be worth doing. With black paint they could be made to look like std. They could also be modified a bit and made a lot stronger. I haven't got A10 cyls to look at but A65 ones are probably similar. I made some alloy cyls for my A65 and made them as strong as I could. So have no air flow between the bores, it is solid. The spigots are also joined, and the flange is thicker. I use 8mm headbolts and studs and have had no problem with threads, which are deep. I run it with 883cc 79.5 bore and 89mm stroke at about 10 to 1 comp. The spigots need the mouth of the cases opened a bit because the bore is so oversize, std is 75mm. Nakisil bores work better than iron liners I used on an earlier version. I use forged pistons and modern chrome rings with close clearances, best ring seal I've ever had and after a few years seems still like new though haven't pulled it down to look.
 This is before plating:
http://i20.photobucket.com/albums/b213/markparker/IMG_5991.jpg
This is on the bike, (I wasn't trying to make this cyl look std.)
http://i20.photobucket.com/albums/b213/markparker/bsa/bsa181008051a.jpg

[muskrat]

 G'day Mark,
                 They look the goods. There's a fellow up here that does alloy casting, will give him a look. I think I would prefer CI liners.
 Got any spares ? Just got a '64 A65 to play with.
 Cheers

[Mark Parker]

The problem with a liner is you loose strength, and the head bolt holes are so close to the bore. Also the Nicasil can run tighter piston clearence, seal better, transfere heat better and have a longer life. I can get A65 cyls cast and heat treated to T6 (so the threads don't pull out) for around $300 but getting them machined is the difficulty.

[Mark Parker]

This topic has me thinking, A10 and A65s must have the same bore centres. The case flange is different, but what if a cyl was cast to suit an A10 bottom end with A65 size 75mm bore or maybe a bit bigger, with head stud pattern to fit an A65 head? I know this might not be what A10 owners would generally want but it would be pretty effective for a 750cc special if it was possible. I don't know if A10 owners appreciate the merits of an A65 twin carb head but they can be flowed using 44.5mm inlet valves and 39mm exhausts and make a lot of power.

[MG]

...combined with musky's through-bolting solution!

Put me on the list for one, a proper pre-unit 750 with twin carbs and big valves, what's not to like about that??? 

[Topdad]

Can't wait to see this idea take off !! strange how abit of reported bad luck with an engine could lead to this ....SRM eat your heart out ,if I wasn't such an old fart it would be enough to get me to move to your fair country ,only plan available to me.... I'll work on the kids????cheers bobh.

[muskrat]

 I agree Mark the lightning heads are great, just put an early one with 40mm inlets on the "64. No more pushrod comb or oil leaks. Only down side is having to remove one rocker shaft to get to two head bolts, and those pesky circlips on the followers.
 I have a spare set of cases, barrels & head I could bring down (2 hours south) and over a beer or twenty recon we could nut something out.
Cheers

[MG]

Bugger, wrong side of the globe for me!

[RichardL]

Back to daydreaming, I ran into a neigbor (who lives just down my street) while waiting for the bus the other day. I says, "Gene, aren't you involved in metals somehow?" He says, "Yes." I ask some questions about getting iron cast in a local foundry and he seems to know all of them. Why? He gives me his card at the end of the conversation and his title is "Sr. Foundry Metallurgist" for an international mining corporation in which iron ore is just one of their products. On top of it, he is a bit of a gear-head and a man who appreciates and has owned vintage motorcycles. What a strange and small world.

Richard L.

[muskrat]

Richard,  get him drunk and take some photos. You'd be surprised  what he might offer for the negs 
Cheers