Thin Flange barrels reliability

[Duncan R]

After my recent engine melt down (spigot breaking off the barrel) I have now sourced a set of thin flange barrels and plan to bore them to + 80 hopefully, the problem is they have damage caused by an errant gudgeon pin scoring the bore, if they won't take a rebore they will have to be resleeved. Before starting all this and spending loads of money can I expect a problem with thin flange barrels? I will only be running 7:25 pistons and std cam and I won't be hammering the engine.

Thanks

[Goldy]

I worked in a foundry for a number of years, and castings do end up with a fair degree of difference. I would make accurate measurements of the barrels and then subtract the bore plus 80 thou and see exactly what you end up with. All the best Goldy

[muskrat]

 G'day Duncan,
                    with low/moderate comp and not being ridden by me, sleeving will be OK. http://www.ebay.com.au/itm/370553475613?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649 with those in you could still go +60 and be safe.
Cheers

[bikerjohndavies]

Hi Duncan. These might do you..

http://www.ebay.co.uk/itm/BSA-A10-BARREL-PISTONS-/130632185535#ht_500wt_1202

[Duncan R]

Thanks all

John, I already got a set s/a thin flange from the same seller that were on +60 but previous owner before the seller forgot to put a circlip on the gudgeon pin and caused a deep score on one bore. I am getting someone to look at them tomorrow to see if they can go to +80 if not it will be a re sleeve - its shame as the barrells are in good cosmetic shape.

Cheers
Duncan

[bikerjohndavies]

Hi Duncan, just thought that if you got them at a resonable price with pistons it would work out a lot cheaper than getting a set bored out to +80 and having to buy +80 pistons or having them sleeved and getting a set of std pistons.
Good luck, John

[Duncan R]

Hi John,

Your right - I take it plunger barrels fit OK? I have put them on watch now. Cheapest + 80 pistons are about £180 + rebore, re sleeving I have been qouted £80 - £110 per bore not sure if thats plus liners then pistons and honing !!!

Can you confirm plunger barrels fit the swing arm engine

Many thanks

Duncan

[Topdad]

Hi Duncan, yes plunger barrels will fit swingingarm cases ,if you rememeber in a pm to you I mentioned that I'd rebuilt a swinging arm one from a plunger doner.I was surprised to see how much the resleeving has gone up ,I'm sure I was quoted about £150  plus pistons , it was afew years ago but not that long.regards BobH

[Duncan R]

Hi Bob,

Yes you did - I thought you had just used the internals from the plunger. Just had a reply back from the gent who sold me the barrels he has got a quote for me of £150 and he has a set of good used std pistons he can let me have cheap, he is a classic car restorer who is into bikes, had a really nice Norton 99 in his workshop.He is a Jag specialist so would imagine the machine shop he uses would be very good

[trevinoz]

Plunger barrells fit but are the wrong shape.

 Trev.

[Duncan R]

Thanks

I am having a test bore done to see if it will accept +80 pistons