Author Topic: Head, barrel & fin repair  (Read 2594 times)

Offline Housewiz

  • A's Best Friend
  • ***
  • Join Date: Aug 2012
  • Posts: 144
  • Karma: 0
Head, barrel & fin repair
« on: 14.10. 2012 15:28 »
I continue to be amazed by the # of broken & chipped fins on my motor parts.  I have done some TIG, MIG, & cast iron welding in the past with reasonable success and would feel comfortable attempting the repair if there was room to get to it!!!  

What have you guys had success with?  My '58 SR has the thick flange barrels so I really want to keep them on the bike but don't like the broken fin look to say nothing of the slightly reduced fin/cooling area.  

Same thing with an alloy head that came on a spare RR motor when I bought the SR.  A large fin is broken/missing which is quite disappointing.  

Recommendations/comments?


Thanks,

Steve


Offline iansoady

  • Valued Contributor
  • ****
  • Join Date: Jul 2010
  • Posts: 471
  • Karma: 9
Re: Head, barrel & fin repair
« Reply #1 on: 14.10. 2012 15:35 »
I don't know where you are but I had an excellent job done for me at a very reasonable price by a friend of an (internet) friend.

Birmingham (West Midlands area.
Ian.
1962 Golden Flash (arrived)
1955 Velo Viper/Venom (departed)
2004 Triumph Tiger 955i (staying)

Offline Housewiz

  • A's Best Friend
  • ***
  • Join Date: Aug 2012
  • Posts: 144
  • Karma: 0
Re: Head, barrel & fin repair
« Reply #2 on: 14.10. 2012 15:38 »
Live upstate in New York State, USA.  Mind sharing the fellow's email address?  You can send it off-Forum to:

steve@housewiz.com

Thanks!!!!

Offline Stephen Foster

  • Valued Contributor
  • ****
  • Join Date: Sep 2011
  • Posts: 481
  • Karma: 5
Re: Head, barrel & fin repair
« Reply #3 on: 14.10. 2012 16:15 »
Little bit confused by Your post ?
Are You having difficulty with access to repair the missing fin , technique,or contact details for a repair specialist ?

Best method on the aluminium head is T.I.G in My experience , M.M.A for cast iron , however "Brian" guided Me recently in repairing fins using M.I.G with good results .
Pre-heat & post-heat may be required .

To reach into the root of a missing fin part way down the head for example usually requires careful removal of a fin above for access , working upwards or downwards as the case may be replacing removed fins subsequently .
I fabricate missing cast iron fins in mild steel leaving an extended tab for coping , this can be clamped or wedged to retain the fin in correct plane .. ground away after the repair is affected .
Hope the above may give You the "bare bones" of a method of progress ?

Regards,
Steve..
I own a 1955/56 B.S.A Swinging Arm "Golden Flash" , had it since 1976 .

Offline Housewiz

  • A's Best Friend
  • ***
  • Join Date: Aug 2012
  • Posts: 144
  • Karma: 0
Re: Head, barrel & fin repair
« Reply #4 on: 14.10. 2012 16:35 »
I haven't begun the search for someone to repair the barrel and head fins. Removing fins above the damaged areas seems like a doable repair by someone who has done at least a few on other engine parts.

I was looking for ideas from Forum members to shorten the learning curve as well as easing the stress on the overall restoration project budget.

Thanks,

Steve

Offline Stephen Foster

  • Valued Contributor
  • ****
  • Join Date: Sep 2011
  • Posts: 481
  • Karma: 5
Re: Head, barrel & fin repair
« Reply #5 on: 14.10. 2012 16:49 »
Best of luck with the restoration Steve !
Probably better practising on scrap materials first ..worth bearing in mind when replacing fins on the barrels they may need reboring after welding ...
I usually try to repair these when a rebore is called for either way .

Best Wishes,
Steve...
I own a 1955/56 B.S.A Swinging Arm "Golden Flash" , had it since 1976 .

Offline iansoady

  • Valued Contributor
  • ****
  • Join Date: Jul 2010
  • Posts: 471
  • Karma: 9
Re: Head, barrel & fin repair
« Reply #6 on: 14.10. 2012 17:24 »
Live upstate in New York State, USA.  Mind sharing the fellow's email address?  You can send it off-Forum to:

steve@housewiz.com

Thanks!!!!

Hi Steve,

I don't think he has one but I can try to find out. He is an old-school welder (I never actually met him, having the job done via my intermediary).

Not sure if it would be viable for you given shipping prices from USA.
Ian.
1962 Golden Flash (arrived)
1955 Velo Viper/Venom (departed)
2004 Triumph Tiger 955i (staying)

Offline Stephen Foster

  • Valued Contributor
  • ****
  • Join Date: Sep 2011
  • Posts: 481
  • Karma: 5
Re: Head, barrel & fin repair
« Reply #7 on: 14.10. 2012 17:36 »
Steve ..
Wonder ..do You have a Technical college or similar close to the area You live ?
Sometimes these have the facilities for this type of repair .

Steve..
I own a 1955/56 B.S.A Swinging Arm "Golden Flash" , had it since 1976 .

Offline MG

  • Resident Legend
  • *****
  • Join Date: Dec 2009
  • Posts: 949
  • Karma: 23
Re: Head, barrel & fin repair
« Reply #8 on: 14.10. 2012 17:38 »
TIG with AlSi5 rods for ally heads (AlSi12 for really unruly alloys, but Beeza heads usually are easy to weld, even with AlMg rods). Pre-heat to 150°C.
Cast iron fins with TIG and nickel rods, pre-heated, step-back spot welding. Tapping the weld spots with a small hammer helps reduce residual stresses and avoid cracks.
Not the only possible way of tackling it obviously, but works for me.

Cheers, Markus
1955 A7 Shooting Star
1956 A10 Golden Flash
1961 Matchless G12 CSR

www.histo-tech.at - Restoration, Repairs, Racing

Austria

Offline Housewiz

  • A's Best Friend
  • ***
  • Join Date: Aug 2012
  • Posts: 144
  • Karma: 0
Re: Head, barrel & fin repair
« Reply #9 on: 14.10. 2012 19:12 »
Thanks guys! I am planning on taking 1-2 years to assemble all the missing/rebuild parts.  This Forum will be a monster help - like having dozens of experienced BSA mechanics in my little shop.

The motor will be a total tear-down.  The lower end and head will be farmed out to a competent English bike mechanic/machinist - I have found two within an hour or so drive. 


Tanks again,

Steve

Offline Housewiz

  • A's Best Friend
  • ***
  • Join Date: Aug 2012
  • Posts: 144
  • Karma: 0
Re: Head, barrel & fin repair
« Reply #10 on: 16.11. 2012 20:40 »
The estimates I am getting from two sources for barrel fin repair plus a possible re-bore may cost more than a used barrel set w/no broken fins.  Found a barrel set that appears to have been bored out .062 over the stock diameter of the factory 70mm..

What's the max cylinders can be bored out and still have sufficient life left for me to put tons of miles on the bike?  How much material would be left in the factory sleeves after that mega-bore which measures 71.58mm (2.818" measured buy the owner)? 

Thanks guys,

Steve

Online chaterlea25

  • Wise & Enlightened
  • *
  • Join Date: Jun 2009
  • Posts: 3146
  • Karma: 45
Re: Head, barrel & fin repair
« Reply #11 on: 16.11. 2012 21:20 »
Hi Steve,
The  usual max is +060 so the spare barrels you are looking at appear to be at this bore size
There used to be + 080 pistons available but I have not seen them for some time
The cylinders can be re sleeved back to standard but this adds again to the costs
Theres a cylinder for sale in the US on ebay number 271103047776 which is statet to be 2.79in (70.86mm)
so its between +30 and +40

HTH
John
1961 Super Rocket
1963 RGS (ongoing)

Offline Housewiz

  • A's Best Friend
  • ***
  • Join Date: Aug 2012
  • Posts: 144
  • Karma: 0
Re: Head, barrel & fin repair
« Reply #12 on: 16.11. 2012 21:30 »
Hey John, 

Thanks for the reply!

I saw those barrels - they have the thin flange base and I would like to stay with the thick flange as that's what is on my SR.

The seller of the barrels I found said the cylinder liners are .150" thick and could be bored out to .080" before requiring re-sleeving.  Is that true?

Thanks,

Steve

Offline mark

  • Melbourne, Australia
  • A's Best Friend
  • ***
  • Join Date: Jul 2009
  • Posts: 119
  • Karma: 2
Re: Head, barrel & fin repair
« Reply #13 on: 16.11. 2012 23:10 »
I am running +80thou Wiseco forged pistons in my Road Rocket and have had no issues. Pistons came from Cake St Classics in the UK.

Regards
Mark
55 road rocket




71 Norton Commando Roadster 750


Australia

Offline JulianM

  • A's Best Friend
  • ***
  • Join Date: Jun 2012
  • Posts: 233
  • Karma: 14
  • www.historiccompetitionservices.be
    • Historic Competition Services
Re: Head, barrel & fin repair
« Reply #14 on: 19.11. 2012 07:33 »
Hi,

I know you say you want to fix it as it's a thick flange barrel etc. However these can be picked up in very good condition for a couple of hundred pounds tops and usually cheaper in the states from what I have seen. 
After hours of messing around you will think that 200 pounds is very cheap compared to cutting off fins and prepping / welding for hours to get the same result or less!

Once you have your replacement, sell your damaged one on eBay to recoup some of your replacement cost. You would be amazed what some people pay for broken finned barrels.

Regards,
Julian
55 Ariel HS mk1,
58 BSA Super Rocket Scrambler special,
60 BSA Gold Star, Jim hunter desert racer,
64 Norton N15CS,
65 Triumph TR6 SS,
66 Triumph Bonneville,
71 AJS Stormer,
71 BSA Rocket 3,
71 Laverda 750SF,
71 Laverda/Egli 750SF, Race bike,
73 Norton Commando 850,
74 Moto Morini 3-1/2 Sport,
74 Bultaco Sherpa 350,
76 Beta Cross 50,
77 Moto Guzzi Le Mans Mk1,
80 Ducati 900 MHR,