Triumphrat

timwil · 05-15-2008

There seem to be about 1/2 " dia inserts pressed into my 1954 T100 alloy barrels which are drilled and tapped for the headbolts. Is this normal or some kind of Asian repair? A couple of these were standing proud a bit and I filed them flat as best I could but blew new copper head gasket at idle. Should I remove barrel and have the surface milled? How about the area between the sleeves where a milling cutter won't go? The head has been surfaced.
Tim in Phuket

oldebonnie · 05-17-2008

tim-

I'm not an expert on any Triumphs, I just know a little about unit 650s. But I thought I would give you a bump back up to the top of the line; I'm sure someone around here will be able to help you.

C'mon guys, give Tim a hand if you can.

timwil · 05-21-2008

Thanks for the comeback on this. Sorry for the delay. I removed the barrel and visited some local machine shops. It seems the inserts are steel and may be threaded or pressed into the barrel. With luck they won't rise anymore (maybe dreaming). Anyway will anneal the gasket, copper coat it, maybe a bit of sealer and put it back togather and hope for the best. I go to sea in 6 weeks and would like to ride the bike a bit before. I have strarted looking for a replacement barrel, any ideas where to look other than ebay.
Tim

timwil · 06-17-2008

Hi Everybody
Sorry to keep pressing this but I didn't get many replys last time and I really need some help. After 1st blown gasket I filed the after left insert ( it had risen about about .1mm, annealed the gasket, copper coated it, and put it back togather. The problem corner took the tourqe mushely but took it. I rode the bike 250 clicks with no problem other than oil leaks which I am learning to deal with. Starts on the 1st kick and runs great, I love it. But ,alas, I started it the day after a 50 click ride and the head gasket blew at idle. I got an 1/8 turn on the two left side head bolts with an 8" open end wrench the rest were tight. I started it, it ran great and went for another 50 click ride with no problems. but I fear my troubles are not over. In my search for a new barrel I came across this NOS one with pistons, very expensive (700 pounds), and it appears to have inserts like mine. My question is could these inserts be original? I have also seen photos of pre-unit alloy barrels where the head bolt threads seem to be tapped into the alloy. Also need help on sourcing another barrel should this one be unrepairable. The part book says E2958 but mine is E2679 The one in the photo is E2958. I think either will work. Help please.Tim
I can't figure out how to make these photos bigger. Please go to my album to view larger

Rob D · 06-19-2008

Tim,
I have never seen inserts in a set of barrels, not saying that it is not a good fix, just saying I have not seen that particualr repair. I used to repair Pre-Unit jugs by tapping the head bolt threads over in SAE 3/8" - 24 fine thread.

Good inserts known as KeenSerts are excellent however, they come with some precautions also. Namely in drilling and tapping for the new insert. You will need to get the Helicoils out obviously, find a supplier of the KeenSerts, get the entire kit for drilling and tapping etc...
The other concern is whether there is room for the repair in the jugs.

http://www.newmantools.com/kee.htm

The first thing that you will need to is determine also which thread and pitch you are going to go with, it will not be Whitworth BTW, insure that you can find these bolts at the proper length and grade, then et the KeenSerts kit.

Not at all surprising that the '54 T100 alloy jugs suffered pulled threads but they can be repaired with care.

Also, Be sure not to just tighten the bolts up rather torque them to spec.

Good play with the annealing of the gasket....

Anyway, the Keen Certs (IMO) will be better than the Helicoils that can move in the threaded hole which is not good.

Best,
Rob

timwil · 4 Weeks Ago

Rob, Thanks for the reply. I checked the Keen Serts site you sent & They may work, but as you said when I tap the existing !/2" plus holes it may break through the barrel walls. I will pull the cylinder and and press out the left sleeve and try to remove the existing inserts and see what I have. Do you think there is any chance of reuseing my newly bored sleeve or will I have to resleeve? I bought a cheap barrel on ebay but think it is for an early 50's hardtail and may not fit my 54 swingarm. I will find out when I get to Houston in 3 weeks.
Regards Tim

bushybester · 4 Weeks Ago

I am not quite sure I understand your exact problem. Let’s see! What size diameter are your head bolts? I think they should be 3/8 in with cycle thread. If that is the case I would start with re-tapping the threads, then if the head bolts are slightly worn I would get new head bolts. And don’t tell anyone else, go to your local bicycle shop and buy bicycle axel's with their nuts instead of new bolt and borrow his tap & dies to clean up your threads.

Good luck.

Rob D · 4 Weeks Ago

bb,
I think the issue is that the holes have already been drilled and tapped for Heilcoils which would have made them oversized already so the re-tap is not an option.

Nice tip on the bicycle axles...

Best,
Rob

Quote:

Originally Posted by bushybester

I am not quite sure I understand your exact problem. Let’s see! What size diameter are your head bolts? I think they should be 3/8 in with cycle thread. If that is the case I would start with re-tapping the threads, then if the head bolts are slightly worn I would get new head bolts. And don’t tell anyone else, go to your local bicycle shop and buy bicycle axel's with their nuts instead of new bolt and borrow his tap & dies to clean up your threads.

Good luck.

timwil · 4 Weeks Ago

Hi Everybody, I am glad I am getting some interest in my problem. My head bolt threads are in perfect condition. The problem is that 2 of the steel inserts that the threads are tapped into are riseing. These are not helicoils or any other kind of repair. I have recently found out that these incerts are original on mid 50's 500cc alloy barrels. Please go to my photo album (timwil) and see the photo of the NOS barrel and the inserts are clearly visable. I don't know how they were installed "at the factory" (threaded or pressed) or how the 2 loose ones can be fixed. Any ideas?Regards Tim

OzBloke · 4 Weeks Ago

Might I suggest you email the guys at British Spares in NZ - sales@britishspares.com

They're very helpful, and possibly have a NOS barrel. If not, they'll be able to point you in the right direction, or try to find one for you. I got a new 750 barrel set from them, c/w pistons and rings, for $500AUS.