Triumphrat

Roger-SA · 06-14-2012, 10:43 AM

I am going to share my progress with my '71 Bonneville OIF rebuild, to as close to factory original as I can get it. I purchased the bike some 25 years ago, from a bike dealer as the client had abandoned the bike. At that point I promptly stripped it, and had the frame sand blasted and painted. The rest of the bit's were boxed. In the process I managed to loose the cylinder head bolts and rocker boxes. When I initially stripped the motor, I was pleasantly surprised to see it had new pistons and must have recently been re-bored, as the piston crowns were new with no carbon deposits. I envisaged a quick restoration as I assumed there were minimal bits missing. So 25 years later, I discover that all the expensive bits are missing, and all the other equally expensive stuff is worn out! Early last year my son Michael showed some interest in us getting the bike restored, so he dug out all the bits from around the workshop.
Here are some pictures of the starting point!

GrandPaulZ · 06-14-2012, 10:49 AM

Welcome to the forum, Roger. There are many interested members here that regularly follow the build threads, a total of three moderators that jump in with advice, and plenty of sources of parts, tools & reference material should the need arise.

You are at a bit of a disadvantage being in SA, as shipping will be a bit of an additional cost burden, but it is what it is, and you've got plenty to work with in those pix.

Lee H · 06-14-2012, 10:59 AM

cool thread... I am currently rebuilding a 71 TR6

Roger-SA · 06-14-2012, 11:20 AM

The next order of business was to definitively find out what all was missing. I downloaded the "Replacement Parts Catalogue for 1971 Bonneville T120R" as well as the "72 Triumph 650cc Twins Workshop Manual" . My engine and frame numbers matched up as DE17892 which places thew bike as an April 1971 Triumph. We then copied the entire parts catalog in the Excel so we would have a tool to manage all aspects of the project. As of now there are 1072 line items in the catalog, which is quite daunting when you are trying to account fro everything. It was also a surprise to deduce that the parts catalogue was silent on a few parts, like the head steady and rear brake pivot pin etc. Using Excel the old part numbers were easily converted in to the new part numbering format.
Next every item we had was identified on the list, as well as an indicator to say what its condition was, as well as how it was going to be sourced/fixed. In the end I had the following categories - New Part, Replace, Repair, Make, Source Local.
I then trawled through all the places that sell bits and pieces, and indicated their selling price, so at a later stage i could make a decision as to where to source the items. As I am located in Johannesburg, South Africa shipping is a huge cost and I needed to optimize this as much as possible. In the end the clear winners were mostly parts supply places in the UK, with good online catalogue's, especially those with pictures to correctly identify parts. Despite all this care and attention, several parts were ordered incorrectly, a few duplicates and what infuriated me most were no shows. i.e the supplier indicated parts availability, but in the end had no stock, leaving me in the lurch as I would have to get the parts from another supplier and incur additional shipping. In hindsight unless you do this everyday, one just does not have the unnecessary experience, and will have to take several bites at it, as the level of complexity diminishes, once parts get hung on to the bike.
I am getting ahead of myself here, as I still had to strip the engine to find out what was worn out. A tip to those contemplating a restoration, don't strip the bike until you are serious to follow through with the job, as in the interim you will loose part's and forget the order of assembly they were in. Sometimes there simply is not enough detail in the documentation.

Roger-SA · 06-14-2012, 11:34 AM

Stripping the engine, requires a few special purpose tools which i did not have, but fortunately I have a well equipped workshop and can improvise as I went along. Here are some pictures of the progress as well as some special tools that were fabricated on the fly.

david_in_ky · 06-14-2012, 12:03 PM

You are off to a good start. My SN was just a bit before yours. Access to a shop and the ability to make some helper/aids goes along way. Be patient, do everything carefully, no rushing, and you will be happier I took almost 2 years to complete...

Roger-SA · 06-14-2012, 12:38 PM

The tools that I made were as follows:
- An impact tool to remove the ignition cam - A suitable bolt welded to a long rod with a large sliding weight on it.
- A puller for the main pinion - Some angle iron suitably crafted to go over my puller bar.
- A puller for the timing gears - The top piece of a Kawasaki KX85 fork stantion, had the same thread, so it was chopped off, and a nut welded in to the other side, and a suitably long bolt added to do the pushing.
- A puller for the clutch hub - This was more difficult as I had to figure out and make the thread.
- A key for the clutch screws.- ugly but it works
- A puller for the primary sprocket - Just some suitable long bolts

I have learned that you really do need the right tools, as pounding on metal will always lead some level of damage and disappointment.

I even threw the tools in to the cad plating batch, so now they look more professional!

GrandPaulZ · 06-14-2012, 12:45 PM

The home-made tools look very nice with the plating. The main thing is, they do the job!

I believe the head steady is on the same page as the wiring harness, or some other totally unrelated section...

Roger-SA · 06-14-2012, 01:00 PM

Some more dis-assembly:
Removed gearbox, split cases removed crank.
Stripped head.
I used a sash clamp as a large shifting spanner to get sprocket nut off, and was not to worried about the sprocket as that would be replaced.
Besides all the crud and rust on the engine side, the gearbox side was pretty clean. Obvious damage after measuring everything is as follows:
Primary adjuster hole cracked on lower case - will need aluminium welding.
Primary adjuster slipper and adjustment rod had been abused.
Main bearing shells and journals were standard, but worn out of spec.
Cam bushes worn way out of spec.
Cam followers and guides worn.
Timing idler gear pin and bush worn
Valve guides and valve stems worn
Although the roller and ball bearings were passable I decided as I had got this far to replace the lot, including all gearbox bushes and thrust washers.
I have also decided to replace the oil pump and pressure relief valve. I cant afford there not to be working 100% on such an expensive rebuild.
In addition I still had the issue of the missing rocker boxes , head stud's and push rods that were missing. This 71 model had very specific head bolt's, and the rocker boxes were different from triumph's before '71.

GrandPaulZ · 06-14-2012, 01:30 PM

Is it just me, or do those valve seats look sunken?