Harbor Freight is your friend. Even if you only buy a big socket and a big breaker bar.
1967/1969 Bonnie Rebuild Desert Sled Project
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speedrattle
Well-Known Member
be careful with the clymers manual. it contains a subset of the factory manual procedures and can be confusing.
if someone offers you a haynes manual walk away
if someone offers you a haynes manual walk away
OK, in addition to the Glenns, what do you recommend? This is a 69 engine with a 800cc big bore kit. Thanks.
I've got the big breaker bar, and I may have the big socket also.
speedrattle
Well-Known Member
the factory 1963-1970 manual is the first source floyd clymers book is a condensed version of it, with the exception of the performance chapter, which is pretty rudimentary.
sonny routts kit originally came with somecsort of instruction did you manage to snag any of it? if not, thats okay, as you have something thats already togethrr.
glenns manual is good for post-1970 650s, iirc, and has a decent section on the 5-speed gearbox. my copy is is the shop somewhere. have to look over it again.
Thank you for the information. I've got nothing from Routt, but should look online for this. I will be curious when I get the head and cylinders off to see if it is still going to be ok to use this big bore kit.
I just use 50/50 Simple Green and hot water, with stiff bristle brushes (plastic normally, brass if really baked-on crud).
OK, great. I like this simple approach. Thanks.
The 1/4" screws that mount the rocker boxes on the head, what thread? 1/4"-20 is UNC is 69 onwards, 1/4"-26 is BSF is pre 69.
If you mean a cast year with little lines radiating around it for the month, it might become visible when you lift the head off the block.
Or, as it is a HDA head, you might see a series of letters and numbers stamped on the head, possibly near the timing side inlet valve?
OK, I'll have to look more closely - and - what is an "HDA" head? Thanks.
One with "HDA" cast on it. Like the one in your photo ...
Stands for "High Duty Alloys" - one of the outside companies that did castings for Triumph.
Thanks, lot's to learn.
Looks like you date mark is very faint - looking at the photo, on the right side hollow between the valve pockets should be a circular cast (raised) mark with several tick marks, and a 2-digit year code. The tick marks represent the month. The year would show that it was cast UP TO a year before it was installed on the assembly line.
So I was chagrined when I came to take the cylinder off tonight, thinking I had the correct tools. But I did not have 12 point Whitworth wrenches, only the 12 point sockets. Plus, it almost looks like I would need very thin 12 point Whitworth wrenches as the clearance is quite small. The clearance on this cylinder seems much less than others I've seen in photos. Perhaps because it is the 800cc big bore cylinder it messes with the clearance?
A couple of other interesting finds - when removing the push rods, one of the rods on the exhaust side came out looking a lot different than the others - very dark and the tip on the bottom side dropped off the rod on its own. The dark rod also had some gouging on it that must have been done to it before it was installed. With some of the things I am seeing, loose and mismatched fasteners, it seems this was not assembled properly the last time or perhaps it just got messed with.
The pistons and chamber are all loaded with carbon. The pistons seem to be highly domed also.
With regard to the head, the place where the date is supposed to be cast in has the oval, but there is nothing in the oval. I have heard that this may be due to is being a replacement head? There is another marking stamped or cast into the head, it reads "23 - D".
So that's it for now. I will have to find some proper Whitworth wrenches to remove the cylinder.
Thanks for any advice, comments, etc.
A couple of other interesting finds - when removing the push rods, one of the rods on the exhaust side came out looking a lot different than the others - very dark and the tip on the bottom side dropped off the rod on its own. The dark rod also had some gouging on it that must have been done to it before it was installed. With some of the things I am seeing, loose and mismatched fasteners, it seems this was not assembled properly the last time or perhaps it just got messed with.
The pistons and chamber are all loaded with carbon. The pistons seem to be highly domed also.
With regard to the head, the place where the date is supposed to be cast in has the oval, but there is nothing in the oval. I have heard that this may be due to is being a replacement head? There is another marking stamped or cast into the head, it reads "23 - D".
So that's it for now. I will have to find some proper Whitworth wrenches to remove the cylinder.
Thanks for any advice, comments, etc.
speedrattle
Well-Known Member
cant remember exactly when triumph went from british standard to unified threads. mid 69? or not until 70? were the 12-point base nuts ever anything but UNF?
if those base nuts are UNF, go buy a cheap half-inch 12-point combination wrench somewhere and then grind or file the box end down until it drops over the nut.
you can fit a half-inch torque wrench into the open end of the wrench when you put it back together and calculate the reduced figure to use to correctly torque the cylinders back on.
if those base nuts are UNF, go buy a cheap half-inch 12-point combination wrench somewhere and then grind or file the box end down until it drops over the nut.
you can fit a half-inch torque wrench into the open end of the wrench when you put it back together and calculate the reduced figure to use to correctly torque the cylinders back on.
You would be even more chagrined if you bought "12 point Whitworth wrenches" ... as the nuts are UNF thread, 1/2" AF for the 3/8"UNF, 7/16" AF for the 5/16"UNF.
Plus you "need very thin 12 point" AF wrenches. While there might be other "thin" wrenches that will not break when you pull hard on them when loosening or tightening the nuts, you might want to consider Snap-On. Not cheap but (should be) no quibble replacement if you do break one.
However, if you will be concerned about correct torque when reassembling, if you buy just a plain wrench with 7/16" AF at one end and 1/2" AF at the other, when reassembling you will need to cobble up something like a fish-weighing scale hooked into the other ring combined with calculating the necessary pull on the scale based on the length of the wrench.
Otoh, certainly Snap-On offer tools with the 12 point ring at one end and a square drive hole at the other end for connecting to a torque wrench. If you have Magpie Syndrome, a Snap-On van is particularly dangerous for your bank balance ...
Regrettably nonsense. When the head was cast, how would the caster know it was going to be a "replacement"?
From information posted on A.N.Other forum, at some point HDA was acquired by a British aircraft maker (Hawker-Siddley?). Primary reason for this was several makers had experienced aircraft crashes, some regrettably with loss of life, subsequent investigations identifying casting errors in one or more critical components (e.g. main wing spars ...) as causes.
This aircraft maker acquired HDA so it could apply stricter quality control to castings; one q.c. measure was to stamp every casting with a furnace and batch code so, any subsequent failure, all castings in the batch could be identified easily. Educated guess says, once the furnace/batch code was being stamped on castings, the previous year-number-month-ticks marking wasn't necessary?When the aircraft maker acquired HDA, Triumph was already one of HDA's customers, HDA continued to cast for Triumph for many years.
It is stamped because it is indented into the casting; "cast" would be raised, like the "H.D.A." and the part number.
Better would be find some proper AF wrenches to remove the cylinder ...?
The UNF/UNC barrel base studs (UNC into the crankcase) and 12 point nuts first appear in the 69 twins parts books. However, aiui they were actually first fitted to bikes made in late (May or June?) 68 production (along with other "69" parts like the 6-3/4" centres fork yokes); iirc there's a 'from' engine number buried in A.N.Other forum?
Just to confuse, aiui there have been (a) aftermarket batch(es) of Cycle 12-point nuts ...
Given the state of the fasteners in your images, the ground/filed box end could well break unless the nuts loosen easily.
Earlier this year, I lent such a modified wrench I had owned for years to a halfwit who had apparently tightened his spark plugs with a three foot breaker bar, but then did not carry a plug wrench (or the three foot breaker bar) in his bike's toolkit ... 
Ime, particularly barrel base nuts, if you did not tighten them with a ground/filed box wrench, luck for loosening them with one.
When you grind the outside of a box wrench for clearance, you can no longer use it in "shock" mode (whacking it with the palm of your hand or ANY hard object).
You must use a steady pull 'till in frees off the fastener (hopefully), or breaks (possibly).
Shock mode just GUARANTEES that it will break.
You must use a steady pull 'till in frees off the fastener (hopefully), or breaks (possibly).
Shock mode just GUARANTEES that it will break.
speedrattle
Well-Known Member
heres one i made
to torque the base nuts i just stick it on the end of a half inch torque wrench
this makes the total torque wrench six inches longer, so i reduce the reading on the wrench proportionally. to get 35 poundsfeet on a cylinder base nut, i think i apply 27 to the wrench, iirc
heres an online formula
https://www.norbar.com/Support/Calculators/Torque-Wrench-Extension-Formula
to torque the base nuts i just stick it on the end of a half inch torque wrench
this makes the total torque wrench six inches longer, so i reduce the reading on the wrench proportionally. to get 35 poundsfeet on a cylinder base nut, i think i apply 27 to the wrench, iirc
heres an online formula
https://www.norbar.com/Support/Calculators/Torque-Wrench-Extension-Formula
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