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The ability to use aftermarket parts opens up a HUGE universe. But, to keep it simple (relatively)........Any sidebag oil tank frame.....64-70, but I would select a 63-65 front frame, 68-70 rear frame, 69 cases, 68 crank, heavy stock rods, Routt 750 kit w/MAP forged 9.5 : 1 pistons, 750 cam pinions, 750 oval port oil pump, JOMO 15 cams, 500 tappets, tubular special pushrods, ground and polished rocker arms, 77-on five speed gearbox, MAP belt drive, Sparx or Lucas 3 phase alternator, Borrani rims, Buchanan's SS spokes/nipples, Westach electronic tach, Smiths speedo, 1978 blackface, 72 Bonneville bolt on manifold head with push-in exhaust adaptors and inlet adaptors for 32mm Dellorto carbs, 71 rocker boxes, 74-on rocker shafts with extra o-ring grooves lathed in, 69-on tappet blocks with opened up drains, late pushrod tubes, Black Diamond valves, Ampco 45 guides, alloy valve spring retainers, hard anodized alloy rocker buttons, allen tappet adjuster and alloy locknuts, rocker spacers.
Alloy engine and pass. peg mounts, Ceriani dual lug road race forks, Ceriani or Fontana 4LS brake, Alloy replica of stock rear hub, Works perf. 13.5" shocks, alloy handlebars, Forged Magura levers, Tommaselli throttle, Alloy fenders, Stock exhaust system, C model headlight and footpegs, custom Belden teflon wire harness.........and a lot more......

[ This message was edited by: Mecchanica on 2006-12-01 19:31 ]
 

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The engine guts I described are pretty much what I have been running for 11 years and 85k miles in a MOST roadable engine. The Bonneville head is the biggest difference, and I specified the MAP pistons, because the Morgo AE pistons I am running in my Routt kit are harder to get, at .060 over.
I'd use the early unit frames because of the 3 degrees less rake, shortening the wheelbase and quickening the steering....also moves the center of mass slightly forward. I would use the 69-on swingarm (or T150), as they are stiffer. I selected the late rear frame because I like the easily removable sidecover which doesn't crack and the early frames used a solid mounted oil tank, and I prefer the rubber mounts on that.
The cams I use have more overlap than the stock ones, lowering the effective pressure in the cylinder at low rpm, thereby reducing the tendency to ping when accelerating from lower rpm even though the bike runs the higher compression pistons, and the five speed is effectively a closer ratio four speed with an overdrive when used with the high final drive ratio, allowing you to keep the engine revs high enough to minimize pinging without overrevving or getting buzzy. Keeping the mixture a tad on the rich side, enough to grey the plug electrodes, but not enough to foul the plugs, also keeps the bike tractable, and heat is a concern here in Hawaii.
I didn't go into detail about the modified oil system. The pressure relief valve won't be in the case anymore. The stock setup dumps excess oil into the timing cover and then back to the tank. This provides most of the lubricating oil for the timing pinions. It also provides drag and doesn't do anything to cool the hottest part of the engine, the head or cylinders......Sooooo I plan to fit a Morgo gear oil pump and then to make an oil manifold. The oil pressure relief valve would be mounted in the end of the manifold and high pressure oil would be fed from the plug that replaces the valve in the case to the manifold via Earls ss/teflon hose. This hose will not pass oil until the pressure in the main oil gallery of the engine raises to the 85 pounds for the engine, then, as the stock bike does, it begins to leak off enough oil to keep the pressure at that level. The oil that bypasses the valve goes into the maifold which feeds the machined Barnett valve adjusting caps. In the end of each banjo bolt, on the inside of the cap, is a Mikuni main jet. This allows me to easily adjust the flow of oil to the valves....more on the exhaust, less on the inlet. The drains in the tappet blocks are drilled larger to allow the additional oil to drain back to the sump, also providing more oil for the tappets and cam faces. The larger drain holes also allow for better breathing from the rocker boxes, reducing leaks.....theoretically. There is another pressure relief valve in the other end of the manifold and when the pressure reaches 95 psi in the manifold, it begins to bleed off oil to a line that feeds back to the timing cover, to lube the timing gears and dispose of the excess oil in the system. On the way back to the tank, the oil passes through a filter/cooler. A similar system works pretty well for my Thruxton, except they use two oil pumps. I thought about that, too. Originally, I was going to fit a second oil pump to the end of the exhaust camshaft, replacing the tach drive, which I don't use. The first iteration of this was to make a system for the gearbox lube, to keep it cool and filter metal bits out. But I think that is probably gilding the lily. A few of the strong little Neodymium/Iron/Boron magnets in strategic locations would likely do as well. I had a couple of them stuck on the back of the oil tank which are now stuck to various bits of the Thruxton oil system, including the filter can. They won't pick up little bits of nonferrous metals, but I suspect they are less of a danger than the hard steel bits.
Now, if we are talking stock forks, certainly the late shuttle valve steel forks would be my first choice, along with a lightened Iron hub DLS Triumph/BSA brake. The only other choice would be the disc brake setup. I think I could bore out the lower legs and the yokes enough to fit 35mm Ceriani stanchions and guts, or perhaps Betor. Then get either the Lockheed calipers or go large and get some four pot billet items, drill the discs, fit a 13mm bore master from those French guys or go cheap with the Grimeca. If we can switch discs, then the 12" floater would go on the list. A fork brace would be a good idea for a single disc setup. EBC brake pads. Earl-s -2 hose.
The target is a 350 lb. reliable roadster.....kinda like my 68, but with more Bonneville power. I've been running a TR head with 32mm Concentric, and have been ok with the power delivery vs simplicity. I would like to try out a single 34 or 36mm Dellorto pumper carb and do a dyno and riding comparison. Well, I DO have an extra TR6 head.........
OH....If they become available again....I'd get one of the Aerco ten bolt 750 cylinders for long rod engines and fit the 10 bolt Bonneville or TR head. Nag Bill Getty at JRC Engineering to get them made again.
Oh, and some years ago, I had a set of Carrillo-style beam rods in ALLOY with steel caps and replaceable bronze bushes. I don't know who made them, but they were just GREAT. Maybe I could nag Carrillo to make them now, with a little help.
 

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The 70 frame has removeable front mounts, which makes it possible to remove the engine intact. But that also adds a touch of weight. And as often as I plan to remove engines, it's not an issue. Plus, I take them apart in the frame to get them as light as I can. Bum back.
68 crank has a light flywheel and two timing notches...actually, there are Mark 1, 2, and 3 versions. Some of the 68s had a second timing hole in the front, as per the BSA and Triples. They dropped that quickly, as it was pretty much unnecessary. Handy, though....easier to get to than the one behind the cylinder. Plus, like the 66 and 67 which also had light flywheels, the 68 was balanced and came with the thicker and stronger late model con rods.
Nourish Racing Engines (England) makes an 8 valve top end, cylinder (of up to 800cc on a unit engine.....bigger with their stroker crank), four valve/cyl. head, pushrod covers, rockers and shafts and a valve cover. Plenty of power, but kinda fugly. Can't use any stock parts, either, so there is the possiblility of downtime if you have a problem.
67 taillight because it is the most beautiful one on any Triumph and better than almost any on any bike. I lucked out, my 68 left the factory with a 67 taillight. I plan to put one on my Thruxton.
OH.....and folding C model rider pegs and C model small light with a high zoot H4 conversion.

[ This message was edited by: Mecchanica on 2006-12-02 15:39 ]
 

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I like the 69 cases as they are the last year to have the timed breather and separate oil for the primary and the first year to have the UNF threads. It was probably the last year of really good quality control. Some say that 67 was the halcyon year, but I like the 69s. Besides, we get to stuff it with neato items from various years of bike.
If I had to pick one bike and keep it stock, no kits or five speeds, it would be the 69 Tiger, followed very closely by the 69 Bonneville, 68 Tiger, 68 Bonneville, 74 Tiger, 65 Bonneville, 70 Daytona, 67 TT special in aubergine and gold. The 68s and 69s had it all, stunning paint, tight engines with all the upgrades....larger oil pumps, better points, shuttle valve forks, dls front brakes, timed breather and separate primary oil system, encapsulated alternator and timing window on primary cover, oring pushrod covers, no oil bleed to the pushrod buttons in the rocker arms. And the Canadian Bonnevilles still had stainless fenders through 70!!!
I'd sneak a four speed from a 71 or 72 into the box, however....if I couldn't have the fiver.

"I see you vote for the 70 frame as well."

The only difference between the 70 and the 69 is the removeable front mounts. If I were racing, that would be an important point...but as I'm not, it isn't.

"Why the DLS brake as opposed to the disc?" (I like the DLS brake too, for its appearance, but wonder if there is a significant weight difference between it and the disc. "

A small weight difference if you are comparing stock systems, but you can save a lot of weight (unsprung weight, at that) if you dump the iron lump of a caliper and fit a Grimeca or better yet, a four pot from Performance Machine, or it's ilk, and drill the disc, or better yet, get the 12" conversion.

"Interesting that you picked a modified 650 as opposed to a 750; is it because you prefer the long-rod engine?"

I like both, the short rod engines give more midrange grunt at the cost of more thrust load on the piston skirts, whereas the long rod engines are freer revving and, in my opinion, smoother running. The pistons last longer, too. This is a function of the rod lenth to stroke ratio....lower ratio makes max torque at higher rpm. The shorter rods induce greater crank angle and rotational moment to the rod big end.
I am not thrilled that the later engines (71.5-72 five speeds and all the 750 twins) changed the right main bearing to a metric 6306 from the English MS11. I don't think it's as tough. In my spare engine, a 78 lower end with right shift covers, I fitted a heavy duty version with more balls, literally, an 11 ball bearing compared to the standard 8 ball item. I am building another one with a roller on the right.

"I bought a grab bag of mostly Triumph stuff not long ago, and one reason I bought it was that it has the Norton type fitting for an oil filter, and three filters among the other stuff. Oil cooler too?"

You can fit a larger filter in the air stream and get some additional oil volume and surface area to cool. HD aftermarket companies used to carry an aluminum finned cup that pushed onto the filter housing and supposedly pulled heat out of the oil. Looked trick.

"I seem to remember nicasil (nikasil) from way back. I didn't know about the aftermarket barrels for Triumphs. Lighter weight always appeals to me so long as it doesn't compromise reliability too much (and isn't too expensive!)."

If you really want light weight and the long rod engine, then MAP will be marketing an alloy kit, sleeved, I believe, but you may be able to source one unfinished and have it bored and nikasiled.....or some other nitriding process which may have become available since. The kit is about $1200, as I recall, and is being produced in VERY limited quantities....machined from a block of aluminum, I believe...not cast. Be worth it just for the bling factor!!!

About the connecting rods....the rods used up through 67 had a web thickness (across the narrow point) of approx. a half inch. Starting in 68, they made thicker and stronger rods. These have a thickness of about 5/8". The 68 is the only year with the heavy rods and a light crank, which is balanced to accomodate them. You can fit the heavy rods to any of the earlier cranks which use replaceable shell bearings and have it rebalanced. The short rods all have thick webs and are fine to use if the ends are checked for ovality and the alloy is highly polished and the nicks removed.

OOPS, missed this...the shuttle valve forks were installed on the 650s and Tridents from 68-70 and on the 500s from 68-74. Only the very last few 500s got the disc fork in 74.
The early 68 forks had CEI threads on the caps and bottom nuts (in the stanchion) but the rest had NF threads.

[ This message was edited by: Mecchanica on 2006-12-03 18:16 ]
 

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OH, agreed. I never even fitted a horn to my 68, or the silly reflectors.....but if you have dual horns, the 69s are better looking. If you're thinking about honking the horn, your aren't thinking about avoiding the bozo.
 

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"Were the threads previously BSF? (Back in the day, we referred to all British threads as “whitworth”.)"

Whitworth is a coarse thread system, roughly equivalent to the NC. BSF is finer. The unit cases up through 68 used 1/4 X 26 CEI cover screws and BSF for the larger bolts and studs, with....excuse me here, made a mistake.....NC threads showing up in 69. NOT NF. I usually use the term "U.S." to cover both NC and NF, but realize it isn't technically correct.....and there aren't any fine threads in the cases themselves.

"So much to learn. (The Bacon restoration book is available from the local library system and is being sent to my local branch, so I will have study material soon.) I didn’t know the case threads changed to UNF in ’69, although I was generally aware that later Triumph used threads other than Whitworth. I have done a little research and have found a useful site to share:

http://www.britishfasteners.com/Merchant2/merchant.mvc

Down the list of links on the left side of the page click on “Learn About British Threads”.

I am hopeful that the Bacon restoration book will answer some of my questions, but would you discuss the changes in threads over time?

For the unit bikes, it's as above. CEI and BSF for the early bikes, NC for the later bikes. The NF shows up on studs, on the exposed end, for the gearbox studs, case joint stud, cylinder studs, alternator and oil pump studs.

“ ...larger oil pumps, better points, shuttle valve forks, dls front brakes, timed breather and separate primary oil system, encapsulated alternator and timing window on primary cover, oring pushrod covers, no oil bleed to the pushrod buttons in the rocker arms. And the Canadian Bonnevilles still had stainless fenders through 70!!!
I'd sneak a four speed from a 71 or 72 into the box, however....if I couldn't have the fiver.“

From reading other threads I understand (I think) Mecchanica’s preference for separate oil for engine and primary. What is a timed breather and why is it preferable?

The timed breather is incorporated in the end of the left inlet cam and bush. There is a hole in the camshaft and a rotating disc valve that allows the engine to push blowby out of a tube near the final drive sprocket. With this, the factory installed an oil seal between the left main bearing and the primary drive sprocket, sealing the joint there. In 70, the factory eliminated the timed breather and the left oil seal, and allowed the engine to breathe into the primary, using the volume of the primary case to mitigate pulses in the breathing system. Not a bad idea, except for the necessity of using engine oil in the primary case. Now that non-energy conserving synthetics are available which have excellent film strength without undue viscosity, it works better than it used to, when thicker mineral based oils with metal salts (like molybdenum disulfide....the "energy conserving" oils) were used.

"I seem to recall that later 650s had a single point setup as opposed to the earlier dual points. "

Nope, all dual points. But there are three basic types of points....63-67 used 4CA type, with the condensers mounted on the points plate. 68-74 used 6CA type, using a single hold down screw and eccentric adjusters for both the gap and to move the secondary plates. 76-on used the 7CA type, with dual hold down screws and a wedge and slot adjuster for the gap and eccentrics for the secondary plate. There are variations of the 6CA which used different primary and secondary plates. The 4CA used a shorter auto advance unit, 6CA and 7CA used similar auto advances, with the later ones using thick, non adjustable spring attachment pillars. Earlier ones you could bend out a little to get more tension, changing the advance curve. (You can grind the weights to slow the advance curve if you want....sometimes this helps with pinging at low to mid speed under acceleration.)

"I also recall from reading earlier threads that there were several oil pump improvements. Could you elaborate on those?

The pumps were basically the 63-65 pumps, small feed and scavenge, then the 66-68 pumps with slightly larger scavenge, then the 69 through E. 73 pumps with larger feed and even larger scavenge plungers, then the oval port 750 pumps.
(I'll have to recheck this info. and the years, but that is as I recall it off the top of my head)

"When did o-ring pushrod covers become standard? Can they be retro-fitted?

Oring pushrod covers came out in 69 and in 70 they were improved with the addition of a 3.5mm rectangular section seal ring, as per the 66-68s, with a "wedding band" to retain the seal, so that it doesn't squish out. So it has the dual seal.
They can be retrofitted to earlier tappet blocks, but you have to trial fit them, note the "squish" ...the space between the head and head gasket, and adjust with steel or fiber washers to get about .060". The best way is to use the 69-on tappet blocks in the cylinders, too. But you have to remove the cylinders to fit them.

What is the story on “…no oil bleed to the pushrod buttons in the rocker arms.”?

The earlier engines used an oil drillway from the bore of the rocker shaft, out through the arm to the pushrod button, which also had a hole drilled accross it and then down the center, to feed oil from the rocker shaft to the pushrod cup. The factory finally figured out that it's more important to get the oil to the spring and valve than the pushrod cup, which retains oil fine, thank you. So the 69 and later arms and buttons were solid (making it easier to grind and lighten the rocker arms) and the oil exits from a notch in the inboard end of the rocker arm, drizzling onto the valve.


Why is the ’71-’72 four speed preferable?

The engaging dogs are larger and less numerous, making engagment easier and quieter, and the camplate was hardened and ground, and the false neutrals were eliminated.

"For the “ultimate” Triumph I gather you would go with a five speed and alter the final drive ration to make 5th gear a poor man’s overdrive."

Exactly. I would have to adjust this depending on what the primary drive ratio is on the belt drive. But with the stock primary chain set up, I would do (and have done) just as I wrote....five speed with 20T and a 43T rear. If running two up a lot, I would go down to 19T and use a heavy flywheel.

“A small weight difference if you are comparing stock systems, but you can save a lot of weight (unsprung weight, at that) if you dump the iron lump of a caliper and fit a Grimeca or better yet, a four pot from Performance Machine, or it's ilk, and drill the disc, or better yet, get the 12" conversion.”

Is there a practical way to reduce unsprung weight on the DLS? Drilling it full of holes may be ok for competition, but for a street rider?

Alloy rims are a good start. You can bore some holes in the side of the hub, and put some screen on it. I don't use the "nave plate", or left side cover plate....just extra weight to me. I also bored the ends of the axle and turned the center down a little. I removed the grease seals and installed sealed bearings. I drilled the brake shoe webs and the retainer ring. I plan to drill the hub flange between the spoke holes and I would like to turn the hub to thin it a little. I made alloy axle caps and other light parts for the forks, too. Delrin or teflon bushes are on the list.

"What is involved in installing a lighter caliper? Do you need to fabricate a different mount?"

The Grimeca, Lockheed alloy, and Performance Machine calipers are all direct mount, as per the stocker, if you use the stock disc. The larger disc will need an adaptor mount, supplied with the kit.

" I never tried to drill a disc. Can I do it myself, or is it best left to machinists? What about hole sizes and patterns?"

I've used holes from 3/16 to 3/8" and it doesn't seem to matter much as far as function or noise. I used a swirl pattern done on an indexing head in a mill, and I would use that system to keep the pattern regular and the disc balanced.

“You can fit a larger filter in the air stream and get some additional oil volume and surface area to cool. HD aftermarket companies used to carry an aluminum finned cup that pushed onto the filter housing and supposedly pulled heat out of the oil. Looked trick.”

"I remember seeing some of those finned covers for oil filters; they did look trick, and no doubt helped to cool the oil too. I viewed the oil filter as both a filtration and cooling benefit. Even if I removed the filter eventually (to save weight) it seems like a mod easily installed/removed and particularly useful during break-in."

Right. I removed my oil filter after changing to synthetics and doing an autopsy on a couple of filters after changes.....no metal in the filter, they looked nearly new inside...just some carbon bits barely visible....nothing which would attract to a strong magnet. I'm using this engine as a test of synth. oils and have been extending the change period every time. I am up to over a year or 8K miles. now. I will be pulling the engine down after nearly 90K miles and doing a report on what I find.

"The nikasil cylinder thing is interesting, but I am afraid there is no room for bling in the budget right now (and for that kind of bling, no room in the foreseeable future!). But even alloy cylinders with steel liners should be good for weight savings. Is there any other option besides the MAP alloy cylinders? (I realize I am getting off the Triumph parts only exercise here, but curiosity is getting the better of me.)"

There were long rod alloy kits made by Wellworthy and by Chantland, but both are hard to find and had stud retention problems. The Harris short rod kits were ok, once the threaded inserts were installed, but are not common anymore. If you aren't going all the way for light weight with the nikasil, I would stick with iron barrels...they are very sturdy and act as an anchor in the center of the alloy engine, tying everything together firmly. It also makes it much easier to get the squish area right and stable, as the alloy cylinders grow much more than do the iron cylinders.


”OOPS, missed this...the shuttle valve forks were installed on the 650s and Tridents from 68-70 and on the 500s from 68-74. Only the very last few 500s got the disc fork in 74.
The early 68 forks had CEI threads on the caps and bottom nuts (in the stanchion) but the rest had NF threads.”

"Were the disc brake forks any better or worse than the DLS shuttle valve forks?"

They are comparable, but you will change stanchions more often with the disc brake forks, as they do not have replaceable bushes, and the chrome eventually wears off at the loaded points, one on the bottom, one at the top of the slider. Both are dual damping, unlike the pre-68 forks, which only damp on the rebound stroke. It's easier to adjust the spring tension with the internal spring forks, but I have seen early forks converted to internal springs. I still think adapting the thin wall chromemoly Ceriani stanchions and guts to the disc forks would be the bomb.

"Ultimate horns?"

Ballast. Toss 'em.

" Thanks for all the input guys. As in so many other things, the more I learn the more I realize how much more there is to know."

And you will know it, just takes time.
 
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