Triumph Rat Motorcycle Forums banner
  • Hey everyone! Enter your ride HERE to be a part of this month's Bike of the Month Challenge!

201 - 220 of 235 Posts

·
Registered
Joined
·
101 Posts
Discussion Starter · #201 · (Edited)
I've watched quite a lot of low brow custom vids, they're really good.

As far as I can see the push rod tubes on this bike are sealed with black gloop from a tube. I am fully expecting them to come off with the head:(

Apparently the head of this bike has been off "more times than I can count" to try and fix push rod oil leaks.

In good news my throttle cables arrived and appear to be correct. They are a lot LOT freer than the old ones. Venhill recommend lubing the ends with copper grease, I was thinking more along the lines of silicone or solid PTFE spray.
 

·
Registered
Joined
·
932 Posts
If Venhill recommend copper grease, that's what I'd use. Some liners don't like some lubricants and not knowing what's what, I'd stick to Venhill's recommendations.

I could do with some new Venhill throttle cables on my T100R. What I have is fairly new, but not as smooth as I'd like.
 

·
Registered
Joined
·
101 Posts
Discussion Starter · #203 ·
I get the feeling they've just failed to update their guidance. It's a stainless steel cable in a PTFE liner...why would you add copper?
 

·
Super Moderator
Joined
·
8,351 Posts
Hi,

I get the feeling they've just failed to update their guidance. It's a stainless steel cable in a PTFE liner...why would you add copper?
Precisely. Actually, it's just weird "guidance", their other cable components are galvanised inner in nylon-lined outer, nylon lining's buggered by anything with any dead dino juice.

Risking labouring a point, I've been using Venhill cables since about the mid-1980's - original triple clutch cables were always nylon-lined; when they finally ran out, Venhill were the only company making nylon-lined as standard. So, when I started using Venhill cables, I already knew what (not) to use to clean and lube.

When Venhill brought out stainless-inner-in-Teflon-outer, their "guidance" lacked any consideration about just how rare 'common sense' actually is - the commonest fault on internet forums was/is interpreting Venhill's "doesn't need any lubrication" "guidance" as 'doesn't need an maintenance at all' ... 😖 ... meaning cables without covers over their ends gradually fill up with road crap, leading to "why is my clutch so heavy"-type threads ...

Venhill recommend lubing the ends with copper grease, I was thinking more along the lines of silicone or solid PTFE spray.
Ime, the last "guidance" I read on Venhill's site for stainless-inner-in-Teflon-outer cables - "doesn't need any lubricant" (sic) is correct; any additional lubricant on any inner that can be exposed, road crap will stick better and be drawn between inner and outer ...

Otoh, my aforementioned 'maintenance' is occasionally to use one of the cable clamps that take an aerosol 'straw', to blow out any road crap with some WD40.

Apparently the head of this bike has been off "more times than I can count" to try and fix push rod oil leaks.
Probably because the saga (and I use that word advisedly) of '69 PRT sealing is exceedingly vexatious ...

As far as I can see the push rod tubes on this bike are sealed with black gloop from a tube.
They shouldn't be; absent the knowledge spread by forums, perhaps the "black gloop" is something your FiL tried in desperation?

'69, when your 650 dates from, Meriden decided to have one of its periodic attempts at 'fixing' the leak-prone PRT (in reality, thanks to the basic design, imho any attempt is a good definition of "polishing a turd" ...). However, the '69 attempt was particularly bad, requiring more changes just over twelve months later (so which didn't make it into the '70 parts books), so you should use a '71 650 parts books for PRT seals part numbers and checking things like the PRT themselves are correct.

One important difference shown/listed '71-on is the E11283 (71-1283) O-rings at the tops of the PRT are Viton, the E7310 (70-7310) shown/listed in the '69 parts books are a material that can't handle the heat at the tops of the PRT, resulting in failure and one source of leaks. That said, Viton isn't great at this either so, if you can turn up O-rings in the right size but in an even-more heat-resistant material, you'll be doing yourself a favour. The same O-rings can be used at the bottom of the PRT as the 1283 and 7310 are the same size.

The other procedure you might want to consider is more modern - Andy mentioned it in his post #200 - "checking the crush" ... of the E4752 square-section O-ring at the bottom of each PRT when the head is torqued down - the "crush" should be in the order of 15-30 thou. but, given you're dealing with a fifty-year-old head, that might or might not have been skimmed ...

E4752 is a nominal 1/8" thick; E3547 is exactly the same ID and OD but only a nominal 1/10" thick; nevertheless as @speedrattle Kevin posted in another recent thread, he's found even that can be too thick, "crushed" much more than 15-30 thou. :(

Another part shown '71-on - "E11707 Sleeve" should be a close sliding fit around the bottom of the PRT; it's supposed to stop the E4752 (or similar) seal being squeezed out when the head's torqued, but the correct seal "crush" causes enough sideways deformation to stop the Sleeve moving upwards; in reality, piss-poor quality control can allow a Sleeve to be either too tight - so the PRT doesn't "crush" the seal at all - or too loose - so the Sleeve later moves up and allows the seal to be squeezed out ... :rolleyes: The 4752 and 3547 seals were used pre-'69, the bottom one sitting in a cup washer around the tappet block to prevent extrusion; works well, Gk why someone needed to reinvent a wheel but failed to make it round ... 😖

good supplier of gaskets? There are a lot out there for these engines...
LP Williams, TMS in Nottingham and Grin
Monty's
+1, plus Hawkshaw is also on my "preferred supplier" list; @rambo Geoff has also recommended Monty plus Tri-Supply.

I've heard about annealing head gaskets before, but for the cost of new ones (especially when you consider I don't have a decent blow torch!) it ain't worth it.
But the point of reusing parts that work isn't always about cost - these days, for these old heaps, your "new ones" can easily be worse-made that your old ones ...

I :love: copper gaskets, I haven't bought new for years ... Only thing you have to watch is the mating surfaces on the components either side are good.

Never any problem annealing; wherever I've lived, if not a blacksmith, there's always been a farrier who'll anneal copper gaskets in the furnace for a couple of beers or a bag of doughnuts. (y)

Another gasket type to consider, particularly on rocker-boxes, is CovSeal. Afaik, they were invented by the legendary John Healy, boss of US Britbikebits wholesaler Coventry Spares; they consist of a layer of rubber sandwiched between very thin sheets of ally, designed to seal the mutilated component mating surfaces found on these old heaps. Sadly, they aren't reusable, other problem is a British retailer; nevertheless, if these are interesting, email Coventry Spares for either a British retailer or, absent one, they might supply direct?

should probably buy a whole head set.
Ime, buy the ones you need by part number, rather than a "set"; assemblers seem to try to include every gasket and seal for every variant from '63 to '83, fail, but include some random unidentifiable ones instead ...

Hth.

Regards,
 

·
Registered
Joined
·
101 Posts
Discussion Starter · #205 · (Edited)
Thread resurrection!

I've been focused on getting my CBR600 back on the road (mission accomplished!) so I haven't been looking at the Bonnie, but I'm back on her now.

I took the head off today. Before I even loosened the first head bolt I had a good idea what was wrong. Loads of small pieces of metal fell out of the right hand silencer, metal that was clearly originally a tube.

Sure enough, the right exhaust valve guide is gone. Gone as in no longer present!

I was expecting the fine a tangled mess of metal in the cylinders resulting from the valve guide making it's exit, but this is what I found instead. Most of the guide seems to have bypassed the cylinders as you'd expect, although there was some in the bore.



 

·
Registered
Joined
·
101 Posts
Discussion Starter · #206 ·
Thread resurrection!

Both I and the bike components have been away for a bit, hence the lack of progress. I sent the head away to get the valve repaired - in the end it needed new guides throughout (oversized in one case), new springs 'cause the old ones were too soft and short and 2 new valves. I also go the cylinders re-honed (didn't need a re-bore) and got some new rings correctly gapped.

Seems like the valves have been recut at some point, 'cause they overlap the spark plugs slightly and I don't think they would have on a standard 1970 model year?







Where I'm a bit stuck now is push rod tubes. I had a look at them to see what kind of seals I should be getting and they don't match! They've got slightly different 'rib' thicknesses. Both have the 'wedding band' on them, but it's pretty stuck in one case. I assume I can just persuade it off?



Should they be the same on this bike?
 

·
Registered
Joined
·
2,919 Posts
that head and barrels are looking good !
yes the pushrod tubes should be same - but not sure which or yours is correct
wedding band should come off relatively easily - probably just some gasket goo holding it
 

·
Super Moderator
Joined
·
13,265 Posts
If you study the parts books, you can make out the "steps" and "ribs" on the pushrod tubes. The illustration for your year should be easy enough to determine which one is right.

Are the cam follower holders the same, as far as "stepping" / shoulder profiles? They should be.

Valve seats may have been replaced, the machinist may have cut a bit of extra material.
 

·
Registered
Joined
·
101 Posts
Discussion Starter · #209 ·
When you say cam follower holders you mean the tappet blocks?

The guy who did the repair did say he thought they (the blocks) were wrong, but also that Triumph changed it alot in 1969/1970 so its sometimes hard to know what's correct!
 

·
Registered
Joined
·
4,277 Posts
Hi Dazzle, Your working on '69 Bonnie is that correct?

I have a few thoughts. First the valve job looks good. Looks like they had to cut a lot off intake seats & relieved the alloy around the area. I feel that's good. In photo it looks like there is shape edge where the relief cut into bottom of spark plug area. Round that area so no sharp edge can get too hot. Put spark plug into hole first so you don't over cut into plug threads. Round it like the diameter of a very skinny wood tooth pick or a skinny tube on can of carb cleaner spray. About like that.

Getting into your question. You have later head than '69 due to it has holes for dowel pins of the later rocker boxes like '71 & later. Also looks like the bore for PRT in head is the deep later condition. So you will need the later tappet blocks & PRT for later '69 & newer 650. The tube on left looks correct. Don't remove wedding band! It's good to have it stuck tight & looks to be be a good place on tube. Loose bands can/will migrate up & not cover seal. As is wedding band will slip over white square perfectly.

The later wedding band type tubes can have different looking shape at bottom & will work fine. The early pre wedding band tubes are only for the early tappet blocks & heads with the shallow bore for PRT. You cannot use early tube with your head. The cly is all the same in regards this process. So you can put early or late tappet blocks in the cyl as needed. Your head will need late tappet blocks, late (wedding band type PRT, to match the late head. Early T140 tappet blocks will work (fat ones with flat top), but not T140 PRT. Your left tube looks later, which is fine. At some point they went back to round top holes.

Here's a link to ID tubes, tappet blocks, head bores.

Vintage Bike Magazine » Push Rod Tubes

Study the above guide, & compare your parts. It will soon be clear what you need to do. Look at sellers & eBay photos, you'll see variations of parts that may or may not fit. Be aware parts sellers & eBay sellers both sell parts that won't work under the same part #s. So you MUST study & learn how to visually identify what will work for your motor. The best way is start from the head & work downwards. You have a late head, so work down from there. This stuff is very confusing. Once you learn it, you'll be good to go.

Notice the tubes that go with your head have a groove that the bottom Oring slips into. 500cc & T140 tubes are way shorter. The other 650 tubes the bottom sets on the seal. Again your type the bottom seal slips into groove. This bottom oring fits snuggly over OD of tappet block. The bottom of the tube sits on top of the white seal. It's soft silicon & compresses easily. If crush is too tight from head skimming etc, thicker head gaskets are available. They work good & don't leak.

Personally I put a thin smear of silicon on the round rings on PRT. & assemble quickly. MOST IMPORTANT TO DEBURR & SMOOTH BORE IN HEAD & OD OF TAPPET BLOCK WHERE O-RING SLIDES OVER. That is key to no leaks. Even micro scratches on rings will leak. Don't stress over PRT seal crush. Anywhere from .015 to .035" will work fine. Actually later motors didn't even use crush. Don't go tighter though. Trial fit head very gently tightening 4 head bolts with finger tips to keep head level. Measure gap to head gasket with feeler blades. Again don't over crush the seals. That can/will bend, distort head.

Should you need to change tappets, you'll need a real tappet block driver with the 2 pegs like shown in shop manual. Not hard to drive out or in. They should be aligned thoughtfully. Not just close enough to get bolt in. Always use viton rings on tappet blocks & the 2 PRT round rings. The with square should be soft silicon.

The photos are of correct original '69 Bonnie production date November '68. Has later head PRT, tappet blocks, cams, but still the early light flywheel.

First photo is tappet block with white seal installed.
Next photo is PRT with wedding band pre installed.
Nest photo is top of '69 PRT. Sorry it's blurry.
Next is original correct '69 head top.
PRT fitted to tappet block. The wedding band was tight on tube prior to fitting tube.
Next is another photo of tappet block for later PRT that came new in this '69 head.
 

Attachments

·
Registered
Joined
·
101 Posts
Discussion Starter · #212 ·
Its a 69, model year 1970 yeah.

My wife's uncle is reasonably sure the head was changed at some point in the 80s following a failure. My FiL would certainly have bought a second hand one, ditto on PRTs, so its not a surprise things don't match.

That link is dead helpful, thanks.
 

·
Super Moderator
Joined
·
8,351 Posts
Hi,

:) Good to see you back and you haven't sneaked the bike away to the scrappie.

To amplify the posts by @wol, @GrandPaulZ and @TR7RVMan, Triumph changed the pushrod tubes, seals, head and tappet guide blocks certainly for the beginning of the '69 model year, then again in November 1969 (because the previous iteration turned out to be a monumental balls-up :(), so the updated part numbers don't appear 'til the '71 parts book. Don has identified the head is probably '71-on; possibly-useful additional information:-

. The circular section O-rings top and bottom of a PRT are the same dimensions so they can be the same part number - 71-1283 is (y) because it's (should be) Viton, 70-7310 is Buna-N. (n)

. 70-4752 between the PRT and TGB is 1" ID fitted over the TGB, 1-1/4" OD, 1/8" thick. If you need it to get the aforementioned correct "crush", 70-3547 is the same ID and OD but only 1/10" thick.

Both have the 'wedding band' on them, but it's pretty stuck in one case.
. A "wedding band" should be a 'close sliding fit' over the bottom of the PRT. Reason is, with it raised so the fit of the PRT on the 70-4752 (or 70-3547) seal can be checked during assembly, the "wedding band" can be slid over the seal before torquing the head - the seal will bulge out slightly but a) the "wedding band" is supposed to stop the seal being squeezed from under the PRT; b) the slight bulging of the seal against the "wedding band" is supposed to stop the "band" moving upwards when the engine's running. One thing a "band" shouldn't need is gasket goo ...

In practice, both originally and since, PRT OD and "band" ID machining has been generally crap - "pretty stuck" could be the "band" isn't a "close sliding fit" around the bottom of the PRT or, if gasket goo is present, it was used to stick the "band" in place because clearance is too great. :(

Hth.

Regards,
 

·
Registered
Joined
·
101 Posts
Discussion Starter · #214 ·
I am back once again!

Hopefully the issues preventing me working on this bike are getting resolved, so I can spend some time on it.

So you may remember dear reader that I've had the bores rehoned and the head rebuilt. This now forces me to clean up the rocker boxes. I was in two minds about whether it was necessary, but now the head is all shiny clean I need to get the boxes cleaned so they match!

I've found a cleaning/vapourmatt firm 2 miles down the road who do classic vehcile parts so that's handy. I've taken the boxes apart in prep...



I'll hopefully get them cleaned up next week. Once that's done I should be finished with "subcon" work and everything else is stuff I can do in my garage.

I have also being going down the rabbit hole of thackeray washers etc. while pulling together the list of seals etc. I need to buy.

I'm pretty confident I know what's going on in my present set up, but my Q is this: Is it worth switching to the later spiral groove shafts while I'm in here? I have rockers with the 'scallop notches' on the ends. The bike has made it to the age of 52 without grooves...but then new shafts are only £50.
 

·
Registered
Joined
·
741 Posts
Is it worth switching to the later spiral groove shafts while I'm in here? I have rockers with the 'scallop notches' on the ends. The bike has made it to the age of 52 without grooves...but then new shafts are only £50.
If grooved rocker shafts are available as a direct replacement for your 650 then I would definitely fit them. They’re not for my 500 and although I made enquiries with machine shops I didn’t have the mod done in the end. Lots of Triumphs are running around perfectly happily with plain shafts but if better lubrication is ‘just’ a case of ordering later shafts and swapping the thackery/thrust washer assembly order then it seems sensible to me. Would a 650 also need two more of the larger (1/2”?) thrust washers?

Chris
 

·
Super Moderator
Joined
·
8,351 Posts
Hi,

Good to see you back once again and you still haven't sneaked the bike away to the scrappie ... :)

If grooved rocker shafts are available as a direct replacement for your 650 then I would definitely fit them.
+1.

have rockers with the 'scallop notches'
my understanding is that part 71-3549 will fit a 650. Indeed I think it may have actually been designed for the 650 but due to political nonsense at Triumph it only ever made it onto 750s?
Pretty-much correct. The primary driver was the earlier rockers are weaker. Umberslade Hall designed a new rocker and the rocker shaft changes and the different order of Thackeray/plain washer assembly to be implemented during '68. However, thanks to the "not designed here" dog-in-the-manger attitude at Meriden, while the new rockers were fitted, neither the shaft was modified nor the washers assembly order changed ... :rolleyes: Exactly the same rocker type, shaft scrolling and washers assembly was specified for the triple engines, built at Small Heath without any argument ...

Lots of Triumphs are running around perfectly happily with plain shafts
Mmmm ... when Meriden built them incorrectly, warranty periods were a fraction of what they've increased to since and we consider normal now. The bikes "running around" now are molly-coddled survivors of the period when poorly-assembled Triumphs that blew up were simply scrapped.

I've seen many rebuilt parts and assemblies that were "running around perfectly happily" while the owner molly-coddled the bike to the pub and back or similar; however, when the owner decided his/her bike was 'reliable' for a longer trip, they failed.

We can easily rebuild all sorts of parts and assemblies better than they were built 'back in the day'. It's what I've always done. Then, if it fails, I know either I didn't rebuild it as well as I could've, or I missed something important, or I need someone with greater knowledge than mine.

Hth.

Regards,
 

·
Registered
Joined
·
565 Posts
I'm ready to be corrected on this, but my understanding is that part 71-3549 will fit a 650. Indeed I think it may have actually been designed for the 650 but due to political nonsense at Triumph it only ever made it onto 750s?

71-3549 TRIUMPH T140 TR7 750cc BONNEVILLE TIGER ROCKER SPINDLE | eBay
The 71-3549 number change was about the UNF thread on the end, not all had the scrolling, and yes, it's a good idea to get two 1/2" thrust washers and run the thackeray washers next to the cases, whether you change the spindles or not.
 

·
Registered
Joined
·
101 Posts
Discussion Starter · #219 ·
I'll get a set of groovey rocker shafts then. Have to say, looking at the original notched design I can't fathom how they would work without the groove either. Sometimes I think Triumph deserved to go out of business, such is the silliness of some of their decisions!

So now I know all the seals, washers etc. that I need - except the PRT ones I can't size without checking the crush on assembly - I can order them all and get cracking.
 

·
Super Moderator
Joined
·
8,351 Posts
Hi,
know all the seals, washers etc. that I need - except the PRT ones I can't size without checking the crush on assembly
Assuming we're talking about the '69:-

. The thin O-rings should be later 71-1283, not 70-7310. Both are the same sizes, just 70-7310 is Buna-N, 71-1283 is Viton - better able to take the heat at the top of the PRT.

. Buy two of both white square-/rectangular-section white O-rings, they're hardly expensive. 70-4752 is approximately 1/8"-square section, 70-3547 section is ~1/8" wide but only ~1/10" thick.

. If you use either 70-4752 or 70-3547, you'll require two 71-1707 (one to fit over the bottom of each pushrod tube and white seal); be aware they should be a close sliding fit over the bottoms of the PRT.

Hth.

Regards,
 
201 - 220 of 235 Posts
Top