Britbike forum Forums British Motorcycle specific Brands Triumph bulletin board 1973 T140 rocker spindles. Oil grooves?

Does anyone happen to know if the rocker spindles on a 1973 T140 have the oil grooves cut into them?

Was this a late model T140 feature only?

The oil grooves were introduced with the 1973 750 models.

Now if you subscribed to Vintage Bike you would know that :bigt

I actually just read that article you wrote ( I think it was you who wrote it) about that issue, with the washers and the spring washers. Your article is what got me thinking about all this since the motor is on the bench right now. I was unsure if it was a mid year change over with oil grooves or if all the '73 models had it. Good to know I don't need to deal with the rocker spindles.

So just to clarify, solid washers against rocker then the spring washer?

I also have the plunger and no leaf springs in the transmission so I lucked out there too.

Hi John, read your article as well, I have a question, have a 1970 T120R, spindles have NO grooves, I will be getting my machinist to put the grooves in, would it be a good idea to change to rockers with the drilled oil holes or are the ones with the notches in the sides,as I have, be sufficient?

Yes, and you will have to buy one pair of 1/2" flat washers (70-1575) to do the job.

You can prove that the spiral groove are cut in your rocker shaft with a hand pressurized oil can. Cover the two feed holes with your fingers and squirt oil under pressure into the hole in the end of the shaft. The oil should flow freely out of the side of the rocker. If the pressure in the can builds, without any appreciable flow of oil out the side of the rockers, the shaft is not grooved.
John

Drat,

I was hoping to find spiral grooved spindles at a reasonable price. Too late. Cat's out of the bag.

John, would you recommend this as an improvement we should use on earlier Triumphs?

I'd say yes since this is why I started the thread. I wanted to have the extra oiling capabilities to the rockers but it seems I already have the grooved spindles.

I'm unsure of the cost of new spindles vs having your originals grooved but I'd do it for sure and go with the most cost friendly method.

I checked one of my extra rocker spindles with a file, and it appeares to be hardened. It may be difficult or impossible to have old ones grooved. I don't have one of the later ones for comparison, so I ask:

Other than the grooves, are all other dimensions the same regardless of year, and are the rockers the same for all years?

Irish:
It is well documented that starting with the 650 engine number DU79965 changes were made to the oiling drilling in the rocker arms. It was based upon engineering done on the triple. It was supposed to increase the flow of oil to the rocker arm, valve guides and push rod cups. While the change was made to the rocker arms and they, and the push rod rocker ball, were no longer drilled. But the changes required for the system to work stopped there.

For the system to work you needed to block the hole in the rocker arm, put an oil groove along the rocker shaft to allow oil to flow to the ends of the rocker arms and flat washers placed against the rocker arm ends instead of the Thackeray washers. This is clearly illustrated in both the Trident parts manual and Workshop manual.

If you look at the triple you will see that the rocker shaft has a oil groove the length of the rocker shaft. This groove allows oil to flow out of the ends of the rocker arms in some volume. That groove was never incorporated in to the manufacture of the 650, or 500 for that matter, rocker shafts. While a small amount of oil continued to make its way to the rocker, little made it past the middle of the rocker arm.

How this happened is a matter of conjecture, but "not designed here" probably had a lot to do with it. The triple was being designed at Umberslade Hall under the direction of BSA and the guys at Triumph had little respect for their efforts.

This oversight continued until 1973 when the rocker shaft finally received an oil groove in the form of a spiral cut along the length of the shaft.

Just an addendum to this thread.

I sent out my rocker spindles to HHB and am getting the other end modified so I am going to run a pair of rocker feeds, one on each end. Figured the extra oiling could not hurt and the aesthetics will be more balanced now and symmetrical. I'll post some pics when I get all the parts back.

Why didn't the unit 500s have the oil grooves. Those motors go back to the 1950s before the internal bickering of BSA/Triumph.

I'm often worried about the oil flow to my rocker boxes. When I open my finned rocker covered I see a very little oil spashed up inside the covers, more so on the inlet side, so I know oil is getting up there.

What modifications can I make to a T100S to improve oil flow? Perhaps a Morgo rotary pump to increase pressure? Can I get the spindles cut?

Matthew,

There was a discussion on that about a month ago. You can see the thread here:

http://www.britbike.com/forums/ubbthreads.php?ubb=showflat&Number=348062#Post348062


Afterthought: If it was me, I'd forgo the Morgo and get the spindles machined.

HTH,

Steve P

I am with Steve.

Hi all, hoping to get my rocker boxes assembled for the last time. 1971 T120. So doesn't have the grooved spindles, but wondering if it would be beneficial to revert back to the rocker arms that had an oil passageway drilled through the arm and into to the pushrod ball-ends? combined with proper washer order.

or is the grooved spindles the only way to improve top end oiling?

I'd think a Morgo rotary would be overkill for a street bike.

The spiral grooved rocker shaft spindles are available under part number 71-3549. They were standard in 1973 and later 750 twin rocker boxes.

dracko,

Certainly not the only way, but perhaps one of the better ways? The grooved spindle was incorporated into the twins after the design on the triple (Tridents and R3s). Whether the grooved spindle is superior (or not) in oiling over the drilled arms, I have no idea.

As John has previously said, the grooved spindle for the 750's will fit the 650's, the only difference being the acorn nut is UNF instead of CEI.

Triumph top ends don't need that much oil. What they do need is a little oil in very specific places.

Steve P

Okay thanks for the info Steve and John. I will do a little searching around for some grooved spindles.

I was also wondering if the drilled rocker arms are better than the undrilled. IIRC, the drilled arms were the earlier version so I wonder why Triumph would go away from them if they directed oil well?

Good question. I suspect no one can say for sure. With those drilled ones and the spiraled rocker shafts you may get more oil, but maybe with the drillings all will go to the pushrod tube, and none of the increase to the valve end of the rocker.

And the drilled one may break.

As I understand from what I have read, they stopped drilling them because some of them broke. I am not sure of that. It maybe it was just cheaper to due it without drilling.

Faced with the choice I would probably perseverate to the point of paralysis and then in the end, opt for spiraled shaft, thackeray washers in the correct placement, and call the improvement sufficient.

It is my understanding that the drilled rockers were weaker than the non-drilled and more liable to break.

Okay so they were snapping, good to know why they changed it up.
yeah I was thinking the same thing. strange design...you'd think they would drill both arms if doing one.

Thanks for the info Btour and Desco, I will continue to look around for some splined spindles and be done with it.

take it easy.

Not so sure they snapped at the arm, but I have seen pictures of ones where the ball end with the hole in it, and the ball, cracked/broke around the hole.

Not so sure how to accomplish drilling the other end. There is the adjuster there. Can't drill that and line up a hole. One would still depend upon oil running along the outside.

Interesting to think what might have been done, though. Piping in the top of the rocker box to drop feed each place it is needed including rocker spindle itself. Much like drip emitters for plants. That is as far as I can get right now.

Well, it wasn't "Triumph" that made the change, but the group's engineers at BSA's Umberslade Hall. On paper all of the engineering transfered from Triumph to the new engineering group set up by BSA. This bit of engineering came from the development of the triple. The triple had this set-up from the first production models in 1969, and unlike the Triumph twin models, it has appeared correctly in the triple parts books and Workshop manuals.

You know this group of merry men at what was fondly called Slumberglade Hall better as the ones that gave us the Oil in Frame 1971 twin models. Remember the frame that the Triumph engine wouldn't fit in when first delivered.

It isn't a secrete that the Meriden Men had little respect for BSA or their engineers and I suppose this didn't improve things.