So much for the "light restoration". That machine has turned into a Jacob's Ladder. Good luck and press on.

@BSAPowerSet

9 ай бұрын

Thank you John. Indeed not very light but the end of the tunnel might be in sight!

A big job that just seems to be getting bigger, hey!!! I'm glad it's you doing it and not me!!!!!!!

@BSAPowerSet

9 ай бұрын

Indeed Phil we should known but we’re all in now so must keep plugging!

Pillar bolts are great, assuming they are torqued properly! They're great because (if you know what you're doing), you can retorque the head bolts including pillar bolts, without having to take the rocker boxes off.

@BSAPowerSet

9 ай бұрын

Indeed Paul - I can see how I think. Thanks for the interest and comment.

The oil goes down the pushrod tubes REVELATION ! I did chuckle. Even on the nine-stud heads, mounted in the earlier (pre-71) single downtube frame, the centre bolt is quite awkward to access with a torque wrench when the motor is in the frame but the engine is almost, or rather completely, impossible to hoik into position with the rocker boxes in situ. Especially single-handedly with no hoist. The sequence for properly torqueing down the head requires that the rocker boxes be in position. It's a Catch-22 situation. With my '67 T120, I had to drop the headless engine into the frame (taking measures to protect the powder coat job), leave it there loose and then continue to build up the top end. I needed the engine loose in the frame because to insert the four inner studs that pass through the rocker boxes required the motor to be rocked left then right to allow these studs to pass the top tube of the frame on their way to the cylinder block. What a palaver ! Once the top end was loosely assembled, the bottom and front mounts for the motor could have the studs run through and semi-tightened. Only then could the final torqueing sequence for the head commence, obviously with the usual worries about pushrod tube seals etc. So, in relation to your video: Whoever last rebuilt that engine couldn't properly torque down those centre, allen-headed, pillar bolts and this led to an exchange of gas and oil between the cylinders and beyond. You may want to have that head skimmed. It has obviously been recently rebored. What are the stampings on the piston crowns? +20? +40? +60?

@BSAPowerSet

10 ай бұрын

Thanks Dave for the interest, comment and information based upon your experiences. Yes I didn’t have brain engaged when thinking about oil return - a true BSA man see? I agree we’ll need to check the head joint face and grind/skim before refitting.

@DaveFiggley

10 ай бұрын

@@BSAPowerSet Yeah, the Triumph unit motors were certainly prettier than their BSA counterparts but those pushrod tubes were, and are, a nightmare to seal. Also, the plunger-type oil pump was always a bit suspect. I believe the BSAs used worm-driven pumps.

@BSAPowerSet

10 ай бұрын

@@DaveFiggley Yes worm driven gear pumps on the A65. Agree the Triumph twins are lookers though.

The bolts that go through the rocker boxes do not clamp the head down, they simply screw into threads in the sleeve nuts, which have already been torqued down on the studs to secure the head, so having the rocker box gasket clamped tighter on the inboard side is not a result of head nut torque, but uneven tightening of the rocker box nuts and bolts. The gasket set should come with 2 o-rings (usually 1 red and 1 black) and a flat, white silicone rubber seal for each tube. Counter-intuitively, the red one goes at the bottom and the black one at the top, with the white seal compressed under the tube and enclosed by the "wedding band" steel ring. For torquing the centre 6 nuts, I made a special tool by cutting an allen key to the right length, then welding a nut on top, which I then ground to 1/2" square. This can be inserted into the centre nuts and the ones inside the rocker boxes, then my torque wrench can be fitted over it, after removing the drive piece from the centre, and the nuts torqued with no clearance issues. Of course, to re-torque the head, you need to remove the large rocker box bolts and tighten the sleeve nuts underneath.

@DaveFiggley

10 ай бұрын

"The bolts that go through the rocker boxes do not clamp the head down.." On all Triumph twins the four central bolts pass through the rocker boxes and into the cylinder block. These are the most important studs when it comes to mating the head with the cylinder block. There are two smaller bolts on each box that tap into the cylinder head and three nuts for each box under the cylinder head flange. When torqueing down the head/rocker boxes main studs, I gently tweak the smaller bolts on each side and constantly nip up the three nuts below. Steady as she goes, right? We're looking to spread the load across the head/rocker box joint. From memory, the main studs require 18 lb/ft. The three nuts under the flange 6 lb/ft and I can't remember what the two outer bolts were supposed to end up at. Probably 6-10 but it's a almost inpossible to get a spanner on them anyway.

@rickconstant6106

10 ай бұрын

​@@DaveFiggley Not all Triumph twins. On my 1978 T140V, which has the same set-up as this 1977 Jubilee model, the head fastenings inside the rocker boxes are studs, held down by special sleeve nuts, which are tightened down, as part of the head tightening sequence, before you fit the rocker boxes. The 3/8" bolts which hold the rocker boxes down do not go through into the cylinder block, but screw into threads inside these sleeve nuts, so do not hold the head down.

@BSAPowerSet

10 ай бұрын

Thanks Rick for the info, advice and anecdotes from experience. Yea the pushrod tubes had no sealing rings at all - just filthy silicon - so thanks for explaining the fitment of those.

@crozwayne

10 ай бұрын

Ridiculous design, absolutely ridiculous, you would never find such a bodge on a decently engineered product

@BSAPowerSet

10 ай бұрын

Thanks for the discussion on this topic guys. I’ll focus on on this at the beginning of the next video. Indeed the fastener design for the head was a workaround on the OIF motors to allow the rocker boxes and head to be removed/fitted from/on the engine whilst in the frame. When the oil bearing frame prototypes for the big twins were first produced, the Triumph motors couldn’t be fitted - they couldn’t insert a complete motor and in the case of a motor with the head off, they couldn’t fit the head and rocker boxes once the bottom end was in the frame. Unbelievable really.

Nice vlog/update, are you resurfacing the cylinder head?

@BSAPowerSet

9 ай бұрын

Thanks Matt - will grind it to resurface with glass and paste.

I can never understand why Triumph didn't cast in the pushrod tubes as part of the head, like a BSA or a Norton. It would have reduced the sealing issues at a stroke. Maybe a cooling issue? Getting the flow around the front tube might have been difficult?

@BSAPowerSet

9 ай бұрын

Wouldn’t that have caused more challenges with removing the head for maintenance Andrew?

@rickconstant6106

9 ай бұрын

@@BSAPowerSet I think the Triumph engineers' attitude was always "if it worked for me grandad before the war, it'll work now".

@andrewwalker8640

9 ай бұрын

If you can get the pushrods out before the cylinder head is off it should be okay but they are dead centre and there's a big OIF tube above. Old Matchless twins had them cast in, with similar fore and aft positions. Can you get the A70 head off with the engine still in the frame? I've read that if you cast them in it makes for a heavy cylinder head, but separate pushrod tubes is really 1930's practice, and you have to get the crush on the seals just right or they leak.

@BSAPowerSet

9 ай бұрын

@@andrewwalker8640 OK thanks for explaining further your thoughts on this. On the A70 yes I can remove head with the engine in frame.

@rickconstant6106

9 ай бұрын

@@andrewwalker8640The later pushrod tubes, like the new ones Angus has there, are not so hard to set up as the earlier ones where you had to get the correct amount of "squash" on the seals. These have an o-ring on the top and another inside the bottom, with an additional soft silicone rubber seal underneath the bottom of the tube. These are quite effective for several years, until they're not. Eventually the o-rings harden and split (usually the top ones), but it's about time for a de-coke by then, anyway.

Hello; the studs should be the other way around. That "tit" down.

@BSAPowerSet

Ай бұрын

Could you clarify which studs you are referring to please? Thanks.

@TheReverb1

Ай бұрын

@@BSAPowerSet H; all the studs should be that way due preventing the full-depth thread at the end of a stud reaching the not-full-depth thread at the bottom of a blind hole in the cylinders so studs should bottoming on tit not on the threads

@BSAPowerSet

Ай бұрын

@@TheReverb1 OK thanks I’ll look into this.

@BSAPowerSet

Ай бұрын

@@TheReverb1 Hi again - I’ve reviewed the parts book and I see what you mean although it only seems to picture the nubs/nipples on the centre studs. I can’t really see that it would make much difference either way round as on these OIF engines the top of the stud effectively screws into a blind ended Allen screw.

@TheReverb1

Ай бұрын

@@BSAPowerSet Hi; problem is to the cylinders; very thin wall there and is not good to make force to the sides (to not distort the cylinders) but to the bottom of the hole. A solution would be to use 4 1/4 balls inside and bottom the studs on the balls. Studs longer thread (see that have that "tit") goes down. Is not my solution, is what good rebuild procedures for these engines is all about. Like using bigger (the same as the ones used on the outer head bolts) washers under the Hex, socket head nuts etc

If only those militant wasters at Meridan had allowed the shop to shut, maybe NV could have managed to save BSA and Norton. the T140 was truly an awful motorcycle, pre oil in frame T120 beats it hands down!

@BSAPowerSet

10 ай бұрын

Hi Croz. Indeed what might have been if Dennis Poore had his way.