1961 CB72 Project

[G-Man]

LM

The 'small' wheel tensioner seems a bit of a mystery. Everything is smaller. and there is no separate bearing. Just a hardend steel center bush running inside another steel bush. Interestingly the lock screw is on the 'early' side, when the part looks like it ought to be later. The arm is different so the primary wheel will not clear.

I found one of these in my own collection and put the parts to one side because the dimensions were all different. Mine had a good wheel so I just used that on yours and put it back together.



G

Tensioners look really good.
Any idea what the deal is with that small wheel?. ..............lm

I thought I would get the "last for now" batch of tensioners completed before I forgot where the parts were. These are a set for LM. One was a later 'small wheel' type in which Honda used a tiny center plain steel bush. I didn't really have any tools available to true that wheel which was pretty horrible and teh arm won't take a primary wheel.

I happened to have a spare 'small' wheel in nice condition so I put that in. The other two were 'primary tensioner conversions' so it was just a case of slimming the centre rib on the wheels and transplanting wheels and bushes into the cam chain tensioner arm. I had to do the conversion from rivet to a 7mm bolt fixing and modify the arm to take the primary tensioner bush but all was well and we got three nice units.

[LOUD MOUSE]

Thanks for the info.
I'd hope more will come from others. .........lm

LM

The 'small' wheel tensioner seems a bit of a mystery. Everything is smaller. and there is no separate bearing. Just a hardend steel center bush running inside another steel bush. Interestingly the lock screw is on the 'early' side, when the part looks like it ought to be later. The arm is different so the primary wheel will not clear.

I found one of these in my own collection and put the parts to one side because the dimensions were all different. Mine had a good wheel so I just used that on yours and put it back together.



G

Tensioners look really good.
Any idea what the deal is with that small wheel?. ..............lm

I thought I would get the "last for now" batch of tensioners completed before I forgot where the parts were. These are a set for LM. One was a later 'small wheel' type in which Honda used a tiny center plain steel bush. I didn't really have any tools available to true that wheel which was pretty horrible and teh arm won't take a primary wheel.

I happened to have a spare 'small' wheel in nice condition so I put that in. The other two were 'primary tensioner conversions' so it was just a case of slimming the centre rib on the wheels and transplanting wheels and bushes into the cam chain tensioner arm. I had to do the conversion from rivet to a 7mm bolt fixing and modify the arm to take the primary tensioner bush but all was well and we got three nice units.

[G-Man]

LM

That tensioner uses a 9mm center pin, compared with the 10mm of the others. Cappelini offers both sizes of replacement pin so there must be some 'out there'. Yours and the single one I had are the only two I have seen. Must pay more attention if I strip any more engines.

G

[LOUD MOUSE]

I can't figure what was up as it has the large right tensaion mount. .....................lm

LM

That tensioner uses a 9mm center pin, compared with the 10mm of the others. Cappelini offers both sizes of replacement pin so there must be some 'out there'. Yours and the single one I had are the only two I have seen. Must pay more attention if I strip any more engines.

G

[G-Man]

Do you think that they could be a batch of replacements made for early tensioners late on?

G

I can't figure what was up as it has the large right tensaion mount. .....................lm

LM

That tensioner uses a 9mm center pin, compared with the 10mm of the others. Cappelini offers both sizes of replacement pin so there must be some 'out there'. Yours and the single one I had are the only two I have seen. Must pay more attention if I strip any more engines.

G

[G-Man]

Fantastic!!

G

<https://www.youtube.com/watch?annotatio ... BM#t=3m11s>

This worth watching for some.

My own correction is the MERLIN was a inline V12 cylinder.
Above is "PRECIOUS METAL" a highly modified P-51 and it has counter rotating props and a V12
ROLLS ROYCE "GRIFFON" V12 inline.
Caught fire (on the ground) last September and is being made flight ready as I send this info. ..............lm



Thanks for the correction.
Here in the US that design (MERLIN) was build by several engine plants.
One being PACKARD. .....................lm

Just a correction and way off topic for this tread.

The Merlin was a Rolls-Royce engine. Merlin was not a manufacturer but a model. It was also used in the famous Lancaster bomber. As it happens I live not far from one of the last two or three flying Lancasters. It turns out that you can rent the thing and occasionally it flies overhead. The sound of those four Merlins is unmistakable.

[Tim Miller]

You nailed it G! I have NOS very early left hand adj. version with both size rollers ( 39 & 43mm OD ). Also I have nos early right hand adj. version in both size rollers. All my new late versions have small roller.

The fact is the more you mess with these thinks the more you learn. Just keep on enjoying.

Tim

Do you think that they could be a batch of replacements made for early tensioners late on?

G

I can't figure what was up as it has the large right tensaion mount. .....................lm

LM

That tensioner uses a 9mm center pin, compared with the 10mm of the others. Cappelini offers both sizes of replacement pin so there must be some 'out there'. Yours and the single one I had are the only two I have seen. Must pay more attention if I strip any more engines.

G