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[nudge]

does anyone know the timing details for a "R" camshaft which i have in my basket case twin, it appears to have one fitted on the exhaust , whilst the inlet has no marks on it at all, also the inlet cam wheel has a number 4 stamped on it!! i would like to try and time it up using a degree wheel and ignore all the marks!! thanks

[Jools G]

I think you'll find it makes no difference what the cams are marked with.

Many years ago I measured all the sets of cams I had, some marked as 'In 2'/'Ex 2', some as 'In R'/'Ex R', and others with no marks at all. Every single one of them gave the same maximum lift, those of the Super Meteor - including 2 sets removed from Constellation engines.

I tried mapping one set at 2 degree intervals, but as my old Baty gauge didn't have a sufficiently refined 'contact' point, I don't recall having too much success.

Just time it up as a Super Meteor using RE's own specs and you won't go far wrong, i.e. ;
Exhaust opens 75 degrees BBDC
Exhaust closes 35 degrees ATDC
Inlet opens 30 degrees BTDC
Inlet closes 60 degrees ABDC
Note - timing with .012" valve clearance

[nudge]

many thanks jools, i have measured my cams, opening closing and have the following
inlet op 40 close 68
ex op 85 close 35
this is with a inlet sprocket marked A
book says
inlet op 24 cl 73
ex op 83 cl 35
i believe my problem is the use of the A sprocket?? the inlet cam has no identification the exhaust has R stamped on it! what do you think? regards d

[Jools G]

As far as I know, there's a choice of camshaft sprocket/cam combination. Those marked with an 'A' are supposedly part number 42507 and used on Constellations which were of course all equipped with magnetos.

The Super Meteor was designed to run on a distributor, but there is also an option for magneto ignition. In this case the part number is 36140, this being common to the first 750 Interceptors.

With a 'sports' inlet cam (35344) and an 'A' inlet sprocket, the data I have suggests the timings should be -
Inlet opens - 22 degrees BTDC
Inlet closes - 75 degrees ABDC

The figures you've reported are more like those for a 36140 sprocket with a standard inlet cam 32705, (opens 35 deg BTDC, closes 82 deg ABDC).

[nudge]

thanks once again!! it all seems strange! the inlet camshaft has a R on the end, the sprocket is a 42507 A and the timing is miles out , the exhaust cam is marked F and times up as per book!, i am planing to get a second hand 36140 sprocket from mr h tomorrow and try that! unless you have any other ideas!! regards d

[Jools G]

I'm afraid it's all part of the wonderful RE experience! Whilst it's useful to have a degree of parts interchangeability, it can prove counter productive on occasion.

To be honest, I don't think any of my Connie inlet sprockets bear markings to the best of my recollection at any rate. I and one of my fellow RE twin owner friends have always rather thought that the 'A'-marked variant of the inlet sprocket were a figment of someone's imagination!

If I were you, I'd hold hard on buying another cam sprocket until you've run the bike. The timings you report aren't that far out from the Super Meteor set-up. The big twins are pretty handy in the speed stakes anyway and I don't think the slightly tamer settings you've got will be any handicap. This was the same set-up I had on my late Dad's Connie when I first had it, and I had no trouble keeping up with my mate who was riding my T150 and thought he'd buzz off into the distance for a laugh. He couldn't believe I'd kept pace with him, and quite frankly I was as surprised as he was!

[nudge]

thanks jooles, the problem is with r/e that the sprockets are keyed onto the camshafts so you are limited to the spacing of the teeth/chain!! regards d