Author Topic: Spitfire cam in a longstroke?  (Read 4257 times)

Offline Rusty nuts

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Spitfire cam in a longstroke?
« on: 21.10. 2009 09:52 »
Hi guys,

Last year whilst trying to source a camshaft for the longstroke, Burton bike bits advised that a Spitfire cam (67-357) would fit a longstroke engine,
but that valve timing would be out. Timing completely different, so more than a little dubious about making that work.   
However a 67-334 standard A7/A10 is only a few degrees diff, don't know if would physically fit.
Eventually had a new 67-695  made by Newman cams, well actually two as it was cheaper that way, sort of *smile*
Not something I'm about to try, just wondering if anyone has tried this & if so how they set up their timing?

Cheers
Rusty
1949 A7 Plunger
1947 A7 Rigid Star Twin
1969 Triumph T120R
1972 Triumph T120V

Online Brian

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Re: Spitfire cam in a longstroke?
« Reply #1 on: 21.10. 2009 10:41 »
I have just bought a cam for the longstroke motor and when it turns up, hopefully in the next week or so, I will compare it to a spare 356 I have.

I would very much doubt that they are interchangeable though as I am sure others would have done it if it was possible. The longstroke cams seem to be very hard to find and I was lucky to find the one I have just bought.

Offline Rusty nuts

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Re: Spitfire cam in a longstroke?
« Reply #2 on: 21.10. 2009 11:01 »
Brian
A good one went on ebay here a few days ago. You?
Rusty
1949 A7 Plunger
1947 A7 Rigid Star Twin
1969 Triumph T120R
1972 Triumph T120V

Online Brian

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Re: Spitfire cam in a longstroke?
« Reply #3 on: 21.10. 2009 11:33 »
I did bid on that one but didnt get it. I was lucky enough to find another one.

Offline LJ.

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Re: Spitfire cam in a longstroke?
« Reply #4 on: 21.10. 2009 12:59 »
Ahh I wondered if you bid on that Brian and you Rusty... Had my eye on it too! missed the deadline though as I'd have had a bid as well... Don't think it went for very much either.
Ride Safely Lads! LJ.
**********************
1940 BSA M20 500cc Girder/Rigid- (SOLD)
1947 BSA M21 600cc Girder/Rigid-Green
1949 BSA A7   500cc Girder/Plunger Star Twin-(SOLD)
1953 BSA B33  500cc Teles/Plunger-Maroon
1961 BSA A10  650cc Golden Flash-Blue
1961 BSA A10  650cc Golden Flash-Red

Offline Rusty nuts

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Re: Spitfire cam in a longstroke?
« Reply #5 on: 21.10. 2009 13:37 »
Didn't bid myself, thought it would go for more. Someone got a bargain at £29.
Did pick up the crank though as it got no bids, may come in handy one day!
1949 A7 Plunger
1947 A7 Rigid Star Twin
1969 Triumph T120R
1972 Triumph T120V

Offline alanp

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Re: Spitfire cam in a longstroke?
« Reply #6 on: 21.10. 2009 16:13 »
What do you mean by 'longstroke' with ref. to BSA twins?
Member of the 'Last of the Summer Wine Club - Jennycliff'.

Offline beezalex

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Re: Spitfire cam in a longstroke?
« Reply #7 on: 21.10. 2009 16:44 »
What do you mean by 'longstroke' with ref. to BSA twins?
1946-1950 A7 easily distinguished by the timing cover shape.
Alex

Too many BSA's


Offline Rusty nuts

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Re: Spitfire cam in a longstroke?
« Reply #8 on: 21.10. 2009 18:15 »
1946-1950 when the design was changed, engines had a longer stroke than later engines, hence longstroke.
Timing cover changed in 1948 as did inner.
Outer cover originally had no piled arms logo and continued for at least part of '48 changed sometime after that, I think 1949.
I know because I have one of each, both of which fit '49 engines
Where's my anorak!
1949 A7 Plunger
1947 A7 Rigid Star Twin
1969 Triumph T120R
1972 Triumph T120V

Offline LJ.

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Re: Spitfire cam in a long stroke?
« Reply #9 on: 21.10. 2009 20:19 »
Interesting stuff! where would we be without the anoraks?

My 1949 A7 Star Twin has the plain timing cover and I have seen the logo type wondering when the plain ones went out which I suppose was when the factory used them up.

Rusty: I didn't bid on the crank as I have one but did have a go on them lovely conrods! another item that went cheaply. grrrrrrr
Ride Safely Lads! LJ.
**********************
1940 BSA M20 500cc Girder/Rigid- (SOLD)
1947 BSA M21 600cc Girder/Rigid-Green
1949 BSA A7   500cc Girder/Plunger Star Twin-(SOLD)
1953 BSA B33  500cc Teles/Plunger-Maroon
1961 BSA A10  650cc Golden Flash-Blue
1961 BSA A10  650cc Golden Flash-Red

Offline Rusty nuts

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Re: Spitfire cam in a long stroke?
« Reply #10 on: 21.10. 2009 20:28 »
did have a go on them lovely conrods!

Didn't see them, same seller?
1949 A7 Plunger
1947 A7 Rigid Star Twin
1969 Triumph T120R
1972 Triumph T120V

Offline LJ.

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Re: Spitfire cam in a longstroke?
« Reply #11 on: 21.10. 2009 20:53 »
Ride Safely Lads! LJ.
**********************
1940 BSA M20 500cc Girder/Rigid- (SOLD)
1947 BSA M21 600cc Girder/Rigid-Green
1949 BSA A7   500cc Girder/Plunger Star Twin-(SOLD)
1953 BSA B33  500cc Teles/Plunger-Maroon
1961 BSA A10  650cc Golden Flash-Blue
1961 BSA A10  650cc Golden Flash-Red

Online Brian

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Re: Spitfire cam in a longstroke?
« Reply #12 on: 21.10. 2009 21:43 »
I bought the inner timing case and the tappet guides and tappets. I would have liked more but being in Aus the postage costs are horrible. I e-mailed him after the auctions ended to see if he had any more stuff and now I have a new camshaft as well !

On the subject of the outer timing cover, I have seen three different ones albeit with only slight differences. There are ones with no piled arms, ones with the piled arms like "stick figures" if you know what I mean and ones with the piled arms like the later A's with the guns thicker and recessed into the casting.

Online trevinoz

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Re: Spitfire cam in a longstroke?
« Reply #13 on: 21.10. 2009 23:46 »
There is no way that the A10 camshaft will fit the early engine.
An A65 cam is more like the early one but the bearing journals are larger.
Trev.

Offline Rusty nuts

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Re: Spitfire cam in a longstroke?
« Reply #14 on: 22.10. 2009 08:15 »
Yes he sold quite a bit of stuff... But these rods! £16.... phew...
When I was looking last year for the plunger the only ones I could find after months of searching were £100 from a supplier often mentioned here.
Ended up buying a whole engine for a bit more just to get the rods, still the rest of that engine is coming in very handy on the rigid build!

Then I got a good pair earlier in the year for £15 from ebay, another very good pair at Netly for £10 but  one of the fork legs the guy sold me has some distortion inside & won't fit hence my post in wanted & for sale.
Still the fork legs were £5 each so it was worth the punt. And he did throw in a pair of matched Star twin cases bead blasted & vgc for nothing!!!!!!!!!
Autojumbles eh!
1949 A7 Plunger
1947 A7 Rigid Star Twin
1969 Triumph T120R
1972 Triumph T120V