Author Topic: Rigid/Plunger A10 Engine & Gearbox upgrade  (Read 1144 times)

Offline Nourish

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Rigid/Plunger A10 Engine & Gearbox upgrade
« on: 23.10. 2013 17:31 »
Hello, I'm looking to buy a Plunger A10 frame and crankcase(would prefer rigid) and have to source the rest. I'm not worried about originality as long as it looks nice, But I would like to include some later parts in the Engine and Gearbox. Is it possible to fit a big bearing crank (I gather that is big Big ends) thick flange barrels and alloy head and box internals - or should I ask what won't fit?
Cheers

Offline Briz

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Re: Rigid/Plunger A10 Engine & Gearbox upgrade
« Reply #1 on: 23.10. 2013 20:01 »
No problem fitting the good stuff to plunger cases at all.
Only thing to look out for is to get the later plunger cases; earlier ones lacked an oil feed to the cam (this is just a relief-valve vent) and a proper crank seal.
Later ones are stamped BA10 (or A7), earlier ones, ZA10 (or A7)
You cant fit the later gearbox internals (& inner cover) without building up the case with weld & machining. I did it years ago; wasn't really worth the hassle. The mainshaft interchanges OK though if you want to run a decent clutch. But a Norton clutch fits the plunger mainshaft.

Online muskrat

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Re: Rigid/Plunger A10 Engine & Gearbox upgrade
« Reply #2 on: 23.10. 2013 20:17 »
G'day Nourish.
The alloy head will be a problem on an A10 plunger (OK on an A7). The extra downdraught angle means the carb sits higher and fouls the frame.
Cheers
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, 88 FXST .
Australia
Muskys Plunger A7

Offline trevinoz

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Re: Rigid/Plunger A10 Engine & Gearbox upgrade
« Reply #3 on: 23.10. 2013 20:57 »
The engines without feed to the camshaft are only the long strke A7s.
All A10 and A7 from AA7 series have oil to the cam.

Trev.

Offline wilko

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Re: Rigid/Plunger A10 Engine & Gearbox upgrade
« Reply #4 on: 23.10. 2013 23:31 »
I saw a rigid frame on ebay somewhere recently. And a rear backing plate.

Offline Briz

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Re: Rigid/Plunger A10 Engine & Gearbox upgrade
« Reply #5 on: 23.10. 2013 23:53 »
The engines without feed to the camshaft are only the long strke A7s.
All A10 and A7 from AA7 series have oil to the cam.
Trev.

Nope; my first ever A10 - a 1950 - was a ZA10 case without the cam feed.


Offline Nourish

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Re: Rigid/Plunger A10 Engine & Gearbox upgrade
« Reply #7 on: 25.10. 2013 01:25 »
I would love to buy the frame - it's pick up ony - any one know the price of a ticket to Aus from the UK?
Sorry I can't help being sarcastic ;)

Offline duTch

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Re: Rigid/Plunger A10 Engine & Gearbox upgrade
« Reply #8 on: 25.10. 2013 07:08 »

 You might have trouble getting it  on the plane as hand luggage.. *eek*

 Same guy must have stripped a longstroke
 http://www.ebay.com.au/itm/BSA-A7-Longstroke-Crank-Cases/190926086101?_trksid=p2047675.m1850&_trkparms=aid%3D222002%26algo%3DSIC.FIT%26ao%3D1%26asc%3D11%26meid%3D2225494138763577697%26pid%3D100011%26prg%3D1005%26rk%3D5%26rkt%3D5%26sd%3D190912606991%26

 I built up my A10 from bits, and didn't have any trouble with fitting a 389 mono carb to the alloy head-(oh just remembered I had to truncate the very top where choke cable would go but don't need a choke anyway), just couldn't fit an air filter, which is why I did the offset inlet tract..
 Also I did graft in some close ratio gears, which worked ok, but needed special attention to bushings, but am not using that box just now, have to dissect it and see what's what...

Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
Australia