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Trying to save a Trials car - engine/flywheel/gearbox advice.
Posted: Mon Feb 21, 2022 3:05 pm
by Dikko
I have a Trials car which was abandoned in Wales after an exhausting life and at some point herding sheep!!
Its engine was an 850 A Series with a 'smooth case' 3 - speed Mowog gearbox. It's certainly from the 1950's. Back axle is Mowog too.
I would like to enter it with The Historic Sporting Trials.
So, engine and gearbox strip-down revealed a cracked block (I'll be happy if all the internals went to a good home to members) and after renovation of the 'box I've fitted a 1275 Engine but without flywheel - which I'm in need of.
I'm a newby to BMC engines but someone has identified the engine as a Marina because the oil filter is next to the distributor (even though it came out of a Midget). The engine plate has 38G493 EP64540 and on the N/S block there's the number C1844.
The gearbox fits the block perfectly, and I've seen on this site some problems about flywheel and clutch mixes I might get wrong...
The crankshaft has a 6 bolt attachment for whatever flywheel I need.
So, to the question, what parts & where can I get the correct flywheel/clutch to do the job in hand?
Unfortunately the gentleman who renovated the gearbox died and the clutch pedal parts went missing so I'll need those too. All in good time though.
I also need an exhaust Manifold to fit a single SU carb...
I'm in Herts so if there's anyone out there with the knowledge, parts and even the expertise who can help I'd appreciate it.
There'll be a rather silly drive up and down ditches in it for you too!! .....If you want of course...

Re: Trying to save a Trials car - engine/flywheel/gearbox advice.
Posted: Mon Feb 21, 2022 3:27 pm
by Sleeper
C'mon Phil..
John ;-)
Re: Trying to save a Trials car - engine/flywheel/gearbox advice.
Posted: Mon Feb 21, 2022 4:14 pm
by philthehill
I'm here.
A photo of the engine especially the rear end of the engine and the rear of the crankshaft (end on and side on) will help identify what you have. Once we have those photos identification of the parts required and a source of parts will be made much easier.
As you have six bolts the flywheel required could be either the ESM modified flywheel or the 1275cc Midget/Sprite flywheel. Dependent upon what flywheel is suitable for the crankshaft will determine what clutch assembly is used.
Phil
Re: Trying to save a Trials car - engine/flywheel/gearbox advice.
Posted: Tue Feb 22, 2022 10:44 am
by Dikko
Righto, will do, I'll be back after I've unbolted the gearbox etc & I've never downloaded a photo, this might take a little time... Thanks Phil.
Re: Trying to save a Trials car - engine/flywheel/gearbox advice.
Posted: Wed Feb 23, 2022 5:10 pm
by Dikko
Taken photos and it's taken me 2 hours longer to try to attach them than it has taking the gearbox out...
One photo is 1.1mb so I think I'm overloading the system.
I'm stumped, I look on with envy at all the other photos posted... if it's any help Phil, the crank width is 3", the gearbox drive shaft entry hole is 1" and the centre to starter teeth is 5". There is a cam cover on the backplate which protrudes 1/4".
Other than that info, in the wise words of someone; 'a picture paints a thousand words' and it seems I'm no artist.
I may have to enroll the services of a neighbour's 5-year old to download the photos...!
Re: Trying to save a Trials car - engine/flywheel/gearbox advice.
Posted: Wed Feb 23, 2022 5:43 pm
by philthehill
Thanks for the reply.
I really do need a photo to be able to determine what you have and what is required.
As regards photos.
Take photo, save to your machine, crop the photo so that it is below the required level of acceptance (1.009 KB seems to be acceptable) save the photo, attach photo to post by clicking on 'attachments', then 'add files', click on 'place in line' and submit the post. I have just had some trouble posting a photo and had to crop it hard.
Re: Trying to save a Trials car - engine/flywheel/gearbox advice.
Posted: Sat Feb 26, 2022 5:28 pm
by Dikko

- Ugbug flywheel new top view 2.jpg (107.88 KiB) Viewed 1184 times
2 hours on Wednesday, 1 hour on Thursday, mental break on Friday... Have I actually added a photo?

Re: Trying to save a Trials car - engine/flywheel/gearbox advice.
Posted: Sat Feb 26, 2022 5:30 pm
by Dikko

- Ugbug fly front.jpg (1.21 MiB) Viewed 1184 times
God, they're rather big...
Re: Trying to save a Trials car - engine/flywheel/gearbox advice.
Posted: Sat Feb 26, 2022 5:44 pm
by philthehill
Thank you for the photos of the rear of the crankshaft.
From what I see in your photos determines that the crankshaft to flywheel attachment comprises qty 6 bolts and one locating dowel - therefore you have a Marina crankshaft fitted.
If that is the case you will need the ESM modified flywheel.
https://www.morrisminorspares.com/engin ... s-p1239064
ESM can supply a suitable clutch assy as well as the flywheel.
Re: Trying to save a Trials car - engine/flywheel/gearbox advice.
Posted: Sat Feb 26, 2022 5:53 pm
by Dikko

- IMG_0301 (1).jpg (1.65 MiB) Viewed 1178 times
Re: Trying to save a Trials car - engine/flywheel/gearbox advice.
Posted: Sat Feb 26, 2022 5:56 pm
by Dikko
Gosh Phil, that was quick. THANK you very much, For your patience - if we ever meet - I owe you a pint.
Re: Trying to save a Trials car - engine/flywheel/gearbox advice.
Posted: Sat Feb 26, 2022 6:10 pm
by philthehill
Happy to help
You will have to use the later 1098cc ribbed case gearbox as the larger clutch pressure plate will not fit inside the smooth case gearbox.
If you need to shorten the gearbox overall length please come back on here for details.
If you have to use the Minor Ser 2 gearbox which is not very strong you could get around the larger clutch fitment problem by having the ESM flywheel re-index drilled and using a early Triumph Spitfire 9 spring clutch assy.
https://www.ebay.co.uk/itm/154672912600 ... Sw1uNhepxu
The clutch in the above link will be more than suitable for your trials car.
Another way around is to have a 948cc flywheel index drilled to suit the Marina crankshaft. The clutch cover and driven plate in the link above will then fit the Marina crankshaft, 948cc flywheel and smooth case gearbox bell housing.
Phil
Re: Trying to save a Trials car - engine/flywheel/gearbox advice.
Posted: Tue Mar 01, 2022 2:22 pm
by Dikko
Thanks again for the advice Phil, I think you've saved me a lot of time. I'll go the 948 flywheel way if I can. Now all I have to do is find one...
I have plenty of internals that would be useful to club members so I'll see if I can swap/exchange on the Free section.
Anyone out there with a flywheel gathering dust?
Re: Trying to save a Trials car - engine/flywheel/gearbox advice.
Posted: Wed Mar 02, 2022 7:44 am
by kevin s
I think I may have one kicking around somewhere, when I get a chance I will go round the lock up and take a look.
Re: Trying to save a Trials car - engine/flywheel/gearbox advice.
Posted: Wed Mar 02, 2022 9:14 am
by ManyMinors
Dikko wrote: ↑Tue Mar 01, 2022 2:22 pm I'll go the 948 flywheel way if I can. Now all I have to do is find one...
Anyone out there with a flywheel gathering dust?
If you have no luck here, a ring around the Minor specialists should soon find one. Not that much demand for 948 parts now.
Re: Trying to save a Trials car - engine/flywheel/gearbox advice.
Posted: Wed Mar 02, 2022 1:08 pm
by Dikko
Thanks for looking out guys.
Kevin S; A friend has pointed one out on ebay and I've ordered it. Next it'll be off to an engineer to be re-drilled to take 6-bolt Marina crank. As long as I get that right and not have it wanting to escape the bell housing I might be on the way.
An engineers blueprint might be good? I think I'm asking too much there though
Historic Sporting Trials website has dates around the country. One day the 'Ugly Bug' will be back!
Re: Trying to save a Trials car - engine/flywheel/gearbox advice.
Posted: Wed Mar 02, 2022 9:07 pm
by philthehill
A blue print - my, that takes me back to my apprentice days.
For those not in the know - a blue print is a plan or engineering drawing on blue paper with the details in white.
https://en.wikipedia.org/wiki/Blueprint
Re: Trying to save a Trials car - engine/flywheel/gearbox advice.
Posted: Thu Mar 03, 2022 1:53 pm
by kevin s
and remember the smell of ammonia.