Dymano Mounting bracket width discrepancy

for those with Series MM sidevalve cars produced between September 1948 and February 1953
gtt1951
Minor Addict
Posts: 901
Joined: Thu Oct 04, 2012 5:01 pm
MMOC Member: Yes

Dymano Mounting bracket width discrepancy

Postby gtt1951 » Thu Jun 11, 2020 5:32 pm

Colleagues,
I've been having some problems, as some of you may know, with my Low-Light 1950 project.
When refitting the C40 dynamo, that came with the car, I had to add about 4/5 washers to take up the gap.
C39 and C40 dynamos should be 145mm (approx) between the mounting plate holes.
I have checked my 1951 side-valve High-light (with the original aluminium water jacket/dynamo mounting) and the spacing is 145mm.
All my spare dynamos (both C39 and C40) are all 145mm, so I have, just now, measured the (what I took to be original) aluminium water jacket/dynamo mount on the Low-light and it is only 137mm
Distance between flange outers.jpg
Distance between flange outers.jpg (402.23 KiB) Viewed 273 times
You should be able to see the pile of washers (just about) at the front mount.
My ESM repro is 145mm (but the threaded bolt holes are the wrong size (UNF instead of Metric 8 Fine).

So what on earth is on my 1950 side-valve? Anyone, out there, have any comparable measurement?
I know the earlier engines had an extension to the head casting, where the dynamo was fitted - but what was the spacing on that?

Has mine been ground down for some reason?

Any information gratefully awaited,

George.
P.S. this engine originally had a blanking plate where the water pump is now fitted.
Image
'50 Low-light with 918 Side-valve engine,
'51 High-light with Side-valve 918 engine,
'55 4-dr with 803 engine,
'56 Traveller with 1098 engine.

philthehill
Minor Maniac
Posts: 8141
Joined: Thu Jul 19, 2012 12:05 pm
MMOC Member: Yes

Re: Dymano Mounting bracket width discrepancy

Postby philthehill » Thu Jun 11, 2020 7:01 pm

A common problem even on the 'A' Series. It is not unusual to have to pack with washers between the dynamo mount flanges and the mounting bracket.


sparesman
Minor Fan
Posts: 485
Joined: Tue Dec 25, 2012 7:40 pm
MMOC Member: Yes

Re: Dymano Mounting bracket width discrepancy

Postby sparesman » Thu Jun 11, 2020 8:09 pm

The original dynamo for an MM was a C39PV , maybe the end bracket thickness or the length of the body was different to the later C40 dynamo. Will measure my water jacket on my low mileage MM engine tomorrow.
Bryan
1934 Morris 10/4 in Dark Green / Black - BGO517
1953 S11 Traveller in Birch Grey - oldest survivor ? Export model now reg PPO924
1953 S11 Traveller in Black - 3rd oldest PPX344
1954 S11 2dr Saloon in Birch Grey - GVG270

seriesmm_1
Minor Fan
Posts: 188
Joined: Wed Aug 10, 2011 3:52 pm
MMOC Member: Yes

Re: Dymano Mounting bracket width discrepancy

Postby seriesmm_1 » Thu Jun 11, 2020 9:29 pm

Hi George,
just measured my water jacket & it is 145mm & fitted to it is as Bryan stated above a C39PV dynamo which fits great.
Regards
Brian R


gtt1951
Minor Addict
Posts: 901
Joined: Thu Oct 04, 2012 5:01 pm
MMOC Member: Yes

Re: Dymano Mounting bracket width discrepancy

Postby gtt1951 » Thu Jun 11, 2020 11:25 pm

The water jacket bracket on my 1951 High-light is 145mm
DSCN1427.JPG
DSCN1427.JPG (1.2 MiB) Viewed 242 times
and it has the original dynamo with the rad fan mount on the end.
Only the low-light mount is the wrong size.
Image
'50 Low-light with 918 Side-valve engine,
'51 High-light with Side-valve 918 engine,
'55 4-dr with 803 engine,
'56 Traveller with 1098 engine.

sparesman
Minor Fan
Posts: 485
Joined: Tue Dec 25, 2012 7:40 pm
MMOC Member: Yes

Re: Dymano Mounting bracket width discrepancy

Postby sparesman » Fri Jun 12, 2020 5:57 pm

Just measured my water jacket. It is 145mm.
If anyone needs one we have an old engine I can take it off.Half of ESM's price !!
Bryan, MMOC Club Spares
1934 Morris 10/4 in Dark Green / Black - BGO517
1953 S11 Traveller in Birch Grey - oldest survivor ? Export model now reg PPO924
1953 S11 Traveller in Black - 3rd oldest PPX344
1954 S11 2dr Saloon in Birch Grey - GVG270

gtt1951
Minor Addict
Posts: 901
Joined: Thu Oct 04, 2012 5:01 pm
MMOC Member: Yes

Re: Dymano Mounting bracket width discrepancy

Postby gtt1951 » Fri Jun 12, 2020 7:13 pm

So were earlier engines fitted with different sized dynamo mounting?
8mm is quite a difference.
Phil, I too have noticed discrepancies in the mounts of the A-series engines. I also remember, years ago (probably not a Morris) of having a C39/40 dynamo with a built-in extension tube!

Looks like I'll have to find a "spacer" that is easier to fit then 4 lose washers.

Many thanks for the answers,

George.
Image
'50 Low-light with 918 Side-valve engine,
'51 High-light with Side-valve 918 engine,
'55 4-dr with 803 engine,
'56 Traveller with 1098 engine.

philthehill
Minor Maniac
Posts: 8141
Joined: Thu Jul 19, 2012 12:05 pm
MMOC Member: Yes

Re: Dymano Mounting bracket width discrepancy

Postby philthehill » Fri Jun 12, 2020 7:35 pm

Looking at the original photo the front mount appears to have been ground back to allow a dynamo of unknown style to be fitted.
Look at it this way - having the washers (front or rear) allows you to centralise the dynamo pulley in line with the crankshaft which is just as important than having the correct mount.
I remember those dynamos with the tube in the rear plate which allowed a degree of adjustment for centralising of the dynamo and using a variety of dynamo mounts. Nearly all alternators these days are fitted with the adjustable sliding tube in the rear mount plate.
Phil



Who is online

Users browsing this forum: No registered users and 1 guest