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Dynamo - distance between mounting faces

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Dace

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When I brought the car (BN7 1960) amoungst the boxes of components were a refurbished starter and dynamo. The starter has been fitted to the newly rebuilt engine and works fine. However the simple task of fitting the dynamo has got me stumped.

When mounting the dynamo on the two top bolts the space between the dynamo mounting faces is wider than the distance across the engine bracket lugs by about 1/2". To check the pulley position I ran a straight edge across from the water pump pulley front face to the dynamo pulley front face. With the block rear mounting lug against the inside face of the dynamo rear mounting the pulley faces line up, but I'm left with having to take up the gap with packing shims. This can't be right, as if to confirm this the sliding bottom mount hits the middle of the bottom dynamo flange rather than abutting one side to alow fitment of the tensioning bolt.

May be I have an incorrect dynamo, any suggestions as to which model I should have for a BN7 or what I'm doing wrong?

Some good news having primed the oil pump and lubricated the bores when I cranked the engine on the starter, without plugs installed, I was getting an indicated 50/55 psi on the oil gauge.
 
--No that is not correct. However, Look on the Dynamo and see what letter code it contains : CP XX, ETC.---Keoke
 
Hi Keoke,
I've now measured the distance:-
1/. Across the outside faces of the block mounted bracket = 6 1/2".

2/. Across the inside faces of the dynamo mounting lugs = 6 7/8"

A difference of 3/8".

The circumference of the dynamo has a number if idents stamped on it , apart from the LUCAS and "Made in England", i.e.
22900F(possibly "E"), one which I think is the type - C42, A further no. 2?65 and 12V .

The block mounting plate has the letters "AEC689" and "FE" cast into the surface.

Anyone any ideas as to if I have the wrong dynamo or mounting casting for a 1960 BN7?
 
It's not completely clear about which dynamo was used on the earlier cars.
The three commonly used sizes were:
C40 - 5.67" outside ear dimension, #22456
C42 - 6.85" outside ear dimension, #22530
C45 - 6.53" outside ear dimension, #22483

It appears that you have a bracket for a C45 dynamo & that your present dynamo is a C42 as used on later cars.

If you have no objection to using the C42, just put a spacer between the ear & the mount. Adjust the tensioning arm accordingly.

The C45 may have the stud type terminals & the C42 the bayonet terminals.

In any event, if you do not wish to be concours correct, the C42 will work. If you want everything as original, find a C45 replacement.
D
 
Dave,
Many thanks. I know the dynamo was recently rebuilt and is basically as new so I will be using it. I may have a look at aquiring the bracket to match as from what you say it will probably remove the need to add a spacer and "crank" the slotted adjuster arm.
 
OK Dace, I suspected that. The C42 Dynamo is the highest capacity unit used on the big Healey. Further, this generator is used with the later RB340 30 Amp 3 bobbin Voltage regulator. I think the PO was upgrading the electrics to utilise this higher output unit. However, utilising the 3/8" shims will not IMOP compromise the installation or operation of the unit.---Fwiw--Keoke
 
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