Progress again!
It's been a long winter and as usual, I was side tracked in between work periods, mainly with fairly hefty maintenance on the MGF, which I'm glad to say is all finished now. I also had the engine out of the RK saloon to fix a slipping clutch, unfortunately, it's got to come out again to attend to one of the starter motor threads which has gone soft.
I started by glazing the back window, this had to be recut because the first attempt didn't fit. The replacement is much better.
DSC_1049s.JPG (Size: 31.09 KB / Downloads: 313)
Next job was to strip and inspect the front seat frames. The drivers seat was bent out of shape and needed some welding here and there (the unskilled MIG operator had been at work again) but the passenger seat was badly rusted at the base of the seat back. Devil of a job to weld, I measured the steel and it's 22 SWG, beaten. Tack and bash again. Seat frames have now been dispatched to David Nightingale for re-upholstering.
On to the wiring. I remember that the dynamo wasn't working from when I briefly ran the engine back in 2018 so I tested it on the bench.
To do this, I connect F and D together and string a 12V, 21W bulb from F/D to earth. Then I use a 1/2" WW socket in the battery electric drill to spin the dynamo. The bulb should light, indicating that the dynamo is generating current, just need to watch the speed in order that the bulb doesn't blow.
No surprises, the bulb wasn't lighting. The brushes came out (seized after 90 years of sitting, doing nothing), commutator cleaned, various wires re-terminated, still no joy. In my experience, the CAV DFL can be temperamental and difficult. I had one, years ago where the armature shorted to earth at 40 MPH. The thing exploded, like a small grenade with all the aluminium at the brushes end broken.
Eventually, I found some alignment marks, indicating the the dynamo had been incorrectly assembled (the body or field alignment with the alloy brush holder was incorrect). Put this right and hey presto! The bulb lights up!
DSC_1048s.JPG (Size: 37.21 KB / Downloads: 313)
The working dynamo is fitted and I go on to start wiring.
I usually wire a system circuit and then test each system to ensure it's correct before proceeding. In this case, the first circuits are charging and magneto earth (stop). Confusingly, to stop a magneto (and hence the engine), you have to connect the LT circuit to ground, via the switch panel, so switching on involves breaking the switch, switching off making the switch. Confusing huh?
All that done and it's time to start the engine again. The car has recently been retrieved from a rather damp wooden shed, where it's been sitting since November but, the power of the SR4 magneto is undeniable and it's able to start the engine first stab of the starter. Looking at the ammeter shows I have a nice 6A being delivered to the battery. It does go to just under an indicated 8A at higher revs but I'll need to check it with the AVO8 at some stage as I don't really trust the calibration of Lucas ammeters.
DSC_1041s.JPG (Size: 23.92 KB / Downloads: 312)
The rest of this week and next week will involve the lighting circuits. I'll be adding brake lights and flashing indicators (it's a driver remember) which will involve some tin bashing to make up the required brackets. More on this later.
It's been a long winter and as usual, I was side tracked in between work periods, mainly with fairly hefty maintenance on the MGF, which I'm glad to say is all finished now. I also had the engine out of the RK saloon to fix a slipping clutch, unfortunately, it's got to come out again to attend to one of the starter motor threads which has gone soft.
I started by glazing the back window, this had to be recut because the first attempt didn't fit. The replacement is much better.
DSC_1049s.JPG (Size: 31.09 KB / Downloads: 313)
Next job was to strip and inspect the front seat frames. The drivers seat was bent out of shape and needed some welding here and there (the unskilled MIG operator had been at work again) but the passenger seat was badly rusted at the base of the seat back. Devil of a job to weld, I measured the steel and it's 22 SWG, beaten. Tack and bash again. Seat frames have now been dispatched to David Nightingale for re-upholstering.
On to the wiring. I remember that the dynamo wasn't working from when I briefly ran the engine back in 2018 so I tested it on the bench.
To do this, I connect F and D together and string a 12V, 21W bulb from F/D to earth. Then I use a 1/2" WW socket in the battery electric drill to spin the dynamo. The bulb should light, indicating that the dynamo is generating current, just need to watch the speed in order that the bulb doesn't blow.
No surprises, the bulb wasn't lighting. The brushes came out (seized after 90 years of sitting, doing nothing), commutator cleaned, various wires re-terminated, still no joy. In my experience, the CAV DFL can be temperamental and difficult. I had one, years ago where the armature shorted to earth at 40 MPH. The thing exploded, like a small grenade with all the aluminium at the brushes end broken.
Eventually, I found some alignment marks, indicating the the dynamo had been incorrectly assembled (the body or field alignment with the alloy brush holder was incorrect). Put this right and hey presto! The bulb lights up!
DSC_1048s.JPG (Size: 37.21 KB / Downloads: 313)
The working dynamo is fitted and I go on to start wiring.
I usually wire a system circuit and then test each system to ensure it's correct before proceeding. In this case, the first circuits are charging and magneto earth (stop). Confusingly, to stop a magneto (and hence the engine), you have to connect the LT circuit to ground, via the switch panel, so switching on involves breaking the switch, switching off making the switch. Confusing huh?
All that done and it's time to start the engine again. The car has recently been retrieved from a rather damp wooden shed, where it's been sitting since November but, the power of the SR4 magneto is undeniable and it's able to start the engine first stab of the starter. Looking at the ammeter shows I have a nice 6A being delivered to the battery. It does go to just under an indicated 8A at higher revs but I'll need to check it with the AVO8 at some stage as I don't really trust the calibration of Lucas ammeters.
DSC_1041s.JPG (Size: 23.92 KB / Downloads: 312)
The rest of this week and next week will involve the lighting circuits. I'll be adding brake lights and flashing indicators (it's a driver remember) which will involve some tin bashing to make up the required brackets. More on this later.
