Model A Ford Technical Tips - From Kevin Draper
Does your Model A Need to Have an inline Fuse Fitted?
The Model A didn’t come out with a safety fuse fitted and probably most of us who have restored our A’s to original standards have never had any problems and have covered thousands of trouble free miles.
Countless hours and thousands of dollars have been spent restoring our cars. For peace of mind an automatic overload relay or fuse can be fitted for only $10.00. Either of these only take minutes to install.
Just think about what can happen if your unfused A does have a short circuit. If you’re lucky maybe there will be a flash somewhere and the end of the wire will burn off.
But if you’re not lucky that short may generate enough heat to make the fault wire glow red hot and take out all other wiring in the loom.
Fitting an inline fuse or circuit breaker wont prevent your A from having a problem but it will give you time to fix the fault with only minimal damage.
Protect your investment . Safety fuse A 11450 SF is available from Snyder at US $9.50 for either a 6 volt or a 12 volt conversion.
20AMP or 30 AMP circuit breaker – auto reset P/N 121 A 20 B2M Bellanco is available from most auto accessories stores for around $10.00. These circuit breakers are for 12 volt conversion.
Faulty Condenser or Bad Earth
Several club members have fitted aftermarket condensers on firewall or coil bracket.
This practice has been carried out for many years and seldom gives any trouble. The main benefit is achieved by getting the condenser out of the distributor and away from heat source (motor) thus giving supposedly longer condenser life.
On at least three occasions I have worked on cars that have either stopped altogether or rapid point pitting has been detected.
One reason for this is because during restoration we have loaded body panels with paint and joint putties thus relying on things like speedo cables etc and the odd bolt to earth the condenser. These problems mainly show up in Tourers and Roadsters. Hard Tops have more areas to pick up an earth for the condenser.
Easy fix – Run an additional earth from battery to condenser mount. A 4mm wire with suitable terminals will do the trick. Just note this was with 12 volt conversion negative to earth.
Check That Oil Pump
Refer to Ford Service Bulletin Page 41.
Many of the Model A motors that we lovingly recondition have had
previous owners remove the oil pumps and fit whatever they found
laying around to bring the oil pumps up to scratch.
Just be aware that the older 28 oil pumps were a forged body and had a 9/16"
dia internal bore. The pump shaft was reduced between the bush
locations to approx 7/16 dia. This was to ensure sufficient oil
flowed to the valve chamber and down to the main bearings.
Fitting the later shaft (which is the normal one supplied as a
replacement) will not allow sufficient oil to pass to the valve chamber and
therefore down to the main bearings.
The earlier shaft with the reduced Dia between bushes will work on
either oil pump.
The later oil pump is a Casting and is easily recognised by the
four ribs on the outer body. The internal bore of this oil pump is 5/8 Dia.
Note: Not a bad idea to fit a new spring A6620, which puts pressure
against the pump to help seal pump in the motor, (even if you think
the old one looks fair.