Bosch Distributor Numbering

[smclaren]

Hi Guys

Can someone explain the difference between Bosch distributor U-VJU6BR50 (GMH 7417802) ... and U-VJU6BR54 ?

My EK has a nasty ignition miss that new plugs, points, leads, cap, button, condenser, coil etc hasn't resolved ... so looking at a dizzy swap.

Mine is a BR50 ... but checking that a BR54 could also work ? Superficially, they look identical.

Cheers

Steve
Sunshine Coast

[Harv]

Give David Andrews a call at Vintage Racing Develipments:

https://www.vintageracingdevelopments.com/


He knows a hell of a lot about grey motor distributors, and is great to work with.

Cheers,
Harv

[ardiesse]

BR50 is EK.
BR54 is EJ.

Part way along EK production, the grease cup (at the base of the distributor body) was deleted.

The vacuum advance in all grey distributors up to and including EK has the female fitting for a 3/16" pipe. The vac. adv. unit in EJ distributors takes a hose. You can swap the earlier vacuum advance unit over onto a BR54 distributor if you want.

Short answer is yes. You can interchange distributors.

But - if you have changed plugs, points, condenser, rotor, cap, leads and coil, that's your entire ignition system. But just to make certain, pull the central HT lead out from the cap and sit it on the rocker cover so there's about 1/4" gap. Crank the engine over. If there's a regular, fat spark, then the problem is not ignition-related. You'll need to look elsewhere.

Are your valve clearances correct?
Are you certain you don't have sticky, burnt or badly seating valves?
What are your compression pressures?

You wouldn't have a cracked cylinder head by any chance?

Remove the air cleaner, start the engine, give it a good rev and clap your hand over the air intake. This'll clear blocked jets. Let the engine idle and spray WD-40 around the carburettor base, the plastic insulator and the manifold gasket at the inlet ports. If the engine note changes at all during this, you've found a vacuum leak.

Take the top off the carburettor and check the float level. Make certain your fuel system can deliver the fuel. Are there bubbles coming up into the fuel pump shot glass when the engine's running? That means you have an air leak in the fuel pipes or hose, and will need to be corrected.

Rob

[smclaren]

Cheers Harv ....

And thanks, Rob ... you've given me plenty of things to check and I'll let you know how I go with them.

Steve