Gunners Garage

"Trust Your Mechanic" Is Distributor Expert's Advice

   I am not a “real” mechanic. I can take things apart and put things together, but I have never really mastered the “fine arts” of auto repair such as adjusting valves, degreeing cams and timing a distributor. That’s why I work with a pro. But even so, I had doubts when we installed the distributor drive gear and distributor in my MG Magnette engine and ran into a situation where the service manual said the drive gear slot should be at the 1 o’clock, but the drawings in the manual showed it near 4 o’clock. My mechanic friend Vince made a little two-lead device with a bulb and a 9-volt battery. He used it to “static time” the engine and said it would run fine with the rotor firing No. 1 at the 4 o’clock position  

   Jeff Schlemmer at Advanced Distributors in Shakopee, Minn. (www.advanceddistributors.com) concurred. He said the Magnette’s BMC 1500 engine uses an even-fire 4 cylinder distributor. “In essence, it doesn’t matter which direction it’s pointing, as long as the timing is correct,” said Jeff. “The drive gear can be installed in literally any position and all that may need to change is the position of the distributor to compensate.” Jeff upgraded my distributor internally, to enhance performance, but he said his modifications might change the position by only a couple degrees. “I see the same thing at British car shows,” Jeff pointed out. “Walk down a line of MGBs and check out the distributor positions. You’ll see a range from 11 to 3 o’clock. “What you’re describing is perfectly normal and has more to do with how the gear was installed on the shaft and where the pin was drilled than anything. There’s a roughly a 30 degree range that’s considered acceptable and you’re within that.”
 
“Trust your mechanic!” Jeff ended. “He seems to really know what he’s doing.”

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