Don Terrill’s Speed-Talk

HELLO: I PURCHASED A USED 1850-S HOLLEY AND NOTICED THAT IT WAS MISSING THE TWO CENTER BASE SCREWS.AFTER LOOKING AT OTHER HOLLEYS, THE SAME SCREWS ARE NOT THERE??? HELP..

I always noticed that too. Not sure why they would do that. I use to take two screws off of a junk Holley and use them. Don't think it effect anything in either case.

They leave em out deliberately so they can't come loose, drop into a single plane intake & get ingested by the engine.

Carbs built for dual plane intakes often have them as the divider on the intake covers the screws so they can't fall out.

thank you,that makes a lot of sense..

I know! A friend had a 1966 SS Chevelle 396 engine, actually one of the 402's. I don't remember whether he changed carb, carb and intake from the stock dual plane or what. But returning to the house he turned a corner and there was this sound coming from engine. Towed the car home, tore the engine down, heads off and there in one cylinder the screw had impressed itself into the piston several times which he replaced. Figured the only place a screw might have come from was the carb, and sure enough it had, whatever he had done prior to the test run he had unblocked the screw area and one came out. Maybe he had installed an open carb spacer? Can't remember as it was back around 1970.

Exact same thing happened to me. Going around a RH corner one of the screws ended up in the No.1 cyl.

After that incident i used to remove and loctite them.