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MG MGA - 1622 head

I have a 1622 motor with a head that has the "15" on it. Looking through the archives I see that there is a possibility it could the right one. The cylinder seems to have a pretty deep chamber but when measuring the valves with a digital caliper I come up with 1.547" on the intake and 1.289" on the exaust. These numbers do not seem to match anything I can find. Before I buy an MGB head I was anyone has experience with this sort of thing. When running the car did seem a little sluggish but I was contributing that to my lack of experience with a Weber carb at the time. All advice appriciated.
John
John Cline

You most likely have a stock "15" head from an earlier engine.

The "15" head was used on all MGA 1500 and 1600 engines. The chamber volume is 38cc. The valve sizes you quote are close to the correct sizes for the stock "15" head as used on the 1500 and 1600 engines.
Intake valve = 1-1/2" (1.500")
exhaust valve = 1-9/32" (1.281")

The 1622 engine used the "16" head chamber volume 43cc, and the valves are 1/16 inch larger:
Intake valve = 1-9/16" (1.562")
Exhaust valve = 1-11/32" (1.343")

About 300 "15" heads were apparently special machined to "16" head specs for use on early production MGA 1622 engines. After that the 1622 engines had the "16" head.

If your measurements are correct, there is a chance that someone may have installed slightly larger intake valves in your head to compensate for valve seat wear.
Barney Gaylord

Thanks Barney,
Sounds right. Looks like I'll go with the MGB head. I think finding a 1622 is going to be tough.
John
John Cline

This thread was discussed between 27/10/2006 and 28/10/2006

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This thread is from the archive. The Live MG MGA BBS is active now.