While replacing the head gasket in the engine (1973) of the MGB, I had the rockers sitting on a piece of cardboard while I worked on scraping the carbon off the head, cleaning, and measuring for warp.
The next morning I start work again and notice this plug/bolt laying in the area very near the rocker assembly. I CANNOT find a location that this would go, either in the rocker assembly or the cylinder head... or the carb (webar DGV) for that matter. I poured through the MG Service manuals, and the Moss catalog as well.
Stats:
- it is about 0.6 inches square (about the size of the Spark Plug at the threads!)
- the threads seem worn down
- it was mostly coated in nice clean oil
- it is not brass
- hex socket is for 5/16ths allen wrench
- It's not an air-injector hole plug
- It's not a rocker/valve gap adjustment bolt
Is it possible the last owner/mechanic dropped it into the engine at some point and it's been rolling around - that may account for the worn threads - maybe??
I have a '77B. There are only two bolts that have that appearance in the engine--one of the eight valve adjusters on top of the rocker shaft assembly, or it's an aftermarket bolt installed into the cylinder head exterior blanking off the four air rail holes.
ReplyDeleteIf it isn't one of those, it could be that a previous mechanic tried installing a non-spec bolt onto the engine and dropped the bolt into the engine, where it made its way to the oil pan.
It is far too big to be either the air rail hole plug or the valve adjusters (though it does look very similar to that one!)
ReplyDeleteThanks for the input! I am leaning towards your last idea: dropped bolt.