Author Topic: Green Mystery Block Identification  (Read 296 times)

Offline jetattblue

Green Mystery Block Identification
« on: July 06, 2020, 01:05:44 PM »
I have been lurking a while and trying to learn as much as I can about Minis while I waited to start on a project of my own. I purchased '73 1275GT with various extra parts - including an engine block, a couple of crankshafts, a camshaft, a rebuilt head, etc. One of my first tasks is trying to identify an extra engine block and crankshaft that came uninstalled - the Green Mystery Block. I am hoping to determine what it is and whether it's worth rebuilding. The car currently has a fully built engine installed - although I understand that it is seized. I'll get to that one next, but this is fairly low hanging fruit to drag home and identify.

So, the Green Mystery Block as 11 head studs, the casting is marked 12G1279, it has the dizzy bracket for a standard A engine. I am really concerned, however, about the cylinders. Although they seem in fine shape (before being mic'd of course), the block seems to have been bored, then sleeved back. This, in turn, seems to have left a small amount of the deck block missing (?) between the cylinders; in other words, it looks in the pictures like a gasket, but that is the actual head. I am concerned that this will leave a gap when a head gasket is installed. I measured the bores at the top, and they measure right at 73mm. I would love to hear your thoughts on this. Again, this block was extra, so it's not catastrophic to me if this prevents re-use.

Offline MiniDave

Re: Green Mystery Block Identification
« Reply #1 on: July 06, 2020, 02:11:17 PM »
That block looks like it has been machined for steel o-rings. Usually used in very high compression race engines.....
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

Offline jetattblue

Re: Green Mystery Block Identification
« Reply #2 on: July 06, 2020, 04:15:46 PM »
Thank you! That makes sense as the fellow that I purchased the car from was planning to make it a racer, and was putting together the parts to do that when a more complete car became available to him. So, Iíve got a 1275 car with apparently some racing bits that were going to be added later. I unfortunately am going for something closer to a stock 1275. I have pistons for this one and brand new in the box rings. I need to see what the crankshaft is thatís currently installed. Perhaps someone will be interested in these parts for their racer?
« Last Edit: July 06, 2020, 07:16:38 PM by jetattblue »