24 replies to this topic

[albo]

mm,, engine number plate and rivet pins would of been removed before a skim or level deck, it has been re stampt to say its a 1300, the L 12 will prob be just a log code to when pistons were  manufactured, an unskimed block usually has a letter , A ,stampt exhaust side between 2/3 cylinders,,to be sure it needs to be measured, i must say by the pic it looks ready for another skim,

but besides all above whats the present condition of your bores.

[albo]

What bearing shells do you guys recommend? Welshminiman and I are building the same engine pre A+ ... mine at 1330cc with 12G940 head, although I think I will go with Mega pistons ... and my engine is inline not transverse (Midget/A35 conversion).

 

There are so many different makes around ... ACL, Vandevell/Mayle, etc ... I want ones to last ...

 

Any recommendations?

king bearings,,these are cheap and if you study reports they have proven to be as good as all stated above,,yanks trust them in there biggy block,,and have reported perfectly matched tollerences between journals where as many others have failed,, end of the day bearings should be aquaplaning if you like when fitted to correct size but on good quality oil

[Welshminiman]

Needs work, not sure if it will just need a re-hone, or bore out to next size.

[albo]

to be fare mate plus 30 is now an odd ball size,,as in finding rings ect,,+ 40 is your next minimum step,,dont be led in to believing a bigger bore hole is better ,,my partner has proven this to me lol

[Welshminiman]

To be honest, I've been thinking about going up to the next size bore, more for the knowledge the bores are in better condition than they currently are.

I found an old picture I took of the pistons a couple of years ago, and they look like the piston tops come flush with the block, but as the picture was taken from above, I can't really tell.

I'll probably buy another engine between this one and completing my van project, but I would like to complete this engine, even if it's only in a mild state of tune.

[Welshminiman]

Provided it is a 12G 1279 block there is no inherent weakness.

 

Checked the block last night, and the block is a 12G1279.

[Welshminiman]

Right, I've re-inserted a piston into the block, and hand tightened (using reasonable force), and would it around to roughly TDC (there was no movement if crank was rotated). Now I do not have a steel rule, but using my drill bits I have, I guessed the gap between the top of the piston to top of block to be around 2mm (roughly)

 

[62S]

21251 are 8.8:1 compression pistons as used in 1275GT, MG Midget etc engines.

 

Yours don't look to have that deep enough dish from the picture of it in the block.

[Welshminiman]

Take a look at post #15, you can see at the bottom of the piston it says 21251.

[gazza82]

Have you got any further forward with your engine?