I've just pulled down my a-14 rally engine, and was wondering if there was any easy way to tell if the crank is an a14 or a15?
thanks.

Since it's now pulled down, you would need to put the crank back in. Secure it with just the No.2 & 4 main caps. Reinstall ONE piston & rod assembly. Leave off the rings for ease of assembly. Nip up all fasteners, but no need to tension anything.
Rotate crank untill piston is at BDC & measure from the top of the piston, around the edge, to the top of the bore. Rotate crank untill piston id at TDC. If piston is flush with the top of the block, then no problems. If this measurement is 77mm, then you have an A14 crank. If this measurement is 82mm, then it is an A15 crank.
If the piston does not rise to be flush, then measure from the top of the bore to the same spot on the piston & deduct the smaller number from the larger. The remaining number should still be either 77 or 82.

A15 has a 82mm stroke...Sorry Dodgeman

ahh, ok thanks I'll do that. (thought there might have been a number or something cast on to it) The head looks like an a14 gx thats had a thorough port an polish done (i'll get some photos up soon) but the pistons and rods appear to be stock. Will there be any great advantage if i put some racing pistons in it? it is a rally engine so reliabilty is utmost.
Thanks guys.

Quote:Whadaya mean,... 77 plus 5 equals 83 doesn't it? It must be all this new-math you blokes are doing, but OK, i'l go with the flow & i have ammended my post.

77mm. definatly an a14 crank then.

If the crank is out of the motor there is another way...You"ll need some basic tools ie, pen/pencil, something flat you can draw on and a right angle device eg, envelope, square,beer coaster, book etc.
Next draw a straight line at least the length of the crank, place the crank on the line aligning the centre of the crank with your drawn line, this is where you need your right angle device, put you r.a device up to both sides of you big end bearing and drop a line down, mark both sides of the big end bearing and then move the crank, you should be left with the centre line and two other marks (your big end journal size, 45mm) halve the two journal marks and then measure from that mark to the centre line and multiply by two and there you have the stroke of your crank.
A14 is 77mm stroke

The crank is still in the engine so i just stuck a tape measure down the bore with the crank at bdc then eyeballed accross the deck of the block. 220mm then did the same thing with the crank at tdc, 143mm.
220 minus 143 equals 77mm. what do you guys think about the pistons?