Piston orientation

Post by **youngun** » Wed Apr 23, 2008 7:50 pm

Just a quick, but crucial, question. The crowns of my pistons have "front" stamped on them, and all have a 2 with a little arrowhead above it. Do these 2's with the arrowheads point towards the 2's on the block, and does the front stamp point towards the front of the engine? The manual is a bit vague on this subject...i.e. no pictures!

cheers,
YG

Post by **superchargedfool** » Wed Apr 23, 2008 7:54 pm

if your pistons are still on the rods then they only go in the correct way round anyway.

Post by **bigginger** » Wed Apr 23, 2008 7:56 pm

Front to the front - '2', I've read, refers to the grade of the piston, I think - but I'll check that

Wrong again - it's an "identification" number - would state the 'Over' size if they were oversize...

Post by **youngun** » Wed Apr 23, 2008 7:59 pm

superchargedfool wrote:if your pistons are still on the rods then they only go in the correct way round anyway.

Correct, but i still dont know which way that is!

Post by **youngun** » Wed Apr 23, 2008 8:00 pm

bigginger wrote:Front to the front - '2', I've read, refers to the grade of the piston, I think - but I'll check that

Front being the water pump side of the engine?, (on the Jowett javelin engine the front is the back....!!)

Post by **bigginger** » Wed Apr 23, 2008 8:00 pm

With 'front' to the front of the car

, so yes, where the water pump, fan, headlights etc are - the front, in fact

Post by **youngun** » Wed Apr 23, 2008 8:23 pm

Nice and conventional then!

Post by **bmcecosse** » Wed Apr 23, 2008 9:16 pm

Front is front!! The 2 in the diamond was supposedly indeed a 'grade' mark - suggesting the pistons were sized carefully and fitted to matching sized bores. If true - must have been just slightly labour intensive. Easier I would have thought to just make the bores right first time - and use standard size pistons. But hey ho - that's BMC for you!