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Could anyone help me I have a three sets of pistons for an Essex V6 all different sizes but cant seem to see any over size marks on the piston top. Is there another way of identifying them without having to go buy a digital vernier caliper to measure them.
Cheers Chris
the size should be stamped in the flat uppermost section of the crown. either STD, PEP or +0.010, +0.020 etc
That is what I thought but none of the sets have any marks on the crown so presumed that the casting marks on the inside of the piston may signify its size. Will have a better look this evening.
Chris
nothing inside the piston will tell you the size, because all the different sizes come are made from the same blanks, they just machine less off the outside to make the bigger sizes
Thanks Graham
I have now inspected the pistons definatley nothing on the crown but there are some marks inside the piston as follows
smallest piston no stamps anywhere
next largest has DL stamped on base of the piston where the rod pin goes in.
largest piston has ID40 stamped on the bottom of the inside of the piston
these are the only stamps I can find
is this of any help identifying the piston sizes
Cheers Chris
no as i said sizes are only ever stamped on the top of the piston.
question, if you dont have a vernier or large micrometer how do you know you have different size pistons?
Easy I have 2 blocks one that fits the large pistons and one that fits the smaller pistons. The smaller piston block is scored badly due to an oil ring twisting and the one that fits the large pistons is a front bowl sump so the block is no good to me as I need a rear bowl sump. My thoughts were to get the original block bored to fit the pistons that I have and put new rings on but without knowing what size they are it makes the job a little more difficult.
Chris
just take the block and pistons along to whoever will bore it for you, they will almost certainly measure it/them for free
Thanks Graham