Page 1 of 1

Piston code

PostPosted: Wed May 01, 2019 9:09 am
by Donels
Does anyone know what the lettering on the pistons in the attached picture mean? The initial letters are followed by 1.016. This cannot be bore size as it would be .020.

Dave

b952ddae-a256-4786-ba32-0c7825cd8561.jpeg and

f501771f-00e9-4792-ad2b-7986f43dfaf6.jpeg and

Re: Piston code

PostPosted: Wed May 01, 2019 11:04 am
by rgh0
Dont know but I presume it is some sort of part number. If you know the manufacturer they can probably explain.

Are the pistons still connected to the crank as the variation in orientation of the valve cut outs would be a concern if they are.

cgeers
Rohan

Re: Piston code

PostPosted: Wed May 01, 2019 11:13 am
by vxah
Not to mention the unusual firing angle 360 degrees? ;-)

Re: Piston code

PostPosted: Wed May 01, 2019 11:47 am
by Donels
No disconnected from the crank so they’ve turned a little. No idea who the manufacturer was as these are the only marks I can find. They look like standard compression pistons but the 1.016 suggested they may be oversize somewhere?

Re: Piston code

PostPosted: Wed May 01, 2019 11:53 am
by rgh0
Often pistons have some manufacturers mark on the underside in the forging or casting so if removed from crank pull out the pistons and look underneath

cheers
Rohan

Re: Piston code

PostPosted: Wed May 01, 2019 1:00 pm
by jono
My pistons have the same - 'BRF +1.016' and it's at +40''

I recall posting exactly the same question on here some years ago and someone explained the meaning and essentially concluded that my engine is at +40 (which I know to be the case). Sorry, I can't recall the explanation and I'm useless with the search function!

Found it!:

0.040" x 25.4 = 1.016mm

Re: Piston code

PostPosted: Wed May 01, 2019 3:32 pm
by Donels
Excellent, thanks. I now know what I’m dealing with.

Dave

Re: Piston code

PostPosted: Wed May 01, 2019 8:38 pm
by Billmack
Dont know but ive seen that i.d. number on hepolite pistons before. The fact that they are stamped and not dot printed dates the pistons as fairly old.

Re: Piston code

PostPosted: Wed May 01, 2019 9:25 pm
by Donels
The engine has not run since 2003 so pistons pre-date this but no idea by how much, hence the engine strip. However it’s in pretty good condition and has completed little running since its last overhaul.

Re: Piston code

PostPosted: Thu May 02, 2019 12:45 am
by Chrispy
I found very similar pistons in my engine. The code on mine was ID6 S41 +1.016.

Same style stamping and the same FRONT stamping, same flycuts and recess on the edge. No idea on what the actual code means though!

I found a AE pistons logo on the underside, and they took standard size rings.

Re: Piston code

PostPosted: Thu May 02, 2019 6:34 am
by jono
....look three posts up and you'll find the answer