Piston grades and numbers

[paulbell6]

Hi all, I have a problem with the grades and numberering of pistons and hope some one can help! When I dismantled the engine some years back I removed the pistons and bagged them individually with the con rod and cap and numbered them. This numbering has vanished and so I am left wondering which piston goes where. I know that the arrow on the piston faces the front of the engine and that they are graded, my right hand bank has four grade g pistons which leaves the left hand bank with f grades. The con rods and caps are numbered 1 to 8 I assume that this relates to the number of the bore also. I am replacing all of the piston rings and big ends and I wonder if that will allow me to fit any g grade piston into any g grade bore. I have a manual that tells me that number one piston is at the front of the right hand bank ( I assume that it is being viewed from the radiator ) therefore how does the numbering go from there? My reasoning at the mo is 1, 3, 5, 7 on the right bank and 2, 4, 6, 8 on the left.I do hope some one can shed a little light for me please.Thanks in anticipationPaul

[Kevin Garrod]

No 1 is the front right as viewed from drivers seat. 1357 on the right 2468 on the left. I'm sure someone else can help with the rest of your question.

[Bob Heritage]

I would have thought that if you have numbered them 1 - 8 and bagged them seperately, then that is your answer. Just to confirm what Kevin has told you 1357 is offside and 2468 is nearside

[dasadrew]

I was going down a similar route (not the bit about not knowing left from right but the bit about replacing rings!) but the resident Stag Guru here advised strongly against it. He reckons that none of the aftermarket rings are as good as the originals and, if you're not going to do a rebore to stick with the original rings.

I cleaned them in an ultasonic bath and they will be going back on to the pistons. The bores are only a mides wing thickness off the as new spec, despite the crank having taken a hammering due to apparent oil starvation.

Is there any specific reason why you are replacing the rings?

Drew

[paulbell6]

No reason other than I thought it was good practice, and now having removed and broken some of the old ones I cannot go back, I suppose only time will tell if the new rings are any good. Thanks. Paul

[flying farmer]

If the old rings were barely worn,and the bores are virtually without a ridge, new ones should be ok. County rings seem better than some cheaper alternatives which I have found wear in thickness very quickly indeed. If you still have the old rings and they are noticeably thicker on the outside edge you will probably be lucky to see ten thousand miles on a ring set, which bearing in mind the cost of the rings and the gasket set doesnt leave a big difference between the cost of a rebore and new pistons
Neil