Bore size

[Al]

Not necessarily it depends what you have got. I have put about eight sets in mine and all have been N on top ring but yours may be different.

AL

[stusco]

Nothing on top ring ,N on the second facing up ,the top ring has a small chanfer on the outside edge but im not sure what way we go , I’ve only checked 2 pistons so i can copy them if they are correct,im still looking for the reason for the smoke

[stusco]

My old man eyes can’t see any markings or bevels on the top ring

[Al]

You said further up that you had yet to gap the rings. I took that to mean you had bought new rings and needed to 'set' them for end gaps.
You dont say what end gaps you have now and i assume this means you plan to use the original rings.
There is no guarantee that the rings were put in correctly and that may be also true for the expander rings which could be overlapping.
The rings should be different materials from top to second ring and as far as i am aware the top is the hardedned or chrome looking item, the second ring is usually self colour and perhaps ductile iron or similar appearance. This is true for new replacement sets but your pistons look to be a fair bit older than they look nowadays so it may not be so obvious.
There is a big difference between chamfer and bevel. Bevel is on an edge and chamfer on a face. Its not clear which you have from your pics or descriptions.
With regard to smoke; there is still a question mark about vertical scores in the bores together with uncertainty about the placement of the rings and the expanders.
Do all four pistons have the same pattern and nature of deposits on the crowns or are some different?
Do all four pistons have a 'clean' annulus of around three to four mm at their outer edge as at least one does in a picture further up?


AL

[stusco]

I haven’t bought new rings yet im checking the ones fitted to see if they are inspec the one piston ive checked (no 2) was 0.014” for both rings

[Al]

The 'instructions' are generic and open to some interpretation / ambiguity but there may be something here of interest.
To give an idea of the long view, i change my rings regularly (it eats them) and they are done at around .0020" thou inch.
By that time the top surface has worn and they have a raised ragged 'lip' at the top outer edge.

AL

[stusco]

I cant get a decent photo of the barrels all 4 pots have vertical marks (quite a lot)a couple are wider but i can’t really feel them with my nail,the piston to barrel clearance is 0.002-0.0024”,ill get all the ring gaps later and try to get a decent photograph of the marks .
I did find a N on one of the top rings.
When you fitted your rings in the past have you had to file them get the correct gaps?
I really don’t want to have to get a set of barrels then get them bored then buy new pistons i suppose I could get them bored to my pistons!

[stusco]

[Al]

I have used the same pistons in two sets of newly bored barrels now and they dont look unlike yours when they come out but there are slight grooves in the barrels as yours are. My pistons show zero signs or wear and i do mean zero after 15 years of thrashing but you can tell they have been used. Your pistons look like they have done no real work but the barrels look like they were re-bored with an angle grinder!!
Cant tell but a light hone might get them right.
Rings look like chrome affair on top and dull version below and the fact that the markings on the top rings is hard to see may be down to the same wear pattern i get with mine.
Your rings may have been put in without being gapped properly. Lower ring gap should be bigger slightly than the top ring gap!
Yes i have had to grind each successive set of rings i have put in and when i got it wrong (too small) it heated up and got tight and heated up some more and..... then they had to come out again!
Just my opinion and only my opinion but i have taken the narrow 'clean' outer circumference to be oil passing the rings and preventing carbon sticking to the crowns round the top outer edge. I can see with mine where the ring end gaps are by the carbon pattern on the crowns together with the biased flame front marks as there are some 'hidden' areas with high compression pistons that you wont necessarily see with your lower comp versions.
Again just my opinion, that the scores in the bores and piston skirts are carbon particles blasted off the piston crowns and lodging between piston and bore. Considering youre setup looks like its low miles from inserting the kit its surprising to see such a high proportion of granular carbon built up on the pistons. For that reason i would guess at oil control ring issues, maybe rings too tight at insertion point, lack of or improper running in and knackered valve stem seals on the inlet side or poor quality stem seals. Both will be dead; inlet and exhaust side..
Check the valve guides for damage like vertical splits but if all pistons look similarly carboned up then its rings, bedding in or stem seals.
AL

[stusco]

Good reply the stem seals were still soft but they might have been crap ,the valve guides feel good clearance wise , ive put a wanted add up for some barrel to see if i can get some cheap enough and get them bored to my pistons get some new rings and go from there .

[stusco]

I meant to post this earlier,is this a lot of debris ? Its like frayed string

[warren3200gt]

Depending when that was last cleaned but it's pretty good I'd say.
I opened engines where I wonder how they ever pumped any oil with the crap that was covering the guaze.
A magnet will tell you if those few pieces are ally or steel.

[Hard Road]

yep ive seen worse !!! the whole point of the mesh