Damage top of the Pistons?Investigation help!

[Billman]

it looks like something went in the engine. detonation marks look a bit like sandpaper like aerea.

[pasbogdan]

some updated!
got all the pistons out today.I'm checking for some any damages.Fortunately,the rest of the parts is fine.Only a light scored cylinder #3
i feel some lightly groove at the bottom of the scored mark line.uptop and middle is smooth.i'm thinking to leave it there and use it.
2 weeks ago all compression readings was 160psi.might be considering another AAN and preparing for swap when the right time has come.
the bearings on 5rods seems perfect.none of any scratches,seems they're still have plenty to go.








my sump baffle





It's superman's car.not sure some graphiti experts at the service shop did it.lol

TDC ring zone on the cylinders seem more than i expected looking at first pics.Seems like 0.07 mm out of diameter.No honing marks,scratch,also some rusted area lower than tdc.I mean,what's needed for you to consider this is not a block to be used with 1.8 bar?

[Dima ABY]

Yes, your wall cylinders are weared.They look like a mirror.This can explain your oil burning.In this conditions bottom end do not deserve nice and fresh head in my opinion.

[newsh]

Yes, bores are glazed, oil gets drawn into cylinder and causes detonation. You need at least rings and a hone depending on actual amount of wear maybe re-bore and pistons or better block..

Still don't think those strange marks are from detonation though, looks much more like some debris has gone through.

I will now get the borescope out and look at my pistons because I think I've been hearing some pinging, especially when my injector plugs had bad contact.

[GazzaG60]

i had very similar on mine on the stock map prior to the vems. little pit type marks on one particular area of the piston. i put it down to det. maybe some bad fuel.

i had all that skimmed off the piston anyway.

[popdemonic]

some little update,i swapped all polished spare pistons in.I decided to leave the little scored on the cylinder wall #3 in there.
the stock rings measurement is 0.9 on the gap(wear limits 1.0mm).they nearly til the end of their lifes.Got 0.5mm on the new replacement
rings.the stock conrods bearing is 0.051mm(new 0.015-0,05mm).very minimal on the wear.the weird thing on the top rings is there's no
"TOP" mark at the end ring gaps or anywhere else on the rings.i visually checked on the rings and decided to put them back with old orientation.
i decided to rebuild the new engine soon so i don't mind running it at the moment with the little scored on the cylinder #3.

[AndyP]

Are those shells in the right way round?? From memory of using sputter bearings, the sputter half is the darker one, and should go in the top half.

[Thuppu]

Pop, did you hone the cylinders?

[popdemonic]

No honing on the cylinder walls unfortunately Thomas.I decided to use it as is since it never been addressed any issues.To be honest i didn't know how long the scored mark was there.1 month or probably 1 year,i didn't care about it since i'm going to build another aan though.

[popdemonic]

Andy,
I just checked on my another 3 spare conrods.It turned out 13 conrods have the whitish bearings on upper shells and the darker one on lower.







not sure if it's worth to get this Dr.Shrick camshafts in?

[pasbogdan]

What rings did you used?For example,Kolbenschmidt has 2 types of rings:for perfect round bores and softer ones for used bores.A hard ring will never seat on an oval bore.

OE rings once taken off the engine,will never 100% seal if remounted.Only if they were put in the same position and i do not see how that is possible.

Calculate the costs for opening the engine several times,head gaskets,head bolts, piston rings and the result will be near oversize new pistons with bores machined.And also consider the result you achieve.

[gnutz2]

That timing map is crazy, I think E85 saved your engine.