Dizings2k

Hi all,

Here are some pics of the inside of all cylinders.. I think these marks are bore scoring, can anyone confirm? The motor does have 10-20% leakdown results on all cylinders.


CYL1

CYL1

CYL2

CYL3

CYL4

zeroptzero

Some of the marks do not look like scoring, it is hard to tell how deep the others are. You can tell if you can get your fingernail to get hung up on the striations but the head has to be removed. With the pistons being coated you will get some streaking marks on the cylinders, hard to say how deep your marks are. Engines with scoring tend to run poorly, how does your car run ? Your leakdown results can be a combination of issues , but they are definitely on the high side. Did you do a compression reading too ? scored cylinders will have poor compression.

Dizings2k

Car runs great. It's an inline pro built F22 with CP pistons, Inline pro rods, ARP studs, etc. 10.6:1 compression. Compression is 197-208psi across the board.

boyguan

to me it looks like a reflection coming off your camera and the side of the piston.

dagle

CYL4 def looks like a score, but that doesn't look bad at all. when you did your leakdown was that on a cold engine? i think it would improve if it were a little hotter when the pistons, sleeves and rings grow a little from heat.

starchland

Def some scoring. I’ve seen these engines compression test A-ok, run great but burn oil due to bad control rings. Does it burn any oil? Mileage on unit?

engifineer

The scoring would be the vertical lines (running on the same line as the piston travels) That line across the cylinder wall is likely a reflection.

Cylinder 2 and 4 look the worst to me but hard to tell if that is bad enough to worry about. If the head were off you could do the whole "if your fingernail catches" test but obviously cannot with the head on the car.

Dizings2k

Few thousand miles on the motor at this point.

Nope, no oil burn.