Just got my Ls block back from the machine shop today and wanted some opinions on how the cylinder walls look. He did a hone job on it and had to deck the block 13 thou. I did some research about block decking and 13 thou seemed to be fine. Im going to be running P30 pistons, so I wonder how much piston to deck hieght Im going to have. I will find out once the pistons are in. About the hone....I asked him about the marks still left on the walls. He said if he took anymore off that it would interferre with the ring gaps. I cant really remember, but I think he said I had 2-25 thou of piston clearence and he said he wouldnt recomend any bigger than that.

But anyways....any opinions on what to do or if these marks are ok to work with.





Thanks fellas.

Matt

 

I would have gone with a .25 mm overbore, fresh hone and a set of .25mm oversize p30's can you catch your fingernail on any of those "scratches?

 

Scratches, Blatches!

Hone that **** and go.

J/K, answer purpleterrors question and go from there.

 

Well, Im sittin on a set of USDM ITR pistons that are .25 over. With rings and all. I just bought the P30s from my boy today but I need to get rings for them. My USDM ITRs already have rings. I wanted to use the P30s for the 11.5 compression. C-speed says my compression will be at 10.8 now with my ITRs.

So you think I should run the ITRs and sacrifice the .7 compression?

Also, I just rememberd. My machinist said the cylinders were a lil out of round.

My finger nail doesnt catch on any of those that you guys can see, but on the other side of the cylinder wall it caught just a very little.

Humph....so what to do? Im sure go with the .25 over.

 

I would sell the p30's and get the oversized piston, especially if the cyl walls are ovaled. Get it overbored and honed

 

Ok. Well, next question.

My options running through my head right now as we speak.
1- Run my OS ITRs I have on my bed now, with a 3 layer OEM head gasket and get 10.8?
2- Run the ITRs and modify the head gasket to a 2 layer to get 11.1 comp? Is this minor of a jump really nessecary? Im only going to be running CTR cams.
3- Buy OS P30s and spend more money?

Bottom line. Is the difference from 10.8 to 11.5 comp going to be that drastic of a comp change? Am I going to be kicking my self in the *** later down the road?

Purple.....thanks for the help. Your the man.

 

those scratches that you are remarking is called crosshatch. (not sure if your aware of it, i'm not trying to be a jackass-wasn't sure if you knew it or not)

 

Ya, I knew that. Im worried about the vertical scratches. You can really see them in the first picture.