I just honed my block with a 400 grit hone ball. When I drop a light into the block I can see a nice cross hatch pattern but I also see fine vertical scratches in several parts of each cylinder. They do NOT go all the way top to bottom, each one is only a couple of CM long. When I run my nail in the cylinder to feel them, unless I knew to look for them, my nail would not catch them.

Am I going to be ok?

I took it apart because it was smoking, so hate to put it back together and not achieve what I was after?

 

if you want to be sure, get it overbored to 75.5 and be done with it

or be frugal like myself and reassemble with new rings and the hone and see what happens.

 

^ you mean 81.25mm or 81.50mm, its a b16

To the OP, your best bet/safest bet is to send it out and get it over bored slightly to 81.25mm to get rid of those scratches. If you dont you may continue to burn oil as it will 'hide' in those scratches

 

ic so even if the scratches don't go all the way top to bottom, it can still burn oil from oil hiding in the scratches?

How deep of a scratch will cause that? I mean I can barely get a nail in these lines.

If I take it to a machine shop, i assume i need to take the crank out? if that is the case, i might be better off just buying a b16 block from someone how just needed the head off of.

 

Here are a couple of photos. Don't mind the bubbles, that is fresh oil on the walls.

 

Get it bored.

 

i would run it like that. does your fingernail catch on it if you run it across?

 

Absolutely wont have a problem with running like that

 

run it.....mine had huge scratches which are visible and you could feel them. i just shoved the damn pistons in anyway. the engine rungs great. great compression and leak down.

 

^ u got lucky lol i did that and few months later burning oil... id say bore it..

 

nail tip barely catches on it. If I did not know the lines where there and I ran my nail, I don't think I would know that my nail caught on it.

I think I'm just going to run it. see what happens.

 

that wall is ruined.

god i love it when people know what they are doing.

 

What do you mean 910? Because of the vertical scratch or my excellent hone job?

 

Did you measure the bore diameter? Usually there is wear associated with scratches like that. No one here can predict accurately whether or not that engine is going to run well or burn oil by simply looking at pictures on the internet. Your hone job looks correct but hopefully you did not take too much material off or your piston to wall clearance will be excessive. My professional opinion would be to bore it oversize but since you are doing the work yourself it's worth a shot just putting it together and seeing what happens if you don't mind the possibility that you will need to do it again in the future.

 

Ditto the above^^^.
I would never just go ahead and use it the way it is, unless you don't mind pulling the engine again.
Get it bored out, do it right the first time. 94

 

Alright, that is what my gut told me to do, bore it out so I decided to go that route. That said, I figured if I am going to dump the money into it, i'd be better off with a b18c, so picked up a block with ctr pistons, but I think i am going to bore this one out and do a fresh build. Anyone want to trade larger size CTR pistons for standard ones?

 

That's gonna be some crazy compression, why not get some 81.25 or 81.5 p30 pistons and sell the ctr's