mother$hip89

I had some scratches in my cylinders. I honed them and the scratches are still there, I can feel some of them with my fingernail but not very much. How can I tell if I can get away without boring.

TripDeuces

I think your finger nail gave you the answer. It's time for a bore

olds 307 and 403

Show us a pic.

CRUZN 66

Hone the cylinder until the scratches are gone, check the bore size and go from there... An accurate measurement is better then a finger nail test...

m371961

x2

mother$hip89

Here's the worst one. It's not worn or anything and the bores are round, I'm just worried about the scratches.

Joe King

Dingleberry the crap out of that thing, that's what I where I would start. I love to dingleberry... maybe I just like to say dingleberry, who knows but just dingleberry it. Dingleberry.

m371961

What are you gonna use it for? Daily driver, putting the miles on? Have you measured it yet? Just for occasional pleasure drives? How much money you gonna spend?
Those are the questions I would ask myself.

mother$hip89

It's a daily driver. Don't plan on putting much more into the engine, it didn't have very many miles on it (It was rebuilt not long before I got it, probably in the low thousands) and everything is good besides the scratches. I had a buddy who does a lot of chevy rebuilds look at it and he figured a hone would do the job, but I'd like to hear from as many people as possible cause I do NOT want to learn the scratches needed bored when it's back together.

mother$hip89

Also imI using one of those 3 stone hones

Joe King

Okay, for real this time, dingleberry the cylinder (or the less fun name, ball hone) it will give you a better crosshatch and the rings will be happier.

Olds64

x2

If you don't plan on taking the block to a machinist or renting a dial bore gauge to measure the cylinders then there's no need to consider a full rebuild.

02WS6SSZ71

I think what everyone is getting at is either
A) spend big money, bore it, buy new pistons and rings, get optimal ring seal, engine has a long healthy life, or
B) spend a few bucks on a ball hone, assemble, lose a little compression, burn a little little bit of oil, engine has a slightly shorter but still good healthy life.

All comes down to if you wanna pony up and do it right while it's out of the car.
At least the scratches aren't at the top of the bore.

mother$hip89

Oh I do plan on measuring the cylinders afterwards. At what measurement am I gonna start to have trouble?

Charlie Jones

Measure the bore about one half inch below the top of the bore . Then measure the bore near the bottom of the cylinder .
If the difference is .010 inches or more , then you should re-bore the engine and replace the pistons .
If less than .010 , then honing and a replacement of rings will probably be successful .

BTW I noticed that the honing marks are all in a straight line . No good . You must keep the hone moving in and out of the cylinder to produce a "cross hatch" pattern .

mother$hip89

I was looking in the 1974 Olds service manual and I found this: "If the cylinder bores are smooth, the cylinder walls should not be deglazed. If the cylinder walls are scored, the walls may have to be honed before installing new rings". It looks like the manual is saying the only time honing is needed is if the bores are scored, and that honing is all that is needed for scored cylinders. What do you all make of this?