.001-.003 ring wear, bore or hone only?

[Sidious]

I have the block to my 98 12 valve at the machine shop. They said the cylinder has .001 - .003 ring wear and are asking me if I want to bore it over or just hone. Honestly I'm not sure and would like some advice one way or the other.


Thanks,
Doug

 

[Mark Nixon]

It all depends on what you're going to do with it.
Also is the "ring wear" tapering of the bore, or is it out-of-round?

If you wanted a looser engine and plan to beat the snot out of it from the get go, looser wouldn't hurt, but if you want a 400,000 miler, it might not make it that far.

Personally, I'd run a quick hone through it and put it back together, but that's the cheap side of me talking.

.003 (Three Thousandths) isn't a terrible amount on a 4"+ bore.

Mark.

 

[95cummins5.9]

It all depends on what you're going to do with it.
Also is the "ring wear" tapering of the bore, or is it out-of-round?

If you wanted a looser engine and plan to beat the snot out of it from the get go, looser wouldn't hurt, but if you want a 400,000 miler, it might not make it that far.

Personally, I'd run a quick hone through it and put it back together, but that's the cheap side of me talking.

.003 (Three Thousandths) isn't a terrible amount on a 4"+ bore.

Mark.

what would be too loose?

 

[Mark Nixon]

what would be too loose?

Anything that allows "fall out". :hehe:

Seriously, though, most auto manufacturers start getting worried at ~.003 taper, IIRC.
I understand that pullers will run blocks honed ~.010 over, but that's to combat piston growth due to heat and the bore generally is a fresh, straight bore, which has no taper, so the rings don't flex, causing the rings to crack.
A tapered block is also harder to get a feasible ring end gap to limit blow-by, but many times a scored cylinder will leak compression much more than a bad ring gap will.

{edit}
I found this article to be interesting:
http://biosystems.okstate.edu/home/fharry/3211/900_Homework/CylinderTaper.htm

Mark.

 

[renopker]

Ill bet its side to side. Put a hone plate on it and strighten the bore out .002

 

[lenahan05]

hone.

 

[cetanefreek]

Hone that sucker and run it.

 

[ahale2772]

hone and use a piston with a lower ring land if possible

 

[Sidious]

Personally, I'd run a quick hone through it and put it back together, but that's the cheap side of me talking.

My cheap side likes to talk to me too, hence this thread :hehe:

 

[Sidious]

Well, just gonna hone then.

hone and use a piston with a lower ring land if possible

Planning on using the 286210 piston with a 14.13 ring landing.


Thanks for the info guys :Cheer: