I bought a fully machined block from a guy, but when it got here it had some minor rust(they didn't oil it down before shipping). There is some on the caps anddeck, which is no biggie.. I can hit those with a scotchbrite pad. but what I am worried about is the cylinders. 2 of the cylinder have a few small patches of rust. I was thining of soaking them with WD40, and rubbing as much off as I can with a rag. I don't wanna hone it anymore, as the piston/bore clearance is dead on... if anything I would want it .0005 smaller.

a hone will kick anohter .001 off, which would put me bigger than I want..

 

yeah that should be good

 

I've seen guys rub a good bit of surface rust off with solvent and a rag...

 

A old ring set on a piston/rod and some cutting fluid, worked for me on a lightly rusted finish.

 

Might have to sell it to a shmuck like me I got $50 waiting right here if yer interested....he he he

Ok fine...Just use some "D40" and yer golden..later man

 

Maybe a few strokes with a 'flex hone'.

 

unfortuatly, I am 1) worried about the flex hone removing any more materiel and 2) the finish won't be as good as whats on it now(minus the rust )

 

That is going to depend on the grit of the flex hone.

 

use some solvent and a rag.....get off what you can and put it together. You'll be fine

 

I'm not big on the flex hones - they can remove material very unevenly. Going through all the trouble of honing a perfectly round and straight bore and then running a dingleberry brush through it is a bad idea.

If the rust doesn't come off with a rag, then try one of those "gentle" scrubbing pads, like something you'd use on a Teflon frying pan (not a Scotchbrite or SOS pad). If that doesn't work, call the local machine shop and ask for their advice - they probably see problems like this on a regular basis.

 

According to the tests conducted and measurements taken, that was the strong point of the flex hone, to actually remove a slight out of round condition (by slight, I mean a 'few tenths'), not to aggravate it.

Eric, do you have some data to validate your claim?

 

The problem I see is with using a flex hone without a torque plate installed. If you bore/hone the cylinder with a plate and then run a flexhone through it without a torque plate, I don't doubt that you'll find some high spots to knock down

As far as "data" to validate my claim, I've just seen a lot of people screw up bores with a flexhone - of course, this is very dependent on the operator, right? Get someone that knows what they're doing, install and torque plate and the main caps, and I'm sure things will end up just fine. Doesn't sound like a backyard operation at this point, though...

 

Jordon,
There's a product I use called "Evaporust". It's non-toxic and uses no acids... doesn't etch the metal. Quite a few engine rebuild shops are using this product nowadays. If you know someone, well you can bum some from them.
If not, then I'd just stick to the "cloth and oil" method... then cover it with some 30W oil until you're ready to get down to business.

Take care,
Chuck Riddeck

 

Sorry Eric. Silly, me for not stating that. I figured the torque plate was a given. My error.