So I have the 226 for the '49 F3 apart getting it prepped for painting and general refreshing.
I've never heard it run but thought it was in decent condition until I had cylinder #1 at bottom dead center.
There are some grooves in the wall (see pictures) that are probably .020" deep.

The bores are all at .040" over already. (original bore was 3.30")

Looking for opinions from folks who have been down this road before......
Will this cylinder smoke or generally be a bad idea to run it as is? Will some new rings and a piston from a 254 cid engine match the bore if I honed this out? (Is the bore size on a 254 at 3.50" ?)
This '49 project is all about keeping expenses low and I'm no machinist or engine builder. The tools in my garage are not much more complicated than stone axes and wooden clubs.

I have no compression numbers from before I took the head off and since the cost of a head gasket is near $80 I only want to have this apart once.

Thanks in advance,

Tom

 

Those score marks look like the wrist pin is rubbing the cylinder wall. I have seen wrist pins wear completely thru the cylinder wall. The cylinder looks good otherwise. If they all look like that one less the score marks, you could have that cylinder sleeved and ring it
Mark

 

Doesn't look like it's in the right place to be a wrist pin...looks more like a broken ring to me. Either way it looks deep, time for a sleeve at least.

 

If the 6's are like the V8's, plenty of meat left for boring, no sleeve needed. The piston shows .040" over already, .060" was a factory O/S. I'd guess it will clean up at that.

 

I would only consider sleeving if the other cylinders are good, otherwise it would be best to bore. That score mark doesn't go all the way to the upper part of the cylinder like the rings and is round on top like a wrist pin.

 

Tom, is the scratch on a line parallel to the crank?

The problem with sleeving is that the bore needed for the sleeve would almost certainly be more than +.060". Although it's unlikely this engine will ever be rebuilt again, a sleeve would remove the option to go +60 on all the cylinders. I wonder if the cost to sleeve the one is really much cheaper than the cost to bore all of them +60 and buy all new pistons/rings? I've never priced it out.

 

Looks to me like the score is east west where a wrist pin score would be north south.
Edit: Just read where it is #1 so I might be seeing the front of the engine instead of the side of the block. ???????????? Ross asked the right question.

 

Are the scratches deep enough to catch your fingernail?
Its easy to spend someone elses cash, being low buck I would hit it with some emery cloth if there are raised spots of the scratch and then dingle hone it. No raised spots just dingle hone only and use moly rings.
Unless you plan on running 100k miles I would give it a shot, when I was younger I did several engines with no regard to cylinder taper or scratches, they all ran fine and were not smokers.
Machine work prices around here are crazy, easy to put $3000 into a stock engine. No wonder crate engines are so popular.

 

There's a lot about this picture that doesn't look kosher...no carbon at the top of the bore and no apparent lip would indicate low mileage. Dark band in the upper inch of the cylinder tells me that there was not much ring contact in that area as opposed to the lower bore. Finally, there sure is a lot of gap between the piston and the cylinder wall. It wouldn't surprise me if this wasn't a botched bore job from the beginning. Sure would like to have a mike on that cylinder and the piston...that would tell a better story.
Tom, what do the other cylinders look like? This would be a good time to mike each cylinder and see how they compare.

 

The dark area at the top looks to me like the smooth area at the top of the cylinder where the rings stop as the piston changes direction. I think it just looks dark in the photo. The piston to cylinder wall gap may just be the chamfer on the top edge of the piston.

 

I saw the same things as Charlie, as far as sloppy fit, but photos can be deceiving. I think Mark is right about the "dark" area being where the rings are at TDC, the area is about the right distance from the deck (see below). Has the ridge already been reamed?

 

Seeing that you already have the head off, I would pull the pan, unbolt the rod cap, remove and inspect the piston and wrist pin carefully. {Where the heck is the index mark on that piston top anyway?} Measure the bore with an inside mic and see how bad it really is, then choose a course of action. It is possible that someone had .040 pistons and a .040 over bore would not clean up all the scoring, but they put it together anyway.

 

Hi Ross, yes the scratch is exactly parallel to the crank. I have not seen .060 pistons available but a set of .040's is over $300. I have not seen any .060 ring sets but a set of .040's can be found for about $45 - just for comparison.

Yep, the scratches are deep but no sharp edge or vertical ridge into the bore - they are flush with the bore.

I was told (I know...a seller will say anything) that the engine had low miles since a rebuild and other indications will confirm that. The other five cylinders look just like that #1 in the picture, minus the prairie wagon wheel ruts. Nice shape in the other five.

[QUOTE=ALBUQ F-1;16140956].... Has the ridge already been reamed?

Not by me, and not since I took the head off. I cleaned the piston head with some GoJo to make it look shiny like it does and to show the oversize mark for the pictures.

Thanks for the replies so far guys. Still listening and learning what to do here.
Tom

 

I'll pull out the piston in the next week or so and report back here with a picture or two. Got snow coming tomorrow and will have to wait for warmer weather to get back out there. I don't have an inside micrometer and off the top of my head don't know anyone local with one.

Tom

 

I agree that the dark area is where the rings are at TDC...my concern is why is there a dark area? If the cylinder has no taper then the coloration of the upper area of the cylinder should be the same as the central and lower portions of the cylinder. That said, IF the piston is too sloppy in the cylinder then combustion would easily blow by the rings and discolor the cylinder.
Given that the scarring of the cylinder is parallel to the crankshaft then I to believe that the wrist pin is the culprit.