SD-220 Rebuild help

I'd still use the palm sander,it's faster and easier to control the down pressure needed. The fine paper removes very little material as well,so with surface rust... Plus most have a dust collector,with my Porter-Cable after mounting the paper there was a fixture you set the sander on with "spikes" on it,push down and presto! you had holes for the dust collector. In addition to rags in the cyl's use a shop vac next to the sander pad as you go.

Furgot about my porter cable random orbit, prolly work just fine.

looking at those pics, that motor looks just fine, a little clean up of cylinder walls and top deck,

most of the water jacket holes look clean, (at least in the pics), I'd button it up and drive,

Just clean it up without removing the pistons or anything? That would certainly be the easiest, if I can get the crud out of the bores.

That's not too bad,from the way you described it I thought the deck was coated end to end with a coat of rust. What the pic does show is where the low spots are,even condensation or morning dew will puddle. Doesn't look bad enough to do more than just giving it a good cleaning.
The mention of Scotch Brite pads reminded me that at Home Cheapo they have 3-4 different courseness of pads like that in the paint dept. They won't remove anything other than the rust and might be the best bet.
I'd coat the rust spots will plain penetrating oil and let it sit at least 1/2 an hour then use the pad on it. Leave it wet though so the particles stay in the oil,wipe clean and repeat as needed.It may even work on that cylinder wall(?).
I sure wouldn't take the entire engine apart to clean up one hole though if honing becomes necessary. If the rings and rod bearings are new they can likely be used again.you did say it was an "unfinished" rebuild?

There is no substitute for doing something the correct way. A machine shop can do the block and head for just over a couple of hundred bucks. We are talking about the engine here, folks. This is not an area to get cheap and start hand grinding. The Ra or R-arithmetic average on a finished surface should be less than 20. This is the measurement between the "hills and valleys" of the machined surface. these numbers are not achievable with a hand held abrasive.
http://youtu.be/ch37NBkvTrs This is a good example of the job not being done right the first time. A hand-held ham-fisted clean-up cannot indicate if the surface is warped. If the studs are trying to fight a warped head, the final clamping force, on the gasket, will be less than what is recommended by IHC and there will certainly be a leak. A leak to atmosphere is unsightly and the lesser of a worse situation. Coolant and lube oil is a fatal mix for an engine. The rotating surface bearings will have the surfaces removed.
If the bearings are going to be installed at home rather than at a machine shop, do not touch the bearing surfaces. There is acid in fingerprints and much worse, the bearing surfaces have been treated with cyanide to prevent corrosion and help with break-in. Google cyanide, it is interesting stuff and will compromise one's longevity.

I agree with Nikki, hand grinding has no place in machineing. If you have a surface plate and a skilled hand, it is possable to scrape a surface to a suprizeing deg of accuracy. This is how the 1st machine tools were made. The time and labor involved to do it by hand make the machinests price seam cheap.
Haveing said that, you can if you know the correct way and are a good judge, cut a lot of corners as long as you are willing to go back and do it right if it doesn't work. As long as you don't do more damage in your corner cutting, it is up to your time and the cost of material.
Over the time I have worked on machines, I have re-used just about everything from head gaskets to bearings and rings and seals. Over the years I have biult up a degree of knowledge on what will work and what will not. When being PAID to do it, I always do it the correct way, on my own stuff, I make judgement calls and have got fairly good at assessing what I can get away with.
If a head or block will not hold a gasket, I would never try and re-surface by hand, it is just too labor internsive and still requires a surface plate.

I agree with Nikki, hand grinding has no place in machineing. If you have a surface plate and a skilled hand, it is possable to scrape a surface to a suprizeing deg of accuracy. This is how the 1st machine tools were made. The time and labor involved to do it by hand make the machinests price seam cheap.
Haveing said that, you can if you know the correct way and are a good judge, cut a lot of corners as long as you are willing to go back and do it right if it doesn't work. As long as you don't do more damage in your corner cutting, it is up to your time and the cost of material.
Over the time I have worked on machines, I have re-used just about everything from head gaskets to bearings and rings and seals. Over the years I have biult up a degree of knowledge on what will work and what will not. When being PAID to do it, I always do it the correct way, on my own stuff, I make judgement calls and have got fairly good at assessing what I can get away with.
If a head or block will not hold a gasket, I would never try and re-surface by hand, it is just too labor internsive and still requires a surface plate.

from his pictures, there is just a small amount of surface rust from sitting, if a straight edge shows it to be a true surface,,,,,,,,,

totally dis-assembling a just rebuilt motor to take the block in for surfacing seems a bit over kill to me, but hey in the end it's his motor,

clean it up and finish assembling, or totally dismantle it and machine an all ready flat surface for peace of mind, either one is probably the correct call.

agreed, I would clean and reassemble but would stay away from trying to resurface the deck by hand. Buffing with a little oil and rag should clean well enough.

Who said anything about "resurfacing" the deck by hand??? THAT would ludicrous.
My suggestion(s) was for methods to remove surface rust which I have used successively many times and are not intrusive to the true surface.
To pull a rebuilt engine because of a little rust is a bit extreme so I side with Jon there.

I agree.

I went out to the garage and dug up the paperwork I got with the pile of parts. I couldn't find a receipt for the rebuild, but I found a receipt for the chrome work and a note pad paper that presumably has everything that was done to the motor (and prices). $174 for a set of pistons, can you believe that? The chroming receipt was dated 1988, so it was done quite some time ago.

I certainly won't be doing any "machining" by hand--that would cause major issues.

The head was apparently on the motor, and the previous owner removed it to inspect the bores since it had been sitting. It's been totally gone through--new bearings, new oil pump, machined crank, something with the cam (couldn't read it), probably machined rods (doubt they were replaced), etc.

I took a straight edge to the block surface, and it's pretty flat. There are some areas you can see light, but it's pretty minimal (a couple of hairs maybe?). I don't know what's considered too much, but I can't imagine it's enough anywhere to cause a problem. It is uniform--no crazy spots or anything. After looking at it again, I think the rust spot in the one cylinder may actually be above TDC--so it may even be less an issue than I thought. I turned it over just enough to verify it wasn't stuck, but haven't rotated it much until I clean it out. Figured it was better for the rings.

I will probably have the head tanked, or maybe I just need to pull it apart and clean it up. It's a little dirtier than the short block. I don't know how long the head was off the motor.

My biggest concern from just using it as is would be getting the dirt out. The side cover was on, but there's some grit in there--and the bores. I can probably wipe most of it out. I'm sure some gets into a motor anyway.

Our old "rule of thumb" at the garage was to check the block/head with a straightedge and a $1 bill.

If you can pull the dollar bill out from under the straightedge without pulling the straightedge over on its side, you need to have the surface machined.

And I just Googled it: a dollar bill is 0.0043" thick. For you folks on the metric system, that's approximately 0.1 mm.