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Geek SHO

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"Mic" them? You mean examine them with a micrometer? That's just like a very precise caliper, right? I should look into getting something like that.
 

Geek SHO

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Really? I was WONDERING why the piston wouldn't go together. Thought I had the wrong sized wrist pins, and I'd have to grind down the crank journals and bore out the pistons.
 

jonheese

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How about piston assembly. Does it matter which way the rods face?
Yes. The "KOA" should point towards the front of the engine. Here's page 83 of the Ford SHO Engine Book, which tells you all about rod installation:
SHO_Engine_Book_pg83.jpg


The whole book is available at:
http://www.jonheese.com/SHO_Engine_Book.pdf (~37MB)
 
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BaySHO Performance

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Well, the cross hatching is way too "flat". There is a certaing way to do it that yields 45 degree patterns. With a ball-end hone this is accomplished by always moving the hone in or out of the cylinder at the sme speed as the hone is rotating. It's a difficult movement to make because it's more natural for us to "drill that sucker" clean with the drill on high speed. Cross hatching is not for making the cylinder smooth, it's for making the cylinder rough so that oil sticks to the grooves.

The wrist pins look fine; but how do they "mic" out. Little pits like that are not a problem unless the outer surfact has started to come off. Mic them to make sure they are not ovalized.

Tom
Sean's short block came from my parted out SuperSHO. I used a ball-end hone on the cylinders, as suggested. I may not have taken it deep enough, so the best thing to do would be to take it to a machine shop that is experienced in honing cylinder walls for a second opinion. Ten minute job to take the cross hatching deeper.

Yes, 5000 miles on the block, 130K miles on Adam Varney's replacement crankshaft after I sheared mine. No miles since the gas nitriding.
 

jonheese

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If I'm not mistaken, it wasn't the depth of the scratches that Tom was commenting about, but rather their angle with respect to the deck surface. That is, they should make a (roughly) 45° angle with the deck surface and the ones in the picture appear to make a smaller (shallower) angle, thus the term "flat".
 

BaySHO Performance

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Yes, looking at the cross hatching, it's at about 30 degrees instead of 45. I'd get a machine shop to look at it for their opinion.
 

Geek SHO

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Ok. I'll pop the crank back off and take the block to a machine shop that I've already gone to for the custom steering wheel fabrication. I can also have them check out the wrist pins.

I think I can squeeze it all into my new ZX2.
 

Geek SHO

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I called an engine shop today, and by my description, they said that I shouldn't have a problem with the mild angled cross hatching hone, assuming that I'm not using "moly" rings, as opposed to steel. Granted, this shop may not know what a SHO engine is, and I don't really know what the rings are made of, except that they are Hastings 3.2 rings. They said something about steel rings seating really quickly to the walls, and it shouldn't be a problem. Are the Hastings rings "moly"?

Also, when I was installing the rings on the pistons, there was no gap above or below the rings, but the install instructions say that there should be 0.004" gap for each inch of cylinder diameter, so I figured 0.014" because it's a 3.5" bore. I could barely get the 0.0015" feeler gauge in there. Are these just "gapless" rings then?

This is turning into a bit of a "How-to-build-an-engine", but that's not a bad thing to have floating on the forum.
 

firebat45

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Also, when I was installing the rings on the pistons, there was no gap above or below the rings, but the install instructions say that there should be 0.004" gap for each inch of cylinder diameter, so I figured 0.014" because it's a 3.5" bore. I could barely get the 0.0015" feeler gauge in there. Are these just "gapless" rings then?

This is turning into a bit of a "How-to-build-an-engine", but that's not a bad thing to have floating on the forum.

I'm no huge expert, but it seems to me that the 0.004" per inch would be the gap between the tips of the rings, not the side clearance of the ring. The side clearance is okay at 0.0015".

I agree, deeper engine repairs like rings, valves, etc would be great to see on the forum.
 

jonheese

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I called an engine shop today, and by my description, they said that I shouldn't have a problem with the mild angled cross hatching hone, assuming that I'm not using "moly" rings, as opposed to steel. Granted, this shop may not know what a SHO engine is, and I don't really know what the rings are made of, except that they are Hastings 3.2 rings. They said something about steel rings seating really quickly to the walls, and it shouldn't be a problem. Are the Hastings rings "moly"?

Well, they are chrome-faced rings, and I believe they are steel under the chrome, as I believe this is the custom. Moly rings are coated in molybdenum instead of chrome. (I think.) In other words, no, I don't believe that the Hastings rings are moly rings.

Also, when I was installing the rings on the pistons, there was no gap above or below the rings, but the install instructions say that there should be 0.004" gap for each inch of cylinder diameter, so I figured 0.014" because it's a 3.5" bore. I could barely get the 0.0015" feeler gauge in there. Are these just "gapless" rings then?

I think that's referring to the ring end gap, which is the size of the gap between the ends of the ring, and has nothing to do with above or below the rings in the groove.

0.004" per inch of bore is a standard recommendation for ring end gap.

See here for more info:
http://www.aa1car.com/library/ring_end_gap.htm
 

Geek SHO

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I think I need to trim the rings. The #2 piston is getting caught on the rings when I compress them. I never thought assembling a short block could be so tedious and time consuming. I called a shop to see if they could assemble the short block for me, and of course they only do it for engines that they rebuilt.

I wonder if I'll ever get past step 1? Frustration!
 

sho_sc

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are we talking about ring end gaps? Which need to be set (ground/cut) prior to installation.
 

Geek SHO

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Yes. Is there an easy way to do this? My dad says that there's a special tool to do this and it's really tedious.
 

jonheese

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Yes, it can be very tedious because you need to make sure that the ends are ground square (well, not really "square", but you know what I mean) and parallel to each other, and you only want to take off a tiny bit of material with each pass (after which you test-fit in the cylinder and measure), so you don't take off too much.

I know there are special high-dollar ring-grinding machines that most machine shops will have, but I've seen one guy who made his own out of a Dremel and some scraps of wood and aluminum. Here it is:
http://www.teglerizer.com/triumphstuff/75w_newrings.htm

You may not want to go to that extreme, but since the rings must be ground/checked/ground/checked/etc., if you have a shop grind them, they'll have to have the block as well, in order to check the end gap in between cuts. I'm not sure if there are cheap ones available somewhere...

Edit: Scratch that, here's a hand-crank model for $53.40:
http://www.amazon.com/Proform-66785-Piston-Filer-Manual/dp/B000630J8E

You might be able to find some cheaper and/or better if you look around.
 
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sho_sc

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Yes. Is there an easy way to do this? My dad says that there's a special tool to do this and it's really tedious.

You can do it with a special file or a wheel (that is mounted). The wheel is much easier and faster. But you need to bore measure each hole and cut the rings individually for each cylinder. Based on manufacture, ring type, bore, and if the engine is going to be sprayed or boosted or N/A, determines the gap. Top ring gap is different than #2 ring.

This takes a lot of time to do right. It's better to have the gap a "smig'n" wider than too narrow. Too narrow is BAD.

BTW, there are easy ways to "bore measure" by pressing the rings down in the cylinder at least 1", 2" is better, and measuring the gap with a feeler gauge. Then cut to your specs.
 

Geek SHO

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Yeah, I think I'll just take it to an engine shop that I think will do it for me. This motor will be sprayed with a Zex kit until I can piece together the rest of my turbo parts, so more gap is probably a good idea anyways.
 

Geek SHO

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Quick update:

Installing the pistons is giving me a lot of trouble still, and I don't know an easy way to transport it to an engine shop. I think my ring compressor is crap (cheap), so my Dad is shipping his known good one to me.

In the meantime, I've been installing the 13" PBR brakes with SS lines and slotted rotors. This also means I have to use my 18" wheels now to set the car back down to roll it. I found that the right front wheel bearing is toast though. I guess I'll order a new bearing and pull the knuckle . . .

Until it arrives, I can work on the back of the car: rear mount battery, strut tower brace, H-brace, aluminum lower control arms, and brake bias plugs.
 
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