F 134

Changing rings and bearings seems pretty straight forward if I take my time and follow the FSM/rebuild manual/ etc.

My fear is finding a reliable machine shop within driving distance, should the block/head/crank need machining. I've been asking around for a few months now, and everyone I know who works on cars says there are only a few active engines machine shops left ...and their backlog is tremendous (2-3 years!!)

I was crossing my fingers hoping for a miracle with this newly acquired olive drab engine, but I tried to cut the first piston cylinder ridge with my newly acquired ridge reamer and may have screwed up my block. The cutting tip was either chipped to start with or chipped right after starting. It made a continuous scratch all around the top 1/4-3/16" of the cylinder. Yea, the original ridge is gone but I'll have to reverse the cutting tool to a fresh side and cut it again to try and take the scratch out. Once you start cutting, you're not supposed to stop. I could see the cutter working but thought I was just seeing debris accumulating. Nope... just one continuous scratch.

My brother thinks it's ridge material left behind and not a deeper cut into the cylinder wall. If he's right it should come off clean without cutting below the desired surface... I guess we', ll see. The pistons are already + 0.030: I really hope I don't need this to go to a machine shop.

 

Wouldn't that area, by definition of "ridge," be in the zone the rings do not travel over? In which case why would it matter?

 

Pete is correct, the only danger is leaving enough ridge for the top piston ring to catch on.

First engine I ever overhauled I didn't own a ridge reamer. My dad removed the ridges with careful application of a round file. That engine ran for many more years.

When you get the ridges reamed and the cylinders honed, be sure you understand how to check ring gap.

 

The ridge was so big on my mini i used the grinder to take it off. like 1/16th easily. It should go to the machine shop but aint nobody got time for that.

 

I actually never wanted to touch the block and was very pleased to find just some superficial rust in only two cylinders. Had it been obviously in need of a machine shop, I would have started looking for a finished rebuilt engine to get my Jeep back in the road. I'm glad that didn't happen,. I wanted this experience.

Several on-line threads talked about ridge reaming being low risk and, I thought, within reach of a knuckle buster diy'er like me. Without a chipped tool, I'd be past this task already. But now it will be interesting to see what happens on a second pass...

I have been reading up on checking the ring gap. It should also inform me if the cylinder is tapered or if the ridge reamer cut is too deep.

I'm thinking that I have to remove the scratch I made, for the same reason I worked to remove the ridge. When the existing (worn, rounded edge) piston rings are replaced, the new ring will have a fresh sharp corner which will smack into any remaining ridge (or scratch) at the top of the stroke. Besides, I want to take the piston in and out the top of the block, which I'm told requires the ridge (or my scratch) to be removed.

I guess it's possible my scratch is removable with a stone or ball hone, but I don't have any experience with them either. I bought a ball hone to provide the recommended cross hatch for good lubrication, which seems very doable. But I'm not at all confident about using honing to sufficiently remove my scratches.

 

Can you find some pipe or old cracked blocks to practice on?

 

Boy, that is an excellent idea!!

 

Yesterday I removed the slinger, spacer, oil spray nozzle, timing gear, front plate, thrust washer and shims. Then I pulled the rod bearing caps, dropped the pistons out the top (no piston ring drag what so ever at the cylinder ridges), and I pulled the main caps.

The number 4 rod bearing and it's journal were both scored. A few others showed some wear but apparent scratches could not be felt. The crankshaft will need polished (at least) and then new bearings all around based on final journal measurements.

There is a 0.001" gap at the edge between the head and block (it rocks up and down when pressed). So, Joe bought a new straight edge to help determine where the irregularity is. One or the other may need re-surfacing. I note the block has never been re-surfaced, (the engine S/N is intact).

The front plate was bowed and a LOT of gasket sealer had been applied. It looked as if the spacer had been installed backwards.

The end play shims were present, hand cut, and there were several... so, we know the PO was aware of them. We measured no end play originally; none at all. But with all the shaft mounted parts off, the crankshaft play was almost 3/16 to 1/4 ".

Next, we'll pull the camshaft. The lobes all look good; polished with no visible wear. We haven't removed the exhaust valves yet. We'll obviously have to do that first. Then a major cleaning of all the oil passages everywhere.

Meanwhile... looking harder for a machine shop here in Pittsburgh.

 

I bought a new Lisile ridge reamer on Amazon. Wow... what a piece of junk. Rusty, chipped cutting tool which then dragged in its holder. And the centering plates had rough surfaces and wouldn't slide without hanging and cocking. I sent it back to Amazon for a replacement.

I should say I had very nearly the same problem with the other one (a "used" K D brand) which I already used on one cylinder. I was able to reverse its cutting tool to a brand new blade, but even after considerabe edging, cleaning, and oiling all the moving parts, I could not get it to center properly in the cylinder. So I could not clean up my first cut. It would be off in one direction, then another, then another. And the same thing happened moving to a different cylinder. So I bought a new one.

 

Remember, ridge reaming, honing, etc are removing metal from the cylinder wall, making the piston fit looser in the bore. Cylinder wall taper is a thing too. Its possible to have piston skirts knurled to help “resize” them, but there are specs for piston clearance that need to be adhered to. Without accurate measuring tools, you can still get a good idea of cylinder taper by placing a piston ring at several different depths (top, inch from top, 3” down, bottom, ect), setting it square with a piston , and using a feeler gauge compare the gap at various depths.
The block may ultimately need to be bored oversize, and new pistons fit.
-Donny

 

x2, piston to bore fit is important as any other part of your engine. The cylinder bore can be out of round as well especially on a "v" design engine. I have tore down v-8's that would have a ring grove on the lower side of the cylinders and none or very little on the upper side of the cylinders. I have never see this on in line engines with all the cylinders operating vertical though.

 

"Gravity. It's not just a good idea, it's the Law."

 

One thing about gravity: It's predictable and relentless. OK, two things.

 

If it wasn't for gravity, everything would fall off the Earth at night when it turns around to the other side.

 

Yes at 390 miles per second.

 

'Enjoying all the "heavy" content

I'll pull a ring from a removed piston and map its gap at various depths in all cylinders. Any diameter variation will be about 1/3 the gap variation (1/pi actually). I have a diameter variation specification somewhere (probably in the FSM). That should inform my next decision about machine shop work for this engine block.

We had some rocking of the head on the block (less than 0.002" at the edge), but after cleaning it a second time with a ScotchBright style rotary pad, and hitting the edge perimeters with a file, the rocking went away. Then we checked the block and head surfaces with a brand new straight edge, a bright light, and a feeler gage... No gaps!!

We removed the crank and cam shafts. The camshaft was perfect, the crankshaft... not so much. I did finally find a highly recommended automotive machine shop relatively local who agreed to look at my crankshaft next week

I'll wait until the block and crankshaft questions are resolved and then buy bearings and rings (and pistons, etc, if needed) to fit the final dimensions.

Until then, all the oil passages are gunky filthy. There's some job security getting them clean again. Someone suggested a rifle cleaning tool, so, I'll also try that. I bought NOS head bolts (eBay), and new crankshaft bearing bolts (Grainger!!). I don't know if I should reveal how much I love handling clean, good quality, new bolts and hardware. It's one of the highlights of this whole effort.

And I'll start servicing, cleaning and painting the accessories and brackets.

The main front bracket was surprisingly bent. The PO used gasket sealer to fill the substantial gap it caused at the face of the block. It will need to be straightened or replaced. And I'm missing the pulley/harmonic balancer shield.

 

Probably worth the expense of investing in a set of engine cleaning brushes. Most of those are flexible and easier to get into passageways.
https://www.summitracing.com/search...der=Ascending&keyword=engine cleaning brushes

Unless you can get that front engine plate perfectly flat, I would replace it. That is a leak prone area even when everything fits as it should.

 

I got the recommended brushes and cleaned all the surfaces and passages in the block with degreaser. Then I hosed it all down with water and used an air hose to dry it. I found out the hard way that old oil likes to pool stubbornly in the hollows at the base of the exhaust valve adjustment compartment. I looked like a dalmatian when I was done.

I followed a suggestion made here that I practice with the new Lisile ridge reamer and ball hone on an old cylinder or piece of pipe. Amazingly, I had a 3-1/8 ID steel tube sitting in the garage and I went to work with the reamer. The Lisile ridge reamer has a tendency to walk up out of the cylinder as it cuts. And I couldn't get it to start cutting far enough down inside my mock up cylinder. It would have missed my lower scratched cylinder surface.

So... I loaded up the crankshaft and the block and dropped them off at the highly recommended machine shop I found. The journals will be polished (at least) and the cylinders will be cut and reamed, and the exhaust valve guides will be replaced. He inspected the lone camshaft bearing and recommended that I leave it, it was unmarked!

Now, what to do with a new Lisile Ridge Reamer and a new Ball Hone...

 

Side note. The engine machine shop called Friday. They couldn't start boring my block because I failed to also provide the main bearing caps, bolts, and old bearings. They use the crankshaft bore as a zero datum and as a tie down for the block. So, I lost a week, and have to get back in line, and I have make an extra 70 mile round trip to drop off the bearing caps. Duh.