Found a cracked block.

[gordr]

Today I decided to strip down and clean up the block from that '63 Lark VI that I'm parting out. Cleaned most of the crud off the outside with a putty knife, then figured I'd run the hone in the cylinders to see how they'd clean up. #4 had been the worst-looking, so I started with it. Quite a lot of pitting near the bottom, mostly below the ring travel area, where water sat on top of the broken piston. The rest of it cleaned up OK, with the exception of some shallow scratches. No ridge to speak of. If the rest of the cylinders were OK, this one, if fitted with a new piston, might burn some oil, but the engine would run, I think.

Ran the hone in #3, and uh-oh, cracks. At least one, probably two, slightly curved, and slightly off-axis to piston motion, so they can't be scratches. I can catch a fingernail in one, after having run the hone. So this block is toast, unless it gets sleeved, and that's scarcely worth doing, seeing as there are uncracked blocks to be had. I won't toss it, because who knows, maybe somebody will want an OHV block to sleeve way down to some smaller displacement for racing purposes.

I removed the camshaft and cam bearings, which all look good, as do the main bearings, which all were in the right way, so no clue why the two middle rod bearings went. No serial number on this block, as it was a service replacement engine.

Guess I will clean up the remaining parts, and store them away.

[StudeRich]

It should be a more desirable Full Flow Block, so couldn't the one hole be Bored Way Oversize, Sleeved and one or all cylinders Bored back to Std. or .020, .030 or whatever?

[swvalcon]

Any good machine shop can sleeve it if it's just one hole. More than that it's not worth it to save the block.

[gordr]

Yes, it's a full-flow block. I'm not going to send it to the crusher, but if I need an OHV six, I have crack-free blocks to use. One good thing. When I took the head off, #3 cylinder showed a little rust around the valves, but no sign of cracks. Finding the crack in the block in that cylinder explains that, and makes it more likely that the head is good. Since good OHV six heads are scarce, I'm pleased with that. I know I have at least one non-cracked block on hand.

[sals54]

Said it before, sayin it again.... drop that boat anchor and get a V8. Cheaper, easier, faster, better, more mpg, more fun, better exhaust sounds, better burnouts, better.......

[dean pearson]

Said it before, sayin it again.... drop that boat anchor and get a V8. Cheaper, easier, faster, better, more mpg, more fun, better exhaust sounds, better burnouts, better.......

He's just passing time until the grass needs mowed again, let the man have his fun.

Dean

[gordr]

Said it before, sayin it again.... drop that boat anchor and get a V8. Cheaper, easier, faster, better, more mpg, more fun, better exhaust sounds, better burnouts, better.......

Hey now! You don't have to convert me to the V8 cause. I'm a believer already, although I do love the Champion and Commander flatties. But I will save known-good OHV six parts, because somebody, somewhere, might want them. I do think, though, that it would be fun to build a DOHC hemi head for the Lark six. Maybe a 4-valve head, since the bores are so small.

[gordr]

Carrying on, I got the solvent changed in my wash tank, and began washing parts. Got the four intact pistons cleaned, and the wrist pins freed up. Must be standard, no oversize markings; same for the bearings. Somebody was into that engine though, because I found hammer marks on the front hub, where it had been hammered (instead of pulled) onto the crank. Got a bunch of parts washed, then got driven indoors by a thundershower.

[sals54]

Hey, don't take me too seriously... I was jus pokin at the bear. Guess I riled him. Just never been a fan of the OHV 6s.

[gordr]

Well, they have to be my least-favorite Stude engine, for sure. I got all the parts washed, even the starter and manifold. Heat riser moves freely, imagine that! The block will go back outside the shop; the head will go inside. Looks like #3 exhaust valve leaks, but it just may have some crud under it. I washed the head and got most of the crud off it, but I will give it a good inspection. I won't pull any valves, though, until it's needed for something. Got the transmission gears off the mainshaft, and aside from rust pitting, they look OK. A transmission built using them would work, I expect, but might be noisy.

[sals54]

One of the noisiest transmissions I ever drove was in a non syncro first gear MGB. It must have been missing more than 2 teeth on that main gear cuz it sounded like someone with a ball pean hammer pounding a quick tempo out of a Jamaican steel drum.

[gordr]

Well, got all the bits cleaned up and put away. The head cleaned up pretty nice, and no cracks between the seats visible, even in full sunlight. Being a glutton for punishment, I dragged another OHV six up from my parts stash, and set it on the outdoor welding table. Nice to have the tractor with a loader to do the muscle work! This engine came in a '63 I got from Norm Searle, and was running, but smoked real bad. I used the head off it for some other project. It has a Type 35 automatic on it right now. Plan is to tear this beast down, too, then reassemble it with the best used pistons, bearings, and rings I can find in my stash, honing the cylinders, of course. I have quite a large stash of such used parts. Then fit it up with a long-tail T96 overdrive. I think I have enough parts to build one of those, too. That will give me a working (not necessarily good, but working) engine that I can put in that '60 Lark I have down in Arizona, which already has a badly-stuck OHV six in it. So it will be a straightforward engine/tranny swap.

[gordr]

The saga continues. Got the second OHV six torn down today, and most of the parts, save for the block itself, washed in the solvent tank. Another front balancer hub with numerous hammer marks, and an over-long bolt with a stack of washers. Found a hunk of thrust bearing material in the oil pan. Coincidence? I think not. Also, the flex plate was cracked about half way around every hole on the converter side, AND the pilot on the converter itself had broken loose at the welds. I think excess crankshaft endplay was the root cause. No ridge in the cylinders at all, and all six pistons came out, but at least 4 had broken rings, which probably explains why the engine smoked so much as it did when I ran it. These pistons are full skirt with a T-slot, and heat dam at the top. Crank and bearings all look OK, leastwise no badly-worn bearings or journals to be seen. Fiber cam gear in this one.

Had a little incident. The short block was sitting on my outdoor welding table, with the back of the oil pan overhanging the edge, so I could drain the oil into a catch can. There was a wood block under the harmonic balancer to make the engine sit level to aid in draining the oil. As I was pulling on nitrile gloves a few steps away, to begin washing the parts, the engine rolled over on its own, and toppled off the table, and landed in the grass. No harm done. But I'm lucky my foot wasn't under it, eh? I got the bare block back up on the table after stripping the crank and pistons out of it while on the ground. I'm thinking this table could use a little jib crane on it, like people put at the back of pickup boxes.

[gordr]

Work continues apace on my "junk" 170 OHV. Block cleaned inside and out, and painted. Main bearings replaced by the ones from the previously described blown engine; the all plastigaged at .0015 to .002" Crank installed, and bearing caps torqued down. Rear engine plate cleaned up and painted. Found a bellhousing, which probably came off a '51 Champion, based on the source of it. Got that centralized to the crank. The dowel bolt holes were nearly dead-on. Found a decent set of rod bearing shells, and they clearance out at between .0015 and .003 inch. Cleaned up an assortment of old standard pistons and rings, and made sure that the wrist pin bolts were tight, and facing the right way. Some weren't. I cleaned all the ring grooves, and the oil holes behind the oil rings. Used old rings, but I "honed" the outer face of each one by very lightly passing the drum sander on a Dremel tool over the surface to break any glaze, and provide a slightly rough surface to trap oil, and to mesh with the honed cylinders. Basically just curious to see what happens.