I picked up an engine from an acquaintance that he had removed from an acquaintances car. He knew the history of the car as she had purchased it new. I just needed the head, but figured if the cylinders didn't have a ridge, I could re-ring it and put some new bearings in for a spare bottom end. It was assembled, so I couldn't inspect the cylinders, but took a chance that the bottom end would be usable. The original owner had said she had to add a quart between oil changes which at the time I wrote it off to old valve seals. I tore it down last night and found that the engine had been recently rebuilt.... undersize crank and bored. The main and rod bearings look like they have less than 1000 miles on them. The piston skirts have absolutely no wear or scuffing. You can still see some cross-hatch on the cylinder walls, and there was very little carbon on the piston tops. I've decided to just clean and re-assemble the rod and main bearings for re-use (they're that nice), but I'm stuck on what to do ring-wise. It was bored out quite a ways and is an odd oversize. The size isn't an issue with these blocks, it's trying to find replacement rings this size that's the problem. I have 3 options..... Re-assemble with the existing rings and run it hoping they are seated. Break the cylinder wall glaze with a ball hone and re-use the rings. Search for new rings, use the ball hone and re-assemble. I've always just re-ringed an engine and had no issues, but this block is so clean and low wear, that I'm wondering the odds of the existing rings seating with a fresh crosshatch on the cylinder walls.
I f you have not removed the pistons put it back together and drive it. If you have disturbed the rings by removing the pistons from the cylinders you will need to re-ring the motor, it is very doubtful the used rings would reseat properly a second time
I have built hundreds of engines in many different ways. I've used all new parts, I've used some new parts and I've used all used parts before. I've built them with new machine work, existing machine work and half-assed machine work. I have experienced just about every result possible. I have found that when working on a used engine, if you pull a piston out for any reason and all the rings on it are intact - your best bet is to put it back in the same hole and use the same rings and DO NOT hone or fuck with the cylinder finish in any way. Now, if it has rusted since the last time it ran, then that is different. But if you hone it and put it back with the same rings - it will use oil. If you hone it and put it back with new rings - it will use oil, more than likely. I have had the best results with putting the shit back just like it was. Of course if you discover broken rings or worn lands on the pistons, then that's a different story. Just my $.02 Edit: Check the ring gap - remember, .004" per inch/bore. I usually allow about a .002-.004" margin of error - to the loose side. The bigger the bore, the bigger the margin.
To hone or not to hone..that is the question, whether it is nobler to To be, Whether 'tis Nobler in the mind to suffer The Slings and Arrows,,wait,,wrong play. Rings are cheap. HRP
whether it is nobler to To be, Whether 'tis Nobler in the mind to suffer The Slings and Arrows,,wait,,wrong play. What kind of poem is that?
If its an odd ball bore size and it used oil I would be checking the ring end gap. On the honeing part reading Grumpys book think se said he found more H/P after he honed an engine after in had been run. Been a will sence I read the book I could be wrong. If you dont hone it put in cast rings and keep a good air filter on it. If you hone it you can use a molly face ring.
Suffer the rings...and narrow end gaps! HRP's been reading Burt Monroe's bio again....! Great stuff, I'm HAMB bound.
Since it used oil before teardown, the rings might never have seated. JMHO, but I'd pull it down, hone, reassemble with moly rings. jack vines
I'll verify the ring widths and bore size tonight and just hone it and put a new set in. $40 bucks more now, maybe a PIA later......
The cylinders are good to hone and figured out what rings I need. I checked the top ring end gap and had .021". Reason I mention that is that the only pistons I've found in this overbore (3.820") are hypereutectic. I know from previous experience that they require a larger gap to keep from blowing the tops off, just don't know a way to ID them (no markings or stampings other than the oversize).
Quick check for possible cylinder taper: Record that top gap, (.021") and push the ring down to the bottom of the stroke. (3.25"?) Now measure the end gap, and divide the difference by 3. (pi, 22/7 or 3.14) Just use 3 for the factor. The remainder is the amount of taper, in thousandths. If the taper exceeds .008", boring is imminent. I don't have a 'home remedy' for sonic testing, however...
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