Thanks BushogPapa Tractor Guru Joined: 26 Dec 2001 Posts: 7991 Posted: Wed Dec 07, 2011 9:03 am Post subject: Re: What is an acceptable amount of out of round in cylin. Sometimes a phone conversation is the best way to solve a problem. Peter Update Well, so much for rebuilding. On Big block Mopars the bores go +. Rods Connecting rods are subjected to tremendous loads. A couple tenths is nothin to worry about and your machine shop probaly checked this with a plate installed. As I have been there and done that on 60's.
What is the threshold before they decide that something is either round or out of round? Carl, A dial bore gage tells you if there are size variations in a bore. The crosshatch pattern will hold oil and help lubricate the piston and rings as the rings wear in to the cylinder. This will skew the statistical tolerance slightly higher and should be considered since parts are rarely perfectly circular. So when we hone cylinders and we find them round after honing and remove the torque plate and re measure and find them out of round and the distortion I find is not really there??? Repeat the process until you are able to take your measurement. This is not to say I haven't bored out some wild and crazy holes. Modern engines have much tighter tolerances, and you will get better results using a good machine shop for the entire process.
Measuring across a bore and then at 90° to first measurement may miss problem areas altogether! Just leave the oil drain out, shield the guts and gears with some cardboard to minimize the spraying of grit, then wash it out using a pump sprayer and sufficient diesel fuel to get it clean. It will leave 4 or 5 little scuff marks on the piston, spanning from transfer to transfer, just above the exhaust port height. It may be tough to know, that after all of this time you've never measured roundness by using your Sunnen guage. Neither one will cure an out-of-round cylinder. It's a big help if the answer still remains unclear.
I think I found one. The block is sprayed with a fluorescent solution containing ferromagnetic particles and an ultraviolet light is shined over the area. The honing head uses a three honing stones 6 inches in length. Sure if it was a big block for an more rare car and I had more money I would go all the way with leaving the block and heads at the machine shop for work and inspection. Anything left in there after washing it thoroughly won't be any worse than the crap you usually find when you tear one down, in my opinion. This is a 4th order bore geometry. I have 30 years experience with honing and can get a good job from a manual hone.
It's almost like there is a ripple in the cylinder or something? Actually, honing itself can be done freehand. When an engine was being refreshed, and it didn't require machining the bores, bearings and rings were changed and the cylinders honed by hand or with a drill to ensure the new rings would seat properly. All you want is to make a cross hatch pattern to help the rings seat. A hone will make it round and straight if it's used properly. But as explained in the text, he has. Have handy plenty of rags. Work clean as you can.
It will be much more round after honing than before, but not because the hone geometry is generating roundness. If it is within that specification you could hone the cylinder and put in a new set of rings. The important point is to know what you are actually checking. A regular cheap hone will just keep wearing more taper and out of roundness. The cheap ones work well for cleaning up a spot of rust or breaking the glaze. The cylinder had a crack so I honed it out and pressed in a repair sleeve and then took that sleeve back to standard bore. This article will talk about the nitty-gritty of real-world engines and list many of those little things you need to know about before attempting a rebuild or selecting a shop to do the work.
If the straightedge T-square, steel ruler, etc. If the piston is fairly tight you might be able to get away with just a hone job and a set of new rings. Replaced all bearings and piston rings too. I just don't want to put a ton of money into a half-ass block. Circularity essentially make a cross section of a cylindrical or round feature and determines if the circle formed in that cross section is round.
I've got to find a decent one first! Two technicians are discussing cylinder bore measurements. Unfortunately, a motorcycle cylinder requires a bit more precision. If any cylinder is worn more than about. Nothing based on % as far as I know. The least wear is at the bottom of the cylinder.
I was initially told by Geoff Walsh that anything more than. Powerhound Production Supervisor Inventor 2008 Mastercam X2 Smartcam 11. You need to set up the work on horses at a convenient height elbow height to you, personally and restraint it from rotating. Places that don't see or need large quantities of oil rely on soft boundary metals in the oil that coat the surfaces. Pistons that show any signs of burning, scuffing, scoring, corrosion or cracking should be discarded. Even in the factories that make the blocks I happen to be an engineer at one the hone tools are free floating. In order to diagnose parasitic battery drain measure the current draining from the battery while the vehicle is at rest.