Salt flats, That is a cool gauge,,,I like that,,,,can they still be purchased ? Most people never think to check the lands,,,that is where most of the rings efficiency comes from. Back in the old days,,,,a lot of people recut the lands and used ring shim stock. It looks somewhat like a slinky. Anyway,,,,clean the grooves good,,check the lands,,,and most oil issues will go away. I have seen several engines with a slight groove cut into the cylinder up and down. Honed it good,,,,but could not get rid of it. As long as the pistons check good,,,,I never had an issue. Glad to see you know your stuff. Tommy
It’s a dial bore gauge, easily purchased, they have a digital version as well. You need the setting fixture to go with it, they are not cheap. Something most home builders will not buy. That is a m*** amount of cylinder wear on that engine!! Sent from my iPhone using H.A.M.B.
What I saw was not a dial bore gauge,,,,I have one of those. He was holding a 4 sided metal gauge,,,,looked like a gauge to measure the ring lands width,,,considering it had the dimensions marked on the outside. He stated it was a go-nogo gauge,,,,we use such things in my line of work. Tommy
Sorry Fargo, I went back to the previous page and saw what you were talking about. Yes,,that is a dial bore gauge,,,,a pretty good brand as well. I have one very similar. By the way,,,after seeing that block he was checking with .017 wear ,,I feel better about my Flathead,,,,it only had .007. Tommy
I am like budget,,,I use feeler gauges. That would be a handy tool to have in your toolbox. Correction,,,,in my toolbox,,,,Lol. Tommy
WoW ! Its hard to believe it still ran without beating itself to death from piston slap. Nice Bore Guage ! There may be others that are as good, but there are none any better than Sunnen. My personal preference is a mechanical measuring tool like your Sunnen because they pretty much last forever. The digital tools give the impression of an exact dimensional reading whereas mechanical measuring instruments require a little "feel" to use. The digital units tend to fail over time and then become useless.....at least thats my experience with them. As for regrooving the piston.........If the bore is .018 larger than the piston, it shouldn't be reused in any case.
Seems to be some mixed up terminology here. The ring "lands" are the area between the ring "grooves". The gauge being shown in use looks to be checking the depth of the top ring groove. The top ring land would be that part of the piston between the top groove and the crown (or the "head" in the picture below).
Nope it a go -no go guage that checks the with of the ring groove. Sawmillers use a reverse type of Go & No Go guage to check the thickness of boards. Usually the off bearer edger man was responsible for grading the lumber and checking the thickness.
The Sunnen dial bore gauge is a nice piece. It is so much easier for me watch a sweep of a dial gauge than digital readout. There was hope for just some rings in this engine, but not happening.
I think this is actually a "Go" gage or a "No Go" gage, but not actually both ............BUT it depends on what you are measuring with it. Let me explain. Usually a Go/No Go will have two separate reference surfaces. One is to check for minimum allowable dimension and one is for maximum allowable dimension. Think of a drilled hole that has ato accept a 1/2" diameter bolt. The hole has to always have a minimum diameter of 1/2". The maximum diameter will be whatever the engineer feels is correct for the situation. In a nominal common hole we can say that .005 is the maximum acceptable oversize. So the hole can be anywhere from .500 to .505. A pin gage can be made with each of those dimensions at opposite ends. If the .500 diameter enters the hole, the minimum diameter is acceptable. If the maximum diameter .505 does NOT enter the hole, it is acceptable. The gage in the picture could have a taper on each small tab to somewhat act as a Go/No Go, but thats unlikely as the surface doesn't look smooth enough. Also, there is only one dimension stamped on each tab.....and its a fraction rather than a decimal and indicates to me that its more for just a quick check to see what size ring fits in the groove. Its possible that someone could use two different tabs to check a groove, but that would mean the grooves in the piston had an allowable width variation of .015 (5/64 or .078) (3/32 or .093). The other tabs are in 1/32 steps so they would be .031 difference between each one. Thats far too much width variation (go/no go) in a piston groove. My best guess is that the gage is just a quick check to see what the general size of a piston ring is needed and that the groove met the minimum size ............they weren't worried about a little too big as long as it was wide enough. For the feeler gage question. Basically feeler gages are just adjustable go/no go gages when used in combination with other feeler gages. Hope I explained that OK............
I can remember lots of guys doing stupid stuff trying to get Chrome rings to seal up. Scouring powder, magic elixirs, the one that I remember as sounding the craziest is blocking the radiator and letting it overheat to the max. I am not sure that I have ever read it in a book (of course knowing how to read may correct that) but I learned to hone with rough (course?) stones for chrome rings. never had a problem.
I think it was explained that if the tab entered the groove it was a go,,if it went all the way to the flat,,,the stop,,,, it was a no go . Sounds simple enough to me. I have had pistons that had 5/64 rings,,also had pistons that had 1/8 inch rings. Seems like a very nice checking tool. Also,,,on the explanation that a .500 pin will enter a .500 hole. An old tool maker explained that to me a long time ago. He said “ son,,,to check a .500 hole you can’t use a .500 pin ,,,,that would be a press fit,,no clearance “. And he is right,,,take a wristpin,,,,when they are right,,,,you can’t enter it into the pistons without it being perfectly straight with the hole. I had some new ones that I had cleaned with solvent and blown dry. After that I couldn’t get them to enter the pistons without a little lubricant. After lube,,,smooth as silk,,,but it was funny,,,I could barely tilt the piston to the side,,,and gravity would start the pin to sliding out. Tight tolerance indeed. Tommy
What you are saying is "exactly right". I was trying to make a simple explanation without confusing it by using numbers like .4998 to represent a .0002 undersize on the "Go" end while the .505 would still have been .505. Just for simplification of the explanation I used the round number. Nope, a .500 pin will not go into a .500 hole. One thing you should realize though is that most holes are not perfectly round unless machined on some very precision machines. Drilled holes are almost never round if drilled with common two flute drills. Thats why they make core drills, reamers and hones.......to make em rounder and precise. The .001 taper will not actually tell a machinist or an engine builder any real useful information. Think about it and you will see that unless the gage is the same width over its whole measuring surface, it only tells you that the front edge of the groove is 5/64 wide. You can only ***ume that the rear of the groove is the same as the front. The narrower part at the rear only tells you that the groove is wide enough to accept the less than 5/64 portion. If you look at the reading on your micrometer it says .083. A 5/64 dim is .078 (.078125). Your micrometer is saying that the gage is .005 larger than 5/64. In a manufacturing operation where someone machined pistons all day long, this would provide a quick check before removing a part and inserting another one once the machine operator had gotten used to what felt right. If it just slips easily into the groove rather than tightly, he needs to change his tooling, but he doesn't have to actually use a micrometer every time. In production, little things like that can work well. In ***embling an engine its better to take direct readings with a micrometer. It appears to me to indicate that it is just for rough verification rather than precise checking because its guaged in fractions and its not actually .078 (5/64) thick.
It is a ring groove wear gauge, if it goes all the way in, the ring groove is worn beyond service life, meaning the ring groove needs cut for a spacer or the piston needs replacing. I know a lot of water has run under the bridge since The rep gave me this tool, but I do remember it's purpose.
The smoother the surface, the less the rings have to wear off and the less the rings will wear. I use 2000 wet or dry wrapped around the 3-stone hone to finish the surface of the cylinder
Yes, that makes sense. It's a "no go" Gage. If it goes in the groove the Piston is not usable or requires machining to accept a spacer.
Hone styles/types, stone grits, and use procedures are only part of any finish result equation. Block/liner material is another that should be seriously considered and factored in. There have been ongoing changes in block/liner materials and production procedures since HAMB pre '63 times. Some combinations that have, and might still, work might not always work for all cases in today's world. A machinist or shop with experience actually working with old iron is usually a big plus. Ed
Semi-related to cylinder honing - we've all seen the pictures or instructions of the rebuilder dunking ***embled pistons & rings completely in a bucket of 30w oil and installing them. Some builders like to install them more or less dry, a light coat of WD40 maybe or Marvel's, arguing the rings will seat better this way, excessive oil just causing trouble is the thinking. Hm.
Dunking was the was I was taught, but now I just coat the rings and piston skirts with oil. Not nearly as messy and gets the oil where it needs to be. But I still use oil! I can’t do anything “ dry” in an engine! Bones
I think the idea of dunking the piston/rod ***embly was that oil could get between the wristpin and the piston pin hole surfaces. Nothing wrong with that other than a little messy. Doesn't really put excess oil in the engine as the excess always ends up on my hands.....and shoes. Ho Ho Ho! Merry Christmas.......
I dunk the pistons in a lube of 50% engine oil and 50% motor honey. I want it to stay there until the engine is started and warms up. and very soon after I get it running I change the oil & filter. and just use oil. If you use good oil no need to add anything to it.
There we go again old Wolf, back when I building a lot of engines, that was my engine building pre lube, 50% STP and 50% 10w40 engine oil. If you have ever got STP on your hands you’ll understand! Like you, I run it a while, change oil to straight 10w40. Never had any problems with this method. Bones
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