My block is fresh from the machine shop .040 over. He pressed on Sealed power hyertectic flattop pistons and sold me mahle rings. I was under the impression that they need to be file fit, but several of my friends and the machinists said they are good out of the box. I measured in the bore and they have .016 gap on every ring. My manual says I Sould have at least .022 on the top ring and .016 should be fine on the rest. I'm gonna run vortec heads and am just looking to build a dependable street motor. File or not to file that is the question.
Seem too tight to me. I go by this chart, never a problem. http://www.manleyperformance.com/dl/tech/piston-rings.pdf
With those Hypereutectic pistons,you've gotta have extra ring gap on the top ring...You need to make those top rings at least .022 like they say...Otherwise she won't live long...........
Yup FILE that top ring like the spec calls for, also remember that there is a certain position that each ring gap should be in when installed in the bore, meaning you don't want them all lined up or oil will get by. If you don't have ring spreading pliers, do your thumbs a favor and get a set.
Good advise above and the ring gaps should not be on the thrust side of the piston and not in line with others.Nothing is good to go out of the box,must check each part for propper fit. Over 400 V8s and never used pliers or broken a ring.
You might want to try filing off .003" on each end and make sure you eliminate all burrs from the filing... But leave a semi sharp corner on the ring ends..
I bow to your solid leather thumbs sir. (keepin' mine soft for the ladies) If you are looking at the block from the side one ring gap goes at 12o'clock,(up by where the intake manifold goes) one at 4o'clock, and one at 8o'clock, dont remember of the top of my head which one of the ring gaps goes where to do it 110% right, but I bet that 'ol leather thumbs knows!
Well its been nearly 30 years! I start with the oil ring and have the gaps on the rails 120 degrees apart and comp. rings just behind the gudgeon so each gap is not in phase with the next ring gap. All gaps are on the non thrust side of the piston. (my wife likes my leather hands) JW
We used to go with .004 per inch of bore, but our engine guy is telling us now that .006 is better, so that is what we have done on the last couple of engines. We have had no blowby or problems, so I guess he was right. Don
.004 per inch of bore was correct with old cast iron rings. All manufacturers include a spec sheet with thrie products and the last engine I built using J&E forged pistons the top gap was .023" and the second ring was .018". Years ago I bought a ring filer and screwed it to a board that clamps in a bench vise, makes short work of getting the gaps right.
A .001" difference in bore diameter makes a ..003"+ difference in ring end gap. The ring manufacturer has no idea as to your exact bore size. Some rings are intentionally made tight so they can be sized to an exact fit. Both professionals and amateurs get away with not checking and measuring. Most of the time that works out well enough that there are no major issues. The chances of not having a problem go up considerably when you don't trust a manufacturer or machinist(even the best have made mistakes), you measure and check everything you possibly can, and you don't just hope or assume everything will fit well enough.
Those ring files are great as they file the end square (or whtat ever angle you need) and no risk of damage in the vise jaws. Always remove all sharpe edges on the ring ends with a fine file and don't over do it, also run a comp. ring in each groove and to check for bruises on the piston ring lands as a tight spot will crack a ring when they are compressed to install in the cylinder. JW
When filing be sure to do both ends at the same time, if you take it off one side it'll wind up like a slice of lemon because of the radius of the ring. I guess i read that somewhere, not like i made that mistake myself. Didn't do it and won't do it again either!
Def. the industry standard for production engines. Of course things change in the high performance world, but that is the golden rule for old school guys/gals. Top ring should def. have more gap due to it being close to the heat/cylinder pressure/etc...
KB hyper' slugs need more end gap, than regular cast or forged pistons. http://www.kb-silvolite.com/article.php?action=read&A_id=32 The alloy contains more Silicone, so they expand less, but also hold more heat. I'm assuming the Sealed Power Hypers are similar.
Pretty hard for a machinist worth his salt to say your rings are good to go without ever even seeing them. But I certainly wouldn't do what the manual said to do. You have measured the ring gap and from what you have told me the ring gap is .016, now the manual says that the top rings needs to be .022 and that the rest of the rings will be fine @ .016. I would probably do one of two things, trust the manual or throw it out. The first is probably your better option.
I never bothered to own a set of ring pliers - until I put the FlatCad together earlier this year. Once you use them, you wonder why you never had them before. Same goes with a nice rod vise - if you plan on doing a few engines in the next decade or so, another worthy investment. Typically the top ring has .002 to .004 more gap, due to the additional heat (and expansion associated with it). Best of luck on your build. B&S
One thing I realized when I started to hang around these forums is that the guys who build high performance engines take steps most of us hobbyists don't. For years I was the guy who took rings out of the box and installed them without checking the gaps, and for the most part I got away with it. But as I started building better, higher hp motors I realized that wasn't going to work any more. I bought one of those ring filers and started to check the end gaps on each and every ring that went into the motor and found some real variances in the out of box gaps. I have started doing the same with bearing clearances and specs in general. I have to say my motors are turning out better. We are also using a fine stone to take any sharp edges off of the ring gap after we use the filer. That has been one of the nice things about being able to rub elbows with professionals on these forums, they teach you things you never knew how to do or better ways to do things. Don
Just to add a bit of detail and terminology here - when I order rings, typically I order them .005 oversize for my given finished bore. Many ring companies call these "File to Fit" ring sizes. The oil rings will be the correct sizes, but the compression rings are designed to be hand fitted to every bore. Even with a professional ring filer it takes a couple hours - but at least you know where you are at. You can usually get away with rings that have a bit too big of a ring gap, but too small can really cause issues - especially in high heat conditions like supercharged and/or nitrous. What happens with too small of a gap is that the ends can butt together, breaking rings or breaking off the tops of the pistons - and your motor becomes a blender in a hurry. Obviously, the more severe the application, the more this all comes into play. Key Point: Also there are many types of rings, so it is just as important to have the right ring package/style for your application as anything else. The days of just throwing in a set of Grant Rings (cause that is what they had) are long gone. (I don't even do this on hypo flatheads anymore ) Example: On our blown FlatCad engine we used Akerly HTD Rings - High Tensile Ductile iron. Similar to the Hellfire rings, they are really designed for high-stress, high temperature applications (which Bonneville racing surely is). We designed our pistons, ring grooves and ring locations specifically to use these rings - making sure that Venolia and Akerly were on the same page. Also, I set the ring package lower on the piston - to keep the upper ring a bit further away from the heat (as we have relieved decks - 3/16 deep, flathead Ford style). Do Your Homework: If you're building a special higher output engine, it pays to talk to the piston and ring manufacturers, you'll find more help and experience than you'll ever need - for free! Best of luck gang, keep building em'
Hypereutectic pistons get a bad rap because way too many people don't gap the rings properly. Ring gap is very critical on a hypereutectic piston. Adhere to the "piston" manufacturer's recommendations regarding ring gap and no one else. You can pretty much guarantee yourself piston failure if you do not follow the piston manufacturer's specs.
I've run JE forged slugs in my last two engines and for a street engine and they reccommend .0045-.005 per inch for the top and .005-.0055 per inch for the second ring, the oil rings can be .004 per inch. The second ring should have a slightly LARGER gap than the first. This contradicts what we did in the 60's but it is what is now reccommended.
Never assume anything is correct, right out of the box. Check everything. If those are Sealed Power's Hyper' numbers, they should be good.
Ditto. Current thinking is larger gaps on the second ring. Opposite of what most of us learned way back when...
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