Piston rings for a 221 c.i ?
 

Installing new rings on my 221 that is .060 over and calculate ring gap should be about .013", does this sound about right? Right now on average the rings are a tight .010", so will have to file them a bit. Question: If my engine was a standard bore would standard bore rings have to be file fitted also? Rings weren't filed when the car was manufactured, why now? Question: In the photo there is no manufactures name on my rings, just FORD service replacement rings, are these N.O.S. rings from Ford? Each ring was packaged individually in cosmoline (sp). The second groove compression ring has an inner ring that goes under the ring, was this 30's thinking and not really necessary? Am going to run just 3 rings on my 4 ring pistons, would the third groove be where I place oil control ring or on the very bottom 4th ring groove on the piston?

Re: Piston rings for a 221 c.i ?
 

Rule of thumb for end gap is .003"-.004" gap per inch of diameter of bore. So, your .010" is bottom limit, you'll be fine.
Sounds like an old NOS set of Ford rings. Use that expander under #2 ring. Fit the oil control ring in position 3

Re: Piston rings for a 221 c.i ?
 

I have always gapped rings at about 0.004" per EACH 1" of bore, measured about one inch down from the deck, and with the ring SQUARED in the bore using the top of a piston. So, with a bore of about 3-1/16", your 0.013" gaps sounds about right. Remember, if using a file to fit the gaps, move the file in only ONE direction.......from OUTSIDE of ring toward INSIDE of ring. That way, ANY stray burrs will not rub the cylinder wall, even though there should never be any "stray" burrs. DD

Re: Piston rings for a 221 c.i ?
 

Throw those ancient rings away and do yourself a favor purchase new rings there is way more technology in today's ring set than what was produced 60 years ago.There is no valid reason to use them.

R

Re: Piston rings for a 221 c.i ?
 

Just paid $115 for the rings, don't think I'll throw them away! I'll go with .013" and use a wheel type file. Thanks for the info. guys.

Re: Piston rings for a 221 c.i ?
 

The ring set for that is still in the 2016 Hastings catalogue. You could walk into any machine shop and order them. Your engine your rules your game just sayin.

R

Re: Piston rings for a 221 c.i ?
 

Way overpriced.

Re: Piston rings for a 221 c.i ?
 

Does this look like the fellow that sold them.

R

Re: Piston rings for a 221 c.i ?
 

I didn't know that the Lone Ranger sold auto parts!

Re: Piston rings for a 221 c.i ?
 

Okay, sent the old rings back and will get the the Hastings.

Re: Piston rings for a 221 c.i ?
 

Smart move the new rings will serve you well.How are you going to approach the deglazing of the cylinder walls? If you need some coaching ask away there are many talented guy's on here that when it comes to engine rebuilding,lots will have solid advice.Is the engine in or out of the car.

R

Re: Piston rings for a 221 c.i ?
 

That sounds like you have made the right move. The guys have given you good advice. I am a little surprised that several other engine gurus who post here never chimed in on this with their opinions as well.

Re: Piston rings for a 221 c.i ?
 

SOMETIMES new is better!! Not always with the flatheads, but sometimes.

Re: Piston rings for a 221 c.i ?
 

This engine had less than 500 miles on it since being rebuilt years ago by me but always suffered from low compression on all cylinders. I've replaced it with a "warmed" over 8BA. After disassembly am thinking maybe it was that the valves (adjustable) weren't adjusted properly. If you look at the cylinder in the picture you can still see the cross hatch pattern from the original honing operation. There was no ridge at the tops of the cylinders either so am hoping the cylinders are useable as is. The engine is out of the car and on a test stand rather than an engine stand, completely disassembled but with the crank still in it. My intentions are to sell it once the problem is solved.

Re: Piston rings for a 221 c.i ?
 

I got a personal email from Bob so did not respond here also.

JWL

Re: Piston rings for a 221 c.i ?
 

Good for Bob, but bad for anyone else wanting to follow an expert opinion. :)

Re: Piston rings for a 221 c.i ?
 

I would not really call that an acceptable cyl for new rings.Having said that it should be de glazed at the least.No mention if there is any taper?I also would use a flex hone for that operation as they are quick and easy compared to a 3 legged hone for de glazing.If you are close to a machine shop see if they will lend you one as the flex hone is probably around the 50.00 mark.Offer to give them some money and leave a deposit until you return.It also appears it was ridge reamed in a previous tear down.Your engine your rules.Just sayin.

R

Re: Piston rings for a 221 c.i ?
 

What is "glazing" with respect to a cylinder, what is the process to de-glaze? Which way does a cylinder taper in respect to top to bottom?

Re: Piston rings for a 221 c.i ?
 

There are many videos of cylinder wall deglazing online, here is some information from a quick search:

The importance of cylinder wall deglazing cannot be overemphasized. The proper cylinder finish will provide the quickest possible break-in and greatly reduce the possibilities of ring or piston scuffing during break-in.

The glazed cylinder wall causes rings to "skate" on the highly polished finish and discourages the minute amount of wear which is necessary to mate piston rings with the bore.

The interrupted "deglazed" finish contains minute hills and valleys which carry a film of oil which will retard which will retard scuffing during break of as well as produce the type of cylinder finish piston rings can mate to very rapidly.

The finish produced by a 220-280 grit stone is most desirable. The cross hatch pattern should intersect at approximately a 450 angle. Too flat an angle leads to ring spinning which prevents seating the rings.

Probably the most critical part of the deglazing operation is the proper cleaning after deglazing. The residue of honing, if left in the engine, will rapidly destroy all moving parts. It is recommended that engines be cleaned thoroughly with soap and water. Clean with soap and water until the bore can be wiped with a clean white cloth without soiling the cloth. After clean up, oil the area to prevent rust formation. Waterless hand soap also serves as an excellent cleaning agent.

CYLINDER WALL GLAZE BREAKERS
This new Deglazer is fast, easy to use a real performer ever under adverse condit1ions. Cylinders can be deglazed and crosshatched in 30 to 45 seconds. Tests made on this tool have proven satisfactory operation up to 14 hours of continual running.

Cylinder Honing Tool for Deglazing

In order to retain or restore engine performance, a cylinder honing tool is essential. In gasoline or diesel engines, pistons ride up and down within the engine, while maintaining a tight seal via the piston rings. Over time, this movement against the cylinder wall creates a smooth finish.

If the cylinder walls are too smooth, the lubricating oil in the engine will not adhere to the surface. In addition, while breaking in newly installed piston rings, a small amount of wear must occur between the rings and cylinder wall in order to seat the rings properly and ensure a gas-tight seal. If the cylinder walls are too smooth, rings will not seat properly and instead, they will "skate" over the surface.

A cylinder honing tool can create an optimal finish in deglazing applications. A mechanic can take apart the engine and deglaze the cylinders using a hone tool, such as the Flex-Hone® tool Using a cylinder honing tool creates a 45 degree angle crosshatching of tiny grooves in the cylinder wall and restores the engine performance.

Re: Piston rings for a 221 c.i ?
 

Cylinders need to be measured top and bottom for out of round and taper. A cylinder would typically be worn more toward the top of the cylinder than the bottom of the cylinder. A bore gauge is used to check the cylinders, but they can also be checked with a telescoping gauge or an inside mic (however it is much harder to do). My advice would be to have a machine shop check the cylinders for you. And you might also consider having them hone if for you. If you don't own a cylinder hone it might be cheaper and easier.

https://www.youtube.com/watch?v=qLzMQtJAljg

"cylinder walls must be inspected for scratches and out-of-round or taper (cylinder wall diameter smaller at the bottom than at the top). Various gauges are used to measure these conditions and only afterwards can the right decision be made whether to rebore or fit new rings only. Most V8 engines allow up to .012 in. (0.30 mm) taper and up to .005 in (0.13 mm) out-of-roundness. Out-of-roundness in cylinder walls makes it impossible for the rings to seal properly. Heavy oil consumption will result in this situation.

Engines that are rebuilt with out-of-specification taper will generally experience "ring float" and tipping of the piston as it travels from the bottom of the cylinder to the top. The rings, compressed against the wall at the bottom, don't have the time to expand in the wider upper section because of the speeds the parts operate. The rings "float" momentarily and the piston tips slightly, causing poor compression and probably damage to the cylinder walls, rings and piston.

Whether a cylinder wall's characteristics are within specifications or not, or if the cylinder has been rebored, the surface of the walls must assist the "break in" or seating of the new rings. Contrary to popular belief, a shiny smooth cylinder wall is not desirable. New rings have microscopic tool thread marks around their edges. The walls must have some texture (tiny scratches) ground into it for the rings to take a "set" within a reasonable amount of time. That is, as the rings travel up and down, both the wall and rings will wear a small amount. High spots on the ring will tend to wear off against the scratches on the wall, allowing the low spots to contact the wall.

Various honing tools are used to properly prepare cylinder wall surfaces and all manufacturers specify the scratch depth and pattern."