All these different manfacturers and no idea which one to use?? What about Summit brand? Why Molly, why not? End gap do's and don't? Can some body help with a little info on setting up rings and a suggestion on types of rings for street application, say over rings for racing application?? There is a difference in prices also so I'm confused as to what to try. Any help or suggestions guys. Thanks


Tazz

Man I'm havin trouble reading, thought you were talking about ring gears. If you read this befor I edited it pay it no mind.

Tazz,

Here's an article I've found helpful in the past.

http://www.carcraft.com/techarticles/77899/index.html

I've had great success with Speed Pro Moly rings. You can file them to the appropriate end gap depending on your purposes. If you are running a blower or nitrous then more heat will be created causing the rings to expand more, hence you will need greater ring end gap.

I haven't heard the greatest of opinions on the gapless style rings. But perhaps other people can offer an opinion on those. My experience is limited to the file fit Speed Pros. Maybe a little more on your motor can helps us?

Good Luck! graemlins/thumbsup.gif

Originally posted by tm53chev:
All these different manfacturers and no idea which one to use?? What about Summit brand? Why Molly, why not? End gap do's and don't? Can some body help with a little info on setting up rings and a suggestion on types of rings for street application, say over rings for racing application?? There is a difference in prices also so I'm confused as to what to try. Any help or suggestions guys. Thanks


Tazz ====
Tazz,
You cannot go wrong with any good ductile moly ring set in a street or street/strip application.
Childs & Albert (my favorite), Sealed Power, Perfect Circle etc all come to mind
For a mild street deal the standard inexpensive cast Moly rings are just fine.
Nothing trick about ring end gaps regardless of all that has been written to the contrary except with KB Hypers which take a wide top ring end gap because the rings is high in the piston & the KB retains more heat in the top.
I use .016-.018 or .004/ inch of bore for the top ring & second. for most "normal" performance stuff. The second ring gap is something I have changed in the last few years because of testing done by Sealed Power among others.
I use .0035/ inch for the second on standard street engines
I normally do not use gapless rings as I have not seen the "magical" HP gains claimed.
If I do use a gapless I only use the C&A brand.
Haven't tried the newer top ring gapless so I can't comment on them but if it is a two piece design like the second ring Total Seal makes I would not use it.
I have taken apart a lot of engines with the two piece type "gapless" rings & in almost every case at least one usually more cylinders had these gaps lined up.
According the manufacturer of this ring, this cannot happen because "the ring will rotate as a unit" from what I have seen, this is crap.
I will give gapless rings this, they will give you outstanding leak down numbers in a cold engine but,,,,the engine does not run cold ;)
As soon as you put some heat in it you have almost no gap with conventional rings.

back to your question,,
As was posted it depends on application but
For street or street /strip & most performance application: Ductile Moly.

For stock or near stock & mild perf: Standard cast Moly.

For Heavy nitrous or hi load blown applications:
Hellfire or tool steel top.

For running through the dessert or other dirty environments: Chrome top

Just a few of my thoughts on rings ;)

I am sure you will get lots more :D

Mike said this, "I use .0035 for the second on standard street engines" Is this correct or did you mean .035"? Either sounds pretty far from the conventional wisdom. I set my rings at .016-.018" for the top and .024" for the second.

Pat
.0035/inch is what I use for standard street stuff that is for stuff that is going together for more than a season or two of racing & .004/.004 for most performance stuff, a little more top for some applications.
016-.018 top, .014-.016 second

I just read my post & see what I did, a little confusing I meant .0035/ inch graemlins/clonk.gif
I will go change it

That makes more sense. Speed Pro now recommends using a wider gap on the second ring. I couldn't find the paper work but it seems they say to use .006" per inch for the second and .004" for the top. They claim a better top ring seal that way. It could be due to the shape of their top ring, but I don't know, and it might apply only to their rings.

Originally posted by Wolfplace:
You cannot go wrong with any good ductile moly ring set in a street or street/strip application.
Childs & Albert (my favorite)
Also my machinists favorite.

Originally posted by Pat Kelley:
That makes more sense. Speed Pro now recommends using a wider gap on the second ring. I couldn't find the paper work but it seems they say to use .006" per inch for the second and .004" for the top. They claim a better top ring seal that way. It could be due to the shape of their top ring, but I don't know, and it might apply only to their rings. =
Pat,
You are right & this is why I went to .004/inch on the second ring for most of my performance stuff.
I used to run .012-.014 & now I run .016-018
I don't go wider on the second than that because of the temperature difference between the top & second.
The new recommendations from Fed Mog are
.004/ inch top & .005 second for moderate street performance
.0045/ inch top & .0055 second for drag race & circle track
These are normally aspirated, non nitrous numbers from Fed Mog.

They had an excellent 1 day seminar at the PRI show 2 years ago called "Run with the Big Dawgs" that was hosted by fed Mog & this was one of the topics.
I spoke with the ring design engineer from Fed Mog Perf name was Scott Gabrielson a little after the seminar & came away with the "feeling" .016-.018 top & second would be a good compromise for me.
Just for info, most of my 4-4.155 bore gap is actually .017-.018

The panel discussion comprised of Terry Elledge from Bill Davis Racing, Rich Gilmore of DEI & Eddie Middleton of Penske & was worth the admission price alone!!
They got into oil pressure, bearing clearance,piston & rod weights, valve springs & a ton of other information re cup engines.
Hope they have another in the future,,,good
stuff :D

The wider second ring gap pretty much flies in the face of the Total Seal concept. After all these decades of engine development you'd think all this would have be resolved years ago smile.gif , but that's the nature of the beast. New materials and new ways of approching things. I'm glad there are people with the resources to explore all this. If us low dollars racers had to do it it would never get done.
And to others reading this, it is better to err on the too wide of a gap then too tight of a gap. Seizing a ring will spoil your day and the loss of compression from being a thousandth or two too wide is pretty insignificant.

Pat,
Most ring designers and professional engine builders are pretty much in agreement that the gap for second groove compression ring should be slightly larger than the top ring gap. This allows the combustion pressure that gets by the top ring to be dissipated. Otherwise this pressure will cause the top ring to flutter at high RPM and destroy the seal function even further.
You are correct, this absolutely counters the arguments that certain manufacturers expound for the virtues of gapless rings. In my opinion, Mike is correct in his statement that the leakdown results are excellent for a gapless ring set in a COLD engine. Once the engine is warmed up there is a heck of a lot more going on in there, especially at high RPM levels.