ring gap question

[zbug]

Hi. I've got these AA 92 thick walls with Deves rings. I went to gap them, and put the top ring in first and got .022 gap. The second was rite at .014. My question is: is this top ring gonna be alright or do I need to get different ring. Thanks

[bugguy1967]

The AA rings are sometimes in that same range. .014" is the minimum gap. Gaps around .020 are fine.

Just wondering, why did you switch from the standard AA rings to the Deves? Not to scare you or anything, but I read a thread here where someone else swapped the rings to Deves and they didn't seal properly. There are many factors, of course, but make sure to measure everything and prepare your cylinders properly.

[zbug]

I actually found a better set of gauges, and its actually .024 The rings the pistons came with, I couldn't even get them off with an expander or by hand without snapping them. I snapped 2 of them. I've done a lot of rings on race bikes and never had that problem. i just started to pull the ring a little from one end and they snapped. I figured they were faulty if they would snap that easy, and didn't want to use them. I've heard that these are a very good product. I would like to find more literature on them, but haven't found any. Thanks for the reply bugguy1967

[bugguy1967]

That's happened to me before. When it did, I decided to get the correct style ring expander, and it's never happened again with the last eight sets I took apart.

[modok]

Throw some grant rings in there. Top ring .018 min, second same as top.
Yes they are CHEEP rings, but they work well with no fuss.

I would not use the deves without re-honing, but if I was gonna re-hone I'd go finer and use total seal Classic race series with a moly top ring....those are NICE, and available in this size.

I know your trying to do yourself a favor with these "nice" rings, but might be shooting yourself in the foot. Results are mixed. They either smoke from the start OR work great but then wear out prematurely.

[mark tucker]

hypers run hoter so they require a wider gap on top ring.but 24 is kinda wide unless your forced or on the jug.with that said I would sell those daves rings and get total seal rings......now where's that spellen teacher

[zbug]

Thanks Glen and Bugguy. your input is greatly appreciated. I'm starting to realize how large the learning curve is here with this stuff. I'm reading too far into some of these builds, and realize I need to keep it a little bit more simple till I learn more.

[bkeith85]

I just started checking the rings on my AA 85.8mm cylinders and I am seeing the same thing. I was comparing my numbers to the Bentley and on this first cylinder, they are all out of spec. I questioned the Bentley specs, but if you go by the 0.004" gap for every inch of bore rule, I still end up with 0.0135", which falls right into the tighter end of the manual spec of 0.012" - 0.018".
My biggest gap is 0.022", which would probably work just fine, but I'm trying to optimize everything as much as I can and getting the ring gap right is simple enough that I'll give it a shot.
Although, I'd hate to buy another set of rings and see the same thing.
Is there any reason that these AA pistons and cylinder might require a looser gap? I'll probably check with AA also to see what they have to say about it.
On the other hand, the side clearance is real tight. The min on that is 0.002" and I mine are more like 0.0015".

I hate that my first post isn't an introduction, but I am right in the middle of this and found a fresh thread to post in.

[mark tucker]

did you read above?????????
remember a loose gap will work .........a tight one will not.
also a find hone or knocking the tooth off will lessen the wear of the ring/cylinder and thus gap will not expand as much as fast due to wear. if you put it togeather that way it is and run it for a month then pull it down the gap will probably be .028, slick it up a bit and it may only change .001~.002", but there are many factors that change things.

[modok]

Off the top of my head I can think of six respected(at least IMO) sources who have tested HUGE gapped rings and say the loss of power was not significant enough to register on the dyno.
On the other hand loose valve guides usually DO show a loss of power, and too tight pistons do too, also may seize come apart.

The AA pistons are a higher silicon alloy, which transfers heat less readily than old school pistons. This calls for a bit more ring gap to be safe, I figure .018" which would be enough margin of safety that you could use the break-in procedure of "drive it like a maniac from the get go", rings seat faster like that

[zbug]

If I may ask, whats the best way to knock down the tooth in your cyl. I've read a couple different. Thanks

[modok]

Sunnen brush hone, for honing machine
http://www.sunnen.com/ProductDetails.aspx?ProductID=51&NavID=694

Wiseco brush hone
http://www.ebay.com/itm/Wiseco-Nylon-Flexhone-Brus...mp;vxp=mtr

http://www.goodson.com/Ultrafinish-Plateau-Soft-Hones-23-sizes/

[zbug]

Thanks a lot.

[mark tucker]

I do it by hand.(knock the teeth out) as for gaps...there are a few different approaches and thoughts, a lot have gone to loose second ring so there is no pressure between the rings witch helps the top ring seal better.also a lighter second ring can be used. for the most part the second ring is a oil scraper for the oil that gets past the oil control ring.
mahle has a lot of good upto date articles on piston rings(pistons too).ring technoligy has come a long way and lots have been learned about them and what works and what works better. my new mahles have a .030 ring package(top&second&narrower oil ring also).they seal better,wear less,weigh less,take up less room so the pin can be higher and no oil rail support is needed.there plasma infuzed.in short there sweet.

[snowbug]

Just bought some Grant rings for my 36hp. After checking the top moly ring the gap it was too small, so I filed the ends to get the minimum .009-.010 thou. Then I noticed in the instruction sheet it says do not file the rings. Why would it say that? Jim

[modok]

That's silly, of course you should open them up if too tight!

Some chrome rings you might chip the chrome, or have a burr at the edge if you use a file, but I don't think it's anything to worry about.
Make sure to touch the sharp edges with a fine stone to de-burr, and I'm sure it will work fine.

[stan_tichomirov]

The way I was taught is to place a fairly large file in a vice, business side up. Square up the ring's end on the file and push away from you to remove material. Only one end, only file in one direction. Only takes a stroke or two, re-measure, repeat if needed.

Stan
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[Quokka42]

Too large a file will be distorting the ring too much. There are tools to do it correctly, or a narrow second cut that fits in the expanded gap can be used with great care.
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[Hustlers67]

I've just checked my ring gaps (New AA 94mm P&C set).

Piston 1 & 2 = .020 top & .020 2nd

Piston 3 = .022 top & .018 2nd

Piston 4 = .017 top & .019 2nd

So there is .005 variance in the top ring gap on 3 & 4. Is this something I should be worrying about?

Should I be trying to even them all to the largest number (that is .022 top & .020 2nd).

Appreciate your thoughts.

[mark tucker]

on a aa piston (cast hiperutectic) I would stay there as those pistons run hoter than a std cast piston and much hoter than a forged piston. so the top ring is gonna expand a lot more.