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Topic Review (Newest First)
06-15-2019 10:50 AM
ericnova72 Ductile for anything that gets run hard...as in 300" or bigger V8's and 500HP or more....the cast and cast moly filled stuff in the $25-60 range is not good enough for a serious HP making or serious rpm engine.

In your case, plasma moly or better. If you are looking to push your BBC above 1100-1200 Hp, then the Hellfire or AP stainless rings or something similar might be more appropriate....but don't go to them without re-doing the bore finish to match them.

Plain cast is daily driver stuff, plain cast moly is factory HP level stuff and claimer circle track and light street/strip stuff.
06-15-2019 09:55 AM
stanley9875 Thanks for the responses and inputs guys, appreciate it, and sorry about the delayed replies I've been slammed with stuff. Yea, gapless rings are out, just seen em but haven't heard much about them so i figured id ask.

Yea I have a hand crank ring filer, the last rings I got came with my pistons, they were regular file-fit moly rings 0.035", but I'm planning on adding more power to this build so I just wanted to gap a bit more to compensate. I'll just have to decide on file or non file fit rings. I'm sure it doesn't matter, just depends how much I need taken off for how much I need to gap them. Made sure the ends were cleaned up nice and well for installation after gaps were set and squared.

Again just for learning purposes, the material of the rings, cast, ductile, regular iron... any benefits or specifics for using either?
06-15-2019 07:45 AM
predator carb guru Can't agree more on this one, get file fit rings...you can set your gaps exactly where you want them, just take your time and don't get in a rush. As to Total Seal gapless.....I've used both the gapless second and gapless top. All my stuff was honed per Total seal for those rings....and no matter what I did I had oil control issues. Couldn't stop getting oil in the cylinder. Went back to standard rings, problem gone. Total Seal makes a great product, but I'm not sold on the gapless stuff. If it was so great, they would be used on the fastest cars in the world and they are not. Look at Pro Stock...1400+ hp from a N/A 500" engine....Matt Hartford is the President and CEO of Total seal and drives their car in pro stock. They do not use them in their engine....that should say something, especially when it's in a class where they will spend $25,000 for 5 hp.....My current build makes 1510 hp @ 7300 rpm, and I use standard rings, running nitrous. Last engine I made just over 1200 and ran gapless tops at first. Oil on the plugs and out the exhaust all the time. Did nothing more than changed rings to standard AP steel and zero oil in chambers after......
06-14-2019 10:21 PM
MouseFink The engine builder I use said he has successfully used Total Seal TSS rings that have gapless second rings in some customers street performance engines that have a maximum of 10.5:1 CR but without nitrous or forced induction.

In 2009, I considered using those rings in my 1963 Pontiac 455 Catalina but I chose to use conventional Speed Pro standard tension rings instead.
06-14-2019 09:01 PM
ericnova72
Quote:
Originally Posted by chasracer View Post
And there you go again MouseFink. Do you have any idea of how many performance engines are built every week that have file-fit piston rings in them? And you think that makes them egg-shaped? Right.


Back to the questions......


Since you're going through all of this work to replace the rings to allow you to set the gaps where you want them, then I would purchase the .035 rings. There are a number of good write-ups, books and videos on performing this work if it is something that you have not done before. To me the biggest pieces of it are having a proper ring grinder. Stay away from the powered models, they're nice but not the best if you are new to this work. The hand powered ones allow you take off a little bit of the ring at a time and sorta sneak up on your preferred gap. Another piece is a method of squaring the ring in the cylinder accurately each time you check it. You don't want it down 1" one time and 3/4" the next. Last, a small file and sharpening stone to dress the edges of the cut ring. You don't want to leave an edge that's going to cut your cylinder walls.



Now Moly Rings. They are really good at sealing a cylinder and they break-in very quickly compared to the old chrome rings. The question in my head is what kind of hone pattern and finish did the block receive? Moly tends to prefer a smoother bore finish where as standard rings need something a bit rougher to help seat the ring. With the limited wear you have on the engine, the Moly might be dead perfect for it but I would check with your machinist.
Reason for my suggestion of forgetting about file-to-fit rings....this is a blown application, his gap requirement is going to be as big or bigger than regular out-of-the-box pre-gapped rings....with the file-to-fit it is more cost, and you just end up with 5 time as much ring to file away before the fit is correct.
I've run into the same thing on engines with a bigger than average nitrous hit planned(300+ hit). I'd imagine turbo builds to be the same way. For power adder applications, even a pre-gapped set will need some more gap files onto them.

If this was a naturally aspirated Super Stock or Stocker type engine or even a long life bracket engine where you would be looking for tighter gaps that you would get from a pre-gapped set then the file fits would be the better plan.
06-14-2019 05:28 PM
chasracer And there you go again MouseFink. Do you have any idea of how many performance engines are built every week that have file-fit piston rings in them? And you think that makes them egg-shaped? Right.


Back to the questions......


Since you're going through all of this work to replace the rings to allow you to set the gaps where you want them, then I would purchase the .035 rings. There are a number of good write-ups, books and videos on performing this work if it is something that you have not done before. To me the biggest pieces of it are having a proper ring grinder. Stay away from the powered models, they're nice but not the best if you are new to this work. The hand powered ones allow you take off a little bit of the ring at a time and sorta sneak up on your preferred gap. Another piece is a method of squaring the ring in the cylinder accurately each time you check it. You don't want it down 1" one time and 3/4" the next. Last, a small file and sharpening stone to dress the edges of the cut ring. You don't want to leave an edge that's going to cut your cylinder walls.



Now Moly Rings. They are really good at sealing a cylinder and they break-in very quickly compared to the old chrome rings. The question in my head is what kind of hone pattern and finish did the block receive? Moly tends to prefer a smoother bore finish where as standard rings need something a bit rougher to help seat the ring. With the limited wear you have on the engine, the Moly might be dead perfect for it but I would check with your machinist.
06-14-2019 12:42 PM
MouseFink Filing the ends of file-fit piston rings makes the rings in the bores egg-shaped. Install standard gap rings.

In 1969, the previous owner bored the 350 CI block .030” os in my 1962 Chevrolet Bel Air. He installed new forged Sealed Power flat top pistons with .0035” skirt clearance for 10.3:1 CR. He used GM rings and standard bearings in the 1968 350 CI engine. He installed a GM 3863151 (RPO L-79) camshaft. The engine had about 20K miles on it and came out of a wrecked 1968 Chevrolet C10 pick up.

The previous and original owner told me the GM rings were the same as the standard gaps and standard tension, Sealed Power rings. Those rings are 5/64” plasma-moly top, 5/64” iron second and 3/16” stainless steel oil rings. When I purchased the car two years ago, the engine had 50k miles on it.
06-14-2019 11:31 AM
ericnova72 The .035" over is either for an .035" oversize custom piston, or it is "File-to-Fit" for .030" overbore and has to have the gap filed to get whatever gap distance spec you are looking for....pretty much a hassle unless you are in top level competition and need every last HP you could get.
Standard .030" oversize is fine in most cases below that level, and check those to make sure you've got enough gap for your planned application and power level/power adder usage.

Something like a blown engine should get plasma moly, and not just lower level plain moly filled rings.
06-14-2019 10:10 AM
stanley9875
Quote:
Originally Posted by MouseFink View Post
The engine builder I have used since 1970 has a Clayton Dyno and he said he has made less power on his dyno with Total Seal gapless rings than he has made with standard gap rings. He also said the reason for tat was Total Seal gapless rings have more ring flutter at higher RPM.

He did not address the power at lower RPM but power loss with gapless rings is likely negligible in a street driven engine up to 4,000 RPM.

Quote:
Originally Posted by ericnova72 View Post
I agree with both previous posts. forget about Total Seal rings, if you don't have precisely the bore finish in Ra, Rk and RMS they can be problematic.

Like chasracer posted, I'd go new rings gapped as you want onto the clean nearly fresh cylinder bores you have. NO new honing is needed nor wanted, the previous set of rings has given you the ideal surface finish, they have scraped all the tops off the micro-peaks in the hone finish.

You'll find Stock and Super Stock racers who will dyno an engine, do their test regimen of xx number of rpm runs, then pull the engine back apart, install new rings and do a fresh valve job...and then it is ready to go in the car.
Perfect thanks for the info guys, yea ill not worry about the gapless stuff. While we're here, is plasma-moly face worth the bit extra money to you guys? What ring material is your preference? Also too on summit there's an option for piston and ring oversize with 0.030" and 0.035" options, since my bore is now 4.280" with the 0.030" machine work, just get the 0.030" correct?
06-13-2019 10:35 AM
ericnova72 I agree with both previous posts. forget about Total Seal rings, if you don't have precisely the bore finish in Ra, Rk and RMS they can be problematic.

Like chasracer posted, I'd go new rings gapped as you want onto the clean nearly fresh cylinder bores you have. NO new honing is needed nor wanted, the previous set of rings has given you the ideal surface finish, they have scraped all the tops off the micro-peaks in the hone finish.

You'll find Stock and Super Stock racers who will dyno an engine, do their test regimen of xx number of rpm runs, then pull the engine back apart, install new rings and do a fresh valve job...and then it is ready to go in the car.
06-13-2019 09:17 AM
MouseFink The engine builder I have used since 1970 has a Clayton Dyno and he said he has made less power on his dyno with Total Seal gapless rings than he has made with standard gap rings. He also said the reason for tat was Total Seal gapless rings have more ring flutter at higher RPM.

He did not address the power at lower RPM but power loss with gapless rings is likely negligible in a street driven engine up to 4,000 RPM.
06-13-2019 08:02 AM
stanley9875
Quote:
Originally Posted by chasracer View Post
With the limited runtime on the engine, I think you MIGHT be fine with resetting the ring gaps. Problem I see is that rings in general hate to be twisted, expanded, etc and having done that to them once already - I would pop for a new set and there's one less worry. Unless you see any major disturbance in the cylinder walls, I would clean them good with paper towels and ATF. Keep cleaning until the towels come out of the cylinder clean.
Like I said, I have no problem on buying new rings especially since I'd be re-buying gaskets and such. Whats another few hundred dollars when youre building horsepower? lol. I was even looking at those Total Seal gapless rings, has anyone used them?
06-13-2019 07:51 AM
chasracer With the limited runtime on the engine, I think you MIGHT be fine with resetting the ring gaps. Problem I see is that rings in general hate to be twisted, expanded, etc and having done that to them once already - I would pop for a new set and there's one less worry. Unless you see any major disturbance in the cylinder walls, I would clean them good with paper towels and ATF. Keep cleaning until the towels come out of the cylinder clean.
06-13-2019 07:23 AM
stanley9875
Piston ring questions for BBC

Hey guys, I have a question I'm hoping I can get some learning and advice from. I built a 454, .030" over, forged internals, roller valvetrain, aluminum heads, roots blower. I have a few hundred miles on the motor, but I've been wanting to put more power into it and start racing it once it gets to be winter time over here (bigger cam, more boost, we got 93 out here plus possibly water methanol injection) but that's not really my question.

My question is I'm wanting to check the gap on my piston rings and expand them a bit more to adjust for more abuse with more boost and weekend racing. So if I were to pull my motor and pull the piston rings out with the motor having a few hundred miles on it, I should get new piston rings preferably? They're a little over $100 so the money isn't a concern I'm just curious from an engine building angle if that's what I *should* do or if you guys think the original rings would be okay, I just keep them in the original cylinders and just gap them a bit more. Also regarding cylinder walls, should I stone hone them with only a few hundred miles of breaking in and street cruising and a few WOT pulls? Or just gapping and reinstalling and bolting it back together wont have any issues? Regarding my current gaps, this is embarrassing but the sheet that had my ring instructions is where I wrote my ring gaps when building the motor is missing. I've went through the box where I kept all instructions and notes when building the car numerous times and cant find it.

Thanks for the help guys, let me know if you need more information

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