Dyno Tested: Are Thinner Piston Rings Worth Horsepower?

[@grabasandwich]

Steve is so laid back. Sounds so humble and friendly. If he's one of the bosses around there, those guys must love working for him.

[@T1000AX]

sometimes it's all the little things that do make the big difference. 8hp here, 15 over there, 5 here, 2 there.. next minute you've got 30hp over the competition.

[@ImTheJoker4u]

Exactly. Freeing up 2-5 HP here and there adds up. How much HP does a mechanical fan and water pump sap away? Not enough to notice in your grocery getter, but its enough to put you in last place on race day.

[@Tekvicious]

Engine Masters did an episode on the fans... 30hp to run the clunky stocker on their engine. Just make an electric setup

[@jakemcintosh2201]

Tekvicious well its not "just run electric fan" necessarily, as the amps drawn will use hp through the alternator

[@Tekvicious]

yeah, like 1hp.

[@anthonyrybczynski5420]

T1000AX yes. Keep thinking the competition is stupid. While you're making 30hp over your stock 5hp engine, others are making3 and 4000hp

[@donogoobo9992]

Not only a few HP, but it allows a more compact ring package and lets you move the wrist pin up farther so a longer connecting rod can be used. That parks the piston at TDC a little longer as well. All small performance gains, but they add up.

[@123Jokkmokk123]

I clicked for Steve Brule!

[@666AL]

likable guy.

[@TheAlpineProject]

He's in it for your health!

[@2of2DCH]

Same! Imagine how many dyno pulls he's done...

[@123Jokkmokk123]

I know right! At least 12. Maybe even 15!

[@borghed3841]

dä gjorde ja mä

[@danielpruitt2747]

One of the best comparison videos I've ever seen. You take the EXACT same engine and make ONE change to see what the results are. AWESOME VIDEO!!!

[@Zamorano27T]

STEVE BRULE is the Wizard from "Alice and the MotorLand"....... The man can tell you how much HP your making.... all the way up to a tenth of the fraction.

[@danielbrealey2924]

Steve's the man. But I'm also excited to see the new direction Evan is taking things since he took over the mag. He's quiet likeable and fairly switched on too. He knows what the people want to see. Well, he knows what I want to see anyway. Can't speak for others

[@EragonSuperM]

just by listening to it

[@Gap_machine]

You guys are killing it with these sick back to back comparisons. It’s great to see proof on what all these little tricks actually gain! Thank uou

[@thewespaul6520]

Please do more videos like this and the eBay turbo kit test!

[@HotRodMagazine]

That's the plan. Thanks for watching!

[@danielbrealey2924]

YES, +1

[@nathanstephenson7917]

GO to motor trend and check out former Editor in Chief from Hotrod, Steve, and Dulcich the Mopar man. They do this all the time!

[@thewespaul6520]

Nathan Stephenson Already paying for motertrend on demand bud👍

[@thewespaul6520]

eXViLs because I drive a diesel that needs a bigger turbo

[@ole661]

This is a great video. Steve's years of experience and some crazy questions. It's awesome to see an apples to apples comparison. I put thin rings in my 66 C10 on a whim and damn I'm happy I did. Thanks guys!

[@danielbrealey2924]

Yeah, I did on my big boost turbo engine too. I'm pretty happy with the result as well

[@earnestbunbury2103]

Smokey Yunick says smaller rings were better back in the 50's.

[@HotRodMagazine]

Smokey was right. But it wasn't until much later that metallurgical advancements allowed thinner rings to last in passenger car applications.

[@383mazda]

I got a test that's up this alley. Test a big block with a big "high capacity" 7qt pan, then swap in a wind age tray, crank scraper, stock oil pan and run it with just 4qts of oil (1qt low).

[@The_Cyber_Nomad]

8hp and better MPG with thin rings.

[@boosted2.4_sky]

Jeremey Allen and less wear and stress on the engine over the long haul...

[@oldstyleanalog6459]

Jeremey Allen mazda did their side seals thinner on 13 b rotary and achieved better results.same with the apex seals

[@InsideOfMyOwnMind]

I also noticed that some rotaries had inner and outer side seals and others had just the one per face per side. I'm wondering what that was about?

[@Kj16V]

FFS, why did I scroll down and let you spoil the result for me?

[@flawns]

not to mention, easier revs

[@vt2704]

I think we people were hoping 20 plus so they got a reason to tear open the block. I was.

[@smh9902]

Good information for the next build!

[@mikes9939]

Great test, this is good info for us folks that had to use a set of pistons for a build that we could only find with a 5/64 ring pack instead of the thinner rings, even 1/16 set, that we really wanted to use. There is indeed some difference but it does seem slight and for many engines would not make a difference, especially in a typical street engine like the one used here. Hats off to you guys for doing the hard work and giving us really useful stuff. Things like this help us out. We also know this was a fair test done by competent people that we know and trust like Steve Brule.

[@michaellee891]

Brule has probably forgotten more than most of us will ever know... But I did notice quite a bit of blow-by when Steve was running the thin rings. It's predictable that there was some cylinder surface discontinuity due to ring wear-in from the thicker rings. I would like to see this test with both ring packs on identically prepared, freshly honed cylinders.

[@tomslater5198]

I like the editing / parts credits on this. Looks good. I'd actually like to see that in Roadkill Garage / Roadkill / HRG, too. Dig the experiment, too!

[@joshtheking1772]

When racers measure their performance in tenths of a second in quarter mile ET 7 to 8 HP is the world. Case Closed GJ guys.

[@johnwilburn]

Not only that, but with increases in bore, stroke, and RPM, the gain should be more because those are more ring surface, more ring travel per crank revolution, and more ring dragging cycles in less time, respectively. That number of 20 is quite likely in Pro Stock.

[@danawilkes6174]

I figured 8 horsepower, exactly like he said. Been around this for over 50 years. Still fun to watch and see what is going on. Most of the time I am correct in my assumptions, however I still get "surprised". Which is what I like. That way I am still learning something new.

[@TurboDog73TX]

Checrolet went to the 1.5, 1.5, 3.0mm rings long before the LS engine series. Pull apart a '96+ Vortec 350 and You will find Hypereutectic pistons ( Made by Mahle ) with that exact ring pack on them.. Sadly, the aftermarket ( at least in budget parts..) keeps selling pistons with the lame 5/64" or the marginally better 1/16" compression rings...

[@pro-seriesfabrication3810]

1.5mm = .059 1/16" = .0625 If 1/16 is only marginally better, than 1.5mm are as well . . . the difference there is almost non-existent.

[@franksandlin8974]

I enjoyed engine masters, but when it went its own way, I'm glad someone stepped up and kept the KZbin videos coming. It's amazing how dynamics have changed over the years. I always told people that the info, in the magazines was the gospel. keep up the great work!!! Thanks

[@skylinefever]

This is a great test. However, it would be interesting to see blow-by numbers from the 5/16 inch rings vs 1.2mm rings. Maybe the performance doesn't entirely come from lower friction, the narrow rings might also be improving power by reducing blow-by through a better seal.

[@HotRodMagazine]

We didn't measure blow by but we did check leak down, which came in at 4% for both ring sets.

[@skylinefever]

Excellent. That helps explain the results of using the narrow piston rings.

[@patw52pb1]

+HOT ROD Network A few questions... What was the ring seating procedure? Were both ring sets seated/broken in the same? Was there a difference in ring tension between the 5/64 and 1.2 mm sets? Was the rotating torque value mentioned breakaway or sustained torque? Entertaining and educational as always, thanks to TEN, Hot Rod, Westech, Brule and the sponsors.

[@jamesdriscoll2478]

i was just thinking did they give them time to seat

[@pospc2]

Was also wondering if any hone was done or needed.

[@karroome]

please do a test comparing total seal gapless rings with normal piston rings

[@sharkbaitsurfer]

You're worth your weight in gold fellas - a single variable test, averaged across three runs - with an enormous amount of work to accomplish it, and a definitive result I salute you

[@kaylapearcey2527]

8 HP is a great gain. Enough for me to use thin rings next build. I was expecting 4-5 HP.

[@bigbothoee8617]

I didn't think was gonna make any difference lol

[@kaylapearcey2527]

@@bigbothoee8617 LOL just started next build but decision is already made for me. Went with a crate motor this time.

[@LaPabst]

Brutal session... Only thing worse than a piston swap is fixing one that didn't quite blow up, but got real sick on a dyno.

[@cobra7250]

Frictional force depends on the nature of the surface in contact. The rougher the surface, the greater the friction involved. Frictional force is proportional to the pressing force, which is the weight of the body. It is independent of the area of contact. Taken from a textbook on Tribology.

[@brianbrigg57]

One thing to remember is that thicker rings carry more heat away from the pistons and into the cylinder walls. That's better for boosted motors particularly and helps with longevity of the pistons. Racers want power now, street cars generally want to run lots of miles. Oil squirters to cool the pistons might make up the difference so if I'm putting thin rings in a boosted motor I'll be using oil squirters for sure.

[@subjectsigma925]

New motortrend series with more Steve Brule would be nice, I could listen to him talk about engines all day.

[@joeymcroberts2686]

I would like to see total seal gapless rings Vs moly ring shootout with HP numbers

[@jamesandannschmitt6835]

Was the oil control equal between sets? Low tension oil rings have been tried before but can be tricky to get oil out of combustion.

[@WholesaleTurbos]

old school rotary guys will remember going from a 2mm apex seal to a 3mm to run more boost and noticed a drop in performance. now days you can get a pretty strong 2mm seal. you never see n/a engines with 3mm seals. its shit. on an engine with very little friction and no valve springs to compress you can imagine the difference it makes.

[@arnoudjanschut]

I think people that go the step to change the rings, also change the piston, and probably, while the engine is apart, change other things like cams, valve springs, etc. So good to see the 1 to 1 comparison, in real life that would be rare to just change the rings.

[@scottmichaels1764]

I think you are correct, but that really wasn't the. The plan was to see if there was a measurable power gain.

[@JerseyMikeP]

Would be interest if they could see how much MPG is changed. There is alot of drag there, and is that why Production cars are going that way..or so the engine wears out faster and they get the customer to buy again sooner?

[@ldnwholesale8552]

Production engines last a LOT longer with thinner rings. 300000km engines still with some hone marks in the bores. And THAT would be a valid test, an engine bored with and without torqueplate. On most Fords you see shiny bits where the head bolts have distorted the block. Both 6 cyl and in particular Clevo. Chevs with 5 bolts per cylinder markedly less so. And that is the letdown with the LS,, only 4 bolts per hole just like the opposition.

[@herbiesnerd]

Very cool. One thing I caught that sounds theoretically incorrect. “Friction loss will increase with increased engine speed”. The law of friction for liquids and solids are opposite. The faster a solid object moves across another solid object the lower the friction loss. The faster a liquid moves through a vessel of any kind the friction loss is increased. So unless the engine oil is acting as a moving liquid, the mechanical parts (metal on metal - rings and bearings) will have less friction loss the faster it moves. The maximum friction loss for the motor is starting it from a dead stop. The least amount of friction is at max rpm. Theoretically!

[@GTOGregory]

In the future, maybe a couple different tests relating to the valve train. One test with roller needle bearings replacing the standard camshaft bearings. Another test to check the gains in rocker arm changes. Maybe roller bearings over bronze bearings or a 1.7:1 ratio vs. a 1.8:1 ratio rocker arm. Another cool test that relates to blow-by is the before and after change from a vacuum pump. Then, you can check the benefits at 12, 18, and 24 lbs. of vacuum.

[@davidreed6070]

I have built road race engines with wide and narrow rings. It seems the wide rings will wear in and lose friction while the narrow rings don't have much friction from the start. Those guys will run engines hot, and the wide rings seem to withstand heat better.

[@MrGregroberts55]

Something people don't think about is thicker rings transfer more heat to the water jacket, running a few seconds on a dyno is much different than driving on the street or racing where the engine is running much longer at high RPM.

[@dontfeelcold]

At a basic level, friction is related to normal forces (the force of the ring pushing on the cylinder wall), not the surface area.

[@danawilkes6174]

We knew about thin rings back in the 1970's. Problem with them was they did not last as long as we thought they should have. Now they do last. We ran the Total seal gapless rings starting in the mid to late 1970's. They worked well, and they continue to improve them. I like them in turbo applications, as they keep the blowby issues down. Knowing this, I agreed with apx. a 8 HP gain, would be seen here...

[@magicyeti9256]

Really need to address cast iron 5.2 durability in older mopars and a mild cam with 340 heads, 10:1 compression and peak rpm.

[@blackericdenice]

My guess is 5 hp. Most people think everything will give them 25 more hp. My coworker has a 2016 F150 3.3 v6. He thought K&N air filter would give him 25 more hp because he thought the stock air filter was restricting hp. I told him the v8 use the same air filter as the 3.3 v6.

[@alexcecil89]

Spin test with the torque wrench was testing static friction. Found roughly 20ft-ls of difference between the two... Given the average kinetic friction of anything is usually about 3/4 to a 1/2 of the static friction max, and small blocks have similar tq and hp readings in na form, an 8hp difference seem about right! Cool test! Interesting to know the little things do add up!

[@danielbrealey2924]

That was interesting. I WAS hoping for a bit more too, Evan. I noticed the top ring was a little higher with the thinner ring packs, it would have effected comp slightly. I wonder how much. The other thing of interest for me personally is; is there any trade off in terms of strength in high boost applications or with big shot's of nitrous??? I'm a turbo guy, so to me this really matters. I'm running the 1.2mm ring pack already on my C P pistons, but am I sacrificing any strength by doing this??? Lastly, I would really like to know is there any trade off in terms of longevity??? Are the thinner ring packs going to wear more quickly? Loving this format, Evan. This and the Ebay turbo kit vids are exactly what people like me want to see. Keep 'em coming, champ. Love your work

[@CanadaBud23]

It's hard to say really. Might be a test somewhere but as far as just looking at it I'd say the bigger pack would last longer simply because of the spread and thickness of the rings. The 5/64 rings are further apart to help stabilize the piston from rocking in the bore (less skirt wear and damage). Also I would guess that the thicker ring would resist more flexing and stay more square in the bore. I think the smaller ring would more likely dig into the cylinder walls as they wear. I think it would be a valid test simply because most people foremost would like to have longevity and reliability over all out power gains. But if they don't wear that much different and you like to rebuild every so often then it might be worth it.

[@ray_collins]

The rings basically "float" around the piston in use, dragged by pressure on either the top or bottom. Since they float, the centering/stabilizing is minimal. Since they're dragged by the flat surface of the piston, their ability to stay square doesn't really matter. While a thicker ring might have more material, it also has more surface area being worn, and the depth is the same, so the difference in lifetime is negligible. Metal expands as it heats, and rings getting too hot and over-expanding is what causes flexing/warping and other issues. That's why guys with nitrous run bigger gaps in their rings; more room to expand. Less material, less expansion, a natural bonus to thinner rings. Of course, piston/bore matching is vital. Thin rings might run into issues on a very loose fit, but anyone buying a piston for thin rings is sure to measure carefully.

[@RacerRickxx]

Given the same material, usage, and design, a thicker piston ring wears longer than a thinner. The main reason is actually because they can transfer more heat and run cooler. The secondary reason is that there is just more material there to wear before things break, loose tension, etc. The thicker rings can also be a little looser in the ring grooves and still seal well. Piston rock is more a side clearance thing, rather than something controlled by the rings. Thin rings are supposed to seal better on a rocking piston because they can flex more. Some of the claimer race motors almost 10 thou piston clearance and seal up just fine with cast pistons and 5/64" rings - 4-5% leakdown. Piston rings do not run perfectly square to the bore (they flex up and down some), and many rings are not manufactured perfectly square. For example, one way to tell if a old school V8 with a standard 5/64" iron ring pack has many miles on it is to look at the 2nd ring. Usually it will start only wearing on either the top or the bottom edge of the ring, and the wear leaves the ring shiny, while the rest of the rings face will be dull. As the miles pile up, and the ring wears more, the shiny wear takes up more and more of the face of the ring until it takes up the entire face. The only way this can happen is if the ring is not square to the bore when the engine is running. Personally, I think super thin rings are overrated when you factor in cost. Those thin rings are not cheap, and neither are the pistons they are used on. I don't know of any off the shelf piston that uses 1.2mm rings for an american V8, so those would be custom. I can think of other places to get more power for the same money. Unless you are running in a class where mods or ci are limited and every single HP is needed, I would pass on super thin rings.

[@danielbrealey2924]

RacerRickxx I agree with everything you've said there. My engine is an RB30 Nissan donk, as I said in my previous reply to another comment. The engine is relatively new to me, I've always been a V8 N/A guy, so the same rules don't apply. I'm on my second build of this engine, but it only had maybe 10000 - 12000 kms on it when I pulled it down last time. So longevity isn't something I've been able to gauge as of yet. They were an off the shelf CP piston, but were fairly new to CP. I reused the pistons when I did the rebuild, as there wasn't much wear on the skirts (maybe 3 - 4 thou on the gauge point of the skirts) and I actually compensated for that when I sent them off to have a coating done to reduce friction on the skirts- they were just plain forged pistons the first time around with no coatings from CP. I've been pretty happy with the way it's turned out. I always like to hear what others have experienced and found in their own set ups. There's a lot of people out there with a lot of knowledge. Although I do this for a living, I'm only 36 and realise I've still got a lot to learn myself. I tend to try new things on my own projects before I spec something out for a customer. If something's going to fail, I would prefer it happen on my own engine rather than to a customers. And lets be honest, tech has evolved in leaps and bounds over the past decade in terms of materials and design. Now it's not uncommon for guys to make 1200+hp at the wheels out of these relatively small Japanese turbo 6 cyl engines like mine. 10 years ago, 500hp at the wheels was pretty impressive for a daily driven engine of this size. That's where the tech has taken us, and it's brilliant

[@danielbrealey2924]

Raymond Collins I had all the clearances done by my mate who runs a machine shop, it was set up on the loose side in terms of piston to bore clearance- but obviously within spec suggested by CP for the application of being a big boost turbo motor. It's funny how big the gaps are on a serious nitrous motor compared to a big boost turbo motor, isn't it? They run quiet a bit more end gap for the nitrous to compensate for the expansion they will see. It's really interesting with some of the new materials being used for piston rings these days. That's more where my interest lies with all of this. I was surprised Total Seal set me a 1.2mm ring pack with an iron Napier style top ring, but a really trick 2nd comp ring. I was a little suspect on that iron ring, but it's held up fine so far. The 2nd ring was really flexible too, it will deff be moving around as the piston goes up and down, but doesn't seem to effect it's seal in any way. As long as the correct RA is machined into the cyl walls, it works really well. It's funny, when I pulled this thing down for a rebuild last time, there were signs that the rings had been slightly butting together and hadn't been opened up enough for the boost I was throwing at it- but it didn't break the ring land, damage the cyl wall or break a ring. So of coarse we opened them up a little more this time around. They give you a range to work within, we tried to stay on the smaller side of the range last time to help with blow- by at low load (cause it's a street/strip car), but it hasn't made too much difference to be honest. It doesn't breathe much harder than it did before, even tho ring end gaps are set on the higher side of that range now.

[@ne2i]

Weird audio artifacts on the dyno runs. sounds like its misfiring (I know it's not)

[@frankclark7039]

That’s the engine dyno putting load on the engine every 300 rpm to take a measurement. Sorry it took 3 years to get an answer.

[@merlemorrison482]

did I hear good for 200,00 miles? also, what did you do to break in the 1.2 rings?

[@tct72]

Just out of curiosity, when you do tests that require the heads to be pulled, do you use new head gaskets each time or do you reuse them to keep cost down?

[@HotRodMagazine]

It depends on the gasket type. For a coated gasket such as we used in this test, we will change them. However, certain MLS gaskets are able to be reused.

[@tct72]

Thanks for the reply. Looking forward to more product tests on the dyno.

[@fatman1288]

good question i was just ask the same thing lol

[@johnparrish9215]

I would love to see a loose, within spec engine VS a tight within spec engine.

[@13coyote13]

8hp was my guess as well, reasoning, the only change in resistance is at the start of the down stroke and the start of the up(or compression) stroke which is the only time the face if the ring is perpendicular to the cylinder wall.

[@jakegarrett8109]

I'm really impressed it made that big of a difference (1.8%). I thought the thinner rings were only for the ring float engines get at high rpm (2 cycle engines particularly since they are not limited by valve speeds). I had no idea a ring could have that much extra friction (aka wear).

[@tptrsn]

Excellent test, thanks for doing the work it took to make it happen!

[@aszilagyi100]

Well done Steve, I liked the fact that you mentioned averaging three runs! Any kind of scientific test needs to be repeatable. And those of us that have done scientific engine testing understand thermal saturation can be involved in small testing error

[@garyhooper2728]

Hi All the low friction benefit is at part loads typically 2.0 Bar BMEP which is the recognized industry and OEM test point, if you had run part load as well as full load you should have seen a bigger difference but a gain at rated is worth it

[@TheBrokenLife]

In the spirit of new vs. old, I think it would be hilarious to see just how bad you have to make a junkyard LS as bad as a 350 from 1980. Is it even possible to make a 5.3 make 180hp at the crank with off-the-shelf parts?

[@TheBrokenLife]

I don't think the data supports your thesis... Modern motor HP claims are made with their full accessories installed and a 5.3, complete with mechanical fan and water pump, is rated at something like 270 stock in '99, which should account for all of that (and I'm pretty sure a bone stock 5.3 makes about 230-240 at the wheels, which backs up my statement). By the same token, that 180hp 350 in 1980 should have been an SAE net number too so the motors should be on equal footing. I can't even find a video where someone bothered to dyno a full smog 350 or a stock C3, but I'd have to imagine they probably put down about 140 to the wheels... Modern truck exhaust is pretty much as crappy as way back exhaust too (especially considering something like 180hp Corvettes, where they at least tried). The carb, I can absolutely agree with you on. Anyhow, I still think this would be a hilarious test. The way I'm looking at it is that they would have to nuke 100hp out of the 5.3, with off the shelf parts changes (no fair just running it way out of time) before it was even. My guess is that even with a carb manifold with a small 2bbl carb bolted on to it with adapter plates that the LS would come out on top. There's only one true way to find out!

[@DBGMLV]

It would be fun to see what it would take to make a 350 perform as well as a 5.3 LS.

[@TheBrokenLife]

Everyone on the planet already knows how to make 270hp with a 350. That's legitimately not a challenge and even Chevy managed to get really close again down toward the end with the Vortec motors. I think a '96 350 is rated at something like 240hp.

[@alvisfranklin8486]

255hp

[@immikeurnot]

I'm guessing you mean "is it possible to get a 5.3 DOWN TO 180 crank HP with off-the-shelf parts, assuming proper tuning?" I'd have to go with a big ol' "no" on that one.

[@blanchae]

My guess was 5 hp improvement. Pretty close but one of those things I never really thought about before. Well done!

[@DataToTheZero]

I think the big benefit to thin rings isn't the 8 hp. But that the lower fiction leads to less heat in heat critical area. They have pretty close to the same area for cooling. The width remains the same which is where most the heat dissipation would be to the piston. The lower heat is going to lead to longer ring/bore life.

[@pauljanssen2624]

I believe the usual thinner piston rings achieve higher RPM vibration there's another word for it like using the right valve springs design intention with the right camshaft or as the right length of connecting rod with engine stroke and piston pin high short rods or long rods

[@tomasnokechtesledger1786]

Yep, but the oil consumption may come higher. But the engine was popping a lot @ last run ... what's that?

[@666AL]

WOO! New episode of engine mast.... potato patato.

[@AreThereNoMoreNames]

Lack of Freiburger energy and Dulcich smarm, but interesting information nonetheless.

[@wika1117]

Steve Brule was in the video so it was almost good as engine masters :)

[@rong4189]

Cool! I just helped a nephew put together his 360 Chrysler short block and he has the 1.5/3.0mm ring pack. We checked the rotating torque and came up with 19 #s. I'm guessing part of that is due to the gooey assembly lube on the bearings (motor oil on the cylinders). Still, I could tell it felt lighter than what I'm used to. Great video, more please!

[@302hobronco]

I know this is an old video. But I would like to see a back to back dyno run where the only thing they change is going from a regular hyd roller lifter, to a hyd roller lifter that has been limited to only .030 to .040 of compression inside the lifter.

[@ldnwholesale8552]

And the huge added bonus is they do not cut the bores up either. Added with ULP replacing rings in a street motor is a thing of the past. Plus generally the pistons are lighter anyway. I have used them for over 25 years and the OEM 10 years longer than that. I am surprised that late SBC engines did not? Ford have since the late 80s. Oh and does anyone like Spirolocks? For me the simple circlips have never caused a problem,,, BUT replace them every time.

[@JerseyMikeP]

6:34s....LOL don't show Freiburger that (OIL POUR) he might Jizz in his pants with Jealousy;-)

[@HammerHeadGarage]

Mean piston speed = bore x rpm divided by 6. Street engines are happiest around 4000fps or less. My 331 sbf at 7000rpm is 3966 fps for example.

[@ZelosZelo]

its banked on that little hp gain, going along with all the other things done to make the car roll faster (less weight, balance, low friction tires etc) and that multiplies its gain too. The hp gain with all those things i believe is worth it, but only if there are plenty of other mods/designed to compliment the gain -otherwise you will just be rebuilding the engine more often.

[@inkno701]

Thanks for doing this test! But what about piston ring tension? What if you adjust the ring tension to the lowest it can be?

[@lilsammywasapunkrock]

Vegaspsycho how long do you think and engine spinning at 6000rpm keeps the tension you set it at?

[@Welcometofacsistube]

lilsammywasapunkrock umm the exact same as the engine being at rest

[@inkno701]

If the ring size makes a small difference in the friction in the piston bores then ring tension surely should also make a measurable difference. While the block is disassembled it would be neat to see them use a pull gauge to see how much force it takes to pull and push the piston in the bore and make adjustments so the rotating assembly moves as smooth as possible.

[@lilsammywasapunkrock]

the bores and pistons expand and contract obviously while the engine is operating. just because the clearance is loose or tight while the engine is on the stand, doesn't mean it will be the same after. plus after break in, it won't be what you set it at anyways. the specs are there for a reason. i know engine builders that won't put engine blocks on stands because it slightly warps the blocks and changes clearances that they have machined for a final tolerance. they did measure torque required to spin the motor over and showed it was much easier with the smaller rings. I am not an engine builder, I would probably barely qualify as an engine assembler. just based on that, I'd leave the "gaps" at the recommended specs.

[@MsVictoriaJean]

The thin ring packs have the same 16-20 lb oil ring tension as the thicker rings. You can get ring packs with really low single digit tension but you're gonna need a vacuum pump to keep the rings sealed. Not something I'd advise for a street application.

[@ZelosZelo]

i predicted 1 to 1.5hp per cylinder also racers do it just the same as them using lighter weight parts, every little bit adds up and can add up to significant savings (fuel, tires, times, etc)

[@dufus2273]

have had two pan failures with Milodon . Glad you are using Moroso. good informative video, got my engine torn down now. good timing.

[@neutrodyne]

Questions one may also consider are- will the rings hold up as well? Will the rings last as long? Will the new thinner rings have more blow by? Are they more apt to break?

[@hayaboosta]

How well will thin rings hold up under boosted conditions?

[@HotRodMagazine]

Excellent. Modern rings are made from high-carbon steel and are much stronger than old-style cast rings.

[@danielbrealey2924]

I asked the same question before I read this. I'm wrapped, there's an answer already

[@RacerRickxx]

This is a loaded question with tons of different, but correct answers. It depends on your application. The style of ring, material, piston design, cylinder wall design and prep all must taken in to account for the right answer. The best answer is to contact your favorite ring manufacturer before ordering pistons with a honest account of what you are going to be doing.

[@RacerRickxx]

One ring manufacturer I spoke to said 1/16" rings or thicker(!) in hard chromed steel for one heavily boosted small big block I was helping build (big bore, little tiny stroke, just over 450ci). The thicker rings were to help get the heat out of the piston head and rings, and to take the abuse of 25+psi with a nitrous shot to spool the huge turbo :) They didn't think the thin rings would be good in a 4.625" bore under that abuse. Rings are available down to something like a half mm with 1.5mm oil rings for super short ring packs. I think they use rings like this in NASCAR. I have seen a used piston from a few years ago from a cup engine and it had super thin rings. Who knows what they use now.

[@danielbrealey2924]

RacerRickxx Yeah I hear ya. I'm a mechanic in Australia myself and am using some pretty trick rings in my current toy I'm playing with (an Nissan RB30ET) - it's been built for 40+psi. I always suspected the new gen materials used in current high performance ring packs were up to the task and did exactly what you suggested and spoke with Total Seal about what I was planning. They spec'd out some new material rings for the 2nd ring, but simply use an iron Napiar style ring for the top ring from memory (the engines been together for a year and a half now- so I'd have to look around the garage to find more accurate info). After buying some trick CP pistons with really thin ring lands, I was a little concerned at first. But they've been rock solid so far, I daily drive it using 21psi and it makes 504rwhp like that. But I always like to hear what everyone has to say, and from there decide where I think the truth lies. You can learn something everyday in this industry, and tech is constantly evolving. Funnily enough, I've seen a few NASCAR motors torn down at my mate's machine shop recently. An SB2.2, an R07 and whatever Dodge calls their now just out of date engines that aren't used anymore- and that was the first thing that struck me was how thin the rings were, but also how high up towards the crown the rings lands were. That works great in an N/A application, but we all know that style of piston doesn't work well in a boosted application. The thickness, or lack there of, of the rings isn't the issue there. The position of the top ring land is the problem... This small block you mentioned sounds interesting! That's a really big bore, isn't it... What block was that using? Obviously not a SHP, maybe a Little M or something I'd imagine. There are a few companies that make some really good blocks like Dart's Little M

[@Limeayy]

Holy crap, i didn't know you can literally use the snap on electronic torque wrench like that. 7:43

[@googlesucks5318]

Skip to 1:30 unless you like MTV camera work

[@p330hne]

GoogleSucks opening sequence says JE pistons then 10 seconds later say SCAT pistons and rods?

[@Markitos203]

Good comparison.. but the party starts ones you use loose rings with gas ported pistons and vacuum pumps

[@superbirden57]

Steve Brule is the god of dynos, testing, and IC. Big fan for a long time.

[@Keifsanderson]

GREAT episode. Love the single-parameter shootout.

[@brandonwytaske9432]

I think of this as a RPM band issue. If you are building a torque monster that will not hit over 5,500 rpm go with the thick rings. If you are building an open race motor that will turn 8,500 rpm go with the thin rings. You can see the charts are diverging and I bet at or over 8,000 rpm we may see close to 20 hp difference.

[@codymoncrief2128]

What about rings with a radiused edge?

[@mikewest712]

Steve likes this kid, he is not like the others.

[@NebukedNezzer]

About 2% thats worth doing on a new or rebuild. I enjoyed this as it answers the question.

[@stuartbuckley6113]

So it's not worth pulling the engine down just for 8 hp but is worth doing in a rebuild or new build. Time / cost per hp factor. My next build will have thin rings with gas ports and coated piston skirts.

[@dangerousfreedom4965]

Do a head gasket vid on LS motors go over how thinner is better vs detonation risk ect

[@hom240]

I will tell you from experience. Thin is fine for stock and some mild performance increases. For anything that will see a lot of high rpm, boost, or NOS. Don't use them. Can't count how many times I either found them broken (yes, I set the gaps at max for boost) or so metal fatigued they no longer push out of the ring grooves. Ran long enough they will get jammed in their groove from carbon via blow by. The symptoms are always the same. Engine runs great for 20-30k. Then the power starts going down over time (10k or so) until the compression has gotten so low that it won't even start. The compression test will confirm your suspicions.

[@4406bbldb]

I was a General Electric Development Dynamometer operator. How accurate is your Water Brake? The test numbers are believable.

[@StingrayOfficial]

I wonder if the weight difference between pistons/rings was and how much that made a difference. What did they weigh?

[@HotRodMagazine]

JE Pistons took the weight of the rings (a few grams) into consideration when designing the pistons so both sets weigh exactly the same. That kept us from having to re-balance the rotating assembly for the second test.

[@ferrumignis]

Thinner rings conform to the shape of the bore more easily than thicker ones, so should create a better seal under working conditions. Lighter piston rings are also less prone to flutter at high RPM.

[@martinmccomb5462]

Good video and a question worth asking, but from the manufacturers side of things, in my opinion it boils down to cost savings. The 8 extra hp is just a little more icing on the cake. The thinner rings will need less material, so they will cost less to make. Even a few cents per ring can make a huge difference over a production run that will be in the hundreds of thousands of pieces annually for perhaps 2 decades? Maybe more? That would be a number to get managements' attention.

[@crhend512]

You need to have the values for ring size either in all frational inches or in millimeters.

[@johnparrish9215]

I wish they would test Positive Crankcase Vacuum with a Vacuum pump. I've heard this is worth up to 20 horses.

[@awittypilot8961]

What happens to power once the rings seat? Might see some more. I see a HUGE difference on Harley engines around 1500 miles compared to brand new.

[@kwik440]

I wonder what power gains were made by ring seal vs. less parasitic drag from the rings? in theory, the thinner rings should seal better, by being able to follow cylinder better. ?

[@aw11man26]

For the OEM the increases fuel economy due to less friction is even more important.

[@mahmoudkobbara9838]

What about compression ratio The new pistons may have higher compression ratio wich lead to higher power production and the friction may have the less effect

[@nonurbuzzness378]

The reason it went from 30 foot pounds of torque to about half is because the new rings and piston aren't set to the sleeves honing it would have helped

[@jbstepchild]

The issue with the rings being thinner is the oil bypass that is going to take place inside the motor bring picked up by pcv an reinjected back into the motor fogging it up with carbon now maybe not on this engine as its carbed but still could be plausible an if it was a non na turbo app then oil blow by would be even more noticeable more like the engine is burning oil rather than using it

[@Hogwarts-Dropout]

Awesome. So if going from 5/64 to 1.2mm rings only gained 8hp, going from a 1.2mm to a 1mm ring set like the ones in the Mahle Powerpak pistons the gain will probably be negligible.

[@theoldwizard998]

Smaller diameter main and rod big end bearing make a difference also. Kind of difficult to prove without spending massive amounts of money.

[@garyhooper2728]

no mention of oil consumption, normal OEM/Industry reference for friction to 2000 2bar BMEP not full load, here the biggest influence can be found in reduced BSFC, for hot rodders no influence!

[@peteabel137]

FirstGeneration ford lighting used a low tension ring to do something similar. Don't know how much horse power it achieved though.

[@ronnieboucherthecrystalcraftsm]

if you use the spiral lock correct fitting tool = there is no real problem ? in fact it is easier than snap ring`s.

[@thomashaugemotorsport6117]

great video. would love to see this test done with gasported pistons. maybe the thinner rings would seal better with som held from the backpressure and then give a few more hp?