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01-23-2007, 10:07 PM
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CC Member
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Join Date: Sep 2003
Location: Pleasanton,
CA
Cobra Make, Engine: CSX4771-CF. 1966 427 S/O
Posts: 197
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Not Ranked
Best method for seating the rings
Just wanted to get some tips on the best way to be sure the rings will seat properly. I plan on honing my cylinders with #220 grit honing tool, V shape style with 3 honing rods. I have brand new plasma-moly rings. Cylinders are straight and true. 427 S/O .015 over bore. 66 cast iron block. 11.3 Static Compression.
-Is Rotella a good break-in oil? Other suggestions.
-When I first start the motor do I let it run at say 2000 rpm's for a certain amount of time?
-First time back on the road I assume I should vary my speed. Should I push the motor hard or take it easy.
-Any other tips/tricks?
Thanks,
Mike
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Rubber peelin' gears a jammin'!
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01-23-2007, 11:49 PM
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CC Member
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Join Date: Dec 2003
Location: Chino Hills,
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Cobra Make, Engine:
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Mike, first off current plasma sprayed moly rings are a very good ring package, I think this is a good choice.
Now for the rest of your question. #220 grit would not be good for these rings but I'd like to ask you a couple of questions.
Are you going to have the block "power honed". If you are using a Sunnen CV/CK type hone would use a EHU525 stone set that is a 220 grit or a 28-35 RA (roughness average) to rough in the cylinder. This is a very rough finish for a moly type ring and is what is used for cast iron or chrome rings. I would use a JHU625 to prep the bore if you think it is currently to the size you want it. This is a 280 grit (16-23 RA) and is ok for moly rings but....
I would finish the hone with a JHU820 (400 grit) stone after using the 625 to get the best finish for your job.
There are many other options for honing bores including a "plateau" hone but you really don't need it for what your doing.
Break-in type oils are only required (IMO) for cam (flat-tappet) break-in. Plasma rings need very little (if any) break-in and can be run underpower as soon as the engine reaches opperating temp. I do keep the engine speed to around 2,000 to 2,500 during this time.
First time out is your call, I'd run it a bit and pull over to check for any coolant or oil leaks and make sure everything was ok and enjoy my ride.
Good Luck on your project
Last edited by dynoroom; 01-23-2007 at 11:56 PM..
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01-24-2007, 12:08 AM
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Senior Club Cobra Member
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Join Date: Jul 2002
Cobra Make, Engine:
Posts: 15,712
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From time to time I see recommendations about 'loading' and 'unloading' the rings. Full accelleration, about 10 times, followed by decelleration to help set the rings.
Thoughts?
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01-24-2007, 12:10 AM
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CC Member
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Join Date: Feb 2006
Location: Gilroy,
CA
Cobra Make, Engine: SPF 2291, Whipple Blown & Injected 4V ModMotor
Posts: 2,719
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Seating your rings
Mike,
Moly rings seat pretty easy. The hone you are using is fairly rough for molys. You might want to consider roughing the bore out with a 280 grit and finishing with about a 400 stone. Some ring manufacturers like to plateau hone the finished bore, check with your ring manufacturer.
As far as seating the ring, again the moly rings seat real easy. Do not baby the motor but don't go out and stand on it in first gear. Even unseated rings will allow the engine to melt your tires, and they won't seat. Take it out to a remote stretch of road go up around 40 -50 mph and stand on it in high gear for a few seconds. Once or twice is all it takes especially with moly.
Don't try to set any land speed records. The seating process is occuring while the motor is grunting not when it is on high C. You should go conservative on your tune up untill you get sorted out. Detonation will knock the moly out of your top ring in the blink of an eye. A more durable but more difficult ring to seat (more grunts req'd) is a stainless top and a ductile iron second. They are also more expensive.
The stainless top ring is as close to bullet proof as you will get and the ductile iron second will absolutely amaze you. Order one extra second ring and try to break it. You can twist it around like a pretzel and it won't break.
A good place to get virtually any ring you want is TotalSeal in Phoenix. Go to their website: http://www.totalseal.com/ and get their catalog download. It is a great technical reference and also a catalog. By the way if you don't see or can't find what you are looking for they will custom manufacture ring sets for you! Neat place, great products, easy people to work with.
By the way your engine will like you better if you do not try to use a synthetic oil during break-in. Use a good detergent between 10W30 and 20W50 depending on how tight you built the motor. After a hundred miles or so switch over to Amsoil synthetic and you will be real happy.
Ed
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01-24-2007, 07:31 AM
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CC Member
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Join Date: Dec 2000
Location: Livermore,
CA
Cobra Make, Engine: ERA #629, BBM Side Oiler Block, 482ci, Richmond 5 speed
Posts: 852
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Mike,
Here's the procedure I use for breaking in my motors. It's tailored to breaking in a new flat tappet cam but on the second page it also addresses what you can do to make sure your piston rings are broken in.
http://performanceunlimited.com/docu...nebreakin.html
Chris
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01-24-2007, 08:39 AM
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CC Member
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Join Date: Apr 1999
Location: cleveland,
OH
Cobra Make, Engine: CSX4000, 427
Posts: 1,999
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While we're talking about rings, what do you guys think about total seal gapless rings? both top and second gapless sets? What about Childs & Albert's Z-gap rings?
I've heard good and bad. I've heard the gapless second rings are not good for dry sump/vacuum systems, or high compression-high rpm engines.
Would you choose total seal gapless top, or Childs Z-gap set?
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"After jumping into an early lead, Miles pitted for no reason. He let the entire field go by before re-entering the race. The crowd was jumping up and down as he stunned the Chevrolet drivers by easily passing the entire field to finish second behind MacDonald's other team Cobra. The Corvette people were completely demoralized."
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01-24-2007, 04:23 PM
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CC Member
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Join Date: Jul 2003
Location: West Bloomfield,
MI
Cobra Make, Engine:
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I've sold more rings than darn near anybody. I promise
First listen to what Mike said in the first response. If you are not using a rigid hone (like a Sunnen) you are just pretending to hone the cylinder...
Next is break in - - I am one of those that likes to see a series of moderate to heavy loads after cam break-in - - thats 8-10 2nd gear pulls to maybe 5000RPM and letting off the gas - - or a few equivalent dyno pulls. Rings need cylinder pressure to seat. No load RPM won't do a thing.
Then I dump the oil and cut open the filter to look for evil things. If she looks OK - - fill the oil & go out and beat the snot out of it! Its as good as it is gonna get.
Almost forgot - - I personally think gapless rings are useless. You car will be faster only because of the reduction in wallet weight.
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01-25-2007, 09:01 AM
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CC Member
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Join Date: Apr 2003
Location: Central Texas,
TX
Cobra Make, Engine:
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Quote:
Originally Posted by Anthony
While we're talking about rings, what do you guys think about total seal gapless rings? both top and second gapless sets?
Would you choose total seal gapless top, or Childs Z-gap set?
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I'm an advocate of the gapless rings in a racing environment especially from the ring life standpoint. I ran a 427 HiRiser with 14.1:1 cr for over twelve years on the same set of C&A gapless rings and while the heads ultimately wore out, the leakdown was still at the desired 2% or less on those cylinders that the heads were not failing on.
On a new engine, engine output can initially be expected to be the same regardless of the ring design if the rings are seated properly and cylinder leakage kept the same. But over time, conventionally gapped rings will ultimately increase the ring end gap over 0.003" for each 0.001" of wear in the bore and this is where the gapless ring design will shine. Over the long haul, the gapless rings will maintain a better ring seal and hence, less cylinder leakage.
As far as ring design between the C&A and the Total Seal brands, I lean heavily towards the Childs & Albert Z gap. Partly in ease of installation and the other in not having to deal with a two piece design that can be contrary at times to install. For a normally aspirated drag racing engine, I prefer a gapless second ring in the convential location but in blown applications I lean towards a gapless top ring with that particular ring spaced further down from the top of the piston.
Ted Eaton.
Eaton Balancing.
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Ted Eaton.
Fe's are fast but "Y-Blocks" are fun when they run in the 9.60's at 135 mph.
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01-25-2007, 04:27 PM
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CC Member
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Join Date: May 2006
Location: St. Louisville,
Oh
Cobra Make, Engine: A&C 67 427 cobra SB
Posts: 2,445
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Quote:
Originally Posted by ted
On a new engine, engine output can initially be expected to be the same regardless of the ring design if the rings are seated properly and cylinder leakage kept the same. But over time, conventionally gapped rings will ultimately increase the ring end gap over 0.003" for each 0.001" of wear in the bore and this is where the gapless ring design will shine. Over the long haul, the gapless rings will maintain a better ring seal and hence, less cylinder leakage.
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Well my first intuitive thought was 3:1 ring gap to bore increase is bull. Then I stopped and did the geometry in my head a minute, and I realized it is actually 0.00314 gap for each 0.001 in bore. Dah it's pie dummy (dummy being me). Wow, that is a very interesting point. Thanks for sharing.
I was reading on an engine builder's web site that they use gapless rings. They mentioned that they do a special proprietory mystical hone job to get these type rings to seal properly. Anything to that?
Last edited by olddog; 01-25-2007 at 04:29 PM..
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01-25-2007, 05:04 PM
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CC Member
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Join Date: Jul 2003
Location: West Bloomfield,
MI
Cobra Make, Engine:
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I ran the Speed-Pro division of Federal-Mogul for 12 years. In that time I supplied rings to many of the premier teams in racing - - NHRA including Anderson (4 time champ team), Reher, Jenkins etc., NASCAR included Roush. All guys that had the finances and research budgets to run any ring that gave them any advantage.
We has the country's finest reseach lab and dyno setup for ring development - - Cray computers, many dynos, radioactive exhaust analysis for oil consumption, etc. (O.E. money). No gapless stuff after many dollars trying it.
A 3 thou increase in gap is virtually insignificant in anything less than a Pro class application - - and a thou of wear is a pretty good number after many thousands of miles. Gapless rings will show the same leakdown numbers even when the working face of the ring is completely worn out. Dynamic seal will be shot - but that guage still looks nice....
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01-25-2007, 08:37 PM
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CC Member
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Join Date: Sep 2003
Cobra Make, Engine: Early 427 car
Posts: 589
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Gapless
nm .
Last edited by Byots; 04-26-2018 at 06:43 AM..
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01-26-2007, 07:49 AM
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CC Member
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I'm letting myself get too involved in this - but what the heck
If gapless has any true quantifiable benefit at less than WOT, why is it not used by any OEM in any application? It does not matter whether we're talking about a Bentley at a couple hundred Gs, a Viper, Zo6, GT500, or a minivan or a econobox. None of them, from any known major manufacturer has gone gapless. These companies have the testing resources to verify any improvement in mileage, gain in power, improvement in durability, or reduction in oil consumption. Any of those would deliver ample reward to offset the cost of the change.
So lets summarize:
1) Few if any Professional race teams use the gapless design (some may - no way to verify that they all don't)
2) None of the OEM manufacturers use a gapless design.
3) The only folks that use a lot of gapless rings are those that believe the advertised benefits and lack the comparative resources to truly verify any gain or loss.
At best, you are out the added expense of the parts - assuming that the performance in your application is equal. The very obvious decision by both race teams and OEMs should indicate that any benefits cannot be verified or quantified regardless of cost. At one time I had access to test documentation that clearly showed negative aspects to gapless rings from a dynamic performance and oil control perspective - I no longer have access to that test data (job change).
Its the internet - - and I'm just another keyboard jockey out here. You don't have to believe me - - and you certainly don't have to agree. But I'm much more comfortable selling folks parts that deliver value for their dollar. And I do not consider gapless rings to be among those items.
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01-26-2007, 09:29 AM
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CC Member
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Join Date: Sep 2002
Location: Hickory,
NC
Cobra Make, Engine: ERA 427SC w/427so, ERA GT #2002
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Mike: I haven't read the responses, so I'm probably repeating suggestions that have all ready been made. First off, you're using moly rings, so the rings will seat quickly. Next, what you said about idling the engine at 2,000 rpm is correct. Do it for at least 20 minutes. By the way, this is to break in the cam (flat tappet) and not seat the rings. After this, check for leaks, snug the hose clamps, then go out for a ride, but avoid wide-open throttle. Instead, use moderate throttle at moderate speeds, accelerate moderately and decelerate frequently, but don't go too far from home. Once you've operated the engine for about 200 miles using this procedure, get on it! Have fun.
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Tom
"If you can make black marks on a straight from the time you turn out of a corner until the braking point of the next turn, then you have enough HORSEPOWER." Mark Donohue
Last edited by speed220mph; 01-26-2007 at 12:52 PM..
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01-26-2007, 10:17 AM
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Join Date: Dec 2003
Location: Chino Hills,
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Well Mike, there you have it, from some of the best in the industry. I'd do a google searh on some of these people to see if they really know what there talking about.
But the answer is here.
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01-26-2007, 01:31 PM
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CC Member
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Join Date: Sep 2003
Cobra Make, Engine: Early 427 car
Posts: 589
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gapless
nm .
Last edited by Byots; 04-26-2018 at 06:44 AM..
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01-26-2007, 01:43 PM
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Location: West Bloomfield,
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True on the financials for the car companies - but...
The same competitive, environmental and mileage regulatory issues have driven them to far more expensive items - roller lifters, electronic fuel injection, stainless steel exhausts. If the wild claims made for those rings were even half true it would easily offset the expense.
Gapless rings in numerous configurations have been in existance since at least the 1930's - - they were designed for use in air compressors - - where a completely different set of dynamics are in play. Any patents have long since run out. Any current patent would be quickly perforated by a corporate legal staff - since prior art is so old.
As I noted - - other opinions are going to exist, and they are certainly valid in the experience of those who have them. Mine is based upon my good fortune to have had access to some very convincing data. Different opinions and approaches are what makes this engine stuff fun!
Last edited by Barry_R; 02-03-2007 at 05:43 PM..
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01-26-2007, 02:12 PM
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CC Member
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Join Date: Sep 2003
Location: Pleasanton,
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Cobra Make, Engine: CSX4771-CF. 1966 427 S/O
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Thanks guys for all the input. I hope to get my ride back on the road soon with some of the added benefits of your sugestions.
Mike
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01-27-2007, 01:47 AM
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Join Date: Feb 2006
Location: Gilroy,
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Cobra Make, Engine: SPF 2291, Whipple Blown & Injected 4V ModMotor
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We used the gapless rings for blown alky applications. The car seemed to mph slightly better but not enough to say the ring was a required component to win. What we did like was low measured leak and the ductile iron second that was essentially impervious to breakage. It didn't need the gapless technology to be ductile but at the time it was one way to get ductile second rings. Our top ring was a stainless .017 Dyke ring that was cerrtainly not gapless.
The two piece ring will flutter before a single piece ring will flutter. Thats probably important to the F1 crowd but not to a blown alky engine and certainly not to a Cobra engine at any rpm they will reach. I'm not persuaded they are an essential component in a engine build for a Cobra.
By the way having said all that, my engine has a 1.5mm stainless top ring and a 1.5mm TotalSeal gapless second ring with a high tension 3mm oil. I did it not because I thought hundreds of horsepower were at risk, I did it because I've had 20 years of good experiences with the rings.
Like I said in my earlier post your molys are good rings and easy to seat. This won't be the last engine you ever do. Moreover you will probably freshen it several time just to try out different ideas and toys. Start with the moly and go up the ladder as your experience grows. No matter what you pick you're not loosing boatloads of horsepower.
Get the TotalSeal catalog (its a free download) and read the tech stuff. Knowledge never hurt anyone, even if it came with a little spin. Ignorance has hurt many. You don't need to buy their rings, you might want to benefit from their experience and research without spending your own money to discover the same stuff, the hard way.
Play with the available toys, decide what you like personally, hang your hat on it and most importantly enjoy your car. They really are a lot of fun.
Ed
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01-27-2007, 06:22 AM
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Join Date: Apr 1999
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Cobra Make, Engine: CSX4000, 427
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Excellent discussion, thanks. One of my engines has the total seal 2nd ring set, purchased years ago, the other engines, all have been built with the standard design.
What I was told by somebody is that "a engine builder building mopar hemi engines using the total seal rings" has had some durability problems, wearing the cylinders excessively. I don't know if they were the gapless top or second ring sets, as I was investigating whether or not to use gapless on my current engine rebuild, and if so, whether to use total seal's gaples top or second ring set vs. C&A's Z gap set.
Quote:
Originally Posted by eschaider
We used the gapless rings for blown alky applications. The car seemed to mph slightly better but not enough to say the ring was a required component to win. What we did like was low measured leak and the ductile iron second that was essentially impervious to breakage. It didn't need the gapless technology to be ductile but at the time it was one way to get ductile second rings. Our top ring was a stainless .017 Dyke ring that was cerrtainly not gapless.
The two piece ring will flutter before a single piece ring will flutter. Thats probably important to the F1 crowd but not to a blown alky engine and certainly not to a Cobra engine at any rpm they will reach. I'm not persuaded they are an essential component in a engine build for a Cobra.
By the way having said all that, my engine has a 1.5mm stainless top ring and a 1.5mm TotalSeal gapless second ring with a high tension 3mm oil. I did it not because I thought hundreds of horsepower were at risk, I did it because I've had 20 years of good experiences with the rings.
..... No matter what you pick you're not loosing boatloads of horsepower.
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Yeah, I think no matter what you use, a good set of rings will be fine, whether they are gapless or not.
I had maybe thought if using total seals gapless design, to use the top gapless set, as the second ring set has a bad rap for flutter, in high rpm or engine scavenging situations, like dry sump or high efficiency exhaust systems. But wondered if there were any issues with the top gapless rings as well.
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"After jumping into an early lead, Miles pitted for no reason. He let the entire field go by before re-entering the race. The crowd was jumping up and down as he stunned the Chevrolet drivers by easily passing the entire field to finish second behind MacDonald's other team Cobra. The Corvette people were completely demoralized."
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01-27-2007, 06:45 AM
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Cobra Make, Engine: Early 427 car
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gapless
nm .
Last edited by Byots; 04-26-2018 at 06:45 AM..
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