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Re: 383man
[Re: 383man]
#696225
05/12/10 11:05 PM
05/12/10 11:05 PM
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Anonymous
Unregistered
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Anonymous
Unregistered
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I agree with Maund--I have used tons of them with no problems-BUT..we see lots of them that have been destroyed---If you are on a budget and can read the instructions they work fine--we always give them some extra piston to wall--they may be engineers but I have to stand behind this stuff so to heck with 2 1/2 thou --give them some more --let them live---they can't take it with a sorry tune up --good racers can do about anything with them--back yard guys that have never understood a distributor etc need forged units to cover their behinds until they get an engine tuned and running proper and another note--not ALL hypers use extra ring gap..just the KB's Sealed Power made an awesome cast 440 piston but then it started being made in India and the quality went to crap--so...KB is the only cast pistons around with the compression height we need --so it is $330 for them or $600 for forged--they really took off and gained market share because of amazing coverage for all combos--NOT because they are good or for that matter cheap and BTW the new Mexico pistons have great pinfit unlike the USA made in the past 
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Re: 383man
[Re: 67MIke]
#696228
05/13/10 12:58 PM
05/13/10 12:58 PM
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Joined: Aug 2004
Posts: 425
Eastern Ontario
shaker340
mopar
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mopar
Joined: Aug 2004
Posts: 425
Eastern Ontario
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I just installed KB107 in my 360 and ordered moly rings for standard bore. I did not read the instructions.....and the engine is all together and in the car ready for first fire. What will happen if the ring gap is not set??
2008 Challenger SRT8
1940 Chrysler Royal coupe
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Re: 383man
[Re: MoparforLife]
#696230
05/13/10 01:27 PM
05/13/10 01:27 PM
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Joined: Aug 2004
Posts: 425
Eastern Ontario
shaker340
mopar
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mopar
Joined: Aug 2004
Posts: 425
Eastern Ontario
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I was just at the Kieth Black website, sure enough they advise setting the ring gap. When we buy rings, what gap are they if one ordered for standard bore?? It seems like I will need around a 0.026 inch gap for street use.
2008 Challenger SRT8
1940 Chrysler Royal coupe
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Re: 383man
[Re: MoparforLife]
#696233
05/13/10 02:40 PM
05/13/10 02:40 PM
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Joined: Dec 2007
Posts: 77
British Columbia Canada
Challenger340
member
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member
Joined: Dec 2007
Posts: 77
British Columbia Canada
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KB "Hypereutectic" Pistons are a "High Silicon" Alloy Cast Piston.
The Higher Silicon makes them stronger, by Hardening the Alloy,
albeit,
more "brittle" because of the Harder Material.
I've used a TON of them in Builds with no problems whatsoever,
that said,
The problems I have seen elsewhere, usually relate back to a Failure to follow the manufacturers(KB) Instructions, regarding Ring Endgaps and Clearance,
and secondary,
"severe tuning" mis-use, ie; really bad Detonation which tends the "Crack" the Harder/more Brittle Material Alloy.
FOLLOW KB's Instructions, and USE a timing light in Conjunction with enough Octane Fuel for the Compression Ratio,
and,IMO,
YOU WILL never HAVE A PROBLEM .
Better to be a "has been" than a "never was".
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Re: KB pistons BREAK IN HALF???
[Re: todd440]
#696234
05/13/10 02:47 PM
05/13/10 02:47 PM
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Joined: Aug 2005
Posts: 4,799
ILL
MLR426
master
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master
Joined: Aug 2005
Posts: 4,799
ILL
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Quote:
I don't use them very often, but they are a good piston. The problem is, people don't read the ring gapping instructions. Since the top ring land is high, you MUST wide gap the top ring, or you will break that sucker!
That's right the ring gap is wide .028 top rings for 440.
logan426
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Re: 383man
[Re: MoparforLife]
#696236
05/13/10 03:14 PM
05/13/10 03:14 PM
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Joined: Aug 2004
Posts: 425
Eastern Ontario
shaker340
mopar
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mopar
Joined: Aug 2004
Posts: 425
Eastern Ontario
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This is my first time replacing pistons and rings. The motor is in excellent condition measurement wise, bores were nearly perfect, very little taper and out of round, but it had 8:1 pistons in it....so I thought it would be good time to upgrade that while the engine needed new gaskets since it was starting to leak oil at the front and rear main seals.
Thanks to Moparts we all get to learn little things that make a huge difference. I'll fix it right.
Edit: I also read KB recommends a few degrees less timing. So 12 degree initial with 32 total would be fine using 91 octane fuel?
Last edited by shaker340; 05/13/10 03:18 PM.
2008 Challenger SRT8
1940 Chrysler Royal coupe
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Re: 383man
[Re: Challenger340]
#696237
05/13/10 03:58 PM
05/13/10 03:58 PM
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Joined: Jun 2008
Posts: 10,847
Oakdale CT
gdonovan
I Live Here
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I Live Here
Joined: Jun 2008
Posts: 10,847
Oakdale CT
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Quote:
The problems I have seen elsewhere, usually relate back to a Failure to follow the manufacturers(KB) Instructions, regarding Ring Endgaps and Clearance,
and secondary,
"severe tuning" mis-use, ie; really bad Detonation which tends the "Crack" the Harder/more Brittle Material Alloy.
LRE (a well regarded Chrysler IMSA car builder) thought I was on crack when I told them there was a problem.... till...
A bone turbo stock car they built broke 4 pistons.
At that point they stopped selling the pistons.
Why waste money on questionable parts? The short block is the foundation of your build.
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Re: 383man
[Re: RoyceFlo73]
#696239
05/13/10 06:05 PM
05/13/10 06:05 PM
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Joined: Jan 2003
Posts: 715
Tulsa, Oklahoma
Charger_440
OP
super stock
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OP
super stock
Joined: Jan 2003
Posts: 715
Tulsa, Oklahoma
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any experience with the rings that KB sells? or other suggestions
In a conversation with a Wyoming State Patrolman... "A 318 ??!!! But I clocked you at 142 mph!!!"
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Re: 383man
[Re: Charger_440]
#696240
05/13/10 06:53 PM
05/13/10 06:53 PM
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Joined: Feb 2003
Posts: 12,675
Columbia, CT
moper
I Live Here
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I Live Here
Joined: Feb 2003
Posts: 12,675
Columbia, CT
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Like anything else, there's good enough for a given application, and better. What I find funny are builders that can't spec a part that is adequate for a job, and others who spec the right part but can't execute the work properly. KB hypereutectics are a victim of the 2nd one most of the time. I've installed sets of them in 360, 318, 383, and 440 engines. All used different end gaps depending on intended use, and none have problems after years. Forged will give you a margine of error while KBs will not when it comes to ring gaps.
If you dont know and used a boxed set of rings, you MUST take it apart and check the gap on the top ring. Because what you need is bigger it's just a matter of the filing and any gaskets you tear. You can do this in the car if pulling it is a problem.
Well, art is art, isn't it? Still, on the other hand, water is water! And east is east and west is west and if you take cranberries and stew them like applesauce they taste much more like prunes than rhubarb does. Now, uh... Now you tell me what you know.
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Re: 383man
[Re: MoparforLife]
#696242
05/13/10 07:52 PM
05/13/10 07:52 PM
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Joined: Jun 2005
Posts: 1,209
Fredericktown, PA 15333
maundmotorworks
Stealth poster
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Stealth poster
Joined: Jun 2005
Posts: 1,209
Fredericktown, PA 15333
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Quote:
Quote:
Yes I was looking at their installation instructions. It shows the top ring should be .0065 inch per inch of bore. They also mention the second ring too at .004 inch per inch of bore. I guess I'll be pulling the motor back out and tear into it to see what the ring gap is.. 
I can't believe you put an engine together without checking the ring gap. Any engine build this is done. 
Yeah, no doubt! Whether the rings are file-fits or not, always always always check your ring gaps! And in the case of the KBs, don't be stingy with the gap on that top ring. The other guy was right, give it a good .028" gap. I do on 440s as well as the 360s though it's on the big side on the 360. So what. It works for me time and time again. And like the others said, knowing the proper parts for the application is absolutely critical and that not just goes for the customer, but the builder too.
Maund Motorworks--supplier of high performance Mopar engines--specializing in B, RB, and Hemi. www.maundmotorworks.com
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Re: 383man
[Re: DennisH ]
#696244
05/14/10 11:46 AM
05/14/10 11:46 AM
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Joined: Feb 2003
Posts: 12,675
Columbia, CT
moper
I Live Here
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I Live Here
Joined: Feb 2003
Posts: 12,675
Columbia, CT
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Yeah, and that happens with cams, lifters, intakes, carbs, ignitions.. notice a pattern? lol
Well, art is art, isn't it? Still, on the other hand, water is water! And east is east and west is west and if you take cranberries and stew them like applesauce they taste much more like prunes than rhubarb does. Now, uh... Now you tell me what you know.
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