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KB pistons BREAK IN HALF??? #696205 05/12/10 03:48 PM 05/12/10 03:48 PM
Joined: Jan 2003 Posts: 715 Tulsa, Oklahoma C Charger_440 OP super stock
Charger_440 OP super stock C Joined: Jan 2003 Posts: 715 Tulsa, Oklahoma	ive been doing some research and had bought some KB 107's to use in my 360 build, but have had 2 builders refuse to use them, saying they have a tendancy to break...crack right down the middle. has anyone had any experience with this happening? these are VERY well known engine builders, not just local guys In a conversation with a Wyoming State Patrolman... "A 318 ??!!! But I clocked you at 142 mph!!!"

Re: KB pistons BREAK IN HALF??? [Re: Charger_440] #696206 05/12/10 03:53 PM 05/12/10 03:53 PM
Joined: Jan 2003 Posts: 1,607 Lapeer, MI. todd440 top fuel
todd440 top fuel Joined: Jan 2003 Posts: 1,607 Lapeer, MI.	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!

Re: KB pistons BREAK IN HALF??? [Re: Charger_440] #696207 05/12/10 03:54 PM 05/12/10 03:54 PM
Joined: Jan 2003 Posts: 9,826 las vegas 70AARcuda master
70AARcuda master Joined: Jan 2003 Posts: 9,826 las vegas	Have a set of kb107 in 360 with thousands of miles of on them...still in one piece. maybe the engine builder did not read the instructions about setting the ring gap for hyper pistons...and probably not since he is well known. Tony 70 AARCuda Vitamin C 71 Dart Swinger 360 10.318 @ 128.22(10-04-14 Bakersfield) 71 Demon 360 10.666 @122.41 (01-29-17 @ Las Vegas) 71 Duster 408 (10.29 @ 127.86 3/16/19 Las Vegas)

Re: KB pistons BREAK IN HALF??? [Re: todd440] #696208 05/12/10 03:56 PM 05/12/10 03:56 PM
Joined: Jun 2009 Posts: 171 Indy M moparman89 member
moparman89 member M Joined: Jun 2009 Posts: 171 Indy	If the builder reads the instructions that comes with the pistons and FOLLOWS them, they wont break. Half the builders throw them away and do their own thing. The engineers who design these things are not stupid.

Re: KB pistons BREAK IN HALF??? [Re: moparman89] #696209 05/12/10 03:59 PM 05/12/10 03:59 PM
Joined: Jan 2003 Posts: 715 Tulsa, Oklahoma C Charger_440 OP super stock
Charger_440 OP super stock C Joined: Jan 2003 Posts: 715 Tulsa, Oklahoma	one was saying that ever since the production went to mexico the quality sucks. i hope he isnt right bcse i have $ invested in these, both of these guys reccommend SRP pistons. any thoughts on that? In a conversation with a Wyoming State Patrolman... "A 318 ??!!! But I clocked you at 142 mph!!!"

Re: KB pistons BREAK IN HALF??? [Re: Charger_440] #696210 05/12/10 04:01 PM 05/12/10 04:01 PM
Joined: Jun 2008 Posts: 10,847 Oakdale CT gdonovan I Live Here
gdonovan I Live Here Joined: Jun 2008 Posts: 10,847 Oakdale CT	Quote: ive been doing some research and had bought some KB 107's to use in my 360 build, but have had 2 builders refuse to use them, saying they have a tendancy to break...crack right down the middle. has anyone had any experience with this happening? these are VERY well known engine builders, not just local guys In 2.2 turbo applications they are avoided like the plague. They are very brittle pistons that are cheap to make.

Re: KB pistons BREAK IN HALF??? [Re: Charger_440] #696211 05/12/10 04:02 PM 05/12/10 04:02 PM
Joined: Jan 2003 Posts: 9,826 las vegas 70AARcuda master
70AARcuda master Joined: Jan 2003 Posts: 9,826 las vegas	and what be the difference if they were made in southern california???? Tony 70 AARCuda Vitamin C 71 Dart Swinger 360 10.318 @ 128.22(10-04-14 Bakersfield) 71 Demon 360 10.666 @122.41 (01-29-17 @ Las Vegas) 71 Duster 408 (10.29 @ 127.86 3/16/19 Las Vegas)

Re: KB pistons BREAK IN HALF??? [Re: gdonovan] #696212 05/12/10 04:11 PM 05/12/10 04:11 PM
Joined: Jun 2005 Posts: 1,209 Fredericktown, PA 15333 maundmotorworks Stealth poster
maundmotorworks Stealth poster Joined: Jun 2005 Posts: 1,209 Fredericktown, PA 15333	Quote: Quote: ive been doing some research and had bought some KB 107's to use in my 360 build, but have had 2 builders refuse to use them, saying they have a tendancy to break...crack right down the middle. has anyone had any experience with this happening? these are VERY well known engine builders, not just local guys In 2.2 turbo applications they are avoided like the plague. They are very brittle pistons that are cheap to make. In a turbo application you're not supposed to use a hypereutectic piston anyway regardless of who manufactures it, and I was told that by representatives from two different piston companies. As for the KB107s, I've used hundreds and hundreds over the years with resounding success, as well as many other KB hypereutectic pistons. Like the others said, follow the directions for increasing the gap on the top ring and you're good to go. Maund Motorworks--supplier of high performance Mopar engines--specializing in B, RB, and Hemi. www.maundmotorworks.com

Re: KB pistons BREAK IN HALF??? [Re: maundmotorworks] #696213 05/12/10 04:17 PM 05/12/10 04:17 PM
Joined: Jun 2008 Posts: 10,847 Oakdale CT gdonovan I Live Here
gdonovan I Live Here Joined: Jun 2008 Posts: 10,847 Oakdale CT	Quote: In a turbo application you're not supposed to use a hypereutectic piston anyway regardless of who manufactures it, and I was told that by representatives from two different piston companies. Which doesn't change the fact there are companies making them for factory turbo applications. Turbo or supercharged or nitrous will reduce hyperutectic pistons to junk quick. Factory cast are better or forged, I have put 30 psi of boost to factory chrylser pistons and they live.

Re: KB pistons BREAK IN HALF??? [Re: gdonovan] #696214 05/12/10 04:24 PM 05/12/10 04:24 PM
Joined: Jun 2005 Posts: 1,209 Fredericktown, PA 15333 maundmotorworks Stealth poster
maundmotorworks Stealth poster Joined: Jun 2005 Posts: 1,209 Fredericktown, PA 15333	Yeah, I know they still make them for turbo applications anyway despite that they wouldn't hold up well. Forged is indeed the way to go since they hold up in pretty much any application. And I think you're right on another account--a cast piston is a tough S.O.B! Look at what the drag guys used to do with cast pistons before the forged stuff came available, and that was even severe punishment for forged pistons. Maund Motorworks--supplier of high performance Mopar engines--specializing in B, RB, and Hemi. www.maundmotorworks.com

Re: KB pistons BREAK IN HALF??? [Re: maundmotorworks] #696215 05/12/10 04:37 PM 05/12/10 04:37 PM
Joined: Jan 2003 Posts: 715 Tulsa, Oklahoma C Charger_440 OP super stock
Charger_440 OP super stock C Joined: Jan 2003 Posts: 715 Tulsa, Oklahoma	my build is not a boosted build. its a LA 360, stock build except cam and pistons. adn ported heads. so, anybody wth an NA build that has actually had this problem? both of these guys work predominantly with race engines, so maybe a street engine they'd be ok? i hadnt heard ths before now, but for 2 ppl in 2 weeks to say it...scared me. In a conversation with a Wyoming State Patrolman... "A 318 ??!!! But I clocked you at 142 mph!!!"

Re: KB pistons BREAK IN HALF??? [Re: Charger_440] #696216 05/12/10 04:55 PM 05/12/10 04:55 PM
Joined: Jan 2003 Posts: 25,200 Upper Midwest M MoparforLife Too Many Posts
MoparforLife Too Many Posts M Joined: Jan 2003 Posts: 25,200 Upper Midwest	Have seen many KB pistons and about the only ones I have seen that break are not installed properly.FOLLOW the directions. Mine have seen many seasons. Clean it, if it's Dirty. Oil it, if it Squeaks. But: Don't fix it, if it Works!

Re: KB pistons BREAK IN HALF??? [Re: Charger_440] #696217 05/12/10 04:56 PM 05/12/10 04:56 PM
Joined: Dec 2004 Posts: 5,278 San Jose, California D DennisH Vacation
DennisH Vacation D Joined: Dec 2004 Posts: 5,278 San Jose, California	Got em in the BB. No problems after 6 years of misuse. My builder is well known.

Re: KB pistons BREAK IN HALF??? [Re: Charger_440] #696218 05/12/10 05:02 PM 05/12/10 05:02 PM
Joined: Feb 2009 Posts: 1,274 Ontario.Canada C can.al pro stock
can.al pro stock C Joined: Feb 2009 Posts: 1,274 Ontario.Canada	..even though most on Moparts recomend these pistons,i also know builders that refuse to use them.

Re: KB pistons BREAK IN HALF??? [Re: Charger_440] #696219 05/12/10 05:44 PM 05/12/10 05:44 PM
Joined: Jan 2008 Posts: 199 douglasville,ga R ramrod member
ramrod member R Joined: Jan 2008 Posts: 199 douglasville,ga	I run KB hypers in my drag car. 360 with cast crank and stock connecting rods. I shift at 7K and the engine has seen 8K a time or two. MANY HUNDREDS of passes with no problem. Pay attention to the top ring gap and you will be fine. "That Plymouth had a Hemi with a Torqueflite." -Driver

Re: KB pistons BREAK IN HALF??? [Re: ramrod] #696220 05/12/10 06:21 PM 05/12/10 06:21 PM
Joined: Jan 2003 Posts: 715 Tulsa, Oklahoma C Charger_440 OP super stock
Charger_440 OP super stock C Joined: Jan 2003 Posts: 715 Tulsa, Oklahoma	thanks for easin my mind fellas In a conversation with a Wyoming State Patrolman... "A 318 ??!!! But I clocked you at 142 mph!!!"

Re: KB pistons BREAK IN HALF??? [Re: todd440] #696221 05/12/10 06:38 PM 05/12/10 06:38 PM
Joined: Jan 2003 Posts: 8,848 poplar bluff mo. T toplescuda I Whine
toplescuda I Whine T Joined: Jan 2003 Posts: 8,848 poplar bluff mo.	just how are they breaking? are they splitting down the middle? or halfway up? or if its splitting down the the middle the rings are not gonna cause a split it would more then likely from having prosity problem(something your not gonna see unless you x ray it(and im sure you guys didnt lol) iv made over 100,000 pistons working for briggs (yes there cast but not hand poured) and have seen my share of problems installing the rings wrong may cause some problems but spliting a piston prob wont be one of them 1970 barracuda convert. 1 of 59 1970 pro street A.A.R. clone (panther pink) 1971 charger 2015 hellcat challenger. Redline red 2014 quad cab 4x4 ram 8 speed hemi

Re: KB pistons BREAK IN HALF??? [Re: toplescuda] #696222 05/12/10 08:21 PM 05/12/10 08:21 PM
Joined: Jan 2003 Posts: 715 Tulsa, Oklahoma C Charger_440 OP super stock
Charger_440 OP super stock C Joined: Jan 2003 Posts: 715 Tulsa, Oklahoma	any suggestion on rings to use? he said hastings rings are like "a bore in a box" he tells me to use speedpro seal power moly rings. any input there? i want something with a long life to it. the originals in my 318 lasted 264k mi before i rebuilt it, i want something thats gonna be there for the long haul, not smoke after 65k mi. thanks guys In a conversation with a Wyoming State Patrolman... "A 318 ??!!! But I clocked you at 142 mph!!!"

Re: KB pistons BREAK IN HALF??? [Re: Charger_440] #696223 05/12/10 08:37 PM 05/12/10 08:37 PM
Joined: Jan 2003 Posts: 8,848 poplar bluff mo. T toplescuda I Whine
toplescuda I Whine T Joined: Jan 2003 Posts: 8,848 poplar bluff mo.	id like to see a pic of the piston the o p said was cracked right down the middle 1970 barracuda convert. 1 of 59 1970 pro street A.A.R. clone (panther pink) 1971 charger 2015 hellcat challenger. Redline red 2014 quad cab 4x4 ram 8 speed hemi

383man [Re: toplescuda] #696224 05/12/10 10:35 PM 05/12/10 10:35 PM
Joined: Jan 2003 Posts: 27,421 Balt. Md 3 383man Too Many Posts
383man Too Many Posts 3 Joined: Jan 2003 Posts: 27,421 Balt. Md	I have KB pistons running in 3 engines and all have worked fine. My 63 and my sons Dart have had them for years with many street miles and a few trips to the track every year. Also have a set in my buddies car. All are bigblocks. Mine is a 440 my sons is a 400 and my buddies is a 383. And as was said you HAVE TO SET THE TOP RING GAP RIGHT !!! Ron

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