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Gen 3 6.1 Hemi woes the saga continues #1754610 02/14/15 08:30 PM 02/14/15 08:30 PM
Joined: Apr 2005 Posts: 936 Deland, Florida B biff426 OP super stock
biff426 OP super stock B Joined: Apr 2005 Posts: 936 Deland, Florida	Well if you read the MSD post where I thought I can an ignition problem and it turned out to be the cam pin broke and bent all the intake valves. I pulled the motor disassembled everything to the bare block and well found nothing wrong other then the cam pin broke. I looked at all the cam bearings all look perfect. Checked all the valve train looks good retainer to seal coil bind all good I did find 2 lifter bores that were .0005 tighter I have .0025 lifter to bore on 6 holes and .002 on 2 holes. I am looking for suggestions on things to look for I sure don't want to put it together again and have the same issue. The piston to valve numbers were .160 intake and .280 exhaust when I get the cam back I will double check this again but it was checked 2 times when I initially put it together.

Re: Gen 3 6.1 Hemi woes the saga continues [Re: biff426] #1754611 02/14/15 08:57 PM 02/14/15 08:57 PM
Joined: Feb 2011 Posts: 4,302 Nebraska 72Swinger master
72Swinger master Joined: Feb 2011 Posts: 4,302 Nebraska	Same thing happened to another fellow on here except he lucked out and didn't bend any valves. Seems some of the aftermarket cam dowels may be weak. I think he put one out of his old 6.1 cam in the new one and has been good to go since. Uhcoog is his user name, Wade is his first name. Mopar to the bone!!!

Re: Gen 3 6.1 Hemi woes the saga continues [Re: 72Swinger] #1754612 02/15/15 12:31 AM 02/15/15 12:31 AM
Joined: Jan 2003 Posts: 8,180 Detroit, MI CokeBottleKid master
CokeBottleKid master Joined: Jan 2003 Posts: 8,180 Detroit, MI	I'm not familiar with Gen3 architecture but why not add more dowels?

Re: Gen 3 6.1 Hemi woes the saga continues [Re: CokeBottleKid] #1754613 02/15/15 12:46 AM 02/15/15 12:46 AM
Joined: Mar 2006 Posts: 9,839 MI, usa dvw master
dvw master Joined: Mar 2006 Posts: 9,839 MI, usa	The dowel shouldn't be the issue. The bolt should have enough stretch to hold the gear to the cam. Doug

Re: Gen 3 6.1 Hemi woes the saga continues [Re: dvw] #1754614 02/15/15 10:13 AM 02/15/15 10:13 AM
Joined: Jul 2009 Posts: 116 Florida mack member
mack member Joined: Jul 2009 Posts: 116 Florida	I had the exact same thing happen to my DP 6.1. Bent all the valves also.... Had just gone thru the engine.. Taken completely down to the block. Learned the cam bolt is a one use item.. Installed a new one and haven't had a problem since... Mack Reeves SST 2377 FS/D 2377

Re: Gen 3 6.1 Hemi woes the saga continues [Re: mack] #1754615 02/15/15 01:19 PM 02/15/15 01:19 PM
Joined: Jul 2010 Posts: 224 in the middle D dodger mope enthusiast
dodger mope enthusiast D Joined: Jul 2010 Posts: 224 in the middle	In 1973 i owned a 1972 newport coupe with a 400 engine,the performance and fuel mileage was a disappointment . after thinking about my options for improvement i decided to advance the cam 6 degrees.a chevy guy that worked for me warned about the the single bolt and make sure the alignment pin was strong enough. when i said you don't need the PIN ,he got lite headed and bet me the cam gear fall off in 10 miles. i advanced the cam without the pin in place and after 10,000 miles collected the $10 bet. the improvement was 14.5 to 18 mpg, with a few carb changes. i traded the car at 150,000.

Re: Gen 3 6.1 Hemi woes the saga continues [Re: dodger mope] #1754616 02/15/15 02:56 PM 02/15/15 02:56 PM
Joined: Jun 2005 Posts: 2,776 Ontario Canada M MattW master
MattW master M Joined: Jun 2005 Posts: 2,776 Ontario Canada	Quote: In 1973 i owned a 1972 newport coupe with a 400 engine,the performance and fuel mileage was a disappointment . after thinking about my options for improvement i decided to advance the cam 6 degrees.a chevy guy that worked for me warned about the the single bolt and make sure the alignment pin was strong enough. when i said you don't need the PIN ,he got lite headed and bet me the cam gear fall off in 10 miles. i advanced the cam without the pin in place and after 10,000 miles collected the $10 bet. the improvement was 14.5 to 18 mpg, with a few carb changes. i traded the car at 150,000. Back then they did not have disposable bolts.

Re: Gen 3 6.1 Hemi woes the saga continues [Re: mack] #1754617 02/16/15 02:16 AM 02/16/15 02:16 AM
Joined: Jan 2003 Posts: 8,180 Detroit, MI CokeBottleKid master
CokeBottleKid master Joined: Jan 2003 Posts: 8,180 Detroit, MI	Quote: I had the exact same thing happen to my DP 6.1. Bent all the valves also.... Had just gone thru the engine.. Taken completely down to the block. Learned the cam bolt is a one use item.. Installed a new one and haven't had a problem since... Ah yes, forgot you old timers don't know about TTY bolts . I'd be replacing it with a nice ARP bolt... no more TTY

Re: Gen 3 6.1 Hemi woes the saga continues [Re: CokeBottleKid] #1754618 02/16/15 02:24 AM 02/16/15 02:24 AM
Joined: Apr 2005 Posts: 936 Deland, Florida B biff426 OP super stock
biff426 OP super stock B Joined: Apr 2005 Posts: 936 Deland, Florida	The bolt was new from the dealer the torque spec was a straight spec not a torque to yield type spec.

Re: Gen 3 6.1 Hemi woes the saga continues [Re: biff426] #1754619 02/16/15 03:31 AM 02/16/15 03:31 AM
Joined: Sep 2003 Posts: 10,645 Houston, Tx A AlexP I Live Here
AlexP I Live Here A Joined: Sep 2003 Posts: 10,645 Houston, Tx	I've seen it happen first hand two times. The first time it popped at idle and bent a valve. No serious damaged to anything else. The other time broke at idle and caused no serious damage but we tore it down anyway. The pop was uncanny. Replaced the dowel and it has survived a bunch of abuse Any machinist can add an extra dowel or two with ease. But if the bolt isn't tight...you're out of luck. Just a matter of time before the walking of the upper gear shears that dowel. Last edited by AlexP; 02/16/15 03:32 AM. My Build thread: Let the hemi swap begin! 1968 wanna be pro touring whatchamacallit with some fancy stuff and a new roof skin.

Re: Gen 3 6.1 Hemi woes the saga continues [Re: AlexP] #1754620 02/16/15 04:05 PM 02/16/15 04:05 PM
Joined: Apr 2005 Posts: 936 Deland, Florida B biff426 OP super stock
biff426 OP super stock B Joined: Apr 2005 Posts: 936 Deland, Florida	Ok may have found the problem one thing I didn't look at was the back of the thrust plate. The cam was buggered up on the snout but figured it was from the cam gear spinning. Well the thrust plate is also scuffed pretty bad. A call to manley and they said they have seen a variance in the length of the cam snouts with the aftermarket cams some of them actually get tight on the trust plate and cause this issue. (would have been a nice addition to the instruction manual) I did not check the cam endplay because there really is not way of changing it without machining so I figured it was thought out in the thrust plate design (shame on me) Soooooo that will get fixed and I should be good to go but add this to your things to check I should have had Steff build me a belt drive!!!!!!!!!!!!!

Re: Gen 3 6.1 Hemi woes the saga continues [Re: biff426] #1754621 02/16/15 04:41 PM 02/16/15 04:41 PM
Joined: Sep 2003 Posts: 10,645 Houston, Tx A AlexP I Live Here
AlexP I Live Here A Joined: Sep 2003 Posts: 10,645 Houston, Tx	I recall hearing that. I'll only ever use a factory 6.1 timing set. My Build thread: Let the hemi swap begin! 1968 wanna be pro touring whatchamacallit with some fancy stuff and a new roof skin.

Re: Gen 3 6.1 Hemi woes the saga continues [Re: AlexP] #1754622 02/16/15 05:59 PM 02/16/15 05:59 PM
Joined: Feb 2011 Posts: 4,302 Nebraska 72Swinger master
72Swinger master Joined: Feb 2011 Posts: 4,302 Nebraska	This stuff makes me feel ALOT better about running a used cam. Probably just jinxed myself.... Mopar to the bone!!!

Re: Gen 3 6.1 Hemi woes the saga continues [Re: 72Swinger] #1754623 02/16/15 06:39 PM 02/16/15 06:39 PM
Joined: Jun 2003 Posts: 9,225 Charleston S sixpackgut Drag Week Mod Champion
sixpackgut Drag Week Mod Champion S Joined: Jun 2003 Posts: 9,225 Charleston	I believe there is the exact number of links holding a stock timing chain together as a double roller. I not only decided to use a stock chain but the same chain after POR fixed the piston issue in my engine Gen 3 power 6.22@110, 9.85@135 Follow @g3hemiswap on instagram performance only racing, CRT, ultimate converter, superior design concepts, ThumperCarbs

Re: Gen 3 6.1 Hemi woes the saga continues [Re: sixpackgut] #1754624 02/18/15 12:18 PM 02/18/15 12:18 PM
Joined: Apr 2005 Posts: 936 Deland, Florida B biff426 OP super stock
biff426 OP super stock B Joined: Apr 2005 Posts: 936 Deland, Florida	Well upon further investigation it is not really a cam end play issue the problem is the snout of the cam is not long enough and when you torque the cam bolt it pinches the thrust plate between the face of the cam and the timing gear. It is tight enough to be a problem but not tight enough to "feel" tight when you spin the engine by hand when assembled but if you torque the gear on with no chain you can barely turn it. I think it is more a problem with the cam then the timing set.

Re: Gen 3 6.1 Hemi woes the saga continues [Re: biff426] #1754625 02/19/15 11:57 PM 02/19/15 11:57 PM
Joined: May 2005 Posts: 723 Houston Tx Uhcoog1 super stock
Uhcoog1 super stock Joined: May 2005 Posts: 723 Houston Tx	This happened to me. Educated guess at my issue: -k1 crank has a radius edge vs 90* on factory crank. Where the timing gear butts up to the crank. -maybe the bolt wasn't torqued properly with locktite Fix: - install factory 6.1 pin in jones cam - chamfer the timing gear -lots of locktite and torque -'02 Dodge Viper Ex-World Challenge racecar -'73 Duster, 6.1 based 392 hilborn hemi, tko600, full floater rear 9", Hellwig custom bars, viper brakes, built for road course

Re: Gen 3 6.1 Hemi woes the saga continues [Re: Uhcoog1] #1754626 02/20/15 06:22 AM 02/20/15 06:22 AM
Joined: Feb 2011 Posts: 4,302 Nebraska 72Swinger master
72Swinger master Joined: Feb 2011 Posts: 4,302 Nebraska	The person I bought my cam from was very adamant about using ONLY a stock timing set FWIW. Mopar to the bone!!!

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