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Re: Anyone broke an LY or 6 pack rod? [Re: GTX MATT] #1723211 01/07/15 09:06 AM 01/07/15 09:06 AM
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: He shifted it around 6500-6800. Obviously he broke it with excessive RPM. And it had heavy TRW 6 pack slugs in it. What stories do you guys have? You are making me cringe. GTX still has "old school" 440 that I built in the mid 90's. Mcandless ported heads with oversize valves, battleship springs with titanium retainers and max wedge rocker gear with a 590 cam. Forged six pack slugs, LY rods that are shot peened with ARP bolts. On its best pass (11.2 at 124) it went through the traps at 7200. I remember looking at the tach as the needle was rising wondering if the blow shield would hold if the flywheel let go... Motor still runs great though I bet the ring seal is not as good as it once was and she marks her spot time to time. "I think its got a hemi"

Re: Anyone broke an LY or 6 pack rod? [Re: GTX MATT] #1723212 01/07/15 11:15 AM 01/07/15 11:15 AM
Joined: Jan 2003 Posts: 13,363 Marion, South Carolina [><] an8sec70cuda I Live Here
an8sec70cuda I Live Here Joined: Jan 2003 Posts: 13,363 Marion, South Carolina [><]	Not me personally, but I bought an old Duster drag car once that had the top 1/2 of a 6 pack rod laying in the trunk. The rod had broken, but surprisingly hadn't hurt anything else except for hitting a piston skirt. I never saw the crank or the other 1/2 so I can't say if it was a broken bolt or a turned bearing that caused it. They swapped in a set of LY rods and kept on going, lol. Had the old 2295 TRW slugs in it. Friend of mine had a 600 hp 440 w/ a stock crank and six pack rods that ran high 9s in a back half cuda bracket car for a long time. I bought the motor and ran it for a little while, but then tore it down for a rebuild and put some Manley H beams in it. CHIP '70 hemicuda, 575" Hemi, 727, Dana 60 '69 road runner, 440-6, 18 spline 4 speed, Dana 60 '71 Demon, 340, low gear 904, 8.75 '73 Chrysler New Yorker, 440, 727, 8.75 '90 Chevy 454SS Silverado, 476" BBC, TH400, 14 bolt '06 GMC 2500HD LBZ Duramax

Re: Anyone broke an LY or 6 pack rod? [Re: gdonovan] #1723213 01/07/15 02:53 PM 01/07/15 02:53 PM
Joined: Jun 2006 Posts: 5,161 CT GTX MATT OP master
GTX MATT OP master Joined: Jun 2006 Posts: 5,161 CT	Quote: Quote: He shifted it around 6500-6800. Obviously he broke it with excessive RPM. And it had heavy TRW 6 pack slugs in it. What stories do you guys have? You are making me cringe. GTX still has "old school" 440 that I built in the mid 90's. Mcandless ported heads with oversize valves, battleship springs with titanium retainers and max wedge rocker gear with a 590 cam. Forged six pack slugs, LY rods that are shot peened with ARP bolts. On its best pass (11.2 at 124) it went through the traps at 7200. I remember looking at the tach as the needle was rising wondering if the blow shield would hold if the flywheel let go... Motor still runs great though I bet the ring seal is not as good as it once was and she marks her spot time to time. I ain't gonna lie to ya Gary 7200 on stock rods would scare me, but lots of people have done it. I built mine to turn 7K with Scat H beams, studded mains, and 525 gram forged pistons and I'm a little scared to bring it up that far. What are you using for bearings out of curiousity and how do you like that 590 on the street? If it makes you feel better the same friend bought a 67 GTX brand new and for 2 years spun the stock short block (never opened, so factory clearance on everything) to 7K, that was brand new of course though but the car saw street duty as well, never broke it. I'm guessing like many others the one on his garage floor started with a rod bolt. Last edited by GTX MATT; 01/07/15 02:54 PM. Now I need to pin those needles, got to feel that heat Hear my motor screamin while I'm tearin up the street

Re: Anyone broke an LY or 6 pack rod? [Re: GTX MATT] #1723214 01/07/15 04:23 PM 01/07/15 04:23 PM
Joined: Jan 2003 Posts: 16,376 D dogdays I Live Here
dogdays I Live Here D Joined: Jan 2003 Posts: 16,376	A while ago there was an interview in Mopar Action with a guy who had been in the engine room at Chryco. I don't remember the name and don't remember what the factory term was for dyno testing, but it wasn't dyno testing. He had tested many many engines and said the 440s they'd run for hours and hours and they kept gaining power. After X number of hours the power would have maxed out, that was the number. If they kept testing the same engine it'd soon break. If a rod broke it'd pull off something like an inch below the pin. I believe this was why the 908 rods were designed with the thicker beam. I don't know why Mopar engineers were so in love with heavy pistons, except that they designed engines that usually had pretty short strokes and the heavy piston isn't so much of a detriment, also the heavy pistons probably were much more durable. R.

Re: Anyone broke an LY or 6 pack rod? [Re: dogdays] #1723215 01/07/15 04:45 PM 01/07/15 04:45 PM
Joined: Jun 2006 Posts: 5,161 CT GTX MATT OP master
GTX MATT OP master Joined: Jun 2006 Posts: 5,161 CT	I don't think they were in love with heavy pistons, I think they were in love with tall pistons, for greater stability in the bore. They were heavy as a product of being tall. They were pretty strong for factory cast slugs though. Unfortunately it also makes aftermarket parts selection harder. Aftermarket rods are all .008 inches short, lots of short pistons, etc. And also so that we could stroke them easy later. Last edited by GTX MATT; 01/07/15 04:49 PM. Now I need to pin those needles, got to feel that heat Hear my motor screamin while I'm tearin up the street

Re: Anyone broke an LY or 6 pack rod? [Re: GTX MATT] #1723216 01/07/15 05:01 PM 01/07/15 05:01 PM
Joined: Feb 2005 Posts: 20,174 PA. pittsburghracer "Little"John
pittsburghracer "Little"John Joined: Feb 2005 Posts: 20,174 PA.	Years ago I had a local coal company that would sell me the 440 engines off their old generators for 50 bucks for a complete forged crank engines. Man I miss those days 1970 Duster Edelbrock headed 408 5.984@112.52 422 Indy headed small block 5.982@112.56 mph 9.42@138.27 Livin and lovin life one day at a time

Re: Anyone broke an LY or 6 pack rod? [Re: GTX MATT] #1723217 01/07/15 05:50 PM 01/07/15 05:50 PM
Joined: Nov 2007 Posts: 277 MN W Willie68coronet enthusiast
Willie68coronet enthusiast W Joined: Nov 2007 Posts: 277 MN	Quote: I ain't gonna lie to ya Gary 7200 on stock rods would scare me, but lots of people have done it. I built mine to turn 7K with Scat H beams, studded mains, and 525 gram forged pistons and I'm a little scared to bring it up that far. Which 440 pistons do you have that 525? Lightest I've seen advertised are CP at around 625. My late 1990's JE's I have on the shelf are 645. I'm curious of what you have, if that wasn't a typo? '68 Coronet 500 w/ Indy EZ-1 headed 446, 727 trans, 9" rear First day at the track with SUV street tires and no traction: 1.688 60', 7.24 @ 101.79 in the 1/8 mile Great customer service from: DominicThumper Carbs, B3 racing engines, Porter Racing Engines, A-1 torque converter's, Quick Performance, Racer Brown Cams, R&R Performance, Manton pushrods

Re: Anyone broke an LY or 6 pack rod? [Re: GTX MATT] #1723218 01/07/15 08:29 PM 01/07/15 08:29 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: What are you using for bearings out of curiousity and how do you like that 590 on the street? Pretty sure they were Clevite bearings as that is pretty much all I would use at the time and the 590 cam was pretty fun on the street. Better roller grinds now though if you have the choice but as far as flat tappet the 590 is nice. "I think its got a hemi"

Re: Anyone broke an LY or 6 pack rod? [Re: gdonovan] #1723219 01/07/15 08:58 PM 01/07/15 08:58 PM
Joined: Jan 2003 Posts: 16,376 D dogdays I Live Here
dogdays I Live Here D Joined: Jan 2003 Posts: 16,376	A 3.75 stroke engine with 7/16" high quality rod bolts and 600 gram pistons should live at 8000 rpm indefinitely. R.

Re: Anyone broke an LY or 6 pack rod? [Re: Willie68coronet] #1723220 01/07/15 09:53 PM 01/07/15 09:53 PM
Joined: Jun 2006 Posts: 5,161 CT GTX MATT OP master
GTX MATT OP master Joined: Jun 2006 Posts: 5,161 CT	Quote: Quote: I ain't gonna lie to ya Gary 7200 on stock rods would scare me, but lots of people have done it. I built mine to turn 7K with Scat H beams, studded mains, and 525 gram forged pistons and I'm a little scared to bring it up that far. Which 440 pistons do you have that 525? Lightest I've seen advertised are CP at around 625. My late 1990's JE's I have on the shelf are 645. I'm curious of what you have, if that wasn't a typo? No typo, Wiseco Pro Tru PT034H3, great price too I paid 500 with rings Now I need to pin those needles, got to feel that heat Hear my motor screamin while I'm tearin up the street

Re: Anyone broke an LY or 6 pack rod? [Re: gdonovan] #1723221 01/07/15 10:47 PM 01/07/15 10:47 PM
Joined: Feb 2003 Posts: 1,099 Massillon, Ohio C cudatom super stock
cudatom super stock C Joined: Feb 2003 Posts: 1,099 Massillon, Ohio	Quote: Quote: He shifted it around 6500-6800. Obviously he broke it with excessive RPM. And it had heavy TRW 6 pack slugs in it. What stories do you guys have? You are making me cringe. GTX still has "old school" 440 that I built in the mid 90's. Mcandless ported heads with oversize valves, battleship springs with titanium retainers and max wedge rocker gear with a 590 cam. Forged six pack slugs, LY rods that are shot peened with ARP bolts. On its best pass (11.2 at 124) it went through the traps at 7200. I remember looking at the tach as the needle was rising wondering if the blow shield would hold if the flywheel let go... Motor still runs great though I bet the ring seal is not as good as it once was and she marks her spot time to time. Sounds like my old combo except I ran the heavy TRW2295 pistons and 6 pk rods. Crossed the stripe at 6800 and ran 10.82 in my Cuda. The most consistent motor I ever had. Ran for 14 yrs until bang at the stripe. Was not pretty. Broke the block, cam, one 6 pk rod in 4 pieces and 3 more twisted like pretzels. Ok

Re: Anyone broke an LY or 6 pack rod? [Re: cudatom] #1723222 01/07/15 11:52 PM 01/07/15 11:52 PM
Joined: Apr 2012 Posts: 18,880 - R RSNOMO Moparts Torchbearer
RSNOMO Moparts Torchbearer R Joined: Apr 2012 Posts: 18,880 -	Got 20 years going on LY's with ARP bolts, under forged, six-pak TRW's...

Re: Anyone broke an LY or 6 pack rod? [Re: RSNOMO] #1723223 01/08/15 12:10 AM 01/08/15 12:10 AM
Joined: Jul 2006 Posts: 684 toronto 6 6PAK70CUDA mopar
6PAK70CUDA mopar 6 Joined: Jul 2006 Posts: 684 toronto	Quote: Got 20 years going on LY's with ARP bolts, under forged, six-pak TRW's... I bought a used bracket 440 off a buddy and heavy (2350P I think) pistons, LY rods, solid lifter cam and usually buzzed it 6500-7000 rpm and it did go when I bent a pushrod and lifter popped and then low oil press and you know the rest... I remember going to a Herb McCandless seminar back at the Nats in the 80's and asked him what could be done to improve RB bottom ends and he replied "they are strong enough; it's usually an oiling problem. If you put beefier parts in you just do a better job of sawing the motor in half when it lets go due to the oiling problem" Now that was well before aftermarket heads and power adders that have us pushing them to power levels previously unattainable but words to consider for those of us running "old school" combos.

Re: Anyone broke an LY or 6 pack rod? [Re: CHAPPER] #1723224 01/08/15 01:43 PM 01/08/15 01:43 PM
Joined: Jan 2003 Posts: 21,072 Niles , Ohio T therocks oh wait.but hey.lets see.oh yeah.
therocks oh wait.but hey.lets see.oh yeah. T Joined: Jan 2003 Posts: 21,072 Niles , Ohio	I have a LY in the garage that is bent pretty good.My machinst asked if the motor ran.I said yes it did and was spun over 6K many times with the bent rod.Its not a slight bend either.Rocky Chrysler Firepower

Re: Anyone broke an LY or 6 pack rod? [Re: JERICOGTX] #1723225 01/08/15 07:00 PM 01/08/15 07:00 PM
Joined: Aug 2003 Posts: 2,401 Tucson, Arizona M MRMOPAR top fuel
MRMOPAR top fuel M Joined: Aug 2003 Posts: 2,401 Tucson, Arizona	Quote: Paging Mopar Billy... I'd still like to see MoparBilly chime in here. He ran LY rods with some very BIG loads of NOS... Somewhere back in the long ago archives, he told the story about that! Made very interesting reading! 68 RR 528" INDY MAXX 07 2500 CTD Southwest International Raceway - IHRA - Tucson, AZ

Re: Anyone broke an LY or 6 pack rod? [Re: GTX MATT] #1723226 01/08/15 10:07 PM 01/08/15 10:07 PM
Joined: May 2008 Posts: 5,399 Aurora, Colorado 451Mopar master
451Mopar master Joined: May 2008 Posts: 5,399 Aurora, Colorado	I'm lucky, never broke one. The old 451 "B" engine used the cut down 440 crank and LY rods with ARP bolts, and light weight Ross pistons. I figured the rods were the weak point of the short block, but they held up very well in that motor, and a broken intake valve did in the engine after 10+ years of street and strip driving/racing. When I first built the engine in the 1990's, several friends asked me what I was going to do when a broke one of the LY rods? I would tell them "I'll build a bigger engine."

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