440 six pack connecting rods

[moparfanUSA]

I am going to build a 440 that was given to me into a 6 pack motor. I am sure that they used a different connecting rod in the 6 pack motors, but when I go online I do not see that anyone sells rods that say they are for a 6 pack. I checked places like summit with no luck. So how do I find rods that will work with a six pack?

 

[RustyRatRod]

The standard 440 "LY" casting or any aftermarket 440 length rod will work fine. No one makes new six pack rods that I know of. They are all over fleabay. You're gonna see people complain about how heavy they are and all that hooha, but you'll never feel the difference if that's what you want to run. I'll put it like this. I've never seen a broke six pack rod. They are some beefy sumbitches.

Here's a good deal on a set. Seller has good feedback too. You'd need have them inspected and maybe good rod bolts installed and get them resized.

http://www.ebay.com/itm/Mopar-440-S...Parts_Accessories&hash=item43b8cfe14b&vxp=mtr

Also, remember too, you have to run the correct balancer with the six pack rods. Their extra weight requires the engine to be externally balanced, unless you have the machine shop internally balance the engine.

 

[67 coronet]

unless you are doing a resto to matching #'s i dont see a reason to use six pack rods.i think they were over engineered from the factory.there are much lighter and stronger rods available today.less weight in the reciprocating mass equals free horse power.

 

[Supershafts]

What the hell do want them for ? hang on the wall ? I wouldn't put them in a build.

 

[RustyRatRod]

unless you are doing a resto to matching #'s i dont see a reason to use six pack rods.i think they were over engineered from the factory.there are much lighter and stronger rods available today.less weight in the reciprocating mass equals free horse power.

Lighter connection rods and or reciprocating assembly will not make more power. That is an incorrect assumption.

 

[Sweet5ltr]

I am going to build a 440 that was given to me into a 6 pack motor. I am sure that they used a different connecting rod in the 6 pack motors, but when I go online I do not see that anyone sells rods that say they are for a 6 pack. I checked places like summit with no luck. So how do I find rods that will work with a six pack?

You'll need to run the appropriate pistons if you plan on internally balancing your engine with the six pack rods. I run the six pack rods, with a steel crank. When mopar moved to internally balanced six packs (in 71' I believe) the move to a lighter weight piston allowed them to do so. My engine is internally balanced, and is a 73'-74' six pack rod/steel crank build out of a wrecked highway patrol car. Rods are rock solid, can't go wrong.

 

[68rt]

I just had my 1970 stock 440 Six Pack Rebuilt two years ago and in the rebuild replaced the rods with a light weight stronger rod. When your reving the motor, it's no longer trying to move all that weight, revs super fast now......

 

[Meep-Meep]

Ditto Rusty's post. I have a set of real nice used virgin six pack rods that I'm saving for a budget build. Aftermarket rods have a good reputation but I have seen those broken as well. If you are building a hot street car then even the normal 440 rods are fine. I'm running the LY rods in my 440 with ARP bolts.

I seen one case where the engine scattered and it had six pack rods but who knows what happened because I wasn't there. But knowing those guys I can guarantee it was nothing good.

Back in the 70's it was recommended that you use hemi rods in a 440 build if you want it to hold together at high RPM's. And this info was from Landy. I believe the six pack rod was also recommended for a highly stressed engine. Even in the days of the 392 hemis the hot setup was to box the rods - i.e. weld steel plates to box the I beam area. Funny, but going back 30-40 yrs and seeing those recommendations, and a ton of successful engines, I find it strange that the exact same components are suddenly junk. I understand a failure point due to stress risers and such, but if you have a set of rods that weren't run through the wringer why can't you run them after a good prep? What changed? If anything the hardware is improved thus giving the older rods some new life.

 

[Sweet5ltr]

I believe people think that what worked back in the 60's, doesn't work anymore. Six pack rods are a solid foundation, and if you already have them, why not use them? YES, their are better rods, but the term better is negligible depending on your application and intended use...

 

[RustyRatRod]

The thing is, if you get a good set of modern lightweight pistons, you just negated the "extra weight" of the six pack rods.

 

[lewtot184]

You'll need to run the appropriate pistons if you plan on internally balancing your engine with the six pack rods. I run the six pack rods, with a steel crank. When mopar moved to internally balanced six packs (in 71' I believe) the move to a lighter weight piston allowed them to do so. My engine is internally balanced, and is a 73'-74' six pack rod/steel crank build out of a wrecked highway patrol car. Rods are rock solid, can't go wrong.

'69 6-paks had standard LY rods and were internally balanced. '70-'71 6-paks use the heavier rods and heavier pistons and were externally balanced. the weight of the rod is not as critcal from a performance standpoint as the piston. reducing reciprocating weight has no effect on horsepower. reducing weight lets the engine rev quicker and takes stress off the crank, bearings and main caps. if the engine is to be balanced run any piston you want.

 

[67 coronet]

the term power is kinda splitting hairs here.if the rotating mass spins up faster,them my power comes in faster and technicaly creats the same power sooner.sure,top hp will not change and power at a given rpm wont be differnt.power band will still be faster and give the illusion of more power.

 

[Budnicks]

'69 6-paks had standard LY rods and were internally balanced. '70-'71 6-paks use the heavier rods and heavier pistons and were externally balanced. the weight of the rod is not as critcal from a performance standpoint as the piston. reducing reciprocating weight has no effect on horsepower. reducing weight lets the engine rev quicker and takes (allot) stress off the crank, bearings and main caps. if the engine is to be balanced run any piston you want.

Bingo, that's a great reasons to use a quality lighter reciprocating assembly/crankshaft & rod combos, magnifluxed, polished, radius & then peened, Nitrited &/or Cryogenicaly {spelling?} treated, with much better hardware, than the stock rod bolts/washers & nuts {maybe even ARP main studs, washers & nuts}... IMHFO there are much better modern H-Beam & I Beam connecting rods, for the money spent to make a set of "old 6-Pack rods viable", especially for a race/performance engine build... But if it's just a milder low revving, performance street/strip build, it doesn't really matter, if you want to use the old "heavy 6-Pack rods", just use quality hardware, quality Clevite Tri-Metal bearing, they are beefy rods, kind of dated, but have a quality reputable machine shop, at least check of cracks & roundness, have them do resizing on both ends {maybe even bush the small ends}, have the proper machining & balancing done, also get a good quality harmonic balancer too... money well & wisely spent, is what it's all about...

- - - Updated - - -

I am going to build a 440 that was given to me into a 6 pack motor. I am sure that they used a different connecting rod in the 6 pack motors, but when I go online I do not see that anyone sells rods that say they are for a 6 pack. I checked places like summit with no luck. So how do I find rods that will work with a six pack?

What are you intending on doing with the engine ??, is it just a stocker type street brawler or a race motor ?? that will determine allot, in getting an educated, well thought out recommendation... try Mancini Racing

 

[Sweet5ltr]

'69 6-paks had standard LY rods and were internally balanced. '70-'71 6-paks use the heavier rods and heavier pistons and were externally balanced. the weight of the rod is not as critcal from a performance standpoint as the piston. reducing reciprocating weight has no effect on horsepower. reducing weight lets the engine rev quicker and takes stress off the crank, bearings and main caps. if the engine is to be balanced run any piston you want.

Good info, I guess I was posting for the H/D applications in non-six pack cars equipped with the six pack rod/steel crank combo as those (or most) were internally balanced in this configuration; using a lighter piston combination to compensate for the six pack rod weight.

 

[RustyRatRod]

illusion

Yup.

 

[lewtot184]

Good info, I guess I was posting for the H/D applications in non-six pack cars equipped with the six pack rod/steel crank combo as those (or most) were internally balanced in this configuration; using a lighter piston combination to compensate for the six pack rod weight.

anything that had 6-pak rods was externally balanced, even '70-'71 4bbl engines.

 

[72RoadrunnerGTX]

Anything? The HD(six-pack) rods and steel cranks were used into the mid-seventies on low compression HP440s and were internally balanced.

 

[lewtot184]

Anything? The HD(six-pack) rods and steel cranks were used into the mid-seventies on low compression HP440s and were internally balanced.

i don't think so.

 

[MikeStahl]

I just took apart a 71 440 that was...from a motor home, steel crank 6 pack rods and internal bal

 

[RustyRatRod]

I don't know about the internal/external arguement, but I have read before and heard from someone first hand that the 1969 1/2 cars with the 440 six pack and the Edelbrock intakes had LY rods. They were considered somewhat prototype and experimental. I've seen it more than one place and talked to an original A12 owner.