Stock rods, better bolts, how much hp ?

[ateam]

These powdered metal rods "look" shot peened, from the factory, I doubt they are. Seems like these would favor removing sharp edges, polishing and shot peening ? ARP 2000 bolts go in without need of resizing rods, by benefit of fractured caps. Discussion ? Thanks, ateam.:coffee2:

 

[Hellcat Cuda]

I'm not so sure they don't need to be resized. I've hung out on an LX/LC forum over the years to learn about these new hemis. Seems I remember talk of them needing to be resized but not absolutely sure on it. I do know that not a lot of people with those cars waste much time with the stock rods. Forged H beams are pretty inexpensive. SCAT has I beams that are only about $350 for a set from what I remember.

 

[johnparts]

These powdered metal rods "look" shot peened, from the factory, I doubt they are. Seems like these would favor removing sharp edges, polishing and shot peening ? ARP 2000 bolts go in without need of resizing rods, by benefit of fractured caps. Discussion ? Thanks, ateam.:coffee2:

Yeah the stock rods are good for a paper weight and that's about it. The advantage to the cracked cap technology is the rod cap centers itself and doesn't allow cap walk.

 

[winstoninwisc]

ive abused the chit outa my 2 340s and 1 360 imeans take it past the limit beatings never used a aftermarket rod always maged if rebuilt and a hone in a few always chandes bolts and never blew ot thru 1 i was only pushing 380 tops but i buzzed them till they broke springs im not a enginge or motor builder im a motor beater i should own stock in bf goodrich broke alot of every thing but never a rod in a mopari am building a 360 now to punnish if i ever get it done i saw a set of sir rods with 4.030 pistons for sale ,thought ok thats a good deal and every 1 is stroking there engines now so the rods all changed to aftermarket my 340 is pooped out so i am going to thro in a i dunno 450 or so 360 so i got the rods and pistons wich said 4.030 in the add and i got them and they are 4.060 they are brand new but cant seem to get rid of them they have rings also so any ways i think a stock 1970 rod will take all the punishment you want to give it in a less than 400 hp engine as long as it is lubing good and crank stays str8 change your rod bolts i like the arp torchm rite and beatem hard as you want if built rite the rod is the part that proved it self to abuse for me at11to1 comp and 7k all day long 12 second cars just check the holes and mag them change the bolts, checkm for str8ness and stretch they been good to me

 

[johnparts]

ive abused the chit outa my 2 340s and 1 360 imeans take it past the limit beatings never used a aftermarket rod always maged if rebuilt and a hone in a few always chandes bolts and never blew ot thru 1 i was only pushing 380 tops but i buzzed them till they broke springs im not a enginge or motor builder im a motor beater i should own stock in bf goodrich broke alot of every thing but never a rod in a mopari am building a 360 now to punnish if i ever get it done i saw a set of sir rods with 4.030 pistons for sale ,thought ok thats a good deal and every 1 is stroking there engines now so the rods all changed to aftermarket my 340 is pooped out so i am going to thro in a i dunno 450 or so 360 so i got the rods and pistons wich said 4.030 in the add and i got them and they are 4.060 they are brand new but cant seem to get rid of them they have rings also so any ways i think a stock 1970 rod will take all the punishment you want to give it in a less than 400 hp engine as long as it is lubing good and crank stays str8 change your rod bolts i like the arp torchm rite and beatem hard as you want if built rite the rod is the part that proved it self to abuse for me at11to1 comp and 7k all day long 12 second cars just check the holes and mag them change the bolts, checkm for str8ness and stretch they been good to me

He's refering to the powdered metal Hemi rods that come in the 5.7/6.1 hemi's

 

[Joe Dokes]

According to internet rumor, the powdered metal rods in a 5.7L Hemi are good for 500HP while the powdered metal rods in a 6.1L / 6.4L Hemi are good for 700HP.

As always your mileage may vary. A well running engine with no detonation and a responsible driver who does't rev the engine without a load might be able to survive a much higher HP than the above numbers would suggest. For example, there are LX cars with superchargers that have well over 500-700 HP and yet they live for quite a while. Yet, many eventually succumb to ventilated block syndrom.

There seems to be some disagreement on the interwebs about resizing cracked powdered metal rods.

This article from Engine Builders suggests that cracked rods cannot be resized because of the nature of the cracked mating surface of the rods. As a result, the only option is to hone the big end over-size and use oversized rod bearings. Unfortunately these over sized bearings are only available for a few motors, the Hemi not being one of them.

Here's two articles on Rod Reconditioning:

http://www.enginebuildermag.com/Art...itioning_more_to_it_than_you_might_think.aspx

http://www.motor.com/article.asp?article_ID=1866

According to ARP installation instructions resizing the rods is mandatory. You can read the instructions here:

[ame]http://arpinstructions.com/instructions/247-6301.pdf[/ame]

I'd call ARP to confirm installation instructions, for powdered metal rods, in light of the fact that they cannot be resized.

According to several rumors on the interwebs, you don't need to resize cracked, powdered metal rods because of the positive nature of the cracked surface means that the rod cap will not move when the bots are replaced.

Also, according to the Dodge Factory Service Manual, there are clear instruction that rod bolts are to be replaced since they are torque to yield fasteners. At the same time, the directions DO NOT indicate the need to resize the big end of the rod prior to installation.

My reaction to all of this research is that the rod bolts can be replaced WITHOUT resizing the big ends. That being said, I'd still carefully inspect the rods, taking care to measure the big ends to ensure that they are not oblong. If any of the connecting rods measure significantly out of round, I'd seriously consider replacing the factory rods with a set of forged aftermarket rods.

The nice thing about aftermarket rods is that you can buy a set that will easily live in a 600-800 HP motor for a reasonable cost.

Regards,

Joe Dokes

 

[ateam]

I had ARP 2000 bolts insalled in a 5.7 and 6.1 set of rods. You almost need a magnifying glass to find the part lines. I suspect these powdered rods will also respond to carefull deburring and shot peening. Manley is only supplier of rods to fit the .984 pin/bummer. Onward, ateam.:wack: