Pmr swap

littleredstroker · Jul 2, 2012

I've got a 96 motor sitting in the barn. Was wondering if I could just swap rods from it to my SD and just do new bearing or not
Sent from my HTC PH39100 using Tapatalk 2

02POWERSTROKE7.3 · Jul 2, 2012

Crank will need rebalanced.

littleredstroker · Jul 3, 2012

Are they balanced to the crank? Saw another write up where they said to just swap em

Sent from my HTC PH39100 using Tapatalk 2

Arisley · Jul 3, 2012

Why would the crank need rebalanced? Swap them in. If you want to get fancy, you can "balance" all the piston rod assemblys after you put the pistons and rings on. Weigh each assembly, remove enough metal from the rod to make them all weigh the same as the lightest one.

I would also replace rings while I was in there. If everything looks good on the crankshaft, I would leave it alone.

Oh yeah, have the oil cooler jets welded on.

ToMang07 · Jul 3, 2012

I haven't done it YET, but I have accumulated a ton of parts, and am swapping my PMRs out of my 02 and installing forged that I had cryo treated. I bought new bearings and bushings, I plan to pull the engine, remove the oil pan and heads, pull the rods, bring them to the machine shop and have the new bushings pressed in the forged rods, wrist pins installed, and then I'm just gonna swap them back in.

Doing 910 springs while I'm in there, as well as melling LPOP, WP, GPs, ARP head studs, and a fuel bowl delete/RR. New oil pan should seal the deal, and she'll be ready for some 250/200s!

farm boy · Jul 3, 2012

Arisley said:
Why would the crank need rebalanced? Swap them in. If you want to get fancy, you can "balance" all the piston rod assemblys after you put the pistons and rings on. Weigh each assembly, remove enough metal from the rod to make them all weigh the same as the lightest one.

I would also replace rings while I was in there. If everything looks good on the crankshaft, I would leave it alone.

Oh yeah, have the oil cooler jets welded on.

:whs:

Diesel Innovations did a rod swap in my truck. No re-balancing the crank req'd. I trust David's advice on not needing to. He has put a few 7.3's together...

Running strong ever since.

golfer · Jul 3, 2012

There's enough of a weight difference...that we would nevvvvver swap forged onto a PMR crank...w/o re-balancing.

Machine shops have called us and said...'wtf' when trying to balance a 'pmr' (originally) crank with forged rods...

so the cranks were balanced...errr...should say weighted differently from the factory with the respective rod.

can you do it? have people done it?? sure...

ToMang07 · Jul 3, 2012

golfer said:
There's enough of a weight difference...that we would nevvvvver swap forged onto a PMR crank...w/o re-balancing.

Machine shops have called us and said...'wtf' when trying to balance a 'pmr' (originally) crank with forged rods...

so the cranks were balanced...errr...should say weighted differently from the factory with the respective rod.

can you do it? have people done it?? sure...

I don't think it's going to make ENOUGH of a difference to cause damage. If it does... I'll pay the piper (pissed of hell of course) and build one from scratch. I just don't have the money or time to put it in a machine shop.

Definitely some crossed fingers, tho, lol

Hotrodtractor · Jul 3, 2012

golfer said:
There's enough of a weight difference...that we would nevvvvver swap forged onto a PMR crank...w/o re-balancing.

Machine shops have called us and said...'wtf' when trying to balance a 'pmr' (originally) crank with forged rods...

so the cranks were balanced...errr...should say weighted differently from the factory with the respective rod.

can you do it? have people done it?? sure...

:whs:

Of course I also like super smooth running engines.

littleredstroker · Jul 3, 2012

So could I swap the 96 crank as well as rods? Just to be safe

Sent from my HTC PH39100 using Tapatalk 2

Groomzybanshee · Jul 3, 2012

Why not just put the 96 motor in??

littleredstroker · Jul 3, 2012

I read on another site that pmrs were good to 500. Now I'm seeing 400 pop up everywhere and am trying to figure out a plan.. I'm guessing I've got more than 400 right now.

Sent from my HTC PH39100 using Tapatalk 2

Buffalo444 · Jul 3, 2012

golfer said:
There's enough of a weight difference...that we would nevvvvver swap forged onto a PMR crank...w/o re-balancing.

Machine shops have called us and said...'wtf' when trying to balance a 'pmr' (originally) crank with forged rods...

so the cranks were balanced...errr...should say weighted differently from the factory with the respective rod.

can you do it? have people done it?? sure...

The source of this alone makes me think you should have the crank balanced.

littleredstroker · Jul 3, 2012

Cause its got 250 k on it and burns about a quart of oil a week mines got 165

Sent from my HTC PH39100 using Tapatalk 2

fatsix · Jul 3, 2012

littleredstroker said:
Cause its got 250 k on it and burns about a quart of oil a week mines got 165

Sent from my HTC PH39100 using Tapatalk 2

All of the more reason to use rods with 250k on them... Are you just going to wing the sizing as well?

A good friend of mine who is a competitive engine builder told me, " Rods are like women, they remember everything you do to them".

Buffalo444 · Jul 3, 2012

littleredstroker said:
Cause its got 250 k on it and burns about a quart of oil a week mines got 165

Sent from my HTC PH39100 using Tapatalk 2

Why not get an entire overhaul kit and build the 96 out on a stand?

fatsix · Jul 3, 2012

Buffalo444 said:
Why not get an entire overhaul kit and build the 96 out on a stand?

And run the piss out of the PMR engine. Doesn't make sense to spend twice the money... I cannot see any substantial good coming out of this. Yeah it might work, for a while...

Buffalo444 · Jul 3, 2012

fatsix said:
And run the piss out of the PMR engine. Doesn't make sense to spend twice the money... I cannot see any substantial good coming out of this. Yeah it might work, for a while...

Coming out of what? Swapping the forged rods into the PMR engine?