Author Topic: 4.25 stroke RB 440 source kit  (Read 1124 times)

Offline moper

  • Resident
  • *****
  • Posts: 2368
4.25 stroke RB 440 source kit
« on: February 16, 2007 - 06:53:47 AM »
Seeing as there were a couple of posts concerning the clearancing and work required for the 440Source.com RB512 kit...I grabbed a few pics from my records. Nothing hits the block right out of the box But it is too close for my comfort at the oil pickup boss and the edges left from the main cap plunge cut at the factory. So I touched up those slightly. Also, the bearings wear not chamfered enough out of the box to give the proper side clearance. In the pics, you can see a narrow shiney line on the chamfered edge of the bearing shell. That's where it hits the crank's large radius. After touching up the bearing's chamfer, side clearance was a perfect .014. Also, the rods had two that were heavier, and those needed to have material removed during balancing. So here's the pics. Any aftermarket parts should be mocked up first to look for problems like these. It's so much easier to fix them now, then look for and try to fix them later.




Offline Chryco Psycho

  • Administrator
  • C-C.com Guru
  • *****
  • Posts: 36620
  • 70 Challenger R/T SE 70 tube Chassis Cuda now sold
Re: 4.25 stroke RB 440 source kit
« Reply #1 on: February 16, 2007 - 07:51:07 PM »
Thanks for the pix :2thumbs:
My kit has arrived so the engine will be going together shortly

Challenger - You`ll wish You Hadn`t

Offline moper

  • Resident
  • *****
  • Posts: 2368
Re: 4.25 stroke RB 440 source kit
« Reply #2 on: February 19, 2007 - 05:50:40 AM »
My suggestion would be to mock up each piston and rod in the block if you dont normally... So far, every rod bearing had to have more of a chamfer added to get the side clearance. I cant tell if the tang slots in the rods are off, or the bearings are off...But something sure is. with no mods, you will have 0 side clearance (may not even turn). With light mods, it will turn, but leave a mark on the bearings shells. With clearancing, you can get .009-.014" (factory spec).

Offline JS29U

  • Jr. Member
  • **
  • Posts: 81
Re: 4.25 stroke RB 440 source kit
« Reply #3 on: February 19, 2007 - 01:08:34 PM »


  Yesterday, sunday, cudaben posted pictures of his block set up for his 4.5 inch 440source.com kit.  on moparts.coms race section.

   Did u ask Brandon what his thoughts were if its bearings or tangs? Maybe he can do some checking, see if its a bad batch.

Offline moper

  • Resident
  • *****
  • Posts: 2368
Re: 4.25 stroke RB 440 source kit
« Reply #4 on: February 20, 2007 - 10:20:24 AM »
At this point, it has been remedied. I'll let Brandon know about my experience when I have all the information in hand. But I'm not waiting or delaying this so he can mail me more stuff, or I can mail it back to him. It's a moot issue for me at this point. So I'll just deal with things as they come. I will be trying a different bearing on one of his rods to see what's what. This is also one of the hybrd chevy/mopar rods. I dont have any BBC rods lying about. I'll have to hit the shop and see what they have lying around for BBC rods, then see if it's a bearing or rod issue. Then I'll call him.

Offline A383Cuda

  • Jr. Member
  • **
  • Posts: 475
    • Sal's Muscle Cars
Re: 4.25 stroke RB 440 source kit
« Reply #5 on: February 20, 2007 - 10:28:53 AM »
You also mentioned a coupleof the rods were heavier, was this a balanced kit? I am considering ordering a 451 kit from them. I was considering having them balancethe assembly while there. Should I leaave this to the machine shop? I don't want to pay twice for this.

Offline Robb

  • Sr. Member
  • ****
  • Posts: 1006
  • Member since: March 20, 2003 - 09:52:47 AM
Re: 4.25 stroke RB 440 source kit
« Reply #6 on: February 20, 2007 - 04:32:25 PM »
You also mentioned a coupleof the rods were heavier, was this a balanced kit? I am considering ordering a 451 kit from them. I was considering having them balancethe assembly while there. Should I leaave this to the machine shop? I don't want to pay twice for this.

Wondering same thing for same reason   (+1)

70 Challenger SE  (440 SIX PACK / Keisler 5 speed, R/T SE replication)       68 Sport Satellite Convertible 383 Super Commando / 727  Survivor

2002 Trans AM WS6 convertible:  DD
1999 4Runner 4x4:  lifted-locked-armored  expedition vehicle
1990 Jeep XJ 4x4:  Front Dana 60, GM-14bolt rear, 3 link, 4link, 5.38 detroits, beadlocked 40's, stretched to 110" wb  Rock Crawler

Offline moper

  • Resident
  • *****
  • Posts: 2368
Re: 4.25 stroke RB 440 source kit
« Reply #7 on: February 22, 2007 - 08:04:30 AM »
This it was ordered before his new balancer. However, after reading his post on how they balance, and seeing the "matched to within .2 grams" that the box of rods says...I dont want it balanced by 440source. That's my choice and my opinion. The set of rods comes with a sheet with the big and small end weights written in by someone. The total weight of the rod is what is "within .2 grams". The differences in the weights of the ends of the rods is the problem. A rod has a rotating weight end, and a reciprocating weight end. They are valued differently in the balancing work. In the case of this set, the big ends had differences of up to 4 grams from lightest to heaviest, and the small ends had differences of 2 grams. So those had to be equalized and that required grinding the ends slightly. The procedure Brandon uses does not match weights on the seperate ends from what I saw and read. If it does, my apologies. The operator uses one rod, the machine weighs it and spits out the specs for the bob weights. Without weighing each end of each rod, it cant be done as accurately as I would like it to. So I prefer to have my shop do it to my satisfaction. Balancing is like torque convertors...Some guys are fine with the cheaper ones, some want more. Some places do more for the cost, some do what will get them by, some guys see no need for a good one, some demand it.