440 Source big block forged cranks

[moparmaniac59]

I just wanted to pass some info along here on the 440 Source forged big block cranks from their stroker kits. I am having a stroked 440 engine built (543 stroker) and brought the assembled short block to my local machine shop for completing. Kurt is a Mopar guy and owns/operates a full machine shop. The short block has a 440 Source stroker kit installed. I have no problem with the quality, just some things to note. Kurt took the assy apart (it was assembled by someone else when I brought it to Kurt) to fully check everything himself. It seemed that the Clevite main bearings were riding up on the steep radius of the crank main journals. You had to have a keen eye to see the shiny places on the bearing edges. Kurt had to add an additional champher to the bearing edge to relieve the problem. I am not an engine builder, but Kurt was noticing an unusually steep radius on the crank main journals. I am guessing it's a bit more than a factory crank. Kurt had pointed out some of the changes Chrysler had made to the main bearings (I couldn't quote him here as my memory fails me ...CRS sydrone), some of which he didn't agree with as far as the width changes. He noted that without relieving the bearings as he did (albeit a fairly minor champher) that I would likely have a premature bearing failure. Just something I wanted to pass along if you are using a 400 Source forged big block crank as something you might want to check!!

                                                 Matt B.

[moper]

yes, you have to chamfer the bearings because of the huge radius on Source cranks. You may also want to have him cycle the rods and check the big ends for roundness, and carefully measure the journals for taper seeing as he's in there.

[bb71challenger]

Doesnt 440source sell the chamfered bearings on their site?  The bearing situation and fix is good to know about, thanks for posting!

[440mike]

how did you guys find the problem ? did the crank have no endplay when you where assembling ?

[Chryco Psycho]

My machinist caught this on the first stroker we built , no big deal
apparently the Eagle cranks are far worse & the extra radius in the journals help prevent cracking

[moper]

Mike, when the rod gets tightened, the first one goes fine. When you try ot do the second, the rod can't slide off the radius and things bind up. It's pretty obvious...