Future 409 Build

Jim Sullivan

Well Known Member
Supporting Member 10
Here is a question for all of you engine gurus. I'm ordering bearing for my stroker engine and rod bearings for a 409 have a different part number than a small block. I am using 6.135 rods. Should I order the 409 rod bearings or small block rod bearings?
 

Murphdog

Well Known Member
Supporting Member 2
Like James said, 348, 409 and BBC use the same rod bearing. HOWEVER, if you have a stroker crank it may have a larger radius on the journals.
If it's a modified 454 crank (stock crank with reground mains) it should use regular 409/BBC rod bearings (Clevite CB743P). If it is an aftermarket 4"/409 crank it may require chamfered or narrowed rod bearings. You would have to check with the crank vendor.
Jeff
 

Jim Sullivan

Well Known Member
Supporting Member 10
They are the same as a big block rod.
Like James said, 348, 409 and BBC use the same rod bearing. HOWEVER, if you have a stroker crank it may have a larger radius on the journals.
If it's a modified 454 crank (stock crank with reground mains) it should use regular 409/BBC rod bearings (Clevite CB743P). If it is an aftermarket 4"/409 crank it may require chamfered or narrowed rod bearings. You would have to check with the crank vendor.
Jeff
Thank you James and Jeff. It is an Eagle 4" stroker crank. I'll see if there are any notes on the paperwork or reach out to them.
 

Murphdog

Well Known Member
Supporting Member 2
The crank description says the radius is .125".
There you go. That will require chamfered or narrowed bearings. 20 years ago when I was regularly building engines, you bought "chamfered" bearings for this situation. Not sure but I think they sell "narrowed" bearings these days to accomplish the same end result. At least I think that's what Clevite does. I just put Tooth's new bullet together with some chamfered FM/Speed Pro bearings I had on the shelf.
I think the rods are your only concern. Don't think the mains need anything special. The larger radius in the rods is to make the crank more durable,. That's where they typically break, unless it's a blower motor and they snap the snout off.
Jeff
 
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