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-   -   350 sbc using 4.0 stroke cranks (https://www.racingjunk.com/forums/showthread.php?t=25196)

jreiley 08-05-2009 11:10 AM

350 sbc using 4.0 stroke cranks
 
Winter project. Rebuild sbc. Any problems using a crank with a 4.00 inch stroke and 6" rods? Any machine work needed to be done on the block?

heshtesh 08-05-2009 11:46 AM

I don't know if a 4" stroke crank will fit in a stock 350 block but if it doe's i'm thinking the block will be one scary looking piece. Seems to me you would have to grind a lot of material away to achive proper clearance.

hink 08-05-2009 12:01 PM

It might cost you a couple blocks if you hit water.

oldandtired 08-05-2009 12:02 PM


Originally Posted by heshtesh
I don't know if a 4" stroke crank will fit in a stock 350 block but if it doe's i'm thinking the block will be one scary looking piece. Seems to me you would have to grind a lot of material away to achive proper clearance.

x2. Even if you use a 2.000 rod, there is way too much material to grind away. When you get .050 clearance, how much block is left to hold back the oil presure or water? Enough to give me nightmares...

Dave

jreiley 08-05-2009 02:22 PM

From what I understand, a sbc 400 stock crank will fit with some machining on the mains. Don't know if this is true. Just thought I'd mention it. There are a few crank vendors that sell the 350 crank with a 4" stroke. Maybe the cranks are for Dart blocks. Don't know.

FullTimeRacing 08-05-2009 03:29 PM

the 350 main don't mean 350 block,You get most aftermarket in 350 mains.

Smaller main=less resistance.Right hink?,Thats what i've been told.

FullTimeRacing 08-05-2009 03:36 PM

Re: 350 sbc using 4.0 stroke cranks
 

Originally Posted by jreiley
Winter project. Rebuild sbc. Any problems using a crank with a 4.00 inch stroke and 6" rods? Any machine work needed to be done on the block?

:?: Why do you want that long stroke with such a small piston?

you building a tow truck?

kwkracing 08-06-2009 07:02 AM

There are several people around here running 4" cranks in stock 350 blocks. i CAn aask but i believe they are pouring very little block filler in the bottom of the block, below the sand casting plugs and then grinding away.

ashbros 08-06-2009 09:36 PM

use a 400 block with a 3.625 rod you'll love the big piston and little stroke

mytmouz 08-06-2009 10:27 PM


Originally Posted by kwkracing
There are several people around here running 4" cranks in stock 350 blocks. i CAn aask but i believe they are pouring very little block filler in the bottom of the block, below the sand casting plugs and then grinding away.

If you run I beams no filler eeded, if H beams, then you will need some...


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