Do some 4-bolt blocks have more 383 clearance?
11-03-2011, 10:46 AM
#1
Do some 4-bolt blocks have more 383 clearance? So I finally tore down my shortblock that I had pulled from my car when I put a new engine in last year. Oil pump was completely seized up, 6 month old Meling Select pump. Anyway, after stripping it down to the block, I decided to put in the Scat 9000 crank that I have (that I am no longer going to use, going forged 396), with the stock pistons and rods on it in just the #1 and #2 cylinders to see how close the clearance was, and it cleared the stock cam and pan rails without touching anything. It did come very close to the pan rail, but never actually touched. Is this unusual?
11-03-2011, 04:43 PM
#3
Well I understand that there should be a minimum clearance for everything, but I am just surprised that I was able to rotate the 3.75" crank with stock rods without it actually hitting anything, I thought a 3.75" stroke usually hits the pan rails with stock rods? If I have slight room with a 3.75" stroke, then I don't think the additional .0625" per side for a 3.875" stroke will be too bad to clearance after all?
11-03-2011, 06:16 PM
#4
Usually you don't have problems with the crank hitting it's the aftermarket rods that you have clearance issues with. The bottom of an H-beam rod is bigger than a stock rod.
11-03-2011, 07:03 PM
#5
Teching In
Join Date: Apr 2009
Location: Wilmington NC
Posts: 42
Likes: 0
Received 0 Likes
on
0 Posts
Agreed. I took my block / rotating assembly to the machine shop for my 30 over bore, rot. assembly balancing, and after looking into the clearance needed my block notched in 16 places for crank / rod clearance. (forged 5.7inch h-beam)
11-05-2011, 09:18 AM
#6
Well I plan on staying I-beam, probably Scat stroker Pro-comps, as they should be strong enough for my use and offer more clearance than H-beams. I plan on doing an N/A, <7000RPM, 14:1 E85 specific 396ci build on this block....eventually.
11-08-2011, 12:14 PM
#7
YES! later blocks have more clearance. I just did a 880 casting vortec block and very little needed to be ground down. I mocked up with stock rods but i will be running ZZ383 rods - which are weird for OE rods - its not a bolt and nut, its not a capscrew bolt, its ARP stud with 12 pt nuts, as the crank and rods/pistons I have is from a ZZ383 crate motor. You will still need to check all areas - especially cam to rod bolt clearance - you want a minimum of .020 there and .050 for rods to side of block, bottom of the bore Its probably worth your time to get stroker rods that are made special for stroker applications
