383 rod clearance
Thread Starter
Racer
Joined: Oct 2002
Posts: 416
Likes: 2
From: Westfield MA
383 rod clearance
I am trying to decide which 6" H beam rod will have the most clearance and keep the "grinding mods" to a minimum. Eagle H beam 3D claims it will "clear cams up to 3.8" stroke with no grinding required". Scat H beam claims "fully profiled for stroker engines and cam clearance". Scat also has a new I beam rod with 7/16" cap bolts that is also supposed to be "profiled for stroker engines". My 383 will be fairly "mild" and I could easily get away with the I beam rods. I'm just looking to minimize the grinding required to make the 6" rod clear the cam and pan rails. Any engine builders out there have experience with any of these rods? Thanks ---------
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Re: 383 rod clearance (SS409 425HP)
The BIG contention of clearence is with the camshaft. Conventional rods with nuts and bolts have a cam clearence issue with the bolt HEAD. A rod with capscrews has much more clearence. I think, regardless of the rod you choose, there will be some grinding necessary at the bottom of the cylinders and the oil pan rail of the block. The Scat I beams ought to do you a fine job. Good luck, and...
RACE ON!!!
RACE ON!!!
Melting Slicks
Joined: Mar 1999
Posts: 2,535
Likes: 2
From: Rochester NY
Re: 383 rod clearance (CFI-EFI)
My 383LT1 use ESP 6.0 H Beam rod. The block will required grinding for clearance and the stock oil pan will not clear it. Will need a aftermarket oil pan. Also use a small base circle camshaft
ps. If your 383ci is gonna be mild then no need to use the H beam. The I beam will do a fine job.
Bruce
[Modified by Bruce, 2:05 PM 3/13/2004]
ps. If your 383ci is gonna be mild then no need to use the H beam. The I beam will do a fine job.
Bruce
[Modified by Bruce, 2:05 PM 3/13/2004]
Le Mans Master
Joined: Jul 2001
Posts: 8,183
Likes: 3
From: Santa Maria, CA
Re: 383 rod clearance (CORKVETTE1)
do not use or recomend h beams :cheers:
Original poster:
It's not at all bad to clearance the block. As mentioned, the cam is what needs to be small base circle.
I figure a machine shop will clearance the block for under $100.00 bux. Some have a CNC machine that they put the block into and the computer directs the drill bit to the appropriate locations.
I did my own by hand. I first bought a carbide drill bit for around $15.00. It cuts thru like a hot knife thru butter so go easy.
I then mocked up the crank on main bearings and a rod with bearings on each throw to see where the rod bolt would touch the block and began slowly shaping away:
*note: on my crank there was abit more throw(3.835) than a 383(400) crank, so you don't need as much material removed as my pics show
You can remove the lower soft plugs in the sides of the block to have a better view of the inside water jacket passage than can be seen thru the coolant holes on the deck surface. If you do break thru with the drill bit, the hole can be welded shut.
[Modified by 89 Paul in Cal, 1:49 PM 3/13/2004]
