383 rods/heads
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Instructor
Joined: Dec 2007
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From: colonia New jeresy
383 rods/heads
I am thinking about pulling the stock engine out and building a 383 what rod would u run and why 6" or 5.7. and i found in good shape ready to run .a set of dart 200 sportsman heads 64 cc i think they r old in the 80s r they any good to make 450 hp 425 tq? he wants $ 400 for them r they worth it thanks
Drifting
Joined: Dec 2005
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From: NORTHEAST
I am thinking about pulling the stock engine out and building a 383 what rod would u run and why 6" or 5.7. and i found in good shape ready to run .a set of dart 200 sportsman heads 64 cc i think they r old in the 80s r they any good to make 450 hp 425 tq? he wants $ 400 for them r they worth it thanks
(1) Any 6.000 rod crank can be internally balanced
(2) Less cylinder wall friction and less rod angle with a 6.000 rod
(3) Lighter pistons
(4) less piston hanging out of the bore at BDC
Here is a build I did years ago with a set of AFR's
http://www.chevelles.com/forums/showthread.php?t=106715
Last edited by BLOCKMAN; Jan 10, 2012 at 09:49 PM.
Instructor
Joined: Jan 2011
Posts: 146
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From: Hillsborough NC
I found the book "How to Build Big-Inch Chevy Small Blocks" by Graham Hansen to be very helpful. In the chapter on Connecting Rods, he suggests that one use the longest rod they can before it gives a compression height that is too small. Assuming you are talking about going to a 4.03 inch bore and a 3.75 inch stroke, then a 6 inch rod will give you a L/R ratio of 1.60:1, similar to the 1.64:1 ratio in the stock motor. On a decked block (say 9.00 inch) with 6 inch rods, you have a 1.125 inch compression height to work with so as to build a good quench motor. w/o decking, the compression height becomes 1.15 inch. Both are pretty standard.
Le Mans Master
Joined: Jun 2004
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From: Seattle WA
St. Jude Donor '14
Smokey Yunick said "use the longest d*mn rod you can fit in the engine" and at the power level you're looking for (and so, the budget you'll be spending 
) you'll want 6" rods. It is a shorter compression height so the ring pack is smaller - but not to such an extent that it's a problem on a street engine.
Best bet is an internally-balanced rotating ***'y vs. individual parts. It'll still need a "touch" from your shop to get it right on - but it's certain that it *can* be balanced without expen$ive machine work. Many brands to choose from based on your budget, but I personally won't use Eagle anything after going through a number of cast cranks with unacceptable taper across the rod journals and being significantly out of index...i.e., junk.
The Dart Sportsman 200 heads I can't speak to. A 200cc head is in the ballpark for the power levels you're seeking, but without specifics it's hard to say. Also, used heads are a crapshoot at best...
) you'll want 6" rods. It is a shorter compression height so the ring pack is smaller - but not to such an extent that it's a problem on a street engine.Best bet is an internally-balanced rotating ***'y vs. individual parts. It'll still need a "touch" from your shop to get it right on - but it's certain that it *can* be balanced without expen$ive machine work. Many brands to choose from based on your budget, but I personally won't use Eagle anything after going through a number of cast cranks with unacceptable taper across the rod journals and being significantly out of index...i.e., junk.
The Dart Sportsman 200 heads I can't speak to. A 200cc head is in the ballpark for the power levels you're seeking, but without specifics it's hard to say. Also, used heads are a crapshoot at best...
Thread Starter
Instructor
Joined: Dec 2007
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From: colonia New jeresy
I called eagle they said i should us a 5.7 rod for the rpm range im running 6000 max on the street. the heads were on my friends engine so i know their good but we dont have any info on them they r 64cc i hope they will make the power i want? i will try to call dart and see what they say i know they r sportsman 200.
Race Director
Joined: May 2005
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From: Millington Illinois
St. Jude Donor '08-'09
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Le Mans Master
Joined: Sep 2001
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From: Unreconstructed, South Carolina
I am thinking about pulling the stock engine out and building a 383 what rod would u run and why 6" or 5.7. and i found in good shape ready to run .a set of dart 200 sportsman heads 64 cc i think they r old in the 80s r they any good to make 450 hp 425 tq? he wants $ 400 for them r they worth it thanks
... Dart Iron Eagle ?
Either way, Fair price; even better if they're truly AOK ready-to-go.
Thread Starter
Instructor
Joined: Dec 2007
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From: colonia New jeresy
Advanced
Joined: Apr 2008
Posts: 92
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From: Carol Stream Illinois
The 6" connecting rod will put less stress on the piston side wall. From a performance standpoint, the 6" rod is held at TDC for a longer period of time during the stroke which will yield more bottom end torque. I have always used the 6" rod in any of my builds.
