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4.5 stoker-- 6.7 rod or 6.8

6K views 11 replies 7 participants last post by  HEMI-HUNTER 
#1 ·
wanting to build 800 hp. 30 over 545 4.5 stroke. My question for all you who make a living at building these engines is, a 6.7 rod or 6.8 and why please.
 
#2 ·
I've heard the 6.700 rod is fine, and was told not to worry about using the shorter rod, however, my last motor was a 4.500 stroke with a 6.800 rod.

I had no mercy for that engine--literally, I had thousands of runs on it, prolly way more than most. I contribute the longevity of the bores/pistons from the longer rod. Who knows, it may just be BS, but personally, I would go with as long as a rod as I could get to work without major complications. With the 6.800 rod, the ratio is very close to a stock BBC.
 
#9 · (Edited)
6.7 or 6.8

is the 6.8 rod not a good combo for the dive block? I am asking all these questions because I want this engine to live awhile at about 700 to 800 hp 6800 rpm braket motor. Park it and race it , low maintnece hopefully. Im givng such a spread in horse power because I am willing to step it down within reason to make it live a little longer. Oxymoron I guess, but you guys are great and have helped me close the 30 yr. gap in technology since I have raced. I thank you all so much for your imput.
I forgot to put this in this post, I always thought that the pin would only be raised .100 in the piston and allow the piston to say at tdc a little longer. I assumed that the stroke would remain the same and the riston would travel the same distance, I need help dont I
 
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