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Discussion Starter · #1 ·
A while back there was a post that was going on about R/L (rod /stroke) ratio. My upcomming 383 (and I guess my current 400) has a R/L of 6.358 rod / 3.375 stroke = 1.88.
That's a pretty good ratio I understand. But what's good about it? Less frictional piston and wall wear and heat I guess. Also might help in the rev department if the cam and heads and everything else keeps up. Anything else? My 383 at .060 over will be a 394 by the way.
 

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Bummo: thats actually a really good r/s ratio. the longer rod, shorter stroke actually does what you mentioned. it reduces side loading on the thrust side of the cylinder wall. if it were a longer stroke and shorter rod, you'd have a much higher outward force on the outside wall of each cylinder. This puts a mildly different wear on the rings as well. Inclusive with a pretty great R/S ratio, youve got a really amazing B/S (bore to stroke) ratio of 1.27:1. Thats much better than the typical 1.17:1 of a 451 stroker. Keep me/us updated on the buildup. I'm following your 383 pretty closely. Get those rods yet?
 

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Discussion Starter · #3 ·
Hoping for my tracking # today, probably next week for pistons, rods, rings, and rod bearings assembled together but never run. If my 452's are 90 cc's, my compression ratio should be about 10.75: 1 or so. Have to wait for decking and head work to know if I can keep it that low. If I ran my 915's it would be 12.5:1, which would mean I would need to run it on natural gas. Thats not going to happen (not available easily enough for a vehicle) but the setups are cheap). Propane with 11:1 or less should be great. I think anything over about 9:1 costs too much in higher octane gas.
 

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Damn server, well anyway read the post in where i gave alot of detail in rod ratios and it's effects on motors and how to build them to work where you want, 1 thing here a rod ratio of 1.50 to 1.70 is safe and a strong low end motor, from 1.75 and higher is high end peaking motor, a 383 is motor that wants to work upstairs not saying it won't work downstairs but the foundation has been laid out already
 
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