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Discussion Starter #1
I am wondering what you guys are finding in regards to this subject... example a sbc 327 has about 1.78 rr a 350 has 1.63 rr and a 400 has 1.48 rr then a 565 bbc with 6.385 rods has 1.5 rr and a 583 & same rods has 1.459 rr … how are all these wearing if possible to make any observations in this regard?? The reason I ask is I am considering a 583 short deck build and the RR will be shorter than all the above so am considering whether a 6.5 to 6.7+ rod would be possible or worth the effort... Not for power but longevity and if it is possible to get a decent ring pack on that piston Thx in advance for any and all input
 

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My pump gas 555 with 6.385 rods has been running 20 years now on the street and track. N/A for years running high 9's....added small turbos about 6-7 years ago and now running 8's. It's been on multiple 2000+ mile road trips. I've had it apart a few times over the years for changes to the combo...but never a wear or ring seal issue. The block is a Merlin II and no wear at all.

JIM
 

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The 454 Chev has one of the shortest rod ratios of all the popular V8s...but the bores don't seem to wear out any worse than say a 426 Hemi, which has a long RR.
 

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Discussion Starter #6
thanks for the nice real world experiences, which allays some concern.. and yes good point Geoff that is true that some of the others with much longer rods don't seem to be better there either... RR Mark is usually discussed in regard to port size and HP output and the ring pack rather than from a longevity point of view which is why I started this thread as I have never seen anything about this,,, and with what has been said that is probably why. coz there is no real issue
 

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Discussion Starter #8
fortunately the newer design pistons , notably the ones I've seen are good in that regard..but yes of course that would make quite a difference for sure
 

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Unless the bottoms of the pistons go below the bottom of the cylinder too much.
That, I think, would only come into play, if the piston was at zero deck, and the stroke was longer then the bottom ring, from top of cylinder to the bottom. Don’t think that would ever come into play, no matter the rod length. Unless the pin was installed so low for some unknown reason, and hooked to a rod designed to pull past the bottom of the cylinder. Who would even conceive of that idea?
 

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That, I think, would only come into play, if the piston was at zero deck, and the stroke was longer then the bottom ring, from top of cylinder to the bottom. Don’t think that would ever come into play, no matter the rod length. Unless the pin was installed so low for some unknown reason, and hooked to a rod designed to pull past the bottom of the cylinder. Who would even conceive of that idea?
I know that using a Ford Boss 8.2 block with a 3.4 stroke crank pulls the piston out of the cylinder bore a bit too much for some peoples liking. Its because Ford shortened the cylinders on that block relative to a stock block length (Dart too).
 

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I know that using a Ford Boss 8.2 block with a 3.4 stroke crank pulls the piston out of the cylinder bore a bit too much for some peoples liking. Its because Ford shortened the cylinders on that block relative to a stock block length (Dart too).
Ok. All things being set up to do so, will do so. All I know is on a sbc, from the bottom oil ring, to the bottom of the 9.025 deck, would take one hell of a stroke, or a misplaced wrist pin in a very heavy piston, with very low placed rings. But I suppose, in some combos, you have to be more careful. Never gave it a thought before.
 

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STD deck(9.800) with big strokes have a lot of bottom pull out as well. Hell a 4.250 stroke with a 6.385 rod looks bad enough. Does it affect ring seal and bore life , probably not. The only engines that I do that rod length definitely plays a factor are junior dragster engines. You have to use such a short rod to fit the 3” stroke in some blocks, I see more wear at the bottom of the bore than the top. It also seems to be more of a problem on the bigger bore engines, a 3.5” vs. a 3”. When I say short rod I’m talking 4.225”, 1.41 rod ratio.
 

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Discussion Starter #13
Ok then maybe we could look at this another way,, which factory engines come with a rr less than a 400 sbc @ IIRC 1.48-1, and which has the longest and there any appreciable wear difference between The two?
 

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Of the most common V8s, I think the 350-400 Chrysler big block engines had the highest RR of 1.88. I don't think they were any better with less wear than sort RR engines. The BB Chrys engines had veeeeeeery heavy piston & pins; I remember weighing a stock piston & pin & it was 1100 gm!
When you consider the effect of 45* of gravity combined with this heavy weight, maybe this would increase wear?
 

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I like Reher and Morrison's approach to rods. The biggest thing we are concerned about is that it is torqued. Choose the piston you want and the stroke you want and go from there.
I build a lot of two barrel circle track its a good think I don't listen to R/M. Rod ratio means a lot to me. Just Saying
 

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Rod length is overrated and over hyped.....
The factories, at least back in the day, seemed to vary rod ratio according to cylinder head size. The bigger the head and the smaller the motor the shorter the rod. The smaller the head and the bigger the motor the longer the rod.

It's a pattern, but might just be a co-incidence.

I'll go with Reher and Morrison. It doesn't make any difference.
 

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"Just Sayin" infers you know something Dave and Buddy aren't privy to.

You don't.
What do you know your not even in business any more LMAO

I can see why selling my buddy Bob 2 sets of square pistons that wouldn't even fit in the bores LOL
 

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What do you know your not even in business any more LMAO

I can see why selling my buddy Bob 2 sets of square pistons that wouldn't even fit in the bores LOL

Wrong again, nit-wit.

I called your "buddy" Bob the last time you burped this nonsense...he said you were full of crap.

And I'm still at it.....
 
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