8.1 inch rod in stock block/stroke 350 and -----

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David Vizard
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8.1 inch rod in stock block/stroke 350 and -----

Post by David Vizard » Sat Sep 23, 2017 1:42 pm

the top ring won't be coming out of the top of the block!

This is a teaser!

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Carnut1
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Re: 8.1 inch rod in stock block/stroke 350 and -----

Post by Carnut1 » Sat Sep 23, 2017 1:51 pm

I am going to guess no rings involved. The rod looks like a stretched 70's vintage smallblock rod.
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Re: 8.1 inch rod in stock block/stroke 350 and -----

Post by David Vizard » Sat Sep 23, 2017 1:54 pm

Carnut1 wrote:I am going to guess no rings involved. The rod looks like a stretched 70's vintage smallblock rod.
Charlie,

All the rings will be in the bores. You are right about the rods - 2 chopped 350 rods welded togeher.


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Re: 8.1 inch rod in stock block/stroke 350 and -----

Post by Carnut1 » Sat Sep 23, 2017 1:57 pm

I hope that rod was x-rayed and heat treated after welding. Interesting experiment.
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Re: 8.1 inch rod in stock block/stroke 350 and -----

Post by Carnut1 » Sat Sep 23, 2017 2:13 pm

I always liked the longer rods, I did a small journal 391 chevy with 6" eagle H beam rods. 3.825" stroke I think, made for a very short piston with the pin in the oil ring. I really don't see how that long a rod can be made to fit a 9" deck and a 3.48" stroke. Thanks, Charlie
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Re: 8.1 inch rod in stock block/stroke 350 and -----

Post by peejay » Sat Sep 23, 2017 2:15 pm

Hmm.... At first I was thinking grooved pin buttons, but now I am wondering if the wristpin tolerance was tight enough you could put the rings UNDER the pins. Or maybe just some grooves for O-rings, the piston and pin wouldn't get hot enough to affect some of the higher temperature O-ring material and there'd be no flow through the area so any gas there would be stagnant anyway.

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Re: 8.1 inch rod in stock block/stroke 350 and -----

Post by pamotorman » Sat Sep 23, 2017 2:25 pm

the advantage of the long rod is weight saving in the piston. the ratio is 2 to 1 for 1 gram of weight you add to the longer rod you save 2 grams in the shorter piston

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Re: 8.1 inch rod in stock block/stroke 350 and -----

Post by BigBlocksOnTop2 » Sat Sep 23, 2017 2:39 pm

I would not trust it as far as I could throw it. Going to be using a .25'' thick copper gasket?

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Re: 8.1 inch rod in stock block/stroke 350 and -----

Post by PackardV8 » Sat Sep 23, 2017 2:41 pm

Interesting math; check me here, but an 8.1" rod and 1.74" of stroke = 9.84"; can't stay under a 9.025" OEM SBC block deck, so that's already .815" out of the deck before we consider the piston and rings?
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Re: 8.1 inch rod in stock block/stroke 350 and -----

Post by gnicholson » Sat Sep 23, 2017 2:47 pm

I'm thinking it doesn't have a traditional wrist pin but rather some kind of captured ball and socket arrangement right under the Piston deck :mrgreen:maybe theres a hole in the piston deck and the pin goes on top. I think I've got it. the deck of the Piston splits with the top cap unbolting and reinstalled after the rod and pin are in place

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Re: 8.1 inch rod in stock block/stroke 350 and -----

Post by David Vizard » Sat Sep 23, 2017 3:00 pm

BigBlocksOnTop2 wrote:I would not trust it as far as I could throw it. Going to be using a .25'' thick copper gasket?
Trust me here but these rods will survive the peak rpm involved for at least 500 hours. Also no head gasket involved.
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Re: 8.1 inch rod in stock block/stroke 350 and -----

Post by PRH » Sat Sep 23, 2017 3:22 pm

Sure...... A stock "350".

But a 350 what?

Might be a 350ci twin cylinder engine that turns less than 2000rpm.
Somewhat handy with a die grinder.

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Re: 8.1 inch rod in stock block/stroke 350 and -----

Post by David Vizard » Sat Sep 23, 2017 3:47 pm

PRH wrote:Sure...... A stock "350".

But a 350 what?

Might be a 350ci twin cylinder engine that turns less than 2000rpm.
Good try PRH but no it is a 350 Chevy block 9.025 height.
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Post by dwilliams » Sat Sep 23, 2017 3:52 pm

I'd love to see some information about the welding job...

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Re: 8.1 inch rod in stock block/stroke 350 and -----

Post by lefty o » Sat Sep 23, 2017 4:03 pm

ive no idea how you can squeeze that long a rod in a stock 350 block without talking something like a 9.5" block with about a 3" stroke crank, maybe even a shorter stroke, and just a big bore...idk. an 8.1" rod in a 9.025deck block dont leave much room for piston pin height nor any kind of stroke on the crank. #-o

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