Don Terrill’s Speed-Talk

2.500" spacers on block with 8 new tall sleeves. O ring block to spacers. Joe-71

David Vizard wrote:

ptuomov wrote:

David Vizard wrote: stock 350 stroke and crank location DV

So is this a piston design with rings below the pin? The wrist pin would have to be inside the dome somehow and rings below the pin.

Well you and a couple of other posters are definetly moving in the right direction.DV

I thought about doing the piston wrist pin bore with caps that are fastened with bolts. Like main caps. That would be heavy, though, but would allow no wrist pin bore openings into the combustion chamber. Then the rings could come high up like in a modern piston, right up to top of the bore.

Guys,

I had little idea the opening posts shot of a long rod was going to cause so much response and interest.

I am off 'down under' to do a seminar in Sydney tomorrow (Mon 25th Sept). I am excited about this one as due to the interest the last one in 2015 caused. I am getting a number of the chief engine development engineers from top teams attending.

Anyway due to this busy trip I won't have time to put up any posts so you will all have to fight among yourselves until after the 5th of Oct.


DV

We'll keep the octagon bloody until you get back, lol.

Move the crank down?

David Vizard wrote:I am getting a number of the chief engine development engineers from top teams attending.

Top teams?

sanfordandson wrote:Move the crank down?

Hmmm.. what could be the purpose in extending the crankshaft lower in the block geometry? Interesting thought.

He has already said stock stroke and crank location in stock deck 350 SBC and no head gasket, has indicated an abnormal CR ratio but not wether that is high or low.
Maybe this is a cooky 2 stroke build with long closed end smaller diameter cylinder sleeves with ports for intake and exhaust,, lol.

2 piece piston to capture the pin.

PackardV8 wrote: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?

The ring stack is irrelevant to the C/H.

He just has to fit the rings, lands, and half the pins into a -.815 C/H

Counterbore the head, and build a piston with a 1.000 top land......

F1 style piston with a short pin.

kimosabi wrote:F1 style piston with a short pin.

F1 has that kind of negative compression height such that the wrist pin is out of the bore?

ptuomov wrote:

kimosabi wrote:F1 style piston with a short pin.

F1 has that kind of negative compression height such that the wrist pin is out of the bore?

Not that much but the pin sits just below the deck. I'm sensing offset pin and offset grind on the crank here too as well as a smaller pin. That pin has to be installed somehow either way.

kimosabi wrote:

ptuomov wrote:

kimosabi wrote:F1 style piston with a short pin.

F1 has that kind of negative compression height such that the wrist pin is out of the bore?

Not that much but the pin sits just below the deck. I'm sensing offset pin and offset grind on the crank here too as well as a smaller pin. That pin has to be installed somehow either way.

He just said stock stroke, stock crank location. There's no way to get the pin below the deck, I believe. The next logical question is how to get the pin inside the dome. I wouldn't want to expose the pin and the locks to the combustion chamber, not even with buttons on holes. I think multi-piece piston with some sort of bolted-on cap or caps is the most likely plan for these rods. Since the main reason that I see for doing all that is to reduce the piston weight for large dome piston (like in a hemi chamber), I don't see it really working out in net given the weight and complexity of a multi-piece piston.