[Jack Gifford]

The billet Moldex crank was cracked in #2 rod journal and #3 main journal. Rather than throw all of it away, I cut out the bad section and adapted two 1350 series U-joints as a connection between the two end cylinders. After beating up many carbide toolbits machining the cranks and U-joint yokes, the bottom end is finally together.
Cylinder walls were beat up from detonation- had to bore/hone to .028" larger. So now I'm waiting on new pistons to be made.

[slowbird]

Just crazy! Seriously outside of the box thinking!

[hgerhardt]

Will be interesting to see how well the U-joints deal with torsional/harmonic vibration. Clever solution and hope it holds up!

[steve25]

Jack what is going to absorb the thrust of the foward section of the crank?

Also are you running no Dizzy ?

[sdbob]

Wow. Amazing. Just for curiosity. How did you come up with this idea, and how are u joints fastened to crank? T.hanks

[Scott Stoneburg]

Wow! That's some impressive work Jack.

[Formulas]

You didn't think outside the box you put the box in a shreader and said ok lets start..

[tom s]

Jack,dry sump?Hope you have a total engine blanket!Tom

[67Fbird]

Just curious WTH are you making here? Back in Tech school I helped the automotive teacher build a V-2 SBC. Everything was cut n welded. (circa 1987) IIRC he made 105 hp around 90 ft/lbs @ 4800. got almost 28 mpg in his CHEVETTE. FWIW that's almost twice the HP and torque of the little isuzu 4 banger in the shuv-it WITH +10 on mpg.

[mgarblik]

I would love to see some better focus, different view angles of the U-joint/crank/bottom end solution. Best of luck with the rest of the build. Mickey Thompson 2.0 !

[Formulas]

Whats the power stroke management going to be like?

i see the 2 crank pins look aligned

a big one cylinder firing or 2 consecutive power strokes or evenly staggered

[Jack Gifford]

The connection between cranks is fixed length, so thrust is taken in the normal manner at #4 main.
The magneto drives off the rear of the exhaust camshaft..
The connection to the cranks is by TIG welding to U-joint yokes, after center-drilling for alignment dowels.
Yes Tom, dry sump- with separate systems for bottom and top end of the engine.
Sorry Mike- my shaky hands prevent in-focus high-resolution images!
It will be an even-firing twin. Any other arrangement would not allow use of the existing DOHC camshafts ($3,200, custom-created from billet).

Mickey preceded me with his two cylinder Pontiac back in the early sixties- half of a Tempest four. But it wasn't hemi-headed nor DOHC!

[Jack Gifford]

Mike- a slightly better photo, without the huge main caps blocking the view. This was a mockup prior to welding, so it doesn't show the weld bead that joins the two center yokes.
There isn't any center main bearing, but the cap will be used to help strengthen the block.

[Half-Inch Stud]

U-Joints are up to the challege. Just perforate their seals to let em get oil. Rotational balance seem correct.

Power balance pairs, for a fully populated V8: 1&6 8&5 4&7 3&2.

Power Balance for 1278 population, wrongly ASSUMING stock cam lobing & dizzy wiring:7218-0000-7218. Maybe power balanced, i dunno, but the 1-rotation no-power gap will be a very interesting idle and acceleration experience.

Light vehicle will allow a stock front damper.

[Half-Inch Stud]

A new twist to "Half a V8". Liking it.

Re-read the "even-firing twin" : power-Balance achievable depending on 2=7 power, and 8=1 power. I think to assume the Cam will have a "cut&reclock" for 2=7.

Will this be like a Harley da-dut....da-dut idle?

Oh funny, the u-joints allow 90* clocking flexibility.

[slowbird]

Just throwing this out. I have always been told to not run u-joints completely straight (they need an angle or bend in them). Will this be an issue?

[mgarblik]

Thanks for the better pic, Jack. Was I seeing a couple jack screws in the block to help support the #2,3,4 mains? Or was this part of the weld fixture? What's the induction system going to look like on this new configuration?

[steve25]

Jack that’s f**%g amazing!

[Jack Gifford]

Originally Posted by slowbird

Just throwing this out. I have always been told to not run u-joints completely straight (they need an angle or bend in them). Will this be an issue?

That is truly a concern. I can only hope that the small amount of run time will minimize it. LTA is down to just one event per year now. And as old-and-feeble as I'm getting, I don't foresee many more years.

[Jack Gifford]

Mike- you were probably seeing the threaded rot which holds the cam bore plugs in place. They are a light press fit to strengthen the empty cam bores, but I didn't want to worry about them moving out of place, since they also close off the cam oil feeds.
The Hilborn 4-port and scoop will look the same on the outside (except 2 hoses missing!), but I've fitted an internal plate to block off the rear two ports. The "big empty box" manifold doesn't really care where it's fed from.