Cylinder Offset Changes Everything
 

This video does a great job of explaining what happens as a result of offset.

https://www.youtube.com/watch?v=gwtZkHoVMso

Stan

Very interesting.

Wonder how hard balancing wood be?

GT

I racked my brain on the optimal CYL angle away from the crank CL. Seem there could be advantage to the cyl pointing toward the rod throw to improve TQ-Arm eff.

But it gets complicated. There is a pony in the poke.

I don't recall balance being a complication. TQ-arm eff IMPROVEMENT across the meaningful CYL PSI makes all the diff. I recall TDC and the cam durations, LSA are effected.

Haven't all Pontiac V8 engines since 1955 had about 1/16" cylinder offset?

Inline would be easy to offset, but a V
configuration complicates things. Even
our 194 is offset 45°.

OHC6, or Iron Duke?

This video was talking about a noticeable crank offset

Just so you know, Suzuki does not offset its cranks. Honda has a 4.5mm offset. KTM and Husqvarna use 5mm of offset. Kawasaki has 8.5mm of offset, and the Yamaha YZ450F offset is 12mm.

https://motocrossactionmag.com/ask-t...-crank-offset/

Stan

I've watched a ton of that guy's stuff over the last couple of years. He explains things very well.

Stan, have you analyzed TQ-Arm eff vs CYL offset from the Mains CL? That would be an eye opener to optimize vs Stroke & Rod length.

Mark,
I have some calculations in my software that I coded sometime ago, but am not sure just how accurate they are.

If you still have my software. You can play around with them on the Comp Gauge screen and let me know what you think.

Stan

The only offset I recall analyzing in labs at GMI was wrist pin offset. This was done to reduce cylinder wall wear more than anything. The cylinder bores were always on the main bearing centerline of the crankshaft though.

One interesting finding during development of the 301 was confirmation that the combustion forces on the main bearing cap were always higher than the balancing load needed to offset rotational forces. That justified removing the crankshaft counterweights on that engine in an effort for better fuel economy.

Interesting Video- More questions
 

Great video, are Pontiacs offset? Also, Pontiacs are known to have more torque than other makes with same displacement, is this due to a smaller piston and larger stroke?

@Stan, i still have your CARFOR SW, but have not run it in awhile (8years?), due to lack of relevant projects. I want to look at that Comp Gauge screen and trysome parameters,,if i only had the time. This Summer is going to be BUSY with work.

X72GPX it’s due to first off the longer strokes that Pontiacs have then other brands on there street production motors.

For example a 455 Buick has a 3.90” stroke as compared to the Pontiac 455 stroke of 4.210”.

Secondly pontiacs rod center to center is a long 6.625” which favors low speed power.

PMDs TQ; yea, long STROKE with Long Rods, then add tall rectangular ports (not round) with a decent Squish chamber+slug Flats sending the mix toward the Spark+ kernel.

And a smokin great Intake, even the 2-bbls.

Didnt flathead fords have a ton of crank offset? like .250"?

Excellent video.