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As far as i know all radial engines have ONE rod journal. But the rods do not connect directly to the one rod journal. There is a hub that mounts to the rod journal of the crank and then the rods connect to the hub.

NOTE that the Napier has cylinders that are not offset. So i would guess that hte Napier also uses a crank journal hub just like the radials.

As a side note on the 'engine balance shaft' as used on motrocycles it is usualy used on mc engines with crankshafts PERPINDICUlar to the wheel axles. Under hard engine acceleration it keeps the bike from tipping to one side. IIRC it is actualy called a Counter Rotation Shaft.

My original question about the Engine balance shaft had to do with www.advanceautoparts.com. While shopping online for some 2.0 ford engine parts i was forced to first choose from only 5 different engine parts sections. One was 'engine balance shaft' upon which i did find a tranmission part listed. That website constantly pisses me off. Just hover over the 'ENGINE Parts' tab. It will show up. AAP is a good parts store and i buy at least $100/month of parts at the store every month but their website is like surfing a tree stump.

Keith, I believe you are correct, the radial engines have a single master rod to which connecting rods from each of the cylinders connect. I don't think the "W" type engines can use a single master rod because their cylinders are arranged front to back, unlike a radial engine where all the cylinders on on the same plane. The "W" engine in question may use a version of an articulated connecting rod where each crank journal has three connecting rods attached. Someone here knows for sure. Interesting...

(o{I}o)

Rusty, thank you for taking the time to explain the function of a balance shaft (btw sometimes even two balance shafts). To write almost the same with other words I would like to substitute 4 cylinder engines by inline engines* and bad secondary vibration at twice engine speed by vibration peaks that occurs two times per revolution - just on the supposition that Keith would like to get it in both ears.

If we are going to be icky about it not all inline engines are prone to vibration. A straight six has the smallest number of cylinders giving perfect primary and secondary balance and overlapping power impulses. A well made straight six is inherently smooth, so is an opposed cylinder engine when it comes to vibration.

A straight eight or V8 can also be well balanced if the crank pins are at 9O degrees to each other. This was the design breakthrough that made the 8 cylinder practical. Before 1923 V8s had a 18O degree crankshaft like a 4 cylinder, and a similar vibration problem. Straight eights were practically unknown, only a handful had been made by Isotta Fraschini and Duesenberg when packard brought out their 1923 straight eight with 9O degree crankshaft.

An inline 3 cylinder should be as vibration free as a six if the crankpins are at 12O degrees.

when packard brought out their 1923 straight eight with 9O degree crankshaft.

I believe it was commencing with the 3rd series Eight that Packard changed their crankshaft from a 4-4 layout to a 2-4-2 layout which also corresponded to a change in the firing order to the more-or-less standard 1-6-2-5-8-3-7-4. I forget the timing order for the 1st and 2nd series but if someone has it handy and can post it, I'd write it down this time.

The crank change accompanied the change in bore for 3-3/8 to 3-1/2

Owen can you clarify this. Did Packard start with a 18O degree crank and if so when did they change. What about Duesenberg did they start with a 18O crank. I know Isotta did. What about V8s I think Cadillac started with 18O crank and changed to 9O in 1923.

This was the final piece of the puzzle to make the 8 cylinder practical it would be interesting to know how it came about.

please excuse lousy typing and punctuation the right side of my keyboard is on the fritz it is a bugger to work around.

Quote:Keith,

Two things spring to mind, 1) a very bad case of imbalance, and 2) I'd like to see that!