Corvair Spyder engine owners,

What is your thought on the forged billet CNCd counterweighted, 1/4 stroked crankshaft in your engine vs. the cast billet crank that had a failure some years ago? I also have the 5th bearing. 

I have a 120 HP and realized that I have a counterweighted, stroker crank from a single forged billet. At least I believe it's not the sand-casted billet. Other than the one incident we're aware of, I've not heard of one happening on the counterweighted stroker version. I don't see a trend but not sure if I should drop 3K to have a one-off new crank made. The ones out there don't fit in my engine as a one-for-one.

My crank is brand new and I know others use it too with no issues. I'm wondering if the forged version makes more sense later when I give her an overhaul or just proactively replace it.


Views: 61

Reply to This

New from Zenith:

Zenith Planes For Sale 

Classified listing for buying or selling your Zenith building or flying related stuff...

Custom Instrument Panels
for your Zenith

Custom instrument panels are now available directly from Zenith Aircraft Company exclusively for Zenith builders and owners. Pre-cut panel, Dynon and Garmin avionics, and more.

Custom Upholstery Kits for your Zenith Aircraft:

Zenith Vinyl Upholstery Kits

Zenith Apparel from EAA:

Zenair Floats

Flying On Your Own Wings:
A Complete Guide to Understanding Light Airplane Design, by Chris Heintz

Builder & Pilot Supplies:

How to videos from

Developed specifically for Zenith builders (by a builder) these videos on DVD are a great help in building your own kit plane by providing practical hands-on construction information. Visit for the latest DVD titles.

Aircraft Insurance:


West Coast USA:

Pro Builder Assistance:


Transition training:

Golden Eagle Aviation

Pianosa Flying Farm

Aircraft Spruce & Specialty for all your building and pilot supplies!

© 2023   Created by Zenith.Aero.   Powered by

Badges  |  Report an Issue  |  Terms of Service