Lehanover@aol.com wrote:

On the other hand, an engine can still breath through a stopped turbine wheel. But not through a stopped roots blower. The

That's one of the nice features of the Paxton blower.  Then engine will still run if the blower stops (belt breaks, etc.) 

I don't know if they still offer the feature, but the Paxton I had in the mid 60's had a  variable diameter pulley (V-belt) so that the output could be tailored to the load.  That feature could be valuable for altitude normalizing vs. WEP for go arounds.

Best Regards,
Dale R.
COZY MkIV #0497