Did you account for the fact that the 20B pump might be belted to run in the reverse direction than the 13Bs? I can’t remember my 20B belt layout anymore……wonder if the alternator does too.
Marc W.
-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Al Gietzen
Sent: Wednesday, November 10, 2004 12:13 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: EWP
Subject: [FlyRotary] Re: EWP
Al,
Good data, but for clarification, aren't you running a 13B pump on your 20B? Are you running stock main pulley or an undersized pulley? The 20B pump should flow more gpm due to a slightly larger impeller. Also, comparing a 20B eccentric pulley with a 13B from an 89 n/a engine, the 20B pulley is larger, which should also increase flow, up to the point of cavitation.
Mark S.
Mark;
Yes, I have a 13B pump housing; I’m not sure what impeller. All I know is Dave Atkins billed it as “high performance”. The pump pulley and the e-shaft pulley are the same size, which I believe is 11 - 12 cm. I can’t confirm right now because I’d have to take the cowl off to check.
Al