Return-Path: Received: from postoffice2.direcpc.com ([198.77.116.30]) by ns1.olsusa.com (Post.Office MTA v3.5.3 release 223 ID# 0-64832U3500L350S0V35) with ESMTP id com for ; Tue, 10 Oct 2000 00:36:17 -0400 Received: from hostname ([206.71.97.119]) by postoffice2.direcpc.com (Post.Office MTA v3.1.2 release (PO203-101c) ID# 0-45425U50000L50000S0) with SMTP id AAA15788 for ; Tue, 10 Oct 2000 00:47:03 -0400 Message-ID: <010a01c03273$18b7cb20$4968140a@direcpc.com> From: "Fred Moreno" To: "Lancair List" Subject: TSIO 550 -E Lean of Peak or rich of peak? Date: Mon, 9 Oct 2000 21:32:24 -0700 X-Mailing-List: lancair.list@olsusa.com Reply-To: lancair.list@olsusa.com Mime-Version: 1.0
A recent article by Orin Riddell in the Lancair Mail periodical issued by the factory had a new set of recommendations for operation of the Continental TSIO-550.  I have copied the information from the table and repeat it below:
 

% Power Fuel Flow Fuel Setting

100% - 350 HP 41-43 gal/hour full rich

75% cruise climb – 262 HP 27-28 gal/hour full rich recommended

65% economy cruise – 227 HP 20-21 gal/hour 100F rich of peak

55% economy cruise – 192 HP 16-17 gal/hour 100F rich of peak

These figures are much higher than initially recommended apparently because experience has shown that the TSIO-550 suffers high wear and premature cylinder removal when operated at lower fuel flows.   I know that with my TurboSkylane RG, operation at lean mixture settings (permitted by "the book" at lower settings) resulted in three burned exhaust valves at about 1000 hours, and this engine operates a lot cooler than the TSIO-550 Continental. 

So I think the answer on leaning is: you pay now (rich mixture) or your pay later (top overhauls), but either way, you PAY.   Unfortunately these high performance, turbocharged aircraft engines have high life cycle costs, taking initial cost, fuel cost, and maintenance cost into account.  Alas.

Fred Moreno