lml@lancaironline.net Mailing List Archive

<<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> << Lancair Builders' Mail List >> <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> Dave, I've met Neal Pobanz, and you're right he is pretty smart concerning the Bonanza's. his comment:<< His parting advice regarding the 550? Don't lean the damn thing, or you will spend $9000 for cylinders way before TBO (paraphased). >> is correct and was probably biased in some manner against the installations that had the "automatic mixture control" aneroid in the fuel system. This unit would automatically reduce the fuel flow above 5000' or so in an attempt to help the pilot. But some pilots are prone to forget, and don't follow instructions, and would start pulling that red knob back in the climb, causing the engine to run too lean, and of course shorten the life of the engine. This system was never on the TSIO engine and TCM decided a few years ago to drop this system (and replace those in the field) in an attempt to cure the problem of pilot inattention to operating details. The issue of water formation in the oil filler tube is a real concern, look at an older engine and you'll notice rust in the cap. Not indicative of what is inside!! The problem is that in the attempt to remove the air/oil separator in the installation (weight/cost I guess) the oil filler tube was designed to become the separator, and a overboard vent line attached about 1/2 way up. Problem is that the space above the hose does not get purged and moisture forms there quite well. Another engineering dilemma. Off the top of my head I can't think of an appropriate alternate location for crankcase vent. If only we had a little more room in that tight engine compartment....... Brent and all, I appologize for mis-representing the problem the TSIO 520 had in the Malibu, it was not removed due to problems in the accessory drive, but as I have been corrected a political problem with the takeover by Millar. He apparently had a pissing contest going on with TCM and was driving toward gettint them out at any cost. The major problem was heat dissipation in the engine compartment and Piper engineering was directed to do nothing to correct the problem. Excess heat gave way to customer dis-satisfaction and poor performance overall. Additionally the power charts were wrong, and the pilots were cruising at apporximately 80%. The one crash that caused a lawsuit was due to a Piper installed BFG Seal, and TCM not only won the suit but acquired 25% of Piper in the settlement. Upon installing the Lycoming engine, the engineers were allowed to install the much needed exhaust outlets and gills to improve the air flow problems. Politics killed the installation, not the engine. And it continues today..... A little history as requested: The TSIO-550A was designed in response to a concurrent request by Lance for the IV, and the other was by a Chinese manufacturer for one of their new design aircraft. The Chinese did not desire the capability of high altitude operations, thus the exclusion of sonic ports on the A&B. Currently the users include Lancair, Adam Aircraft (Scaled design), other companies that are in the experimental stage who's names cannot be disclosed. Mr. Henry Van Kesteren in St. Petersburg Fl. has a STC to install the TSIO 550-C in the Malibu. This is the same engine, with a 8 Qt. oil sump and the engine is de-rated to 310 hp. to meet the original certificate and they install a certified MT 4 blade prop. They de-rate it by reducing the RPM to 2500, and MAP accordingly, only when the new owner gets away from the shop, they usually turn the wick back up to 350 hp. Something about too much power never being enough. Mike DeHate LML website: http://www.olsusa.com/Users/Mkaye/maillist.html Builders' Bookstore: http://www.buildersbooks.com/lancair Please send your photos and drawings to marvkaye@olsusa.com.