Return-Path: Received: from imo18.mx.aol.com ([198.81.17.8]) by truman.olsusa.com (Post.Office MTA v3.5.1 release 219 ID# 0-52269U2500L250S0V35) with ESMTP id com for ; Fri, 9 Jul 1999 01:40:42 -0400 Received: from N295P@aol.com by imo18.mx.aol.com (IMOv20.21) id zFAFa22742 (4242); Fri, 9 Jul 1999 01:42:37 -0400 (EDT) From: N295P@aol.com Message-ID: <2e1b72c1.24b6e5cc@aol.com> Date: Fri, 9 Jul 1999 01:42:36 EDT Subject: Re: Problems with installing IO-520 To: ken@quickturn.com CC: lancair.list@olsusa.com X-Mailing-List: lancair.list@olsusa.com Mime-Version: 1.0 <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> << Lancair Builders' Mail List >> <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> >> Hi Ken: So, you are considering putting an IO-520 into a IV. Here's the details. When I was ready to buy an engine (non-turbo) for my IV, in 1995, I had two choices: a new, new-design IO-550, no cores on the market for rebuilds, OR build-up an IO-520, for which there were/are good cores available. TODAY, I would use an IO-550, new from Lancair, certificated engine/prop, engine has proven to be a good one. I am not addressing the TSIO-550, or Lycoming TIO-540 installations. I love to fuss with engines, so I applied myself to fitting in an IO-520 in 1995. Using a good shop, Victor Aviation in Palo Alto was crucial, they were great to work with. They found me a good IO-520BB core, fitted 6 new cylinders, heavy crank, con. rods, all the mods, ported and balanced. All big Continentals share basic dimensions. The IV installation requires a shallow oil pan, dynafocal case-mounted feet, making it a drop-in fit to the stock engine mount, stock Barry isolators. Lots of room above the engine as intake and exhaust are below. Intake crossover tube is switched to the rear of the engine, custom fitting needed below cyl. #2, close to mount riser. Throttle body is from a -NB engine, mounted below front lip of oil pan and feeding the intake manifolds from the front. Welded-up tubing to make connections. Custom intake fitting with alternate-air door. Controls from Spruce readily fitted for Throttle, Prop and Mixture. All hoses from Sacramento Skyranch, lifetime, integral firesleeve design. Great service from the hose shop guys. (re-read the measuring guide twice in your Spruce catalog, angled fitting at one end, keep the other end straight, if you must have an angled end). Since you do not have turbos, you do not need the two blisters on the IV cowl bottom. I used an ES cowl!! No mods to the top, added a chin bump-out to accomodate the throttle body and a NACA scoop on the bottom right. Prop is the same, no bad RPM ranges per Hartzell. Use stock IO-550 exhaust from Lancair, made up 1" taller, to clear intakes. Since they make them long anyway to bend and cut them down to size, this is easy for them to supply. Heat muff same. Few teething problems, only real added mod was to install a richer injector on #5 cylinder, which was leaning too early. Lots of work for an IO-520. You would have a simpler time of it with the 550. Insurance and resale considerations push you to the 550 too (certificated engine/prop). I am quite happy with my IO-520, cruise 200Kts true at 12,500, burning 12gph. I'll be at Oshkosh, if you want to see my bird, look for N295P in the camping area south of row #60, check the registry. Good luck, Robert >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> LML homepage: http://www.olsusa.com/Users/Mkaye/maillist.html