I continue to be amazed that Mark has time to not only buy, build, crash and re-build but also track down esoteric forums on VW heads. I would guess Mark doesn't get much sleep.
Thanks to the link I've discovered a new tool - an "air file". I don't need one but do enjoy buying stuff I don't need so I'll surely get an air file at some point. What a great idea for getting at hard to reach areas. Something like that could be used for cleaning the narrow slots on my car wheels that collect brake dust and are so hard to clean. Chucking a narrow brush in this device would be the cat's meow for doing this job - I've tried everything except taking the wheels off and putting them in an acid bath, so this tool is a great find. Re high cylinder head temps - keep in mind that once you get beyond 3200 RPM you're generating a huge amount of heat just from internal friction. Whatever additional thrust you get at running the prop tips at or above mach comes at great cost in heat, noise and is just generally wasteful and destructive. Keep the RPM's down and you keep the internal friction down. Keeping internal friction down keeps heat levels down. My opinion is high RPM's for extended periods are going to kill the engine a lot faster than poor baffling - or even poor circulation from casting leftovers that haven't been cleaned. Running the engine at 3000 or under will do wonders for engine longevity and compensate for a multitude of sins. I don't know how important it is, but I've always used Valvoline 15/50 synthetic from NAPA. It's what Steve (Bennett) was using in the engine when he had the plane and I've just continued using it. Synthetic doesn't break down with heat nearly as much as conventional oils. Re Bob Hoover - I once considered anything he said to be golden - until I read where someone said that he (Hoover) recommended that valves need to be replaced every 150 hours or whatever it was - that's plain ridiculous and calls into question everything else he had to say. One bit of very valuable advice I did get from reading Hoover is how important it is to run the engine cool. That _is_ golden. Just for general information - putting on a nice coarse prop will give you plenty of thrust for takeoff and climb but most especially cruise, yet will keep the engine cool since you can't turn any faster than 3200 with a 2180 with a 52 x 56 Sterba - and that's only at altitude with WOT. My takeoff RPM is plus or minus 2800 RPM. It gets off and climbs fine with me and a 21 gallons of fuel and a baggage compartment stuffed with tools and water and my travel bag with clothes, computer & whatever. Last Saturday I left San Felipe on the Sea of Cortez about 2 in the afternoon - temps over 100F and gusty strong winds blowing straight across the runway. Cylinder and oil temps stayed within limits throughout the takeoff and long cruise climb up to 8500 back to SDM. I didn't go higher because it's a short distance between MMSF and KSDM and also because my recently filled oxygen bottle had sprung a leak sitting out on the hot ramp. The seal between the regulator and tank valve badly needed replacement I discovered once I got home. Just run the VW somewhere around 3000 RPM and it'll chug along forever. Bob Hoover was nuts to suggest rebuilding the heads everytime you turn around. Good valves are important - and all stainless valves aren't the same. Spend the money and get some Manleys. They're not that expensive and they're the best. Use swivel feet on the rockers - that's absolutely essential to keep your guides healthy. Even with Manleys, put them in a lathe or valve grinder and make sure they are true. Even Continental and Lycoming valves can't be trusted to be true out of the box. If the stem is even slightly out of true they won't consistently seat perfectly (and they must) and when they don't seat perfectly you get what Mark's friend Jim Hill had with his engine. You can't trust new valves to be true, no matter who makes them. They need to be trued when you put them in. And use new springs of the best quality (not stronger - that'll just wear out the cam lobes) you can buy. Re-using valve springs is a felony. And read Langford's tutorial on building his Corvair. Read it a bunch of times. Mike KSEE ____________________________________________________________ Affordable Wireless Plans Set up is easy. Get online in minutes. Starting at only $9.95 per month! www.netzero.net?refcd=nzmem0216
