That sounds exactly like the DH Gipsy engine system, the warm air (not hot as it comes from around the cylinders not the exhaust) is the normal feed and the selector flap is spring loaded to this, the last half inch or so of throttle lever travel over rides the spring and selects cold air for full power.Maybe the carb heat should be half on normally all the time. The pilot could "override" this carb heat momentarily for takeoff with a spring loaded gate valve that snaps back to normal.
There still seems to be plenty of the 44's out there - and I somehow missed the Small Engine Warehouse site. I hope I'm just being pessimistic but I can understand the logic of jumping from the 44 to the 61 and discontinuing the 49. I wonder if there is enough material in the 44 block casting to bore and sleeve for the 49 pistons?Hopefully there are enough OEM users of the 810 (and 40/44-series engines) out there to pull it through.
It looks like they already have a "universal" 61 series block in production. I haven't researched it enough to tell if it is truly universal or if it just has mounts for both the vertical and horizontal shaft. It think it would be a pretty simple thing to locate the internal oil pickup so that it worked for both if that was part of the original plan.I'd think that re-tooling for a new universal engine would be out of the question.
I'm a little less worried than I was when I posted about the apparent supply problem. I too have been keeping an eye out for an alternate but so far there just doesn't seem to be much. The next step down in displacement just isn't going to provide the power that is needed (IMHO) for even the small light aircraft we are thinking about. The 1L class are significantly heavier.I am worried enough about the future availability of the 810 that I am looking for an alternative.
Agree. The 28-30 HP using direct drive is enough for the project I'd like to build, and the HP/lb is more attractive than smaller or larger twins. The fact that new ones sell for a good bit less than a smaller horiz shaft engine is a pleasant plus. If they sold a horiz shaft 810cc engine, it would be interesting to see where the market would price it.I too have been keeping an eye out for an alternate but so far there just doesn't seem to be much. The next step down in displacement just isn't going to provide the power that is needed (IMHO) for even the small light aircraft we are thinking about. The 1L class are significantly heavier.
I have no doubt the series will still be produced, but if I were in the position of B+S management I could see a pretty strong case for dropping 2 of the sizes. Every part number or variation they can get rid of makes the production cheaper, along with reducing the repair part numbers stocked.(just different bore & piston and some minor items). That's why I'm quite confident that this series of engines will stay