Ik zag ook een paar RC v8 lijnmotoren op youtube dat is ook wel leuk natuurlijk maar of die voor vliegtuigen geschikt zijn ?
Dit was ook wel interessant om te lezen:
[SIZE=+1]Although the Quarter-Scale Merlin is intended to look as much like the real Merlin as possible, it is not intended to be an exact scale model, right down to every external and internal detail. This would be a worthy goal, and would produce an extremely interesting engine. However, it would greatly increase the amount of time required to produce a complete engine, since every detail requires time to implement. Simplicity is favored to further the goal of producing a running, functional engine as easily as possible. For example, the present design uses two valves per cylinder, instead of four. The usual reasons for using four valves per cylinder are: to maximize valve area for good flow at high rpm, to allow better cam profiles because of lower valve weight, and to avoid the problems of valve cooling associated with large valves. If the scale Merlin were intended for all-out performance, these factors could possibly (but not necessarily) become important; however, it is primarily intended to a scale airplane with realistic sound; this means it must operate efficiently as close to the real Merlin's rpm range (a normal maximum of around 3,000 rpm) as possible. For an engine of this size, 3,000 rpm is very low, and using four valves per cylinder would give absolutely no advantage.[/SIZE]
[SIZE=+1]Another area of simplification on the prototype was the use of glow plugs (instead of spark plugs), for the simple reason that that was the easiest way to get it running. However, the glow plug/alcohol-fuel method brings its own set of problems. The prototype was equipped with an oil pump, which drew oil from the sump, filled with castor oil. Used and pump bypass oil returned to the sump. After a few minutes running, the oil pressure started to drop, and it was obvious the oil was becoming contaminated. Surprise, surprise, there was a great deal of blow-by, with 12 single-ring pistons and plenty of excess fuel. It seems that most engines which run on alcohol have this problem. In racing, the solution apparently is to change the oil after each run, or to run what is called a 'total loss' system, where no attempt is made to reuse the oil pumped into the engine (great for the track!). The latter was a temporary solution to the prototype Merlin's problem; the oil was in a separate tank, with the oil pump bypass returned to it, but the oil which was actually pumped into the engine drained into a container. In regular four-stroke model engines, the ring-bypass effect works to our advantage, because of the large amount of oil that can reach the crankcase. Actually, there is probably no reason why the quarter-scale Merlin couldn't run this way (using conventional oil-mix glow fuel instead of having an oil pump) since it seems to work well with large four-stroke model engines. For maximum longevity, an oil pump is probably best, but oil mist lubrication may be satisfactory. Another solution, of course, is to set the engine up to run on gasoline, with spark ignition. This will be attempted on the current model. The real Merlin has two magnetos, one on either side, with one firing the inside plugs, and the other the outside. It would be possible to build functional magnetos for this engine, although they would almost certainly require coil boosting at low rpms because of the inherent ineffficiency of small magnetos at low rpm. Since this is the case, it would seem logical to just use the magneto housings as distributors, and skip the extra complexity of the magneto windings.[/SIZE]
ASH
Heb je ze met alusoldeer gemaakt? Waar koop je dit soldeer? Is dit ook voor een 1/4 spitfire? Wat voor motor gebruik je? Heb je ook nog een normale tussendemper gebruikt. Heb je ook meer foto's heb je .....
