ktcanuck

I believe someone asked this before but it wasn't fully answered. I am about to mount one in a TopFlite Bonanza. The Bonanza nosewheel is offset to starboard. I would like the exhaust exit on the port side so I have more room to route the exhaust internally without conflicting with the nosewheel mount or cowl.

I guess the first observation is about that crankcase vent. It looks like it must be mounted close to the bottom so oil doesn't build up in the crankcase. What tolerance can be applied to the mounted orientation of the crankcase vent?

Second question is whether you can separate the cylinder assembly from the crankcase and rotate it 180 degrees so the exhaust is on the right, carb on the top and vent on the bottom - all looking from the front. Can the timing be maintained?

Answers much appreciated soonest - I am at engine mount stage right now!

Keith

bugerdup

Yes you can rotate the top half to make the exhaust come out either side. I rotated mine to have the starting socket on the right. but you must time it before you loosen the bolts and lock the cylinder so it does not move, ( a pin through the exhaust and carb openings works great). once you have done that, lift the top half off the gears the rotate 90' left or right. make sure that the crank and piston are at TDC, top dead center. then carefully lower the top half down on the gears making sure nothing moves. it may take a few try's before your sure that it is timed corectly. it is farlly straight forward. hope that helps.

ktcanuck

Thanks bugerdup. You rotated 90 degrees? As delivered and looking from the prop end, my starter socket is on the right, the crankcase vent on the bottom, carb on the bottom and exhaust on the left. So presumably your exhaust is now on the bottom?

On the RCV website some pics show the crankcase vent on the bottom and some show it on the side. With it on side I guess it would act a bit like a sump overflow.

bugerdup

hi, One thing I was told was to break in the engine as it came from the factory and then open it up and clean out the case, metal filing do build up. then rotate it and clean it out again after your happy with the tuning and several tanks of fuel. what i did was rotate the lower half 90' to the right so the exhaust is still on the bottom. It is mounted in a top-flite corsair. I asked Kondor Model Products this same question and they told me it can be mounted it any position. I just did not want a big hole in the top of the cowl. the vent is on the side as well with no problems, I think having the vent on the side keeps some oil in the case to keep the gears lubed up and keeps them cool as well. Also, starting this engine does get easier the more fuel you run through it. hope that helps.

Joe Lott

Hello ktcanuck,

My engine came with the starter bolt on top, the crankcase vent and the carb on the right side, and the exhaust on the bottom-just as shown in the picture. Sorry about the duplicate pics. I hit the upload button one too many times.

bugerdup

What you should do is just mount the engine 90' to the right "without" splitting the case and that will give the exhaust on the left and the carb on the top and the starting bolt on the right. Having the vent on the top should not be a problem.

ktcanuck

It's the vent that is troublesome to me. It is hard to tell where the seals are that might stop a build up of oil being exposed to the base of the piston. Perhaps, when it is operating, the crankcase is full of oil vapour which vents neatly at any angle and just settles when non-operating. Logically, as RCV does not warn against it, you should be able to mount it at any angle. And I am not suggesting you cannot. I would just like the comfort of hearing it from RCV as nowhere in their docs do they say you can even though nowhere in their docs do they say you can't. In an earlier message someone asked this question amongst others. The RCV answer covered everything except this specific question.

Just trying to be prudent here...

Joe Lott

ktcanuck,

There is an updated operating manual on RCV's website. It recommends hanging your model nose up. That would alleviate the possible issue with oil build-up at the piston base after it has been run. From my experience thus far with my engine, it really blows a lot of oil out that vent tube while running, so I never considered it as a potential problem. The crankcase vent actually has enough pressure that you can attach the vent tube to your muffler via a second nipple and vent the oil out your exhaust. At any rate, you might want to start another thread and, in the title, address it as a question to Keith Lawes. He invented the engine and drops in occasionally to personally answer questions. If you do this, it might keep others from responding and give Keith a chance to answer your questions. I know he put my mind at ease by answering my questions.

Good luck,
Joe

ktcanuck

Joe,

Done, and thanks...

Keith

keithlawes

Hi

Sorry about delay in replying

Answer is that the position of the vent will have almost no effect whilst the engine is running. With the crankshaft whirring round at 12000RPM, and 20cc of gas trying to get into and out of the breather every cycle the interior of the casing is a very violent place and gravity will have little or no effect.

Once its stopped I think that hanging the model vertically might help a little but dont think its that important. We've had engine hanging around here for years with little or no care and attention between runs and the'yre fine!!

ktcanuck

Thanks Keith - I figured that might be the case.

One supplementary: I have mounted the engine on my own stand off block and the carb centreline is offset down about 1cm from the centre of the tank. The layout of the Bonanza didn't give me much choice without major reconstruction. I don't think 1cm will make a discernable difference, do you?

Keith