mwright

My Feedback: (5)

Background:
I recently needed to change the head on my 46FX (to diesel) and the screws were stuck and various lubricating fluids did not help. So I did what any impatient and desperate person would do, I broke off all the fins and then got the screws loose.

Question:
Is is possible to reinstall the head (with no cooling fins) and expect the engine to be alright? The engine would not be cowled but open to the air. I suspect that if it were ok to run without fins then OS would make it without fins but still I thought I'd ask.


One last thing, I'll go ahead and say what you all are thinking, you must be really stupid for doing this and then asking a question about it.....It may be the 15 days of rain we have received in NC, maybe my mind is as mushy as our field.

Marcus

trailingedge

My Feedback: (1)

Lack of air time makes us all do strange things. The fins are on the head for cooling. I would probably find a used head with fins on it or opt for a new one before you go out. The added heat may not hurt a thing, but in my book, it's better to be safe than sorry. The engine will run a hotter, but I'm not sure how much hotter.

jharkin

My Feedback: (2)

Id agree with trailing edge, get another head.

Keep in mind too that the head is the hottest running part of the engine (since thats where combustion happens), not the place I'd like to reduce cooling...

mwright

My Feedback: (5)

Thanks, I looked it up and the heads are only about $14, pretty cheap insurance I guess. Another 3 inches of rain forcasted for Sat I guess I'll have time to run the engine up see how it does with a NEW head.

therotund1

Marcus,

Did you not like the diesel? I'm gonna try it on a 40LA as soon as the parts get here. I'd like an opinion. My goals are to get a bigger prop and more torque to use it. It seems logical to me. What do you think??

mwright

My Feedback: (5)

Diesels..... I did not try this engine out as diesel but was trying to test a diesel head for correct fit that someone had sent me.

I have run an OS 40FP much like your 40LA on a Davis conversion head. See this tread:

http://www.rcuniverse.com/showthread...45#post1035213

I can turn a 12x6 on the little bushing 40FP at 9300 rpm with lower noise less fuel and weight but for that I must have fresh fuel (biggest issue), tygon fuel lines, correct tank stopper and correct fuel pump (when using kero based fuel, with bio-diesel only fresh fuel is needed). I also have to contend with adjusting two variables (needle and compression). Lastly, you need to divert the exhaust away from the plane.

Some people will not like the fuel issues or operating issues. I happen to enjoy extracting power from all things mechanical or electrical.

My personal advise is two fold, 1) if you want to investigate another aspect of this deep hobby go for it but 2) if your primary focus is to get more power and fly with modest effort and time investment and you already operate 2-strokes then buy a larger 2-stroke or better brand or use higher nitro fuel or make a Mousse can pipe.

Hope this helps. Marcuss

Bax

My Feedback: (11)

If the ends of one or two fins are broken, the engine will suffer only in looks. If many fins are broken off, you should get a new one.

therotund1

Marcus,
I too, truly enjoy getting the biggest bang out of an engine. My interest is also part of my personal learning curve. I think it'll be neat. Too bad they don't run off regular diesel. I have 2 pickups (Ford-IH), a Volvo SW and an Isuzu Imark (yuck!) all diesels... A stinky airplane will fit right in with my stinky fleet. Thanks! I'm gonna give it a try.