h-ray-RCA

Hey all,

I’m trying to mount this engine in this a/c and am having problems with the firewall being too close to the carb to allow a hookup of the throttle cable. Should I just install maple rails and forget the kit engine mounts? If I do I’m going to have to extend the engine out another 3/8” and it’s going to look odd, plus the longer moment arm that will require more weight in the tail to compensate.


Thanks

FHHuber

Which 4-stroke?[&:]

Not sure how you'll solve it on the .40 size... here's how I solved it on the 4*60:

make a U about 1 inch wide, about 2 inches long on the end of the throttle pushrod. the throttle pushrod exts at a more convenient location.. and the U brings the pushrod BACK to the carb.

I ran nyrod to about 1 inch short of the firewall and a 12 inch pushrod (threaded end threaded into the nyrod) was clipped to appx 6 inches to make this.

The way I solved it (more room) in my Fokker Dr1... I drilled the sside of an engine bearer forward of the engine's bolts, and mounted a 2-arm (180 deg) servo arm as a bellcrank. Again... the throttle pushrod exits where its convenient... and the throttle is operated by a 4 inch puyshrod off the bellcrank. (has 3 or 4 bends to get back to the carb and not hit anything.)

sandal

I turned the carb throttle arm around (pointing straight up at half throttle). The throttle cable is routed out through a hole in the top deck. Looks strange, but works. (FS-52S)

h-ray-RCA

Thanks guys. I had thought about doing the u-turn but there still wasn't enough room to do that. I woke up this morning realizing that I could turn the throttle arm to the top and run the cable out the top of the cowling. Then I woke up and read sandal's post. I must have forgotten to log off last night and the matrix emailed it directly to me.

Thanks again, once the basement warms up I'll be a working.

MinnFlyer

My Feedback: (4)

Here's what FHHuber was describing:

Baelzebob

I have a Saito 4 stroke in a MIDstar .40 (Saito 52 I think.. older engine.) I drilled a hole in the engine mount forward of the engine case mounting on the excess mount area and in a position advantageous to the throttle horn. I then used a throttle cable routed to come out from low in the firewall and making approx 90 deg bend to nearly vertical, through the engine mount (the cable sheath was ca-d to the mount) and to the throttle horn. Works very well for me. I would only advise not to drill your hole too close to the actual engine mount holes and don't bend your cable too sharply so it doesn't bind.

Edit... I realize actually that the throttle is behind the engine and it does work fine... I have used this method on a few aircraft, to include 2-strokes.

Elwood

My Feedback: (2)

Servo Horn with a Brass Insert from the servo mounting kit. This is from my 4*40 with a Saito .56. Think I reversed the carb.

FHHuber

Yep... you reversed the carb. Looks basicly like what I did for my Dr1... except I did it on the other side of the engine.

The only problem with that is... might be a tight fit for the linkage inside the cheek cowl. I'd think you wouldn't have room for it with the Saito .56 in a 4*40 without chopping off part of a cheek.... or mounting the engine off to the side just a bit.

GoMike

Here's what I did on my Tiger2/OS70FS: I cut a good sized hole in the firewall and built a small box onto the back of the firewall over that hole. My outer nyrod-type tube ends at the back of the little box. That way my throttle inner rod (a weedeater string with a plastic clevis glued on the end) exits about 1/2 inch behind the firewall and has enough room in that little box to flex in all directions for the movement of the throttle horn.

I had to drop the level of the fuel tank to do this - and my battery isn't in the tank area as recommended - it's way back in the fuselage to offset the engine weight.

It was a little more trouble than most methods, but my home-made (tight) balsa cowl precluded a u-bend or bellcrank.

==Mike==