Hi,

I am building a Great Planes P-51 kit. I already drilled the firewall to accept the Great Planes .40-size engine mount. I was originally going to use an O.S. 46 FX in this plane, but I am now considering the Saito 72.

Will the Saito 72 fit in the Great Planes .40 engine mount (which is supposed to accept up to .70 4-stroke) ?

Also, according to the plans for this kit, if you are going to mount a 4-stroke .70 engine (the one shown on the plans is the O.S. 70), then it is recommended to mount the engine directly to the firewall with a different kind of engine mount (either for vibration dampening or because the 4-stroke engine is longer and needs to be all the way back to the firewall for proper nose length) Since I already drilled the firewall for the Great Planes mount, I would prefer to use it.

Has anyone out there mounted a .70 or .72 4-stroke onto a Great Planes engine mount on this plane and had it fit?

Any input would be greatly appreciated!

-Dan

I think you will find that you will need the universal engine mount that is two separate legs which allows you to bring the engine all the way back to the firewall. My GP's P-51 has an OS 70 and this is the only way I could get the engine to fit. Since you mount the engine to complete the shaping of the plane's nose I imagine you could do some fabrication to extend the nose to allow for the added length created by the engine mount, but at $5.00 for a new mount I would save the work and try to keep the scale appearance. Just plug some round wooden dowel material into the holes in the firewall and drop some CA on them and your firewall will be as strong as new.

Thanks, Dan B. Who makes this "universal engine mount" that you speak of?

-Dan

I picked my mount up from the local hobby shop and I can't remember the manufacturer. I am out of town till Thursday, if no one else responds on the manufacturer I will go by the hobby shop and get the name. This shop orders through the same distributor as Tower. I looked on the Tower web and could not find it, but sometimes you have to know the manufacturer to find things on their web site. The mount just looks like two separate "T"'s made of a black nylon type material.

I flew my GP P-51 kit wih a Saito .65, and it flew absolutely fantastic! It's a nice flying sport scale warbird. I think I settled on an APC 12 X 9 prop, and it seemed a good combo. I can't help with your engine mount question, but you should have a nice flying Mustang once you get it done. Good Luck!

The GP 40 mount will hold a Saito 72 just fine.I have one on a GP Spitfire and a GP Mustang

I'll post a few pic's during construction of my OS 70 Surpass on the same plane. It worked fine.

Another pic

one more

Hey, thanks for all of your responses, guys!

Saturn V, I have a few questions.

First, did you need to modify the mount at all to slide the engine as far back as possible?

Secondly, did the length of your P-51 nose come out similar to what was shown on the plans?

Third, from one of your pics, it looks like the nose of your plane points down a bit. Is this because you inverted your engine, or was your pic taken from a weird angle?

Thanks a lot!

-Dan

I mounted a magnum 80 4st and bought a GP adjustable mount for it, .60 to .120 size. it mounted without a problem. currently installing the retracts, so all I have done is run the engine so far. Good luck, the .70 should be perfect.

1.) No, it was an adjustable mount.

2.) Yes the length was close, the support beams needs to be trimmed to the correct length. There's a section in the manual about mount the back of the spinner with a spacer, etc.

3.) I hope it's just a weird angle, the motor mount is square with the firewall. I may not have trimmed the supports perfectly square. Here's a finished pic.

For what it is worth, the Universal Motor Mount is made by Carl Goldberg Models. I did have to shorten one leg on the mount to allow for the carb linkage travel. With this mount you can bring your motor all the way back to the firewall and match the motor mounting laid out on the plans.