Scale engine position

[Douglas P Shepherd]

I have a project that I am working on, I need to see if a .67 scale engine. Can be installed in the horizontal position instead of vertical Pros or Cons Thanks for any input on this project Doug Shepherd

 

[dave roach]

Doug

So what you are saying you what to lay the engine on it's side.I think that would be a great idle.

Dave Roach

 

[u60]

I have a project that I am working on, I need to see if a .67 scale engine. Can be installed in the horizontal position instead of vertical Pros or Cons Thanks for any input on this project Doug Shepherd

Doug- I replied in the wrong section... Anyway I have seen this done on a Speedy Printing scale boat.. The particular boat had a really wide engine well so it was easy to lay it over and still have access to everythig. It seemed to work OK. In a boat with a narrow engine well it will be a bit difficult to get to everything in my opinion. Im not sure of any gains in mounting the engine this way. Perhap a slightly lower CG.

 

[Douglas P Shepherd]

Not looking for the performance gains but for problems above the beck line (clearance.) I know the airplane engine work well in this position.

 

[Bigbird]

Makin scales look more better...lol

 

[Hydro Junkie]

I don't see why it wouldn't work EXCEPT all the fuel would be forced in through the transfer ports on the bottom side of the cylinder. This COULD cause a fuel/air mix problem as air would be pulled into the cylinder easier than the fuel. I would suggest settting up a test stand and side mounting the engine and see what happens using a large pusher aircraft prop for a load. One other thing, don't forget to turn the carb so it's in a standard horizontal position or that could cause problems as well

 

[SayMikey]

Glow plug access would be a pia. I had a 21 lay down Crapshooter years ago

 

[Douglas P Shepherd]

Mike did the engine run as good ? I have checked the fit in the scale hull and all can be made to work. I am going to put a known engine back on the dyno, In this postion and check the new number to the post. Thanks Doug

 

[SayMikey]

I think it will run just fine, mine ran well

 

[PakMan]

I don't see why it wouldn't work EXCEPT all the fuel would be forced in through the transfer ports on the bottom side of the cylinder. This COULD cause a fuel/air mix problem as air would be pulled into the cylinder easier than the fuel. I would suggest settting up a test stand and side mounting the engine and see what happens using a large pusher aircraft prop for a load. One other thing, don't forget to turn the carb so it's in a standard horizontal position or that could cause problems as well

What??? Please explain more. Your transfer port, and carb position comments interest me. I think that must be why I'm running lean in the turns.... my starving stbd transfer must be causing a 'fuel/air mix problem.' Just so I understand, how many times does the pistion go up and down per second in a .67 greenhead, at full throttle? If I can only find the 'sweet-spot' regarding engine position, I can really haul through the corners??? But what about the Carb angle? That must be super important too. What angle would you suggest, and to the PORT, or to the STBD....Thanks for your input.

DJ

Doug - Lay it over if you have the room. It will work great! Harder to change plugs, but lower CG, and Head-scratching by your buddies.... will make up for it... besides, you shouldn't have to change plugs often with the CMB Greenie, if it's working properly.

 

[RodneyPierce]

I dont think it matters honestly. Look at an outboard. No issues there.... Wouldnt think this would be any different.

 

[Duck899]

It makes no difference which way the engine is mounted..... my airplanes run inverted engines and side mounted engines.... I've seen a few engines layed on their sides in scales and hydro's..... Randy Seiser back in the 80's used to run a 3.5 K&B in a homebuilt hydro on its side....really cool set-up.

Dave, I was looking through my pics from the 2009 and 2010 northwest champs race cause I know I saw a boat in the Jeff Snell camp in a speedy printing style boat with the greenie on its side.... requires a removable engine mount and some carefull design to make it work.....some guys are always looking for an edge....and hey, why not?...thats what life is all about....different ideas abound!

 

[Douglas P Shepherd]

Thanks for the info. Would anybody have a pic of Jeffs motor mount?

 

[Ken Hildreth]

Hey Doug,

Rich Zimmerman had a 40 twin he had built this way, the motors seemed to run just as well laying on their side. I dont think he gets on here much but I think I have his email address. I know he built his own mounts for them. Ken

 

[Dasboatman]

Hey Doug,

I did a Sport 40 with the engine in this position. Tub was too narrow, and it became more of a pain in the arse than it was worth - tough to get to the glow plug, and getting the engine in and out was a pain. Engine is now vertical in this development hull.

The airplane world has done this very successfully for many years - inverted, on their sides, vertical with jug up - ran fine in every position. Carb position is not of concern, and the delivery to combustion chamber couldn't care less. We used to ensure that the center of the tank was in the center of the carb more so that a higher mounted tank would bot gravity feed and fill the jug on an inverted engine installation. In the case of a boat tank, I believe the fuel pickup in the lower , rear corner would not be an issue with gravity feed. Pipe pressure will put it to the spray bar, through a hopper tank without problem.

DJ,

I can't understand why you are leaning out in the turns with horizontal mounted engine. Is the plug to Starboard or Port??? I'm thinking more a fuel delivery issue.

I saw this 8255 hull for sale by Gene Gager a while back with engine on it's side. Here are a couple pics FYI.

CHEERS !!! Bob

 

[Duck899]

Yup, the Miss Houston is the boat I saw at the northwest scale championships..... really cool mount idea.

 

[Dasboatman]

Hey Rob,

The SP42 I did had a Marine Specialties insert screwed into oak motor mounts - Profile C/L airplane style. I had a removable panel in the hull bottom to get to the screws to get the engine, and /or the mount oul. Too small a space for this old Swede to get his hands and feet into. The gain in performance wasn't worth the pain it the arse it was as far as I was concerned.

The 8255 hull with the wide open tub is my kind of space. I could get my hands an feet into that. Custom motor mount looks nice. Murphy's Law would dictate have two the same to eliminate single point of failure.

I'm thinking I'd want the engine jug on the port side (other side from Gene's for you land lubbers) to counter torque some also. Looks like Gene's boat would be platform to do this in. My 8255s all have the engine vertical and tub only houses tank, pipe, engine and drive line. CHEERS !!! Bob

 

[gene gager]

when i installed the engine in the houston in picture in last post by dasboatman, look closely and you will see that the motor is also turned to the left to get the weight even more to the left front. the flex shaft tube has an extra bend in it. worked great. still working. a 2 cycle engine don't know up from down unless its got float bowl type carberator. engines don't have any brains, they only do what you make em do. also in the same picture notice the piano wire just aft of the bulk head.. thats hooked to the turn fin so the presure on the turn fin in a corner is transfered to the oposite side of the boat. in essence it pulls the boat together as to pulling it apart. this worked well as the boat was built light and fragile, bigger hammer and more glue

 

[Mike Hughes]

I don't see why it wouldn't work EXCEPT all the fuel would be forced in through the transfer ports on the bottom side of the cylinder. This COULD cause a fuel/air mix problem as air would be pulled into the cylinder easier than the fuel. I would suggest settting up a test stand and side mounting the engine and see what happens using a large pusher aircraft prop for a load. One other thing, don't forget to turn the carb so it's in a standard horizontal position or that could cause problems as well

What??? Please explain more. Your transfer port, and carb position comments interest me. I think that must be why I'm running lean in the turns.... my starving stbd transfer must be causing a 'fuel/air mix problem.' Just so I understand, how many times does the pistion go up and down per second in a .67 greenhead, at full throttle? If I can only find the 'sweet-spot' regarding engine position, I can really haul through the corners??? But what about the Carb angle? That must be super important too. What angle would you suggest, and to the PORT, or to the STBD....Thanks for your input.

DJ

:lol: :lol: :lol:

 

[dschigoda]

when i installed the engine in the houston in picture in last post by dasboatman, look closely and you will see that the motor is also turned to the left to get the weight even more to the left front. the flex shaft tube has an extra bend in it. worked great. still working. a 2 cycle engine don't know up from down unless its got float bowl type carberator. engines don't have any brains, they only do what you make em do. also in the same picture notice the piano wire just aft of the bulk head.. thats hooked to the turn fin so the presure on the turn fin in a corner is transfered to the oposite side of the boat. in essence it pulls the boat together as to pulling it apart. this worked well as the boat was built light and fragile, bigger hammer and more glue

Aaaaahhhhhh! I thought there was a story behind that wire and turn-buckle. Nice job.