Long time coming

[Randy Ryan]

OK, well after allot of personal turmoil I've finally returned to modeling and more specifically my 4 stroke experience. Stock TF SCORE and Saito .56, Master Airscrew  12-6 3 blade. this is the exact setup Mike Alimov let me fly at the Cleveland meet several years back. I got about 10 flight in yesterday with varied results. The airplane itself flys quite well and I did get a bit of trimming in but in all those flights I managed only 1 good run. I had started out with a 2 oz suction tank which no matter how I played I could not complete the pattern. I calculated the fuel consumption and ended up making a 3 1/3 oz tank. Even at that I could not quite finish the pattern, obviously something was wrong. So I decided I'd try muffler pressure and ended up with 8 minute plus runs so I presume my earlier issues were NV adjustment finis', I've never run a 4 stroke before and I'm still on the steep part of the learning curve. Still not running consistently  I tried cleaning the NVA and spraybar and after that is when I got my on excellent run. The flight after that when I started it acted rich so I touched the needle lightly to lean it, not even 1/8 turn. Took off and about a half lap in it cleared its throat and really ran strong, and too lean to maneuver with. the last flight, richened back to the original position did the same thing. I am going back in and clean the fuel system and replace the fuel filter, if I could get back to that one run quality I could really start some serious practice.

Comments please..........

[Mike Alimov]

Ahhh, Randy, Randy...   The cornerstone of my Saito setup is the wedge uniflow tank (the one I brought to the Detroit Auto Test show for you to see).  Once again, uniflow, not suction.  Heavily wedged outside rear (pickup) corner.  One internal baffle.  About 3 oz total (only for the Saito 62; the 56 needs about 2-1/4 oz).

I am well aware that many people on this forum have used the Bob Reeves setup - which includes a suction tank - but then you would have to copy all the other elements of his system.

I'm on my 5th year flying my uniflow setup with no issues whatsoever.

Your choice.

Having said that, a clean fuel system (and filtered fuel) are a must no matter what.  By the way, have you ever changed the glow plug?  I don't know how many hours that Saito had when I sent it to you, but the plug was original...

[Randy Ryan]

Ahhh, Randy, Randy...   The cornerstone of my Saito setup is the wedge uniflow tank (the one I brought to the Detroit Auto Test show for you to see).  Once again, uniflow, not suction.  Heavily wedged outside rear (pickup) corner.  One internal baffle.  About 3 oz total (only for the Saito 62; the 56 needs about 2-1/4 oz).

I am well aware that many people on this forum have used the Bob Reeves setup - which includes a suction tank - but then you would have to copy all the other elements of his system.

I'm on my 5th year flying my uniflow setup with no issues whatsoever.

Your choice.

Having said that, a clean fuel system (and filtered fuel) are a must no matter what.  By the way, have you ever changed the glow plug?  I don't know how many hours that Saito had when I sent it to you, but the plug was original...

Mike,

I did build up the tank radically wedged, but the venting to be honest I forgot. Shoulda just called you I guess, but I also wanted the feedback I could get from here. Guess I'll pop the tank and re-vent it, not difficult because made it to bolt in. I did allot of flying yesterday, girlfriend over with 3 daughters and a niece, plus her learning to fly. Just getting my Skyray back together after one students perfect figure 9! I'll pull the tank next, clean everything up and change the vent. I'm anxious to start getting consistent runs so I can actually practice.

Ok, tank Uniflized (is that a word?) Now far more nice weather to see what happens.

[Mike Alimov]

Randy, one more thought about run consistency (assuming it wasn't simply dirty fuel).
4-strokes are notorious shakers.  During the power stroke, the torque applied to the prop, and the resulting twisting forces on the front portion of the fuselage, are quite large - larger than those on the 2-strokes.
I once had the entire nose of a converted RC ARF (along with Saito 56) "detach" in flight. I also wasn't able to get consistent runs on that plane. Probably due to fuel foaming.

So, on my TF Score, I ended up installing a 3/32 aircraft ply floor plate (replacing stock plate) from the firewall back to the high point of the wing, where it was spliced with the remaining balsa floor running back to the tail.  Then the bottom was re-covered in matching white monokote.

[Randy Ryan]

Randy, one more thought about run consistency (assuming it wasn't simply dirty fuel).
4-strokes are notorious shakers.  During the power stroke, the torque applied to the prop, and the resulting twisting forces on the front portion of the fuselage, are quite large - larger than those on the 2-strokes.
I once had the entire nose of a converted RC ARF (along with Saito 56) "detach" in flight. I also wasn't able to get consistent runs on that plane. Probably due to fuel foaming.

So, on my TF Score, I ended up installing a 3/32 aircraft ply floor plate (replacing stock plate) from the firewall back to the high point of the wing, where it was spliced with the remaining balsa floor running back to the tail.  Then the bottom was re-covered in matching white monokote.

Interesting you mention that, I was just contemplating the same thing, it needs something, that is a very "flexible" nose structure. I need to dowel and bolt it tho, I want access to the tank easily while I'm learning the setup.

Also looking at a clean venture design as we discussed, I remembered much more of that conversation for some reason!!!