Stalker .81

[John Leidle]

 I took my new Stalker .81 out toda in my old Red Impact, The engine seems to fly it pretty well.  I used 10% nitro with 20% oil 5% castor, 15% low viscosity synthetec oil  & a 12- 6 ,  12.5- 6  prop 7900 rpm. I runs fine & holds a steady speed, lotas torque & doesnt speed up in manuvers.  Any thing I need to do to improve it? I think I only have one venturi & didnt measure it.
  Any ideas? John

[Air Ministry .]

Get Two .

[PJ Rowland]

Whats it not doing that you want to improve?

I've got 3 of the .81s - I guess the only thing you might want to try is adding another 2 shims from standard, going up in pitch and getting it to lock into a more solid stable 4 stroke.. without hearing it or seeing it, there is little advice I can offer.

[WhittleN]

Hi John
Gordan Delaney has one of the nicest running Stalker 81's ever in his big Tony.  It came alive with a .328" venturi and 10% nitro.  The venturi that came with Gordan's engine was kind of restrictive.

Regards
Norm

[PJ Rowland]

Venturi size is dependant on how you want the engine to perform. I would say experiment

I generally ran .322 however I have incremental increases from .290 - .335

[John Leidle]

    Mine has a .312 venturi     .

[Ted Fancher]

John, PJ et al,

Interesting prop choice.  I ran 12 X 6 Rev Ups on my Tiger .46s.  No clue what RPM 'cause we didn't use tachs in those days.  Could larger props for an engine more than half again larger be worth investigating?

Ted

[PJ Rowland]

I have a large selection of Eather props.

I found I used alot more pitch than I ever have before - due to the Stalkers developing power much lower down.

12 x 7 3/4

During the nats before I put it away - I went up in pitch in Muncie to

12 x 8 1/4 Launch RPM 6900 - 7150

I have also gone up to as high as 12.5 & will handle 13 .. however I prefered the pop to the corner that a 12 " gives.. despite the engine size.. Again feel free to experiment - this is only what I found works for me.

[Bob Reeves]

John, PJ et al,

Interesting prop choice.  I ran 12 X 6 Rev Ups on my Tiger .46s.  No clue what RPM 'cause we didn't use tachs in those days.  Could larger props for an engine more than half again larger be worth investigating?

Ted

I was thinking the same thing, I'm running a 13-7 on a Saito 56 and 13-6 three blade on a Saito 62.

[Gordan Delaney]

Ted,

You are right. I use a 13.25x6 three blade. Halls the Tony just fine. The motor has a lot of grunt. launch rpm is 8200.

328 venturi and 10% nitro.

Gordy

[John Leidle]

   What glow plug are you boys useing?
  john

[Gordan Delaney]

John,

I`m using a Thunder bolt Idle bar plug.

gordy

[PJ Rowland]

Thunderbolt Big bore.

[John Leidle]

 Are you guys useing any castor in the fuel ? 

[Gordan Delaney]

I`m running 11-11- 10.

Gordy

[PJ Rowland]

Same as Gordon.

I have gone up to as much as 15% Nitro.

11 - 11 - 10 is ideal.