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Author Topic: Stalker .76re tank selection and fuel consumption  (Read 2459 times)

Offline Daniel_Munro

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Stalker .76re tank selection and fuel consumption
« on: September 16, 2020, 02:08:43 AM »
Wondering g if anyone can give me some insight into how much fuel a Stalker .76re will use for a 6 minute run? I’ll be running zero nitro 8% castor 8% synthetic fuel and spinning a 13x6 prop. Stalker claim 100ml for 6 minutes but this sounds far too little.

Also fuel tanks. Once I know what capacity I’ll be needing I can get on to buying or making a tank. Kaz sells some beautiful carbon fibre uniflow clunk tanks, has anyone got some experience they can share on these? I’ve never had a great time with clunk tanks in the past. Typically I just buy or make a uniflow wedge tank and have had good success.
NZL7396

Offline David Campbell

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Re: Stalker .76re tank selection and fuel consumption
« Reply #1 on: September 16, 2020, 06:25:14 AM »
I am using a Stalker 76 re with a14x6 prop using 120 ml to fly the patten. Engine revs at about 7000 rpm the tank is a uniflo

Offline Air Ministry .

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Re: Stalker .76re tank selection and fuel consumption
« Reply #2 on: September 16, 2020, 07:44:01 PM »
Will vary a degree on the plane size & weight , intake dia. & prop .

Found these new yatsenko props , for me , are a lot better than the old white wide blade ones . Which gave a high reaction n hard corners - nose swing .



Where this type have least, and best ' traction ' .

Had the 66 & 76 in a 80 ounce ship ! . , .312 in or .320 intake . What aircraft have you gottit in .
« Last Edit: September 17, 2020, 07:19:45 PM by Air Ministry . »

Offline Air Ministry .

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Re: Stalker .76re tank selection and fuel consumption
« Reply #3 on: September 16, 2020, 07:51:37 PM »
Quote
Stalker claim 100ml for 6 minutes but this sounds far too little.

Probly adequate for a 50 ounce ship .
Ive gotta fancy tank , that works . Tho the size resivoir shown only gets 4 1/2 laps , past half tank. Flat & level .

https://drive.google.com/file/d/15qe7H9ag3ztBK0PHA3kPtbkCc83uf0lo/view

About 50 x 25 x 115 O/A . inthe Folkerts . As per picture below . Borrowed from elsewhere .



His suggested return on the wall would effectivly reduce rear by that length, so if using as a brace , keep it down to say a millimeter .
Plus , my uniflow pipe feeds down conventionally , as does the feed . Uniflow bunged & drilled or slit . at fwd. end of rear compartment .

Its really just a box tank with a wedge rear & solid 2/3 width baffle . Sealed .

Tube through center to attach allows easy shimming . Filler vent / s to suit plane .

Offline Daniel_Munro

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Re: Stalker .76re tank selection and fuel consumption
« Reply #4 on: September 16, 2020, 08:30:33 PM »
Will vary a degree on the plane size & weight , intake dia. & prop .

Found these new yatsenko props , for me , are a lot better than the old white wide blade ones . Which gave a high reaction n hard corners - nose swing .



Where this type have least, and best ' traction ' .

Had the 66 & 76 in a 80 ounce ship ! . , .312 in intake . What aircraft have you gottit in .

Thanks, I’ll look into getting some of those props to try out too. I’ve not yet finished the plane it’ll be going in, it’ll be going in a semi scale warbird, don’t want to let the cat out of the bag yet as to what I’m working on.... it’s a little special.
NZL7396

Offline Brian Gardner

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Re: Stalker .76re tank selection and fuel consumption
« Reply #5 on: September 17, 2020, 12:02:53 AM »
I personally suggest using 17% all synthetic oil fuel. (in the 66 and 76. The smaller Stalkers require 20-22% all synthetic.) They are prone to varnishing with castor use, and it is hard to get good quality castor.

13x6 prop is a bit small.

I sell 14.2" diameter props specifically made for the Stalker 76 (although out of stock at present)

Use a hot plug like Thunderbolt 4 cycle/big bore (again I sell these)

Offline Daniel_Munro

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Re: Stalker .76re tank selection and fuel consumption
« Reply #6 on: September 19, 2020, 02:22:53 AM »
I personally suggest using 17% all synthetic oil fuel. (in the 66 and 76. The smaller Stalkers require 20-22% all synthetic.) They are prone to varnishing with castor use, and it is hard to get good quality castor.

13x6 prop is a bit small.

I sell 14.2" diameter props specifically made for the Stalker 76 (although out of stock at present)

Use a hot plug like Thunderbolt 4 cycle/big bore (again I sell these)

Brian. Thanks for the info. I used to run my Stalker .51 on 20% Klotz synthetic and had hundreds of flight out of that engine before I broke it in a bad crash.

I’ve don’t mind going all synthetic. Could get the Klotz 80/20 syth/castor as an alternative.
Props I’ve ordered are from Brian E, 13x6 three blade and a 13.5x6 two blade and a Yatsenko 13.25x6. This model should come out pretty light so I’ll start with them and see how it goes. As for plugs I’ve got a heat of Super Tigre hot plugs that I like a lot.
NZL7396

Offline Air Ministry .

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Re: Stalker .76re tank selection and fuel consumption
« Reply #7 on: September 19, 2020, 09:10:14 PM »
Somebody says you need MOTUL to get the Retro Discoveries to run smooth . 2T . Just looked and theyve FIVE 2 stroke oils .  :(

How dead is your 51 ? any recoverable parts .
« Last Edit: September 20, 2020, 07:05:50 PM by Air Ministry . »

Offline Reptoid

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Re: Stalker .76re tank selection and fuel consumption
« Reply #8 on: September 19, 2020, 10:21:21 PM »
Somebody says you need MOYUL to get the Retro Discoveries to run smooth . 2T . Just looked and theyve FIVE 2 stroke oils .  :(

How dead is your 51 ? any recoverable parts .
Only one is recommended for Methanol mixing; Motul Micro 2T. Works great
Regards,
       Don
       AMA # 3882

Offline Daniel_Munro

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Re: Stalker .76re tank selection and fuel consumption
« Reply #9 on: September 20, 2020, 03:22:39 PM »
Somebody says you need MOYUL to get the Retro Discoveries to run smooth . 2T . Just looked and theyve FIVE 2 stroke oils .  :(

How dead is your 51 ? any recoverable parts .

I’m not sure if Motul is readily available here in New Zealand. If I can find it I’ll give it a try.

The .51 will need a new NVA and crank case to be used again. All internals are ok.
NZL7396

Offline Air Ministry .

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Re: Stalker .76re tank selection and fuel consumption
« Reply #10 on: September 20, 2020, 07:05:34 PM »
Yep , sorry about the spelling .

Motorcycle Shops might carry it .

Theres a Adamisin thing on these , https://stunthanger.com/smf/engine-set-up-tips/os-40-fp-set-up-q's/msg576693/#msg576693 which says, I think , 18 % UCON .

Offline richardm

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Re: Stalker .76re tank selection and fuel consumption
« Reply #11 on: September 20, 2020, 07:19:37 PM »
Try your local motorcycle shop

https://motul.co.nz/product/micro-2t-12x2l/

Richard Mc Fadden

Offline Reptoid

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Re: Stalker .76re tank selection and fuel consumption
« Reply #12 on: September 20, 2020, 07:53:49 PM »
Regards,
       Don
       AMA # 3882

Offline Brian Gardner

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Re: Stalker .76re tank selection and fuel consumption
« Reply #13 on: September 22, 2020, 07:03:03 AM »
I can supply a case if you want.

Brian

I’m not sure if Motul is readily available here in New Zealand. If I can find it I’ll give it a try.

The .51 will need a new NVA and crank case to be used again. All internals are ok.

Offline Air Ministry .

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Re: Stalker .76re tank selection and fuel consumption
« Reply #14 on: December 04, 2020, 08:36:21 PM »
This is the one . Only $ 50 per litre !



DONT try the 800 .  >:(



Quote
Lubricant specially formulated for 2 stroke engine model vehicles (cars, boats, planes etc)
Miscible with Nitromethane, Methanol/Ether


Offline John Leidle

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Re: Stalker .76re tank selection and fuel consumption
« Reply #15 on: December 04, 2020, 11:13:31 PM »
   I was going to suggest going to the bank & make sure your account is high before you buy Motul. I used it a while back in my motorcycle & it was real pricey.
        John L.

Online Massimo Rimoldi

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Re: Stalker .76re tank selection and fuel consumption
« Reply #16 on: December 05, 2020, 04:57:42 AM »
This is the one . Only $ 50 per litre


Hi. 
Motul Micro is sold ONLY in 2 liter bottle, I don't know where you read the price but I can assume it refers to the packaging so the price per liter should be half the price.  You can check the link given in answer # 12

Massimo

Online Lauri Malila

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Re: Stalker .76re tank selection and fuel consumption
« Reply #17 on: December 05, 2020, 06:18:13 AM »
I think it would run even better with 15% of Maxima Racing Castor #927. Or not think but know🤗 L

Offline Chuck_Smith

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Re: Stalker .76re tank selection and fuel consumption
« Reply #18 on: December 05, 2020, 10:36:21 AM »
I've never run the Stalker but I'm going to assume it's similar to the K77.

I've tried the K77s and on low pitch/pipe combo it guzzles. If I had enough fuel I was either nose-heavy early or tail heavy late. Increased the horizontal tail volume on a subsequent build an it allowed me to fly with the CG a bit more aft which helped.

Switching to 0% nitro helped the fuel consumption problem more than anything else.

Anytime you have rear exhaust and need a big fuel tank things get a little hairy trying to make it all fit.

If I did it over I would make the fuselage wider allowing for the tank not to be as long, move it aft and that should help with the CG shift, but when a plane sheds 1/7th of it's mass over a flight - trimming can be a bit of a challenge.

I've not seen Kaz's tanks but thanks for the head's up, I'll check them out.

In peace,

Chuck
AMA 76478


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