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Engine basics => Engine set up tips => Topic started by: Daniel_Munro on September 16, 2020, 02:08:43 AM

Title: Stalker .76re tank selection and fuel consumption
Post by: Daniel_Munro 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? Iíll 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 Iíll 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? Iíve 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.
Title: Re: Stalker .76re tank selection and fuel consumption
Post by: David Campbell 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
Title: Re: Stalker .76re tank selection and fuel consumption
Post by: Air Ministry . 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 .

(http://discovery-aeromodels.com/images/propellers/wooden-propeller-discovery-360-150mm(14.2-6).jpg)

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 .
Title: Re: Stalker .76re tank selection and fuel consumption
Post by: Air Ministry . 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 .

(http://images.vfl.ru/ii/1543346174/438ad729/24379276_m.jpg)

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 .
Title: Re: Stalker .76re tank selection and fuel consumption
Post by: Daniel_Munro 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 .

(http://discovery-aeromodels.com/images/propellers/wooden-propeller-discovery-360-150mm(14.2-6).jpg)

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, Iíll look into getting some of those props to try out too. Iíve not yet finished the plane itíll be going in, itíll be going in a semi scale warbird, donít want to let the cat out of the bag yet as to what Iím working on.... itís a little special.
Title: Re: Stalker .76re tank selection and fuel consumption
Post by: Brian Gardner 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)
Title: Re: Stalker .76re tank selection and fuel consumption
Post by: Daniel_Munro 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.

Iíve donít mind going all synthetic. Could get the Klotz 80/20 syth/castor as an alternative.
Props Iíve 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 Iíll start with them and see how it goes. As for plugs Iíve got a heat of Super Tigre hot plugs that I like a lot.
Title: Re: Stalker .76re tank selection and fuel consumption
Post by: Air Ministry . 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 .
Title: Re: Stalker .76re tank selection and fuel consumption
Post by: Reptoid 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
Title: Re: Stalker .76re tank selection and fuel consumption
Post by: Daniel_Munro 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 .

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

The .51 will need a new NVA and crank case to be used again. All internals are ok.
Title: Re: Stalker .76re tank selection and fuel consumption
Post by: Air Ministry . 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 .
Title: Re: Stalker .76re tank selection and fuel consumption
Post by: richardm on September 20, 2020, 07:19:37 PM
Try your local motorcycle shop

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

Title: Re: Stalker .76re tank selection and fuel consumption
Post by: Reptoid on September 20, 2020, 07:53:49 PM
Not sure about shipping to NZ but you can buy it here:
 https://www.amazon.com/Motul-105940-Powersport-Mix-Modeling-Fluid_Ounces/dp/B07JJBJG65
Title: Re: Stalker .76re tank selection and fuel consumption
Post by: Brian Gardner on September 22, 2020, 07:03:03 AM
I can supply a case if you want.

Brian

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

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