Question about fuel tanks

Just getting back into the sport after a 15 year layoff. I'm putting the finishing touches on my new Brodak Cardinal Profile. I plan on using one of my old ST 46's for power. Can someone please advise me as to what size fuel tank I will need? I'm thinking 4 oz, but I'm not positive. Any recommendations as to a manufacturer/supplier? Should I stick with a metal tank, or will one of the plastic tanks work?

Thanks,

LAST EDITED ON Oct-05-04 AT 04:17 PM (CDT)
 
Lets see...

At the usuall thumbnail of 1oz per .10 displacment you'll need 5oz per flight.

Depending on how your engine is set up you may need a bit more but 5oz 'should' do.

ST-46s are pretty thirsty but worth it. I'll bet that you'll have a dynomite combo and setup should be a breeze.

Just last night I was working at my bench and watching a tape of the original being test flown with several modern 40s. The Cardinal is the best flying profile that I've ever seen!

Start with a 5oz Uniflo metal tank and add capacity if you need it. You can order one from several suppliers including our host or directly from Brodak's.

Good luck,

>Just getting back into the sport after a 15 year layoff.
>I'm putting the finishing touches on my new Brodak Cardinal
>Profile. I plan on using one of my old ST 46's for power.
>Can someone please advise me as to what size fuel tank I
>will need? I'm thinking 4 oz, but I'm not positive. Any
>recommendations as to a manufacturer/supplier? Should I
>stick with a metal tank, or will one of the plastic tanks
>work?
>

You'll very likely need more than 4 oz if you are doing a full pattern. More like 6. Clunk tanks will work, and metal tanks from Brodak will also work.

Yeah, Bretts probably right (Again.).

Better go with 6oz.

>Yeah, Bretts probably right (Again.).
>
>Better go with 6oz.
>
>BIGS

Yeah, I'm using a Sullivan 6 oz. clunk. Tried other tanks but this plastic tank is the most consistant. My ST 46 uses 5 1/2 oz. running on 15% nitro on profile. This is with Bretts recommended .173 dia venturi. On 10% nitro it uses 5 oz.

>>Yeah, Bretts probably right (Again.).
>>
>>Better go with 6oz.
>>
>>BIGS
>
>Yeah, I'm using a Sullivan 6 oz. clunk. Tried other tanks
>but this plastic tank is the most consistant. My ST 46 uses
>5 1/2 oz. running on 15% nitro on profile. This is with
>Bretts recommended .173 dia venturi. On 10% nitro it uses 5
>

That sounds like a pretty tight engine. The fuel consumption can be all over the place on these engines. Most of the good ones use around 6 oz of 10% nitro at sea level. But I had one that only used 4 1/2.

Three years ago I used a ST .46 on my Cardinal and a 6 ounce tank. Just enough for the entire pattern and about 10 laps at the end. I changed engines to an OS .40 FP to fly in the "P40" event, did not change tanks and flew over 9 minutes!! oops!! ST .46's love fuel. I flew on 62 foot line, eye to eye, BY&O 11 x 4 prop.

LAST EDITED ON Oct-05-04 AT 11:01 PM (CDT)
 
Better to go with a fuel tank that is to large than too small. If the tank it too large you do not have to fill it completely full with fuel. If the tank is too small it might be hard to change it depending on how you build your airplane. I have a 4 oz tank on an OS Max 40LA I get about 5 1/2 minute flights. I would go with a 6 oz tank minumum maybe larger.

LAST EDITED ON Oct-06-04 AT 07:36 PM (CDT)
 

<4 1/2.

Yeah, This motor has really good compression and better than most that I've seen. It runs in a strong 4 stroke most of the time. Not anything I did. I just lucked out with a good ring in the motor I guess.

Greg L. Bahrman