I have a H9 CAP 232 and am going to be putting a Moki 2.10 in it. The CAP came with a 18oz. tank but that would only give me about a 7 minute flight. I would like to put a 32oz tank in my plane. How big are people going? How big of a tank can you get in this CAP? How do yoiu modify it? Does someone make one that fits in it the way it is set up? All replys are much appreaciated. Thanx.
John

John,
I've got the Midwest Cap but I have a 24 oz tank with the Moki 2.10. I get about 12 safe minutes of flying time but I seldom full throttle it. I know I had to add quite a bit of nose weight, and was thinking about going to at least a 28 oz tank. The Moki manual says about 2 1/2 oz per minute at full throttle. Given that, if you hot-dog it a bit, seems like 18 ounces would'nt give you much air time. I don't know how much time on your Moki, but you will see a big difference when it's truly broken in.

Good Luck
John

What is the biggest tank that you can fit into the plane?

John,
I don't think there would be a problem with 32 oz. I just had a 28 oz tank and checked for fit and had plenty of room. And the Moki, no problem at all with power. Sullivan website has deminsion for most of their tanks on-line. You might want to check that out. The only other minor problem I see is if you've already installed the throttle setup. You might just have to relocate that more to the side.

No i have not alreday installed the throttle
What is the Sullvan website? By the way, I have the 1/4 scale

I've found it before. Try Sheldonshobbies.com. They have Sullivan stuff. Other than that, I found it somehow by just surfing. Anyway the Midwest Cap is 27% and was designed by Mike McConville (spelling?) and so was the Hangar 9. I've seen the H9 at the fields and with very little minor differences in a few things, they almost looked the same.

John, you will NOT be able to fit one of the big Dubro tanks into your H9 73" CAP without butchering the rear of the tank compartment and the second former. The tank compartment on this model is basically square. I had the same problem. The issue tank is typical Pacific Rim; IOW, not something I care to use.

The largest Dubro that will fit without former surgery is a 16 ouncer. That's not enough for the Saito 150 I'll be using, so I ended up fitting a four-ounce Hayes "Saddle tank", plumbed in conjunction with the 16 ounce Dubro.

I just didn't feel comfortable with removing any wood up there. This model has gone through several "beef-up" modifications to prevent the firewall from departing due to engine vibration and stress.

YMMV...

Steve

So will a sulivan 24 or 32 oz tank fit in teh compartment? Or can you get more square like tanks?

32 Oz. is a lot of nose weight. If you really want and need that much fuel onboard, it's best to fit a pump/regulator so you can place the tank over CG.

1. You'd have more room there.
2. Draining the tank won't cause CG and trim changes.

IHMO, you're better off putting at most a 24 Oz. tank and limit your flight time. Don't know about you guys, but my neck hurts after 10-12mins.

What type of tank will fit in the H9 CAP 1/4 scale that is 24oz.?

If by "fit" you mean sliding right in without carving the formers, the answer is more than likely 'none'. The stock cutout are for a 500cc (~18Oz.) tank, I believe, so no 24 Oz. tank is going to fit.

But... cutting the formers are not all that big a deal. Just be sure to cut no larger than necessary. Glue on plywood reinforcements or fiberglass if it makes you feel safer. You're already slapping on enough additional weight with that Moki that another 1/2 Oz. of former reinforcement is not gonna make a difference.

Well if I was going to cut the formers then why not jsut cut it for a 32oz tank?

Indeed you could.

Instead of one large tank, why not try a 24oz and 16 oz hooked together. That will give you 40oz of fuel.

Here is the DuBro 16 ouncer with a Hayes four ouncer alongside.

As you can see, the DuBro barely fits.

Volfy may be right, in that you can relieve the second former somewhat without compromising airframe strength.

But if I were you, I'd take his first suggestion; fit a pump of some sort and mount the main tank BEHIND that former. There is plenty of room between the former and servos to mount a big tank transversley (sideways).

Steve

Geistware
Have you ever tried to link a 16 to a 24? How do you do it? Do you have to have a pump? Got any pics?