Supercat vs. Pepsi can

[big_load]

I've seen many reports extolling the high efficiency of the Supercat relative to other stoves, so I've been considering ditching my Pepsi can in favor of it. I built a Supercat with a Fancy Feast can according to Jim Wood's directions, and got a very nice, clean flame.

Here was the outcome of my head-to-head test.

Test Description
---------------
Air: 78F, still (closed garage)
Water: 2 cups, initial temp 64F (minumum tap output temp)
Pot: MSR Titan Kettle, room temperature
Fuel: 12 g S-L-X Denatured Alcohol
Test: 30 second warmup, put on pot, note time to boiling (or final temp) and total burn time, with a view toward comparing mass efficiency of fuel

1. Pepsi can w/ cutout hardware cloth stand
total burn time 6:17
final temp: 200F (136F rise)

2. Supercat
total burn time: 5:13
final temp: 184F (120F rise)

Observations
------------
A. flames from the Pepsi can stove are more focused underneath the pot; the Supercat's flames spread out more and reached up the sides to some extent.

B. I normally would have used more alcohol, but I wanted to push it a little.
C. Sorry for the mixed units, thermometer didn't have C scale.

Conclusions
-----------
The Pepsi can stove and pot stand had a slight edge for this pot and air conditions. I say slight, because the difference in burn time and temperature rise are just on the edge of corresponding to the maximum possible measurement error. However, it is safe to conclude that the Supercat does not outperform the Pepsi can in fuel mass efficiency when used with the MSR Titan Kettle in still air. It may do better with a larger diameter pot. For what it's worth, I was hoping for the opposite result.

[Dusty Boots]

When I 1st started playing around with alcohol stoves, the 1st one I built was a Cat type stove. I then built a Pepsi-can stove and found it to be a better performer, for my smaller diameter pot(GSI Double Boiler) for the same reasons as you stated.
The Cat is a side burner, while my Pepsi-can is a top burner, which concentrates the flames and heat on the bottom of the pot.
The Cat performed well on a larger(wider) MSR 2 litre pot, but that's too big and heavy for solo use.

I teach an alcohol stove building seminar at a local outdoor store and it's the Pepsican stove that I get them to build.

Thanks for the side by side comparison.

Dusty

[WildlifeNate]

I use the Primus Litech tea kettle with a supercat and I can get tap water to a boil in still indoor air in less than 5 min (if I recall, it was in the vicinity of 4:45)...and the stove has a fair bit of fuel to burn off once a boil is reached (using 2 fl oz of fuel). Even outdoors at 20 deg cooler with a little bit of a wind (pushing the flames to one side of the cat can), I reach a rolling boil with a couple seconds worth of fuel left.

I'm sure pot diameter has a LOT to do with it. The larger diameter pot exposes more surface area of the pot (and also the water) to the flames of a side-burner like the supercat. With a narrower pot, more heat is allowed to escape up the sides without affecting the temp of the pot/water.

[mn_backpacker]

I built a pepsi/guiness stove as my first alcohol stove. I loved it, but read about people who had more efficiency out of their supercats. I proceeded to make one of them and then did a similar test to yours. Here is a photo from that test:



These are both MSR pots (1.5L and 2L). Swapping pots between the two stoves yielded almost exactly the same results. The pepsi stove performed better than the supercat in all my tests. I also noticed the pepsi stove had a much more blue flame than the supercat. I don't know why this it, but it would lead me to believe the pepsi one is burning hotter and more efficiently.

I also discovered, in a later test, that with my AGG 2 qt pot the pepsi stove performed much better due to the narrower pot. The supercat sent a lot of flames licking up the side of the pot.

I like that I can load more alcohol into my pepsi stove if I need to boil more water. I often bring both stoves since they weigh less than 1 oz combined, but I never use the supercat. I really like the windscreen/potstand I made that uses tent stakes, and the whole system works well.

[big_load]

Originally Posted by mn_backpacker

I also noticed the pepsi stove had a much more blue flame than the supercat. I don't know why this it, but it would lead me to believe the pepsi one is burning hotter and more efficiently.

I can see that in your picture. Jim's manufacturing specs suggest adjusting the number of vent holes to get the right flame color. You might be able to get it to burn more efficiently by varying this.

I would be much happier if alcohol were as weight-efficient (joules/gram) as white gas. Including a camp day at the trailhead, I'll need 8 days worth of fuel.

[mn_backpacker]

Originally Posted by big_load

I would be much happier if alcohol were as weight-efficient (joules/gram) as white gas.

If that were the case, we'd probably have a lot of exploding soda can stoves.

[Gazbo]

Big Load -- I have both stoves (and quite a few more) and my results are extremely close to yours but I now only use my SuperCat. WHY? Because, in the scheme of things, it performs almost as well when I use my Evernew .9L pan (5 inch base) or my Primus Tea Kettle and I love the simplicity of it. No stand, it primes easier, and if it gets a little bent, it still works o.k.

They're both great stoves and I have to admit that when I want show someone not involved in backpacking just what lightweight packing is all about, I usually get out my pepsi can stove and fire it up.

[big_load]

Originally Posted by Gazbo

... when I want show someone not involved in backpacking just what lightweight packing is all about, I usually get out my pepsi can stove and fire it up.

Me too. The Pepsi can stove has a certain cool factor appeals to almost anyone.

[jasonklass]

Originally Posted by big_load

I've seen many reports extolling the high efficiency of the Supercat relative to other stoves, so I've been considering ditching my Pepsi can in favor of it. .

In my opinion, the Supercat is not effecient. It usually takes me almost an oz. of alcohol to boil 2 cups. Compared to a tea light stove, this is not effecient at all. The virtues of the Supercat are it's speed, light weight, and fact that you do not need a separate pot stand. As was mentioned above, the wider the pot, the better.

[Paul]

I use the White Box stove from Bill in montana. I don't need a stand, but would probably be more efficient if i used one.

White Box Stove

[PBF Support]