MYOG SUL Remote Inverted Canister Winter Stove V8
The V8 weighs 75 grams. It is the eighth generation of Roger Caffin’s remote inverted canister stove, documented in a September 2026 Backpacking Light article: a vortex burner built to work where upright canister stoves fail. It is not his lightest; the V7 weighs 45 g. [1]
What follows is a spec-level breakdown of the engineering behind that project.
Why Canister Stoves Fail in Winter
In an upright canister the liquefied fuel boils inside the canister, and the vapor flows through the valve to the burner. The system depends on the fuel maintaining sufficient vapor pressure to flow reliably. Isobutane’s boiling point is approximately −11 °C (12 °F); propane’s is approximately −42 °C (−44 °F). [2][3]
As a canister cools — from ambient temperature or from the endothermic effect of vaporization itself — vapor pressure drops. Flow rate drops with it. Output becomes erratic, then insufficient. On snow at −10 °C the propane also boils off first: Caffin describes an upright canister left two-thirds full of liquid butane with nothing coming out. [1]
Conventional workarounds: carry a liquid-fuel stove (heavier, more involved logistics), pre-warm the canister in a sleeping bag, use a canister sleeve, use a winter-blend canister (Primus rates its Winter Gas down to −22 °C) [4], or switch to an inverted-canister design.
What Inverted-Canister Operation Actually Does
Invert the canister and liquid fuel — not vapor — feeds the fuel line. The stove then vaporizes that liquid fuel at the burner, using heat from the flame itself. That is a fundamentally different thermodynamic arrangement.
The advantage: propane and butane leave the canister together, and the burner, not the canister, supplies the heat to vaporize them. Canister pressure still has to push the liquid out, so cold still sets a limit; Caffin notes that a 70/30 n-butane/propane mix boils at around −24 °C. [1]
The disadvantage: the stove must return enough flame heat to where the liquid enters to vaporize all of it, and it needs a warm-up first; in Caffin’s V4 test the stove ran on gas feed and heated up before the canister was inverted. Too little heat and liquid reaches the jet: flare-ups. Too much and the Viton O-rings and PFA hose suffer; Caffin puts their limit at about 250 °C. [1]
Commercial makers use the approach too: MSR’s WindPro II is a remote inverted liquid-feed canister stove, and the hybrid WhisperLite Universal also runs canister fuel in liquid feed. [5][6] When Caffin started, the commercial remote units were a bit heavy, and some were clumsy. [1]
The Remote Configuration
“Remote” means the canister is separated from the burner by a fuel hose rather than threaded directly beneath it.
First consequence: the canister can be positioned horizontally or inverted without destabilizing the pot support. A canister screwed directly to a burner and then inverted would be top-heavy. The hose solves that geometry.
Second consequence: the canister can sit on an insulating pad, off the snow, and its temperature can be managed separately from the burner.
Third consequence: the cooking vessel sits lower, which improves stability on uneven ground.
The weight cost is real. Caffin built his 45 g V7 around the BRS-3000T, which he chose as the lightest burner available; it weighs about 25 g. [1][7] The V8 weighs 75 g including a long carbon-fibre handle, plus a 12.5 g titanium-foil windscreen. His earlier stoves were generally about 90 g; commercial remote inverted canister stoves are all heavier. [1]
Eight Generations of Iteration: What Changed
The Backpacking Light article walks through each version in turn, from V1 to V8. The main areas of refinement:
Airflow geometry
The V8 uses a vortex burner, which Caffin likens to the classic MSR XGK: a chamber with the flame inside and more flames coming out of the top. The air supply must be balanced. A small excess ensures complete combustion and avoids carbon monoxide; a larger one cools the flame and makes lighting harder. [1]
Fuel vaporization
Caffin’s stoves have no preheat tube. The upright-burner versions use an aluminium heat shunt; on the V7 he switched to a more conductive 5005 alloy and bent the shunt tip into the flame. In the vortex versions, heat from the burner chamber radiates down onto the base plate and jet. His reasons for avoiding a tube: weight, and the difficulty of hermetically joining an alloy tube to an aluminium body. [1]
Burner chamber size
The open question for the V8 was whether an SUL vortex burner was possible: would a mini burner chamber work? Caffin built and tested a series of chambers to find out. [1]
Component field-worthiness
Early titanium-wire pot supports relied on spot welds, which Caffin says are not true metal welds and fail under load. Titanium zigzag legs gave way to lighter wire legs that proved strong enough. On the V7 a 2.0 mm PFA hose in a custom stainless braid replaced the earlier 3.2 mm hose. [1]
Thermal balance across the power range
Keeping the stove body hot enough to vaporize all the fuel but cool enough to protect its seals, from a very low flame to a very high one, is the hard part. Caffin prefers about 120 °C and everything below 200 °C. He measures in his lab at +20 °C and subtracts 40 °C to estimate snow conditions. The V6 body peaked just above 120 °C, so roughly +80 °C at −20 °C, far above butane’s boiling point of about 0 °C. [1]
Measurable Trade-offs
Weight: 75 grams as reported, including a long carbon-fibre handle, plus a 12.5 g windscreen. The canister is extra, as with any canister stove. Acceptable for SUL winter use. Not competitive with three-season upright designs.
Output reliability in cold: Better than upright canister stoves below about 0 °C, because the butane leaves the canister as liquid and is vaporized at the burner instead of being stranded in the canister. Pump-pressurized white-gas stoves keep an edge in extreme cold.
Durability: No long-term record for the V8 itself; a forum member reports his V4 still working perfectly. [1] This is a MYOG project, not a production item, and no third-party testing data exists.
Cost: No commercial equivalent exists in the same weight class, so there is no like-for-like price. Replication cost depends on the builder’s access to tooling, materials sourcing, and time.
Complexity: Higher than upright canister stoves. The remote inverted system requires a preheat procedure, attention to canister orientation, and working knowledge of liquid-feed stove behavior. Wrong for users unfamiliar with that operating mode.
Who This Stove Actually Suits
The V8 addresses a narrow but real use case: SUL winter travel where a liquid-fuel stove’s weight and fuel logistics are unacceptable, and where an upright canister stove’s cold-weather limitations are also unacceptable.
That describes ultralight winter camping on snow (Caffin designs for about −20 °C) and cold high-altitude trips where both weight and reliability are constrained.
It does not suit general three-season use, where an upright canister stove performs adequately at a fraction of the complexity. Nor does it suit buyers: the V8 is not a retail product, though Caffin has sold small runs of earlier versions, including about 115 V1 stoves. The Fire Maple Petrel Summit (111 g) is a commercial remote stove that runs upright or inverted [8]; Caffin faults its single valve at the canister and its lack of a fast emergency shut-off. [1]
For the MYOG community, the eight-generation documentation is as valuable as the final product. The iterative methodology (measure, find the failure mode, revise the geometry) is a transferable framework for any combustion system project.
Where to Go Next
The full article, with build photographs and Caffin’s temperature measurements, is member-exclusive on Backpacking Light. The free preview covers the version history up to the V8 and links his five-part series on the original V1. Builders adapting the design should read it directly. [1]
For background, Primus’s fuel guide rates its gas blends by temperature, and the NIST Chemistry WebBook lists fuel boiling points. [2][3][4]
Sources
[1] Backpacking Light. “MYOG: SUL Remote Inverted Canister Winter Stove V8.” https://backpackinglight.com/myog-sul-remote-inverted-canister-winter-stove-v8/
[2] NIST Chemistry WebBook. “Isobutane.” https://webbook.nist.gov/cgi/cbook.cgi?ID=C75285&Mask=4
[3] NIST Chemistry WebBook. “Propane.” https://webbook.nist.gov/cgi/cbook.cgi?ID=C74986&Mask=4
[4] Primus. “Different types of fuel.” https://primusequipment.com/en/blogs/koksguiden/different-fuels
[5] MSR. “WhisperLite Universal Stove.” https://cascadedesigns.com/products/whisperlite-universal-stove
[6] MSR. “WindPro II Stove.” https://cascadedesigns.com/products/windpro-ii-stove
[7] Red Beard’s Outfitter. “BRS-3000T Ultralight Titanium Backpacking Stove.” https://redbeardsoutfitter.com/products/brs-3000t-ultralight-titanium-backpacking-stove
[8] Fire Maple. “Petrel Summit Titanium Backpack Stove.” https://firemaplegear.com/products/petrel-summit-titanium-ultralight-backpack-stove