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by David Foster

I can’t remember ever buying ready-mixed fuel from a shop. I’ve always mixed my own. Not only do I know what I’m getting, ‘home brew’ costs a fraction of proprietary fuels. My ‘straight’ (i.e., no nitro) glow fuel costs $3.70 a litre; the hobby shops charge around $13.00 (fuel prices went up 10% with the GST because there was no wholesale sales tax previously). I use about 75 litres of fuel a year so the savings are really worthwhile.

How do you do it?

Simple enough. For an everyday 2-stroke sport fuel you can mix 1 part Morgans Coolpower or Klotz oil and 4 parts methanol (20% oil, 80% methanol). That brew that will give good performance with most 2-stroke engines. I usually use 15% Coolpower, 5% Castrol M (castor oil) 75% methanol and 5% nitromethane. The castor provides an extra margin of protection in case of lean runs and the nitro improves performance a bit as well as making starting easier. For my 4-strokes I use 15% Coolpower, 75% methanol and 10% nitro. The higher nitro content ensures better idling in 4-strokes.

The castor versus synthetic oils argument still rages. I have been using Coolpower for years and never had any problems. Also Coolpower is much cleaner - it doesn’t turn to varnish and clag-up the engines’ internals (particularly the ball races) like castor oil does and the models are much easier to clean.

Having said that I still like a bit of castor for the extra protection it provides. Some of my engines have been in constant use for more than 15 years without any problems or parts replacements, so I must be doing something right.

Just as important as what you use is the way you use it. Cleanliness is the key. Ensure the containers and measures you use (if plastic make sure they are not styrene) are perfectly clean before you start. Ialways strain my fuel through several layers of old nylon stockings in a funnel when decanting into the final plastic jugs. It doesn’t take much to block jets in your engines’ carbies, so eliminating any foreign bodies is a worthwhile step.

I’ve heard getting methanol on your skin is not a good idea, so I always wear rubber gloves when mixing fuels. Also methanol is hygroscopic - it absorbs moisture like a sponge. So always keep methanol containers tightly capped when not in use - that applies to fuel containers too. Water-contaminated fuel degrades engine performance and causes glow plugs to burn out quicker.
If you suspect your methanol or fuel is water-contaminated, leave it in the freezer overnight. The water will freeze and the other components won’t - so you can pour off the de-contaminated fuel into another container.

Where do you get it?

Most hobby shops sell Morgan’s Coolpower in 1 US gallon (4 litre) jugs at around $50.00. Castor oil (Castrol M) is available through Castrol stockists or direct from Castrol at Guildford. There are several sources of methanol. Incidentally, make sure you are getting aviation grade methanol. Warren Lewis, one of our members, organizes a bulk purchase one or two times a year and you might be able to get in on that. Phone Warren on 9417 0269. I buy mine from Whitey’s Workshop, Cnr Kenyon and Fowler Roads, Merrylands (phone 9637 3097). They charge $1.21 a litre inc GST, (take your own drum) which I think is the cheapest anywhere. You can buy Shell A Racing Fuel in 20 litre drums through Shell dealers or direct from the Shell Terminal at Clyde. Shell A contains about 5% acetone, which I’ve never found does any harm - in fact the acetone acts as a performance improver. Klotz oil and nitromehane are available from Hobby Headquarters at Kareela, however if you know someone who’s intro drag racing he can probably get nitro for you much cheaper than there.