Open question on converting to Methonol 1

[evelrod]

Many years ago, too many, I raced several bikes and cars on Methanol. However time and distance has converted all that knowledge into "legend". Considering converting a small 1300cc displacement engine to an alcohol type fuel using a 45 DCOE-9 carb. Your thoughts and suggestions.

Rod

 

[patprimmer]

I think you already know, but I will reinforce.

Corrosion can be a longer term problem. Counter measures are mostly obvious.

Use fresh DRY fuel.

Coat zinc/aluminium parts where practical with epoxy or other methanol resistant coating.

Hard anodise aluminium parts where practical.

Use a little castor oil or modern proprietor additive to help protect metals.

Drain and blow out the system and spray with corrosion protection substance when not in use. Make sure the substance is easily washed off with methanol and will not form jells over time. I simply use WD40 or fuel additive.

You need the entire system to handle a fuel flow increase of just over double. That includes emulsion tube channels idle and transfer passages and slots etc. At least with a Webber everything is replaceable and adjustable and they are originally built to handle high fuel flow.

On carby/methanol, I am normally inclined to use twin carbies in place of a single, but reduce choke size to similar airflow but more fuel flow capacity. Having said that, I imagine a single 45DCOE should handle all the methanol a 1300cc engine will require.

Regards
Pat
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[patprimmer]

Opps, I almost forgot, you need a stainless steel needle and seat without a rubber tip on the needle. The typical Viton tips on std needles tend to be eaten by the methanol. Sure they may leak a bit at idle but as you use twice as much fuel at idle they tend not to flood so long as the fuel pump turns off with the engine. Hmmm, its been to long. maybe Webbers have full metal (brass or SS) needle and seats std.

Regards
Pat
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[evelrod]

I have questions about AN fittings, AN hose, rubber and teflon lined. Aux Venturi sizes.
A lot I need to thrash out but mom is yelling at me to come eat. More tomorrow.

Rod

 

[tbuelna]

evelrod,

Methanol is corrosive to aluminum or magnesium, so precautions should be taken even if these materials are anodized. The stoichiometric A/F ratio for methanol is far different than gasoline. Plus the knock limit is also different, due to the greater latent heat effect with methanol.

It is standard practice with engines using methanol to "pickle" or purge the fuel system using gasoline prior to shutting them down and storing them.

 

[patprimmer]

Terry you would think it would be standard practice, but actually I am considered pedantic for simply wanting to drain, blow dry and spray.

Regards
Pat
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[evelrod]

Okay, I'm back for a couple minutes.

Y'all know, at least Pat knows, that I am not a novice at non traditional fuels, e.g. Methanol.
It's just been so many years that I have not been up on anything current such as the any problems with AN type anodized fittings and AN lines, rubber and/or teflon. I've not used Methanol with a Weber carb, only Delorto and Amal (which gave no problems with AF ratios around 6:1 or so using 100:1 mix of de gummed castor oil). Fuel cell foam must be changed, a given but, what about the std Carter electric pumps (65gph@ 4.5psi) since the electrics are submerged in "fuel". Jetting for the carb is not a problem as in the past something close to 95% increase in fuel was common (over rich is pretty difficult to achieve unless you just leave the jets out completely---not unheard off ). Reduction in size of air corrector, ???. Size of Aux. venturi, ???.

My old style procedure, post race, was to re jet, blow out lines, drain tank and refill with a bit of race gas and fire up the engine, run until it quit from lack of fuel, blow out the lines and tank. No cell/foam in those days so, I'll probably need to manually clean the ATL fuel cell which will be a PITA but necessary, none the less.

What am I missing?

Rod

 

[patprimmer]

Anodised aluminium AN fittings are very commonly used. It seems everyone has to follow the fashion. They stand up for a few years. As soon as you see the first trace of white powder forming throw them away or clean them up and use them on oil or petrol lines.

The rubber lined SS braided hose seems to work well so long as you keep suction sides fairly straight to prevent the rubber kinking and sucking in at the bends.

The fuel lines need to be real big.

I don't like Teflon lined hose as it is always a bit porous and weeps fuel which can leave vapours laying around if a vapour trap inadvertently exists. The Teflon itself will be very resistant, but due to extremely high melt viscosity, they cannot extrude it to get better than a good sintered effect between particles.

Personally I like SS tanks and SS or brass fittings and SS or copper lines where practical with short SS braided rubber lines where they need flex. The issue then becomes cracks rather than chemical degradation.

Of course there are now a lot of different SS hose suppliers so it would be wise to verify methanol compatibility first.

I always lose the SS and brass vs aluminium argument as the owners always want to follow fashion and pretty or cool factor anodised colours and light weight.

Aluminium can work, BUT you really need to be vigilant with the maintenance and be prepared for short life with expensive fittings.

Regards
Pat
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[evelrod]

Okay, what I have...two AN8-rubber suction to two Carter 65gph pumps feeding a Mallory three inch dia filter to a six inch AN6-rubber/Al bulkhead fitting/ 10' AN6-teflon/Al bulkhead fitting/six inch AN6-rubber/Holly pres reg/six inch AN6-rubber/45dcoe9. I'm convinced flow rate is not a problem but all the Al fittings are, potentially. Main concern at this point is a "starting point" for the dyno, re Aux Vent and pump jets. Just double them and hope for the best? That's the option. At 15:1 the engine is running well enough on 110 even though the "experts" say it should not because of "massive" pumping losses (?). I'm determined to try this when I am able to build a second test engine. Secondary is the use of E85 and or Ethanol. I have no experience with these fuels.

Oh, one thing I did find years ago...the simple addition of a few percentage points of Nitro made the addition of castor oil redundant. Did not take much, 10% was as high as we went on go kart engines, not my karts but my engine setups. Like I said, it's been 40 years plus.

Rod

 

[patprimmer]

Rod

I never played with the yellow peril but I suspect it might be against class rules. I would double up on any fuel metering orifices.

Methanol will run safely over a pretty wide a:f range when not under load. Don't be even slightly lean under load though.

I don't know enough about Webbers to comment on booster venturies or emulsion tubes for that matter other than to say the ones used on real high power per choke should be the best. I had never touched methanol when I played with Webbers.

Ethanol is a lot milder when it comes to corrosion.

Regards
Pat
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[evelrod]

"Ethanol is a lot milder when it comes to corrosion."

Yeah and, a lot harder to find around SoCal. VP Methanol is easily available from my existing VP 110 dealer for something like four bucks a gallon. I've been asking about and E85 seems an "easy out" but since this is a "science project" (as I would NEVER use an illegal fuel in club racing because, who needs a 1400lb. Mini with 130+ whp?). I'll look into E since a lot of the big race organizations are now using it exclusively. I know that Sunoco supplies most of them. I have a while to work on the new engine, Pat. I found out today that my problem may extend out to 21 more weeks... :-(

Rod