Walbro 257 Kit - A1!

beans · #11 (**permalink**) 09-05-2007, 08:37 PM

Hey sammy what castor oil you useing.castrol M or what

SAM272 · #12 (**permalink**) 11-05-2007, 01:56 PM

i was going to use castrol m, a mate uses it in his drag car and gets it almost by the pallete load but its in 5ltr tins and i wouldn't use that in a year the rate im going, so i got some Penrite - Sin Race Castor, you can find spec sheet here: http://penrite.com.au/files/TVL5ZW7L...RACECASTOR.pdf

it comes in 1ltr containers and mixes properly with methanol! it is slightly dearer per ltr but i guess it depends on the supplier ... penrite is available at my local car shop, whereas my mate is the only one i know that can get castrol m easily.

Crash Dummy · #13 (**permalink**) 11-05-2007, 03:00 PM

If it helps you at all Sam I do know for a fact that Maxima Castor 927 oil will mix with methanol. Maximal Castor 927 is a semi synthetic oil. It has the usual degummed castor base along with some synthetic stuff thrown into the mix for helping keep everything working freely. Mainly power valves on high performance 2 stroke applications.

beans · #14 (**permalink**) 11-05-2007, 10:09 PM

SAM just watch out it doesnt blow up.Run a whipper snipper on that and she went bang.Had loads of power but..Hard to get the lube to the piston and bearings.COOD LUCK.

SAM272 · #15 (**permalink**) 14-05-2007, 01:56 PM

well beans, from my previous experiences of a few tanks of straight methanol before i pulled the engine apart for upgrades theres no problems with lube thats for sure

if anything it was getting too much oil and i think thats a result of having twice as much fuel going through it but the same oil ratio which means twice as much oil as it needs ... i'm at about 35:1 now and that seems to be a good ratio.

that maxima stuff sounds very similar to the penrite stuff im using, i can't remember the specifics, but its got a mixture of stuff to make it 'heaps good'.

i went out sunday arvo for a bit of a test and tune session ... unfortunately i ran outa light but i have got it running alot better on straight methanol, just needs a bit more tweaking then it should be sweet ... so far it looks like the walbro 257 works alright with flow for methanol ....

Crash Dummy · #16 (**permalink**) 14-05-2007, 02:44 PM

Sam if I were you I'd try mixing your fuel at a ratio of at most 40:1 That's going to be equivalent to about 16:1 on petrol. 50:1 would be ideal. I think 60:1 would be best and if you like lean oil mixtures then going as lean as 75:1 might not be a bad idea either.

Right now your saying this guys nucking futs. Indeed. No not really. The theory is that when you run straight methanol you need about 2.2 times as much of it to do the same job as petrol thus if your still running the same old mixing ratio you would on petrol your engine is getting at least twice as much oil as it should be. Great for lubrication. Not so great for keeping the fire burning. For the best performance and reliability on methanol I'd personally recommend changing your spark plug to a much hotter plug then would be used for petrol as well as leaning off your oil mix to 40:1 as a starting point, more ideally would be 50:1. And of course use a advanced timing key. The methanol burns real slow and cool so you need to start the flame front ignition much earlier. The hotter temperature range plug is used to keep the plug electrode within the correct temperature range to prevent fouling and of course less oil so your not choking the poor engine too much. This one also falls into the category of preventing plug fouling.

Hopefully it works out well for you. Hey try keep an eye on the engine temperature too. If it's running really cold it could very well work in your favor to go for a lightened flywheel with many fins removed or if the methanol cooling properties are strong enough even have no cooling fan at all.

It might sound crazy but it's not. In the land of drag racing once you start getting up there in the performance stakes say around Top Alcohol is the norm the blocks are either constructed with no water jackets at all or they fill them in with a kind of epoxy to strengthen the block to the max. Because they run methanol they have no problems running with no cooling at all other then the fuel that powers the beasts. They have time to start up, idle for awhile then rip a burnout, get staged then pull 2 - 3000hp for around 6 seconds.

The stock cag motors can nearly run with no fan on petrol if you keep them moving at speed but do eventually overheat. I'm confident you could get away with no fan assistance at all on methanol. I'm actually tempted to give it a shot myself. It's just a shame methanol is so expensive at a dollar per KM value of approximately 4x that of pump premium unleaded.

SAM272 · #17 (**permalink**) 15-05-2007, 01:37 PM

i don't think your nuts at all because alot of what you've just said i already know and agree with the theories, especially the oil one, i just haven't been too keen to go super lean on the oil yet as im still tuning it so i don't want to seize it up ... but i will probably go 40-45:1 soon as with the 35:1 im using now its still a bit more smokey than the petrol 25:1 was ....

i have the advanced timing key already in there along with the different plug, however im not sure about its heat range, although i can tell you that after a long run on the bike i can pull up and hit the kill switch and it will keep running for a few seconds (all be it rough) so i usually let it idle for a minute or two before shutting it off just to let the plug cool off. i can only imagine it as a red hot glow plug

i have removed half the fan blades but i think i will leave the others there for idle cooling purposes.

so far it hasn't yet run really cool, but the carby is

... my pipe is still original chrome colour whereas my mates is a browny chrome colour which tells me his is running alot hotter than mine .... mine is still too hot to touch for more than a split second ....

i agree with methanol being a fair bit dearer for the same distance ... i get it off a mate for $1 per ltr and so far haven't had any problems supply wise so im happy to do that for the time being, and the smell when it burns is just magic! reminds me of the old speedway ... i wish they never bull dozed it!

a bit more tuning and i should be happy with it, next on the cards is to take to the expansion chamber with a grinder and oxy to see if i can't 'tune' the pipe to better suit my needs ... currently its like two funnels butted together, im thinking a bit of a straight piece in between them should give it a bit more ommph in the mid range! but i still have to do some calcatrons and measurements before i go and do that!

thanks for your thoughts crash dummy, its good to get another persons views on it and stuff!

Crash Dummy · #18 (**permalink**) 15-05-2007, 05:08 PM

If your engine will run on after you've given it a flogging I'd be seriously suspecting the possibility of hot carbon continuing to ignite the fuel rather then plug itself. Once again from running too much oil lol. Just keep in mind that once you lean off your oil content a bit you'll need to lean the carby too because it will then be too rich. At least with methanol it has a rather large usable window of usable mixture settings.

You'd have to read the plug to see if it's getting too hot. Defintely try a new plug and see what happens. I reckon stick in a fresh plug and take it for a strap then try shut it down and pull the plug for a look. Look at the plug for inspection and of course see if the bike will stop.

SAM272 · #19 (**permalink**) 16-05-2007, 05:46 PM

well im probably not running the right plug anyways as i have one out of a car in there to get it to go further into the chamber to up the compression a bit, but yeah i did actually have a look at it the other day and it doesn't appear to be getting oil fouled, it was a very nice tan colour actually on the electrode insulation.

SAM272 · #20 (**permalink**) 02-06-2007, 04:25 PM

well bit of an update on this one .... the walbro is great, methanol however seems not so great

after various attempts to get the bike to start i was continually getting lean out and it would stall shortly after starting .... i eventually decided to pull the carby apart fearing i had something blocking a jet or something .... turns out there was alot of gummy stuff in the carby and was blocking the gause filter thing, so i gave it a good clean out and put it all back together and its now running fine on petrol ....

i was enjoying using methanol but i guess over time its just not worth it ... im not sure if its just from sitting for a few weeks since i last rode it or just from a slow build up over the last few months of methanol use.

Walbro 257 Kit - A1!

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