useful ways to burn money

[bob]

It's a common misconception that Avgas is the thing for tuned engines, it ain't necessarily so....
I used to use it in my spaceframe race bike mixed 50/50 with Shell Optimax as it can help prevent pre-ignition on high compression engines. I used it simply as an insurance against detonation.It doesn't in itself increase power but because it might allow you to run a bit more advance it could  be seen as an aid to increasing power.

Depending on the spec of the Avgas [there are quite a few variants] it can actually create a slower burn rate which is undesireable in a high revving bike, this is why it tends to get mixed in with Optimax or similar.

Depending on where in the world you live you can get high octane race fuel delivered to your door. This will be superior to Avgas for our type of application.  In the UK Shell will deliver drums of anything up to 110 octane straight to your door. I've also seen similar stuff at foreign circuits so I assume it's fairly common practice for the big fuel companies to supply this type of thing.

 

[Grant]

Bob, good information.
I suppose it's a bit like the very early days of the internal combustion engine being used in mass transport, where you had to go to your local chemist shop to buy tins of petrol.
Now we have come full circle it seems! 

The reason for my query is that with 10:1 pistons and a Sachse ignition system I may be able to play with settings and remove the potential for detonation by using a booster in the fuel and different curves in the black box.

 

[laverdakeith]

Tip half a pint of methanol into a tankful of gas, used to make my old 11:1 T120R go like a cut cat....

 
    Keith.

 

[sfcpiet]

Or do you mean to overhaul the current carbs? That's been done: blasted, ultrasound cleaned, new jets, new gaskets, accelerator pumps redone

Mingh,

That's only the beginning..... unless you really know how old or new the needles are, replace the needles and needle jets.  Replacing worn slides evidently helps, but check the linkage shafts, there should be, at most, very little play in the shaft bushings.  Usually the shafts are quite worn, so new shafts are needed too.  Don't think it is finacially viable to re-work worn shafts, a NOS set from OCT costs around ?100.  

Unfortunately, total parts cost for a complete carb overhaul can easily top ?400 if you DIY.  ?850 buys you a new set of RS36.... tight budgets are bastards!

piet

These came out nicely, will put the owner back about ?500!

 

[henry]

back in the early 80s the joburg racers used to go out to rand airport and buy what they called avgas 130 in 25 l drums - it was greenish in colour, and mostly they used it neat (high altitude??) and just threw some castor oil in the tank as insurance, for what i'm not sure!
i tried it in my guzzi once. didn't seem to make any noticeable difference except the exhaust burnt a lot cleaner/lighter.

 

[Rufustbear]

You have already made the most sensible mod by putting flat pistons in,leave it alone and enjoy 

 

[Rufustbear]

Eh ive got four stars how did that happen,always told you lot i knew what i was talking about 

 

[andychain]

Used to run my karts on Avgas. The rule said only road side fuel could be used so I used to go to Shobdon airport, laugh a field for microlights, where the road went past the avgas pump. Mine used to be a light blue in colour and when mixed with the 2 stoke oil gave a very slight increase in power but more importantly burnt a lot cleaner so no plug fouling on the ine waiting for the flag to drop.