Wgtn bucket racers that use Avgas

[CookMySock]

The Amsoil 100:1 doesn't burn, so it accumulates in the engine. It is now basically mandatory for the two-stroke microlight boys - or die! Every other oil will kill a two-stroke microlight engine.

It's a pity those who are so unable to believe anything different to what they already believe, are so ready to bash the messenger. Perhaps you think I sell the shit or something ?

Rude.

DB

[F5 Dave]

At top level racing, GP MX or whatever you will find the teams using the best oil they can & at large ratios. The harder the engine revs the more oil. There is so much evidence from engine manufacturers & oil manufacturers that wear rates increase exponentially the less oil you run (from about 40:1 depending on application) that is not folklore "our oil is magic" BS. I hear Amsoil is a good oil, but at top level the GP teams used to (in the 90s at least) largely use Castrol A747 (no matter what stickers they ran on the fairings & paid for by team budgets).

On top of that, the dyno tests (again by the players above) have proved that more oil = more power. Seals the rings better.

Believe what you want but a little research will have you clinging hard to believe 100:1 is a good thing for a racing engine.

[bungbung]

Perhaps you think I sell the shit or something ?

Funnily enough, some of the pro Amsoil campaigners can sound a bit like Amway.
Want to be a dealer? you too can make unimagineable riches...

[speedpro]

What F5 says.

I've pretty well always used Avgas or 100 octane racing fuel from Mobil or Shell. It's always the same no matter when or where you buy it. My engine is currently running a measured 15.2:1 compression ratio. It's been good for lots of years, still got the original ring in it and possibly the same plug. I only run Motul 800 at 40:1 and the few times I have had a quick look inside it's been oily and clean.

Bob Haldane did testing years ago with a TZ 250 I think, on the dyno. The more oil they mixed in the more power it made till it got to the point where it just loaded plugs. I think they got down to 16 or 18:1. Jim Steadman runs his bucket on A747 at 18:1 and he's won more GPs than everyone else put together. That is castor based though so you do run it at lower ratios.

[Buddha#81:Me]

Put me right if I'm wrong, but I've heard that if you go too high with the oil ratio the bike can run lean due to the oil thickening the fuel and allowing less flow through the jets? I think that that would have to be at the extream end of the range.

[F5 Dave]

That is right but for slightly wrong reason. The engine will suck a certain amount of fluid through the particular jet size. If you want more then you change the jet.

More oil you add the less petrol is contained within that amount of fluid hence if you increase the amount of oil radically then you are leaning off the jetting. A lot of these tests on dynos people mention checking the jetting through the tests.

The higher viscosity of the oil compared to the petrol probably affects flow, but bugger all & you can just alter the jets size. It is always possible to make the mixture too rich so any argument about less petrol is pretty weak.

[Buddha#81:Me]

That is right but for slightly wrong reason. The engine will suck a certain amount of fluid through the particular jet size. If you want more then you change the jet.

More oil you add the less petrol is contained within that amount of fluid hence if you increase the amount of oil radically then you are leaning off the jetting. A lot of these tests on dynos people mention checking the jetting through the tests.

The higher viscosity of the oil compared to the petrol probably affects flow, but bugger all & you can just alter the jets size. It is always possible to make the mixture too rich so any argument about less petrol is pretty weak.

Ducks sake now my head hurts!

[pete376403]

[QUOTE=koba;1513840]Not sure, but F5 dave built it and will probably know.
Probably around (maybe not quite) 15 to one.
Come to the buckets and have a looksie if ya wan't it is a great day out and full of innovation and homebuilt stuff, sounds like you might like it.QUOTE]

Yes I'd like that - where and when do you race?

[Skunk]

Come to the buckets and have a looksie if ya wan't it is a great day out and full of innovation and homebuilt stuff, sounds like you might like it.

Yes I'd like that - where and when do you race?

All the info is here

It's The Slipway drift track.

[koba]

[QUOTE=pete376403;1517812]

Not sure, but F5 dave built it and will probably know.
Probably around (maybe not quite) 15 to one.
Come to the buckets and have a looksie if ya wan't it is a great day out and full of innovation and homebuilt stuff, sounds like you might like it.QUOTE]

Yes I'd like that - where and when do you race?

All the info is here

It's The Slipway drift track.

Yeah, bowl on up and say hello, I will be the guy in green leathers falling off the little pitbike.