2 stroke thread (with occasional F1 relevance!)

All that has to do with the power train, gearbox, clutch, fuels and lubricants, etc. Generally the mechanical side of Formula One.
Tommy Cookers
Tommy Cookers
577
Joined: Fri Feb 17, 2012 3:55 pm

Re: 2 stroke thread (with occasional F1 relevance!)

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J.A.W. wrote:
Wed May 04, 2022 11:55 am
Alcohol fuels run cool, as such usage of methanol as a race fuel allows 'classic' air-cooled bikes to
run sans the power-robbing heat-soak they suffered from by racing on petrol, back then.
there is no such thing as 'power-robbing heat soak'
engines work by in-cylinder conversion of heat into work

the amount of alcohol that can burn in-cylinder adds more heat in-cylinder than does the equivalent amount of petrol
roughly 5% more with ethanol and 10% more with methanol
it's simple chemistry

that's why 'they' use methanol
that's how methanol gives about 10% more power without any increase in the CR

people should get this into their heads
the methanol engine should have the same gas temperature pre-spark as should the petrol engine
cylinder cooling was generally reduced for methanol use eg the JAP speedway engine that won about 20000 races

yes even if cylinder cooling wasn't reduced power would still be better - hence the 'cool is good' myth
usually methanol is overfuelled because the jets had anyway to be huge ... and ....
methanol's much wider explosive range allowed/encouraged far more over-fuelling than would petrol

johnny comelately
johnny comelately
41
Joined: Thu Apr 09, 2015 11:55 pm
Location: Australia

Re: 2 stroke thread (with occasional F1 relevance!)

Post

Tommy Cookers wrote:
Wed May 04, 2022 1:03 pm
J.A.W. wrote:
Wed May 04, 2022 11:55 am
Alcohol fuels run cool, as such usage of methanol as a race fuel allows 'classic' air-cooled bikes to
run sans the power-robbing heat-soak they suffered from by racing on petrol, back then.
there is no such thing as 'power-robbing heat soak'

the amount of alcohol that can burn in-cylinder adds more heat in-cylinder than does the equivalent amount of petrol
roughly 5% more with ethanol and 10% more with methanol
it's simple chemistry

that's why 'they' use methanol
that's how methanol gives about 10% more power without any increase in the CR

why can't people get this into their heads ?
The piston soaks it up by negative egress and changes phase thus robbing power (hybridised comment :wink: )

J.A.W.
J.A.W.
109
Joined: Mon Sep 01, 2014 4:10 am
Location: Altair IV.

Re: 2 stroke thread (with occasional F1 relevance!)

Post

Tommy Cookers wrote:
Wed May 04, 2022 1:03 pm
J.A.W. wrote:
Wed May 04, 2022 11:55 am
Alcohol fuels run cool, as such usage of methanol as a race fuel allows 'classic' air-cooled bikes to
run sans the power-robbing heat-soak they suffered from by racing on petrol, back then.
there is no such thing as 'power-robbing heat soak'
engines work by in-cylinder conversion of heat into work

the amount of alcohol that can burn in-cylinder adds more heat in-cylinder than does the equivalent amount of petrol
roughly 5% more with ethanol and 10% more with methanol
it's simple chemistry

that's why 'they' use methanol
that's how methanol gives about 10% more power without any increase in the CR

people should get this into their heads
the methanol engine should have the same gas temperature pre-spark as should the petrol engine
cylinder cooling was generally reduced for methanol use eg the JAP speedway engine that won about 20000 races

yes even if cylinder cooling wasn't reduced power would still be better - hence the 'cool is good' myth
usually methanol is overfuelled because the jets had anyway to be huge ... and ....
methanol's much wider explosive range allowed/encouraged far more over-fuelling than would petrol
"Cool is good" is no "myth", high output crankcase induction 2Ts must run cool, for G.P. racing they
went to water-cooling; non-ferrous cylinder liners; pumped gear-set lubrication (to keep hot oil low),
auxiliary injector jets on closed throttle over-run, & other needful developments.

Heat soak/power fade is real, along with the razor-edge tune required to make best power yet not
run hotter as a result for hard-tuned air-cooled 2Ts.

Alcohol-based fuels not only offer a significantly better 'latent heat' cooling effect for crankcase
induction, it is markedly less sensitive to exactitude in jetting, being far more tolerant of rich
mixtures which aid top-end cooling.

Anyone with experiential/empirical - 'hands on' knowledge of these things knows it to be a fact...
"Well, we knocked the bastard off!"

Ed Hilary on being 1st to top Mt Everest,
(& 1st to do a surface traverse across Antarctica,
in good Kiwi style - riding a Massey Ferguson farm
tractor - with a few extemporised mod's to hack the task).

johnny comelately
johnny comelately
41
Joined: Thu Apr 09, 2015 11:55 pm
Location: Australia

Re: 2 stroke thread (with occasional F1 relevance!)

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Some light hearted 2 stroke comparisons sort of entertainment

johnny comelately
johnny comelately
41
Joined: Thu Apr 09, 2015 11:55 pm
Location: Australia

Re: 2 stroke thread (with occasional F1 relevance!)

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500 Gas Gas (KTM) gas exchange (BRC Racing) using TPI which you can see
Image

J.A.W.
J.A.W.
109
Joined: Mon Sep 01, 2014 4:10 am
Location: Altair IV.

Re: 2 stroke thread (with occasional F1 relevance!)

Post

johnny comelately wrote:
Fri May 20, 2022 9:54 pm
500 Gas Gas (KTM) gas exchange (BRC Racing) using TPI which you can see
https://images-wixmp-ed30a86b8c4ca88777 ... tfZxZ6O8SY

Yeah, &...?

Well, anyhow Johnny, this mob reckon they can do a 600cc 2T roadbike:

https://brcracing.ca/brc-r600/
"Well, we knocked the bastard off!"

Ed Hilary on being 1st to top Mt Everest,
(& 1st to do a surface traverse across Antarctica,
in good Kiwi style - riding a Massey Ferguson farm
tractor - with a few extemporised mod's to hack the task).