Random Drag racing questions.....

[Turn7]

Why do blown alky motors do that pulsing tickover thing ? I love it, but understand why it happens....

[fttm]

Lumpy cams ?

[Nigel_O]

Look up ‘blower surge’

[Turn7]

Nigel_O said:

Look up ‘blower surge’

Thanks !

[Nigel_O]

Turn7 said:

Nigel_O said:

Look up ‘blower surge’

Thanks !

No problem… if you really want to see/hear it in action, do a YouTube search for ‘boxvette’ and turn up the sound… ;-)

[Camaro]

Blower surge is something that you most commonly get on mechanically injected setups. It's cause is from the fuel pump going overly rich and the idle speed dropping off, that idle speed dropping off then means the fuel pump speed slows down and the mixture goes lean, which has the effecet of speeding up the engine speed. Then so the cycle repeats.

You're hearing the hunting of rich to lean and back again.

[Turn7]

Great answer, thank you !