octane & duration ?

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Jan 13, 2018 | 03:02 AM

ls1 trex

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Staging Lane

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octane & duration ?

hi guys

i want to know about duration

is it true ?

low duration means needs more octane

high duration means needs low octane

Jan 13, 2018 | 07:57 AM

HCI2000SS

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From: Howell & Fenton MI

Duration of what?

Jan 13, 2018 | 08:23 AM

ls1 trex

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Staging Lane

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for camshaft

Jan 13, 2018 | 08:28 AM

HCI2000SS

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From: Howell & Fenton MI

Not with the cams that we run for our cars

Jan 13, 2018 | 09:05 AM

ls1 trex

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Staging Lane

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like this simple

is it that cam shaft

225/236 .629"/.615"

need more octane than

235/248 .649"/.615"

Jan 13, 2018 | 09:09 AM

HCI2000SS

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From: Howell & Fenton MI

Nope it's not going to make hardly any difference all on its own

Jan 14, 2018 | 10:12 AM

.boB

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Quote:

Originally Posted by ls1 trex

hi guys

i want to know about duration

is it true ?

low duration means needs more octane

high duration means needs low octane

Sort of. More duration means the intake valve is open longer, and usually means it closes later in the cycle. That means it will increase dynamic compression and cylinder pressure. That's kinda the point, because that's how you make power. To prevent detonation, you would want to use a higher octane fuel.

But as said above, the example you've given in an otherwise stock engine probably won't be a big enough change to matter all by itself.

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Jan 14, 2018 | 12:17 PM

Crf450r420

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Look up dynamic compression and that will help show you see how that is correct. The closer the intake closes to BDC the move volume that is compressed in the cylinder and the more that will heat up when compressed.

Jan 14, 2018 | 11:26 PM

#10

ls1 trex

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Staging Lane

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thanks guys ,,

Jan 20, 2020 | 09:54 PM

#11

qwiketz

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any updates on this one? I just paid about $12.xx a gallon for sunoco 260 plus... Wondering if this is really pricey or basically the norm these days.