SBC NASCAR V8 firing order

[amc fan]

Does anyone know the firing order of Chevrolet NASCAR V8 engine? Is there any advantage of using it on a regular 18436572 engine for less crank fatigue and better cylinder filling?

[Newold1]

Firing order is still 18436572 in chevy's Nascar RO7 engine and that is mandated by the rules. If you want some better harmonic crankshaft loading, use the LS firing order, 18726543. This is what some now call the 4-7 & 3-2 swap.

[amc fan]

Thanks Newold1 that is what i was looking for. Someone I know had a new cam ground with the 4-7,3-4 swap and the idle sounds a little different , and picked up little in performance.

[Walter R. Malik]

Firing order is still 18436572 in chevy's Nascar RO7 engine and that is mandated by the rules. If you want some better harmonic crankshaft loading, use the LS firing order, 18726543. This is what some now call the 4-7 & 3-2 swap.

Also, Ford 351 Cleveland, 351 Windsor and 351M-400 firing order since 1969.

[af2]

Thanks Newold1 that is what i was looking for. Someone I know had a new cam ground with the 4-7,3-4 swap and the idle sounds a little different , and picked up little in performance.

Idle yes, Performance Pipe dream

[swampbuggy]

AF2....would you consider the idle sound better or ?????? Mark H.

[Scott]

Firing order is still 18436572 in chevy's Nascar RO7 engine and that is mandated by the rules. If you want some better harmonic crankshaft loading, use the LS firing order, 18726543. This is what some now call the 4-7 & 3-2 swap.

Also, Ford 351 Cleveland, 351 Windsor and 351M-400 firing order since 1969.

" Cleveland firing order is 13726548 "

[cjperformance]

Firing order is still 18436572 in chevy's Nascar RO7 engine and that is mandated by the rules. If you want some better harmonic crankshaft loading, use the LS firing order, 18726543. This is what some now call the 4-7 & 3-2 swap.

Also, Ford 351 Cleveland, 351 Windsor and 351M-400 firing order since 1969.

" Cleveland firing order is 13726548 "

Think 'firing pattern', draw it out and all will be revealed.

[swampbuggy]

Well somebody's got to be wrong on those numbers

[John Wallace]

NO.
Diagram it?

13726548 - ford
26543187 - convert the cyl # to GM # from ford numbering

18726543 - then start at #1

[Walter R. Malik]

NO.
Diagram it?

13726548 - ford
26543187 - convert the cyl # to GM # from ford numbering

18726543 - then start at #1

YES ... the "Pattern" is the same; the cylinders are simply identified and numbered differently.

[swampbuggy]

Okay guys I get what you're saying now my bad. Mark H.

[midnightbluS10]

This should help

[Roundybout]

Isn't there also a cooling advantage moving the adjacent firing cylinders to the front of the block?

[MadBill]

Since 90° @ 6,000 RPM is only 2.5 milliseconds between firing #5 and #7 vs. 10 ms. until the pattern repeats, I think there's far too much thermal mass for any measurable temperature fluctuation to occur between cycles either way.