Does Changing Firing Order make more Power?

[dmcclanahan]

I know most chevy V8s its 1-8-4-3-6-5-7-2, but would it give it more power then the firing order of say 1-2-3-4-5-6-7-8?

[INSIDIOUS '86]

The engine couldn't run like that. The only thing you can do is a 4-7 swap with a 4-7 swap cam
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[Dalaigh]

no, and running it at 1-2-3-4-5-6-7-8 would distroy your engine. It would vibrate like an old tractor. The firing order is designed to limit the engines vibrations, and the cam shaft is designed to run 1-8-4-3-6-5-7-2.

[camshaftgsxr]

the 4/7 swap is to make it smoother, it is what the ls engines run on (i think)

[franky69c10]

Originally Posted by camshaftgsxr

the 4/7 swap is to make it smoother, it is what the ls engines run on (i think)

How would that work on TBI engines
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[grs]

I don't think it would even run.

[406 Q-ship]

Originally Posted by camshaftgsxr

the 4/7 swap is to make it smoother, it is what the ls engines run on (i think)

The 4/7 swap does not make the engine smoother, that was done by racers to get rid of the 5 and 7 firing so close together. Does not work because then 4 and 2 are now sequential.

The LS is a 4-3/7-2 swap to make the engine run smother. LS firing order is 1-8-7-2-6-5-4-3. This is the one racers should do to get the cylinders to not fire sequential. If you renumber a Ford 351 (or all later Ford V8s) cylinders to the same way GM does it, you will see that the firing order is the same (so Ford got it right....ouch that hurts to say).

1-8-4-3-6-5-7-2 STD most V8's
1-8-7-3-6-5-4-2 Swaped 4 and 7
1-8-7-2-6-5-4-3 LS V8s

[Corts60]

I agree with all above, swapping the firing order around will either get you nothing or a lot of trouble. Do not do it. Camshafts and crankshafts are made for a specific firing order and if a spark comes along when a cylinder isn't expecting it....trouble.

[54Caddy]

Originally Posted by 406 Q-ship

The 4/7 swap does not make the engine smoother, that was done by racers to get rid of the 5 and 7 firing so close together. Does not work because then 4 and 2 are now sequential.

The LS is a 4-3/7-2 swap to make the engine run smother. LS firing order is 1-8-7-2-6-5-4-3. This is the one racers should do to get the cylinders to not fire sequential. If you renumber a Ford 351 (or all later Ford V8s) cylinders to the same way GM does it, you will see that the firing order is the same (so Ford got it right....ouch that hurts to say).

1-8-4-3-6-5-7-2 STD most V8's
1-8-7-3-6-5-4-2 Swaped 4 and 7
1-8-7-2-6-5-4-3 LS V8s

Ford did not get it right, Ford does not use the same cylinder relation as chevy does as far as the left bank being 1 3 5 7 and right bank being 2 4 6 8. Ford is left bank 5 6 7 8 right bank 1 2 3 4. so if you draw a diagram with the two number for the firing order they will not match not even close. GM is totally different than the Ford block. So there is no relation at all between the two

[Josh]

Originally Posted by Evil Trailblazer SS

I'm right there with you, but I knew going in that my post would likely not stay up. Instead of teaching members to use a little common sense before asking such ridiculous questions, we apparently have to play the role of teacher and help them to understand that what they said was far beyond stupid. Or we just have to keep letting them make fools out of themselves for fear of hurting their feelings.
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Originally Posted by Evil Trailblazer SS

Anyone who doesn't understand the concept of a firing order and it's effects on the symphony of various moving parts and the general harmonics of an engine should not be considering such radical changes. Dumb is dumb no matter how you slice it...I'm sorry, but that is the truth.
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All questions deserve an answer that is why we are a community. Belittling someone and acting like a superior fool is not beneficial to the community and is not acceptable. If you wanna act that way take it somewhere that is less inviting or friendly. That is the "truth" of how we do things around here.

[SCOTI]

I don't see anything wrong w/the original question. A guy should be able to reach out & ask his peers a question w/o being ridiculed. I didn't know about the 4/7 cam swap tech stuff until I learned about it (years ago). You gotta' learn somehow. I never wondered if GM's sbc/bbc firing order could possibly be 'better' but apparently the OP was thinking more outside the box than me & did question it. Kudos to him.

It can be frustrating when a guy asks a question over & over getting different responses yet he keeps asking until someone tells him what he wanted to hear all along even though other answers were better/correct.

I always try to research info before asking something that I might think to myself "WTF was I thinking when I asked" type questions . If you knew my friends, you'd always look over your shoulder too .

[joe231]

Originally Posted by SCOTI

If you knew my friends, you'd always look over your shoulder too .

Now I want to meet your friends!!
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[camshaftgsxr]

Originally Posted by 406 Q-ship

The 4/7 swap does not make the engine smoother, that was done by racers to get rid of the 5 and 7 firing so close together.

which makes it run smoother

[406 Q-ship]

Originally Posted by camshaftgsxr

which makes it run smoother

Incorrect sir because you chose to ignore the next sentence that I wrote...

Originally Posted by 406 Q-ship

The 4/7 swap does not make the engine smoother, that was done by racers to get rid of the 5 and 7 firing so close together. Does not work because then 4 and 2 are now sequential.

The LS is a 4-3/7-2 swap to make the engine run smother. LS firing order is 1-8-7-2-6-5-4-3. This is the one racers should do to get the cylinders to not fire sequential. If you renumber a Ford 351 (or all later Ford V8s) cylinders to the same way GM does it, you will see that the firing order is the same (so Ford got it right....ouch that hurts to say).

1-8-4-3-6-5-7-2 STD most V8's
1-8-7-3-6-5-4-2 Swaped 4 and 7
1-8-7-2-6-5-4-3 LS V8s

then 2 and 4 become sequential which just moves it to the right front corner rather than the left rear corner. So no balance improvement nor a performance gain and the has been tested. I have seen tests that say it works on a race engine and I have seen tests that say it does not work.

Originally Posted by 54Caddy

Ford did not get it right, Ford does not use the same cylinder relation as chevy does as far as the left bank being 1 3 5 7 and right bank being 2 4 6 8. Ford is left bank 5 6 7 8 right bank 1 2 3 4. so if you draw a diagram with the two number for the firing order they will not match not even close. GM is totally different than the Ford block. So there is no relation at all between the two

Again incorrect, I said number the Ford like a GM engine and start from the GM number one and you will see it is exactly the same as the LS/LQ series. Ford in red

1 5 2 1
3 6 4 2
5 7 6 3
7 8 8 4

1-8-7-2-6-5-4-3 LS/LQ Firing order
1-3-7-2-6-5-4-8 Ford 351 Firing order

Now if you start both engine on the same cylinder the Ford Firing order becomes

5-4-8-1-3-7-2-6 Oh looky it is the same sequence as the LS.

BTW that diagram does not give the whole issue, you must go throught the whole firing order not just half.

[grs]

The person that put this thread up was not stupid, or dumb. He was ignorant. Ignorant means= lacking knowledge, information,or awareness about something in particular. The person that said he was stupid is not stupid. He is ignorant. He is also a mean person. People who dis respect people should be kicked off the site.

[camshaftgsxr]

Originally Posted by 406 Q-ship

Incorrect sir because you chose to ignore the next sentence that I wrote...


then 2 and 4 become sequential which just moves it to the right front corner rather than the left rear corner. So no balance improvement nor a performance gain and the has been tested. I have seen tests that say it works on a race engine and I have seen tests that say it does not work.



Again incorrect, I said number the Ford like a GM engine and start from the GM number one and you will see it is exactly the same as the LS/LQ series. Ford in red

1 5 2 1
3 6 4 2
5 7 6 3
7 8 8 4

1-8-7-2-6-5-4-3 LS/LQ Firing order
1-3-7-2-6-5-4-8 Ford 351 Firing order

Now if you start both engine on the same cylinder the Ford Firing order becomes

5-4-8-1-3-7-2-6 Oh looky it is the same sequence as the LS.

BTW that diagram does not give the whole issue, you must go throught the whole firing order not just half.

good info, but why does anyone make a 4/7 swap cam? it seems like its only going half way in sorting out the firing order.

[Pyrotechnic]

Originally Posted by 406 Q-ship

If you renumber a Ford 351 (or all later Ford V8s) cylinders to the same way GM does it, you will see that the firing order is the same (so Ford got it right....ouch that hurts to say).

Everyone always mentions the LS order being the same as The Ford 351W and late model 302...and it most certainly is, but don't ever get the notion that GM copied Ford on this one, or that Ford did it first.

A little know fact is that the Cadillac 472-500-425-368 use the LS firing order. The Cadillac 472 was introduced in 1968. The Ford 351W was introduced in 1969. GM used the firing order before Ford did. I've also read that the head design of the LS motor is loosely based on the Cadillac V8 as well.

GM actually did get it right!

[1LowToy]

Believe it or not firing order can be changed. Not to the 1 2 3 4 5 6 7 8 but it can be changed. I.e. marine engines. There are several modifications to marine engines one of which includes a change in firing order and the direction of which the motor is turning. I also dabled in Fords. I put a 351 windsor cam in a 302. It all works but the firing order is different between the two motors. Really pissed of the next mechanic that worked on the motor too He couldn't get that thing fired up for nothing using the 302 firing orfer.

[babyJay]

It won't run long if it even starts. Impossible, I believe. I've never heard of it being done.

[grs]

Originally Posted by babyJay

It won't run long if it even starts. Impossible, I believe. I've never heard of it being done.

I did drive a VW into the VW garage when I was a VW mechanic in 1969. It was only hitting on one cyl. That surprised the shop foreman. He rechecked it, and I was right.

[Evil Trailblazer SS]

edited by staff.

[one low c10]

the 4-7 swap only makes more hp in high rpms

[85Bowtie]

Originally Posted by Evil Trailblazer SS

edited by staff

I see how it is....this is an acceptable response but mine get's me a "warning" from one of the mods....must have to be one of the boys on here or something...

A stupid question deserves a stupid response.

[Evil Trailblazer SS]

Originally Posted by 85Bowtie

I see how it is....this is an acceptable response but mine get's me a "warning" from one of the mods....must have to be one of the boys on here or something...

A stupid question deserves a stupid response.

I'm right there with you, but I knew going in that my post would likely not stay up. Instead of teaching members to use a little common sense before asking such ridiculous questions, we apparently have to play the role of teacher and help them to understand that what they said was far beyond stupid. Or we just have to keep letting them make fools out of themselves for fear of hurting their feelings.
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[Liz]

if you see an issue use the report a post feature... please check the attitude while you are away