Firing order mixup question

[tenxal]

Race shop topic today:

BBC was converted to cam with LS firing order. If the firing order was reorganized to the standard 1-8-4-3-6-5-7-2 firing order, how would the engine run and/or sound? Just down on power? Shooting ducks? Both?

Anyone ever run into this?

[Dave Koehler]

So, you did not match up the firing order?

[CamKing]

You would be running on 4 cylinders, so power would be cut in half.
On the other 4 cylinders, you would be trying to ignite the air/fuel mixture during overlap, and I can't imagine the utter chaos that would cause.

[tenxal]

So, you did not match up the firing order?

It's a hypothetical question.

[peejay]

You would be running on 4 cylinders, so power would be cut in half.
On the other 4 cylinders, you would be trying to ignite the air/fuel mixture during overlap, and I can't imagine the utter chaos that would cause.

Got in a Cobra kit car (Factory Five) with a Ford "302" crate motor in it, and I bet you already have a good idea of what happened, and you'd be right.

It ran fine,actually, but between the firing order mixup and the non-crossover side pipe exhaust, it kinda sounded like an aircooled VW with a dual exhaust. Didn't vibrate unduly, didn't backfire or afterfire, and it didn't even really seem down on power because the car was so light.

Of course, it was a completely different animal when the plugs were rerouted to the correct 5.0/351W firing order.

[Newold1]

Bottom line here is it's gonna "Run like Shit!"

Depending on how the cylinders are fired by electronic or a distributor, set the plug firings to match the camshaft firing order. For LS it should be 18726543 and no other!

[tenxal]

....set the plug firings to match the camshaft firing order. For LS it should be 18726543 and no other!

Yes...got all that.

I think peejay is close.

[Circlotron]

BBC was converted to cam with LS firing order.

Do BBC and LS cranks have the big end journals in the same relative positions?

[Walter R. Malik]

BBC was converted to cam with LS firing order.

Do BBC and LS cranks have the big end journals in the same relative positions?

YES ... that LS firing order is the same firing order which 351 Fords have used for the last 50 years.