Piston fire sequence ?
Team Owner
Joined: May 2002
Posts: 24,337
Likes: 25
From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
Re: Piston fire sequence ? (Curveit)
The 4-stroke cycle might be easier to remember as..... Suck-Squeeze-Bang and Blow. I learned that as a kid. :D
Team Owner
Joined: May 2002
Posts: 24,337
Likes: 25
From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
Re: Piston fire sequence ? (neverendingproject)
The firing order for the Gen.III smallblock and the 2001 8.1 liter (496 cubic inch) big block is 1-8-7-2-6-5-4-3. Eight individual ignition coils are computer controlled. No conventional distributor is used. The new firing order smooths out the running motor and eliminates the previous problem of the #5 and #7 cylinders firing right next to one another and causing fuel and air distribution problems.
This firing sequence is actually the same. It is an exact mirror image (front to back) of the standard 18436572 firing order. When you flip it front to back, cylinder 7 becomes cylinder 1. (And of course, the number 1 cylinder is arbitrary, only the order matters.) If ANY advantage, it would be that the two cylinders next to each other in order are now 3 and 1. And it's probably easier to feed #1 a little extra air to make up for what #3 is stealing from it, since #1 is at the front of the intake manifold, and the first one inline in the plenum.
18436572 mirrored front to back= 72654318
Now reorder that sequence, putting the one in front... 18726543... tada!
1-8-7-3-6-5-4-2 gives the actual 10hp gain & also stated that reliability is increased.
[Modified by CentralCoaster, 2:32 AM 9/10/2003]
