how do i know if i have an even or odd firing engine??
my firing order is 1,3,4,2 so even??
not sure what this tells MS, but i have been running as even fire.
james
even or odd fire??
Forum rules
Forum rules
Read the manual to see if your question is answered there before posting. If you have questions about MS1/Extra or MS2/Extra or other non-B&G code configuration or tuning, please post them at http://www.msextra.com The full forum rules are here: Forum Rules, be sure to read them all regularly.
Forum rules
Read the manual to see if your question is answered there before posting. If you have questions about MS1/Extra or MS2/Extra or other non-B&G code configuration or tuning, please post them at http://www.msextra.com The full forum rules are here: Forum Rules, be sure to read them all regularly.
even or odd fire??
i know nothing about electronics...NOTHING!!! my questions may be silly but my intent is noble.
-
Bernard Fife
- Super Squirter
- Posts: 1009
- Joined: Mon Feb 16, 2004 3:15 pm
even or odd fire??
James,
Odd-fire or even fire doesn't refer to the firing order, but rather the interval between successive firings.
So if you have a 4 cylinder, and a spark every 180 degrees, you have an even fire. Almost all 4 cylinder engines are even fire.
However some 90 degree V6s, and most V-Twins (usually motorcycle engines), as well as a few others, have 'odd-fire' arrangments.
For example, from 1978 to 1984, the GM V6 (200 and 229 cid) had a semi-even fire sequence, with firing intervals of 132°/108°. It is "semi" because the rod journals are offset, but not quite enough to make for even firing intervals. In MegaSquirt terms, this is an 'odd-fire' engine, because the interval between firing can be either 132° OR 108° degrees.
There's more in this thread:
http://www.msefi.com/viewtopic.php?t=4520
Lance.
Odd-fire or even fire doesn't refer to the firing order, but rather the interval between successive firings.
So if you have a 4 cylinder, and a spark every 180 degrees, you have an even fire. Almost all 4 cylinder engines are even fire.
However some 90 degree V6s, and most V-Twins (usually motorcycle engines), as well as a few others, have 'odd-fire' arrangments.
For example, from 1978 to 1984, the GM V6 (200 and 229 cid) had a semi-even fire sequence, with firing intervals of 132°/108°. It is "semi" because the rod journals are offset, but not quite enough to make for even firing intervals. In MegaSquirt terms, this is an 'odd-fire' engine, because the interval between firing can be either 132° OR 108° degrees.
There's more in this thread:
http://www.msefi.com/viewtopic.php?t=4520
Lance.
-
efahl
- Site Admin
- Posts: 232
- Joined: Mon Feb 16, 2004 3:15 pm
- Location: San Clemente, California, USA
- Contact:
Re: even or odd fire??
jiminy14 wrote:
Some other common odd-fire motors are 90 degree V6 motors that use a common crank pin for the pistons on opposite banks (as opposed to the same block containing a crank with offset crank pins that make it into an even fire motor; there was just another thread on this recently, I think it had some pictures or links to some of these).
--
Eric Fahlgren http://www.not2fast.com/
Yes, it's even fire, but not because of the firing order. Odd-fire is what we call engines that have uneven intervals between spark plug firing, the most obvious example is a Harley-Davidson 45 degree V-twin. If your I4 had a twisted crank, you could get it to fire at intervals other than every 180 degrees of crank motion, but that would be insane.> my firing order is 1,3,4,2 so even??
Some other common odd-fire motors are 90 degree V6 motors that use a common crank pin for the pistons on opposite banks (as opposed to the same block containing a crank with offset crank pins that make it into an even fire motor; there was just another thread on this recently, I think it had some pictures or links to some of these).
--
Eric Fahlgren http://www.not2fast.com/
even or odd fire??
The only 4 cylinder motors that I am aware of that are odd fire are V4.
So if you have a boxer or an in line you have an even fire motor.
-Phil
So if you have a boxer or an in line you have an even fire motor.
-Phil
even or odd fire??
thankyou guys. i know it was kind of a noob question.
james
james
i know nothing about electronics...NOTHING!!! my questions may be silly but my intent is noble.
-
Bernard Fife
- Super Squirter
- Posts: 1009
- Joined: Mon Feb 16, 2004 3:15 pm
even or odd fire??
James,
It's a good question, and I will add this material to the manual.
Lance.
It's a good question, and I will add this material to the manual.
Lance.
even or odd fire??
In standard Megasquirt, what does even/odd-fire setting affect, while it's not sequential, and does not handle ignition? This has puzzled me a bit. More averaging to rpm calculation or..?