Engine RPM Pulses

[emersom]

Might seem a silly question but how many pulses per revolution are there with a Ford 1600 Crossflow Engine. The reason I ask is that I am getting soem strange figures!

Any help would be gratefully received.

[pault]

A Ford 1600 crossflow is a 4 stroke, 4 cylinder engine. So four ignition events (one per cylinder) in two revolutions (which is 4 strokes), which means 2 ignition pulses per revolution.

Paul

[midlana]

Four strokes, but only one is combustion. So for every two revolutions of the crank it needs only one spark, so it's: ignition pulses = engine rpm / 2.

[Dan in Saint Louis]

Might seem a silly question but how many pulses per revolution are there with a Ford 1600 Crossflow Engine. The reason I ask is that I am getting soem strange figures!

Any help would be gratefully received.

I'm going to stick my neck out and say pault is right if your pickup measures all cylinders, and midlana is right if it picks up only one cylinder.

[pault]

Well I read both of the previous posts and I have to agree with both Dan and Midlana. My number is only correct if you are looking at the coil or the HT lead to the center of the distributor and I'm wrong if you are looking at a single spark plug lead.

So I then went to my vehicle settings in analysis (I run a Ford 1600 Crossflow in my Formula Ford) and my number for this field is set to 2 and my rpm traces are correct. If I change it to 0.5 it doesn't work, which I suspect is due to the default filtering on this input. I also checked some pictures I have of the engine bay (the car was sold 2 years ago) and the rpm pickup is clearly on a spark plug lead. So I'm really confused now.

So I supposed this just reinforces the need to test your settings after installation and before heading out to the race track.

Paul

[Adam37tr]

Surely if you try 1 then 2 etc eventually you will get it right

[midlana]

Agreed, there's no sin in trying a conversion constant, see what the resulting reading is, figure how much it's off by, and adjusting the constant. You know where you're trying to go... make it happen.

[DMKMM]

Surely if you try 1 then 2 etc eventually you will get it right

+1