Coyote cam - what's the big lobe for?

[Circlotron]

Each cam has an extra lobe, bigger than all the others. What is it for?
Picture --> http://cdn.speednik.com/files/2016/01/2 ... -38-56.jpg

[Dragsinger]

maybe balance?

[pamotorman]

runs the high pressure fuel pump ?? I know chevy does that on their DFI pump

[CamKing]

It doesn't look like it does anything. You can see that they've been rough ground, but not finished. Maybe they were going to use them to control injector pumps,

[roc]

maybe balance?

My guess too.

[bobalattie]

We have a couple apart at the shop right now that don't have that lobe on the cams.

[CamKing]

We have a couple apart at the shop right now that don't have that lobe on the cams.

That's what I figured. That was probably some prototype deal they were trying out, and now the lobes don't do anything.

[MadBill]

Weird finish on them though...

[peejay]

Coyotes aren't DI, and anyway injection pump drives generally have half as many lobes as there are cylinders, so a V8 would have a four lobe drive, not a single lobe.

Very odd. The extra odd thing is that the one on the intake and the one on the exhaust cam are not in sync relative to the valve actuating lobes. Comparing to cylinder #2's valve lobes, the mystery lobe on the intake is well before the intake valve event and the mystery lobe on the exhaust is well after the exhaust event.

[MileHighMan]

According to what I read from Comp Cams,,,they are counter balance weights to improve valve train Harmonics and vibration....Dan.

[pamotorman]

looks like there is also a extra lobe on the back cylinder intake cam

[CamKing]

According to what I read from Comp Cams,,,they are counter balance weights to improve valve train Harmonics and vibration....Dan.

Now that's funny.
When Hot Rod did the story on my Cam-Wave cam balancing 10 years ago, the guys at Comp were telling everyone that balancing cams didn't work, and if it worked, they'd be doing it..
http://www.hotrod.com/how-to/engine/ctr ... balancing/

They were so upset with Hot Rod, when they found out they were going to run the story, they threatened to pull their advertising, and made Hot Rod run Comp Cams adds down the sides of each page of my article. When it came out, Ed Iskenderian called me up, laughing, and asked me when I got bought out by Comp.

BTW, if those lobes are for balancing, they're doing it wrong. You don't want a lobe shape. You want the mass farther away from the centerline.