Infinite camshaft variables...

[Mark]

My eyes are bleeding from hours of reading about camshafts, studying camshafts, watching videos about camshafts.
Heck, I dreamt about camshafts. Learning a lot though.

 

[Broncobowsher]

And you are just looking at fixed cams. Considering nearly everything made today has variable cam timing. The basics start with advance/retard the intake lobes, if not the whole cam. Then goes up to variable intake and exhaust cams, but each can do there own things. Next up is the 2-stage cams (Honda V-tec is probably the most known) where there is a big cam lobe that only works at high speeds. Then there is the variable cam, not just on/off big/small. My cargo van has a variable intake cam that changes lift and duration besides the timing as well. But the exhaust is still a fixed lift/duration.

If that isn't enough variables for you, there are also variable compression ratio engines out there. 8:1 when running boost and will vary up to 14:1 for light load cruise.

I don't think they made it into production yet, but there are camless engines running around. Valves open and close based on actuators and computer programming only, no lumpy spinning profiles. Computer controls the profile. Surprisingly not that new, but the new controls work way better. https://www.hagerty.com/media/buying-and-selling/589-flat-six-tucker-engine-mecum-auction/

Yes, a simple small block ford camshaft isn't that complex afterall. Unless you find a vintage vari-cam drive for it.

 

[Mark]

Love the advancement in tech, even at the cost of sanity. hehe
Damn near installed a cam I would have been very unhappy with. Now I just hope I don't ruin my engine doing this.

 

[nirvana]

Funny, I wanted to post about what effect can you achieve by retarding/advancing the cam. Does this change the power curve? spark timing.? When I was younger I could see in my mind the workings of this scenario and figure out such complexities. Now when I try to imagine it all I can see is a closet full of old jackets and then begin to wonder why I still have them.

 

[Mark]

Funny, I wanted to post about what effect can you achieve by retarding/advancing the cam. Does this change the power curve? spark timing.? When I was younger I could see in my mind the workings of this scenario and figure out such complexities. Now when I try to imagine it all I can see is a closet full of old jackets and then begin to wonder why I still have them.

that's one of the things I'm getting ready to look into. What advantage/disadvantage is there to advancing the cam one or two degrees.

 

[Broncobowsher]

that's one of the things I'm getting ready to look into. What advantage/disadvantage is there to advancing the cam one or two degrees.

That would be very much a cam to cam specific question. If there is a profile that would work better with 2° advance, maybe the cam maker already engineered that 2° into the design? There will never be a blanket answer of X° advance (or retard) is always the right answer. If you get one custom ground, what you asked for is already ground into the profile.

Where it could matter is if you are taking a less than ideal off the shelf grind and trying to alter the basic function of that specific cam.

 

[Mark]

That would be very much a cam to cam specific question. If there is a profile that would work better with 2° advance, maybe the cam maker already engineered that 2° into the design? There will never be a blanket answer of X° advance (or retard) is always the right answer. If you get one custom ground, what you asked for is already ground into the profile.

Where it could matter is if you are taking a less than ideal off the shelf grind and trying to alter the basic function of that specific cam.

Ya, Summit has a brief description that mentions built in advance/retard for custom grinds
Mine is an off the shelf grind so I'm going to look into it a bit

https://help.summitracing.com/app/answers/detail/a_id/4706/~/advancing-/-retarding-a-camshaft

It's quite a process
https://help.summitracing.com/app/answers/detail/a_id/3949