I obviously know the difference between a solid and a hydraulic cam. I was just wondering at what point for a non-race car does it make sense to switch to a solid cam? Or does it for mostly the street and maybe a little strip? I am talking non-rollers here, and small block. I run a Comp XE268 with Comp hydraulic flat tappets, and I am very happy with it.
Great question IMO. In short, I’ll say when you want more top end power but still have the same/similar/superior low end torque and/or operate in the same low rpm are when just driving around. This would be accurate if the cam sizes between the Hyd and solid lifter cams are the same.
This is how I see it. This is also written for new guys.
A Hydraulic lifter was designed to be quite in a running engine. This was done for the public. Making a performance cam in this fashion is …. OK. The general public still has a quite engine with increased performance and rpm. If you did your exhaust right, the car inside is still quite and people chat away.
The industry kept increasing the size of the camshaft. IE; duration and lift, to fit the growing performance market and keeping the engine quite.
What you find is a limitation to the Hyd. lifter. It can rpm very well! No doubt. But the solid lifter offers a broader and longer rpm range. This is at the expense of a little noise at the rocker meeting the valve tip.
(OH no! LMAO!)
The wider the lash the louder it gets.
When do I swap over from a Hyd. cam to a solid cam?
I’d answer that with, “Are you looking for more rpm on the top end?” The solid lifter doesn’t collapse at higher rpm’s. The power graph between to otherwise identical cam except there lifter design will show that the solid lifter holds onto the HP curve longer and higher than a Hyd. cam will.
Your XE268 was given a rpm band by comp cams of 1600-5800 at a 224-230@050 duration w/.477/.480 lift.
I can’t find a mechanical cam equivalent very quickly. So I’ll step up 1 step higher.
Notice the advertised duration vs he duration @050 on the cams below. Compare them and the lifts that go with each cam from Hyd. to mechanical to solid roller.
(sorry if it is blurry, IDK why that screen shot did that, but the cams are all comp and the left is a XE274, the other two are listed as 268 advertised.)
Noticed how the duration @ 050 is greater than the Hyd cam and the lifts grow. This adds to top end power. As long as your cylinder heads and intake can feed the lift of the cam, your going to make more HP.
