if I was to put solid lifters on a hyd cam would it pick up anything? just curious bacause I was spiining the motor to 7k and I think the hyd were holding it back somewhat

 

no, they will tear up the cam, from what i understand you need a billet cam

 

Solid lifters require clearance and that is built into a solid cam as a gentle ramp. With a hydraulic cam this ramp is not there so it will be very aggressive on valvetrain. Also the springs for solid cams have a much higher rate.

 

It might not cause any problem, but there would be a performance loss and not a gain. You need lash (clearance) with a solid lifter. this takes away from the "effective" duration and lift. So, there is no reason to try it.

Rich

 

How about we figure out WHAT problem you have now is and we can fix that.... you can run a solid lifter on a hyd cam but you need to know what works with what.

Bret

 

I can tell you that I tried using hydraulic roller lifters on a solid roller cam earlier this year only after Cam Motion instructed me to do so. They said to set them with pre-load, but I tend to think we should have put lash in it. I wasn't real happy with the results.

That said, lots of guys are getting hydraulic cams to really rev these days. We used to think you can't go over 130 lb seat pressure or the lifter wouldn't last. People starting setting them up at 145 and not having problems. A few months ago, when I built my motor, Geoff Skinner instructed me to set up mine at 160 lb on the seat and assured me it won't cause problems. Now, INTMD8 is running his hydraulic at 180 lb seat.

I believe the trick is to run as much seat pressure as you can, while keeping open pressure below 450 lb. You have to spend a little time looking through valvespring catalogs, but it sure seems to work if you set it up right.

Mike

 

i don't have a problem... with the valve train
just after talking to some stock eliminator guys the run a modified stock lifter the told me a could pick up some serious power by just switching to a solid lifter.
it is a billet cam with similar spec. to a stocker. This is not a luancher cam tho

springs i'm running are 140# seat and #395open i'm limited to a 1.26 diameter spring stock retainer etc

my goal is to keep this car legal to run stock...just for a few races

 

Looks like you have specific rules that you have to run... which makes it more important to get the details right.

Mike,

You really need to watch everything, seat pressures, nose pressure, cam material, component masses and stiffnesses. It's not just a generic "just cram seat pressure to it" in fact I know of and have run a wide variety of seated pressures with different setups to get them working correctly. No matter what I've done i've always found that getting the setup to work with lower pressure will always work the best.... same thing is true for the NASCAR guys as well.

Bret

 

Yes, and to really do this properly, you have to play with the lobe shape too. I've been involved in some testing at Comp where a solid roller lobe ~250 @ .050 and .394 lift required 220+ seat pressure to control. The lobe was slightly modified and lift was increased to .410 and then 130 lb seat would control it. But, as always, 99.9% of the guys out there (even fast guys - some record-holders) will first simply add some spring pressure to solve their valvetrain instability issues. In almost all cases, it's more cost effective and less time-consuming that re-engineering the dynamics of the valvetrain.

My point was that, rather than switching from hydraulic to solid lifters in an effort to rev the motor higher, you can simply try adding some spring pressure and it's safe to go over 150 lb seat and 400 lb open with hydraulic lifters.

 

What you were suggesting is a simple fix and it might or might not work.... it's a little more than 99% of the time.

If you design the system correctly from the get go you don't have these issues..... and your example on the SR dropping seated pressure from 220-130lbs is a good one.

Bret