I'm having a hard time deciding between the 2. I've been told that a solid roller makes more power, but is this true with everything being equal (bore, stroke, heads, intake, etc.)? How much power are we talking? I'm just trying to justify if its worth the extra trouble of having to monitor/adjust valve lash on almost every past. Seems like a pain to me espeically with the limited space that these cars have. Also, with all the new valvetrain out, they're supporting high rpms. What should I do and why? Thanks.

 

With everything being equal you prolly wont see any gain. What a solid roller set-up allows is better control of the valvetrain at higher RPM, and to allow the use of a more agressive cam without the worry of collapsing the lifter.

 

I agree with DONAIMIAN, switching to a solid set up that is exactly the same will produce within a couple of hp of each other but will allow you to spin the motor higher which might help out in large cam applications. I would say if you are planning on turning less than 8 grand hydraulic would be sufficient.

 

Guys,

A solid roller is worth power....all else being equal but keep in mind the duration numbers at .050 need to be about 8' larger to be the equivalent of a hydraulic lobe (to take up the valve lash for the most part).

You may want to check my 383 Dyno thread where I install a solid roller that is essentially the same size of the hydraulic I swapped out (verified by the idle vacuum remaining the same) but it produced 15 more peak HP and 20+ past peak. The solid did give up a little bit of power early in the power curve.

A solid roller will typically make more power than a hydraulic due to a few reasons....a more aggressive cam profile that provides more airflow due to having more area under the curve, extremely accurate valve control assuming the right spring, and the fact they typically bring a little more lift to the table as well but dont compromise valve control in the process unlike the radical hydraulic lobes such as the LSK lobes and others.

Are the gains in peak and after peak power worth the hassle....IMO yes, but it really just comes down to how much you value the additional power. In the event of an over-rev or something similar you are far more likely to sustain engine damage with an aggressive hyd. roller set-up than you would with a solid....another bonus to running a solid valvetrain. If your extremely serious about the engine build and want the most from your combination a solid roller is hard to beat IMO but it does require a little more time and money to initially set-up typically and periodic adjustment of course while you are running it. Note that you will never see me run a hyd. roller in any of my own future projects so you know how I feel about it....LOL

Hope this info helps...

Regards,
Tony

 

Tony, What do you think about the new 8500 rpm hydraulic race lifters from GM? Can a properly designed hydraulic set up keep up with a solid roller using these?

Nevermind...I am sure the Solid roller will still out perform the hydraulic. The Cadillac team MUST use hydraulic rollers to be legal. If Solids were legal in their class, they would use them without a doubt.

GM's hydraulic race lifter, link below:
https://ls1tech.com/forums/generation-iv-internal-engine/580686-new-upgraded-hydraulic-roller-lifters-sdpc.html

 

I bet there are 1000 posts on this exact topic.

 

Years ago before roller lifters became prevalent, many racers would use solid cams and OEM flat tappet hydraulic lifters so they could pass inspection and still race (though this was still cheating). For the most part this worked well as the more aggressive profile gave better power under the curve, but they ran into valve float much sooner if they stuck with softer springs. Or they would eventually collapse the lifter plungers if they went with aggressive springs intended for solid lifters.

IMO, below about 5500rpm, the difference in power between solid and hydraulic roller is negligible using the exact grind. After that, the gap widens very quickly.

Jason

 

This seems to be a hard and debatable subject. I've read that you begin to see valve float around .600" of lift. I used stock rocker arms and lifters on my stock longblock using the T-Rex cam that had .608/.612 lift and had no problems. I have no idea what specs the new cam will retain for the new build, but I'm sure it will have lift in the .600s.

 

GM is using the same lifters as we do for the C6 Z06's and warranty's them with a 7000rpm redline with .600" of lift on both sides. I doubt the valvetrain is any lighter by a meaningful amount because of the bigger valves.

Jason

 

Here's the thread Tony is talking about. Very interesting and amazing results.
http://www1.ls1tech.com/forums/showt...=384450&page=1

 

If I went solid roller, I was going to use Morel lifters and T&D rocker arms. If I went hydraulic, what do you guys suggest I use for lifters and rocker arms?