98camaroLS1M6

iTrader: (35)

What's the main difference between a solid lifter cam and a hydraulic one and why do many people go solid for race cars?

Ryan02SS

iTrader: (3)

From a design/engineering standpoint a hydraulically actuated lifter assembly is a series of convenience compromises. We spend thousands of dollars to eliminate deflection from our valve train; a hydraulic lifter has deflection designed into it. Their designs work very well in utilitarian vehicles, but are they mandatory in moderate performance applications as well?

Fact is, solid lifters do everything better than hydraulics from a design/performance standpoint. They open the valve farther, faster, and quicker (lift/velocity/acceleration) than a hydraulic ever could. They make more torque/power everywhere in the curve. The new designs, once they take a set, can go an entire season on one a lash adjustment.

Solid roller lifters are lighter, reducing the mass on the pushrod side of the fulcrum, promoting greater dynamic stability. They have fewer moving parts. They don't pump up or bleed down, virtually eliminating valve float and lifter collapse. They eliminate plunger deflection. They do not have plungers to stick from particle contamination in the oil. They are not spring limited by design, which is critical. The valve spring is the single most important element in controlling valve train stability. This allows you to run the proper spring for your RPM range and component mass.

Are they for everyone? Not necessarily. For the plug and play type who want to set it and forget it stay Hyd roller.

Asmodeus

Now tell him about how they effect/ how they act in a daily driver.

Asmodeus

Remember, duration is measured AT THE LOBE. With a solid cam, however much of the duration is consumed while the lash is being taken up; so from just purely a duration standpoint, a solid cam with a given duration spec will "act" "smaller" than a hyd with the same spec. However it may make more power, because the ramps on a solid are almost always steeper than those on a hyd.

Solid rollers are a problem on the street. The problem is, not enough oil gets to their axles, especially at idle and real low RPMs. They fry during extended low RPM operation. Probably the best ones are the Isky Red Zones, which have pressurized oil fed to the axles; or the Crower ones with the HIPPO option. All the others, as far as I know, only dribble oil onto the outside of the roller, which since it's spinning throws the oil off and not enough gets into the axle. Once the engine speeds pick up though, there's usually enough of an oil mist whipped up inside there, to keep them from running dry. Lash adjustments will need to be made a lot on a DD.

Too little spring pressure, EVERYTHING tears up at high RPMs.

Too much spring pressure and not enough oil, lifter axles tear up at low RPMs.

Ryan02SS

iTrader: (3)

While this is true of older solids, almost all solid rollers now incorporate the EDM pressure fed oil into the roller wheel. Even Comp has their Endure X EDM oiling.

I don't get where this comes from? I used to run a solid setup in my boat and once everything was broken in, it never needed adjusting. I would check it 2-3 times a season but it never changed. I don't see how it would need readjusted unless a component was wearing improperly?

Everything else is right on! If you want plug and play stay Hyd roller. If you want max performance and are willing to pull valve covers now and again, go solid rolller. As with anything you can go mild solid to wild solid.

Asmodeus

why aren't people throwing them in in place of Hyd Lifters if this is the case?

1slow01Z71

iTrader: (36)

Think he was acking what is different about how they are made. Since cams are labeled as hyd or solid. I know the lobes are MUCH more aggressive on a solid cam but dont know if they are made differently.

BOWTIE

For one, most people do not want to spend the money it takes to make the valvetrain adjustable, for two most people do not want to have to adjust the valve periodically even if it is just a few times a year (keep in mind a car usually runs more than a boat and whether or not they need to be adjusted, they still need to be checked), lastly most of us do not spin the motors high enough to really take full advantage of a solid roller anyway (afterall from the knowledge gained here, most LSX manifolds are tuned to produce peak numbers in the 6200-6500 range). As for his boat, I would assume it is a big block which most likely has a very heavy valvetrain, consequently a hydraulic roller would most likely be a thorn in his side even though he most likely does not spin it any higher than we do our LSX's. (Disclaimer... lots of assumptions were made in this post)

slow trap

iTrader: (22)

well i don't know about how often they may or may need adjusting for a dd but i had a weekend warrior and rarely had to readjust the sr cams i had in it. one cam was fairly mild at 255/255 @.050 and .575/.575 but the other one was 259/267 @.050 with .638 lift and with some pretty strong springs and i may have had to readjust the lash once over a couple thousand miles.unless something is wearing or your locks have come lose on your rockers adjustment intervals should be few and far between.as for daily driving them if people bitch about a hydraulic ticking sound they will really bitch hearing rockers tapping with .020 thou or more lash.

Ryan02SS

iTrader: (3)

Boat was actually a AFR headed 355ci SBC, cam was 257/269 duration @ .50. Spun it to 6500rpms.

You are right about why most of the general community do not run SR's. They also make more noise as you always have a lash of .10-.20". The larger the cam and spring pressure the more wear on your valvetrain. Think springs, valve seats, PR's, lifters, and rockers.

As to the cam itself they are made of the same material it's just the solid will have much more aggressive lobes.

99blancoSS

iTrader: (115)

No need ($)for a solid lifter in a street car is the basic answer. Their value, as I see it, is higher reving. There is no real need to produce power above 6000rpms in a street car.

brad8266

iTrader: (23)

Whats with the sig quote?

99blancoSS

iTrader: (115)

I thought it was funny

brad8266

iTrader: (23)

So do I, since when are 1.7 rockers a secret??