Its called we would really like to promote one version over the other. They purposley shut the test down to not show the solid just walk away from the juice cam. People do like to talk about the new LS7 going to 7000. They don't seem to mention the $1600.00 worth of titanium valves to help it rev that high. I guess everyones pockets are so deep they can spend around $1000 to put in a regular hydraulic roller setup then add in an extra $1600.00 for valves for that extra 500 rpm of bragging rights. But then i have been watching this forum a few yrs. Never once noticed someone install a hydraulic roller then turn around and put $1600.00 titanium valves in it. But then for a mere $70,000 or so you can just drive away with titanium included.

 

We all agree that in a pure racing application a solid roller is the best choice. The point I would like to get at is probably 95% of the corvettes on the forum are not optimally geared for a cam that peaks over 6500 RPM. and of those cars more than 95% of the time they are not running that kind of RPM. For the 5% that could actually properly use the advantage of the extra RPM range solid roller is the best choice.
Even for them if they use the AFR eliminators with lightweight ls series valves, titanium caps and beehive springs and the new short travel lifters this will extend the operating range of the hydraulic roller to well over 7000 rpm without costing a fortune and virtually no maintainance. The technology today with hydraulic roller valvetrains is way ahead of what it was even 5 years ago. For the vast majority of street cars the hydraulic roller is the best option.

 

Can't disagree for the average smallblock. Big blocks are a whole 'nuther deal if you want to really rev it.

Valvetrain weight is the killer for sure. Folks work like crazy to get a HR to rev to the moon and they pretty much stop the one thing it does best...be quiet. The short travel lifters are pretty noisy and were invented for class racers who had to run hyd. cams. Before that they machined washer to shim them up and essentially make solids out of them.

Then we try more serious cams to make more power...which need more valve spring. besides being noisy with the fast ramps...they have begun to start eating parts just like solid rollers due to high spring pressures etc.

There IS some really good spintron work going on that is very interesting. It's all in the cam lobe design and it's super critical with a hyd cam to make it rev. You can't slam them around like a solid roller...but you can get close if you really work at it. But as mentioned...many of them are using titanium valves and stuff. But I do know of a few 7000 rpm small blocks with *normal* hyd rollers. Just takes good parts.

You can easily make 550-600Hp with a hyd roller under 7000 rpm in a Gen I..but it won't likely be as dead quiet as people might like.

The LS motors have a huge cam lobe and shaft, shorter pushrods, lighter valves etc etc to help them out.

JIM

 

it says "article not found"!, can someone please post alternative link of the article?