Jordon

Guess I'm still not getting it.

Why does the valve stay open longer on solid rollers vs a hydraulic?. Why can't the difference be ground into a camshaft? I’m not saying you have to compare the exact same grinds, compensate for the same bottom line difference.

The LSx dyno sheets really are remarkable these days. 470 rwhp using a stock block is not uncommon with the new packages. Even better, the powerband using hydraulic lifters is killer flat on top. I saw one H/C package make 482rwhp breaking the 450rwhp mark at 5700 rpm and still making 470+ @ 7200 rpm. I have serious doubts your gonna pick up 50rwhp just from having solid rollers. Seems like that would be the first thing they would do if true.

I also don’t get it on the valve train stuff.. You installed the last camshaft in my car yourself. I’m positive you didn’t find anything off regarding the valve train. Neither did the other numerous shops whom checked the engine. The valve train had been checked, rechecked and checked once more.

I may just have the worst luck in the world, but I've known others who also had problems with solid rollers on the street.

 

I noticed no one mentionsed the larger Base circle on the cam. It has some to do with the Lifters reving higher as the ramps are softer even though they are bigger

 

Another thing to think about is the technological advancement of the hydraulic camshafts that are out today. You can get the type of aggressive profiles in a hydraulic without the valve lash checking

Z9's, what lifters do you use?

 

Comp Cams R 875-16

 

I'm no expert on the subject, but here are a few things to consider, maybe someone with a bit more knowledge can add to (and/or correct) my points:

- solid lifters have less mass; do not fill up with oil. Less mechanical parts (internal).

- solid lifters do not bleed down/ nor pump up (high RPM lobe ramping/under float conditions)...therefore the gross lift is maintained at all times

- solid cam designs can offer more radical lobe profiles for valve
open/close conditions (because of the points stated above).

 

- solid lifters have less mass; do not fill up with oil. Less mechanical parts (internal).

- solid lifters do not bleed down/ nor pump up (high RPM lobe ramping/under float conditions)...therefore the gross lift is maintained at all times

- solid cam designs can offer more radical lobe profiles for valve
open/close conditions (because of the points stated above).

I hear what your saying regarding theory, but the proof is in the pudding. Check out this dyno sheet using hydraulics.

http://forums.corvetteforum.com/zerothread?id=701358

Something good is going on.

 

Just a clarification: I'm not supporting the idea of solid cams in a
street car, I'm just listing possible reasons why solid cams make
more power than a hydraulic.

From my previous replies you'll see that a proper hyd. setup will
have no porblems making needed power for the street.

Nice graph on that LS1!

 

Thats what I wanted to hear. Thanks Chris!

 

When comparing LT1's to LS1's, probably because of the better heads on LS1's, they don't need to run as radical camshafts as LT1's would to get the same power output (or, to get the same amount of air flow through the cylinders). Probably to maximize the valve lift and duration, LT1's run closer tolerances (valve to piston) so running with solids will be more accurate and consistant than using hydraulics. Since LS1's just "work" better, a little less aggressive cam will still net the same results without resorting to solid lifters.

That's my guesstimation of the matter! Anyone agree/disagree?

 

Denny-
I am thinking your heads were setup with too much seat pressure, but its hard to say.

solid vs hd.

Picture a cross section of a lobe. the more area it has, the more air can get in. although this is exteme, think of a hyd as a triangle, and a solid as a rectangle. areaRect = b*H, areaTri = B*h/2

hyd cam ramps aren't as steep, and solids are more steep.. closer to vertical ramps(rectangle).


As far as teh LS1 stuff goes, its really the heads that are making that extreme power. Also, the cam and valvetrain setup (big base circle) is better, period. Also, more and more LS1s are dyno ****** and dont run the numbers. I have seen many that dyno 460+ that cant even trap 125.

 

Capt Pete:

I'm going to have to disagree with you , only because i know the
LS1 carries a heavier camshaft to compliment the heads.

With all that extra flow, the valve timing would have to be opened
up quite a bit.

The LS1 uses 0.559"/0.566" 267/ 275 degrees whereas
the LT1 is a little more conservative at Lift 0.459"/0.485" 242/254 duration

 

"Dyno ******" what's that, you can't make a stronger point so you say that? You're lucky I don't link this thread to my site you'd be as popular as the flu after that.

I honestly think that solid rollers are for race cars.

I think that LSX combos are making big power and hitting 7000+ because of the amazing amount of r&d going on by shops, customers and manufacturers to find what works.

Don't be surprised when we start seeing 500rwhp 346ci LSX combos getting spun to 7500, because cam, valvespring, lifter and rocker arm technology has come along a long way.

We spun my old ARE 422ci up to 7200 on the dyno a bunch of times.

My new combo is set up with Crane springs, Comp R lifters, Y/T 1.7 rockers, an FMS (Cam Motion) camshaft, and meant to pull up to 7200. I could have run even more spring pressure too.

At some point folks are also going to run the lightest valves possible ie. titanium. Good stuff going on.

 

i totally agree..........considering that they are hitting 470-480rwhp with the ported LS6 heads............i think people will be pushing 500rw now that the AFR heads are on the way.

 

I don't believe the LS1 cams are spec'd like that. Well, not the lift anyway. They're closer to .500" lift for '98 - '00, and around .479" lift for '01 - '02. Someone please correct me if I'm wrong, but even on SLP's website where they advertise the 1.85:1 RR's, they say that on stock cams it will increase lift to .544" or .521" respectively, so on a stock 1.7:1 rocker, that's ~.500" or ~.479".
Compared to what? LT1 cars that dyno 460+? A lot of factors play in how a car performs at the track. I don't think you can compare dyno numbers and track numbers the same. If you're comparing LT1 - LS1 cars, put the 460 HP LS1 into the LT1 car, and I'm sure it would run over 125 mph. All the power in the world is useless unless you can put it to the ground, and maybe that's the case you're describing?

 

Obviously the power/power curve people are making with the LS1 has caught my ear and I’m in agreement that 500 rwhp 346ci stock H/C combo’s are right around the corner. As mentioned…….. something good is going on. I’m just trying to figure out what and take as much advantage of it as possible.

I happen to really like my LT car and am just waiting for the C6 to come into it’s own before making any moves.

I’m still thinking less cam duration and more heads may be part of the trick.

Jordon

You could be very right regarding the spring pressure but the kicker here is I broke solid lifters with the 227 AFR heads and the GTP LT4’s. Two different set of heads with different springs. The only thing in common were the pushrods and rockers. The geometry was check several times.