[71 Ventura II]

If I have a hyd roller cam specs: .555-.555 @.050 .246-.254 308-316 lsa 112

Is this a mild enough cam to try running a tight lash sold roller setup? Also, if you run solid lifters does it change the spring requirements? This cam comes with dual springs with a #438 rate. Help? JD

[Tim Corcoran]

Curious why you are not happy with the HR roller?

[tom s]

might do a search,TONS of info on the subject.Tom

[Steve C.]

If you are interested in using solid roller lifters on a hyd roller lobe, be very aware you cannot run a similar amount of spring pressure as a normal hyd roller cam with hyd lifters. You need more. My opinion, use no less than what you would for a mild Comp XE solid street roller set up. Cliff Ruggles has posted he has 159 lbs seat pressure, others similar. I know of at least two other set ups with the same cam upwards toward 200 lbs seat pressure.

[71 Ventura II]

Originally Posted by tom s

might do a search,TONS of info on the subject.Tom

That might be a legitimate suggestion only the wording of the search is hard to find. I too recall many threads talking about the scenario. However unless you know the verbage used in the thread the search brings up very little.

If you have links to the actual threads that would be great! JD

[screamingchief]

Originally Posted by 71 Ventura II

That might be a legitimate suggestion only the wording of the search is hard to find. I too recall many threads talking about the scenario. However unless you know the verbage used in the thread the search brings up very little.

If you have links to the actual threads that would be great! JD

It always works better if you pick one of the "usual suspects" screen-names and put that in when doing the advanced search,and then use a not so common keyword like "lash" "ramp" or "solid" or such and search only in the street and/or race forums,that'll usually "weed out" a whole lotta useless posts.

At least that always helps me a lot when I'm digging around in there for something.

HTH

Bret P.

[Cliff R]

The tight lash solid roller lifter on the HR camshaft works pretty well for us. I have two engines out of our shop that use this set up with zero issues anyplace. I have several customers running engines prepared here with the same deal, zero issues anyplace.

We have settled on .005" lash, dead cold. Working fantastic and these engines are very quiet. Something I'm not used to, as every single engine I've every owned that had a hydraulic cam in it, had one or two "clickers" someplace.

What we are essentially doing here is using a true "anti-pump up" lifter. No hydraulics to come into play at high rpms, and the lifters are much lighter than their hydrauilic roller counterparts.

We use the Crower HIPPO lifters with the positive oiling feature. No block restrictors are required, they are self metering.

I would add here that it is difficult, if not near impossible to get oil up to all the rockers on the engine stand (unless you want to smoke your 1/2 drill) by turning the crank and running the pump with a drill at the same time.

In use, the Crower lifters do an EXCELLENT job of oiling the top end of the engine, while keeping plenty of oil in the bottom end where it counts.

I can't remember the springs Dave set up my heads with, but they are the same ones he uses for HR camshafts. I'll ask him about the pressures again, I was thinking he said they were up near 380-400 lbs open.

In any case, the biggest difference I notice between this engine and my last one that used HR lifters, is that this one races right past 5800rpm's so quick you can't move the shifter fast enough. The old engine was pretty much done at 5800rpm's, either by being a smaller cam with smaller runner heads, or loosing some lift/duration due to the hydraulic lifters, not sure?.....Cliff

[PONTIAC DUDE]

Originally Posted by Cliff R

In any case, the biggest difference I notice between this engine and my last one that used HR lifters, is that this one races right past 5800rpm's so quick you can't move the shifter fast enough. The old engine was pretty much done at 5800rpm's, either by being a smaller cam with smaller runner heads, or loosing some lift/duration due to the hydraulic lifters, not sure?.....Cliff

I would say the smaller cam w/ smaller heads had more to with rpm range then the hyd rollers.

[Steve C.]

"I can't remember the springs Dave set up my heads with, but they are the same ones he uses for HR camshafts. I'll ask him about the pressures again, I was thinking he said they were up near 380-400 lbs open."

I have a copy of the specification/flow sheet for a set of aluminium d-port cylinder heads set up from SD Performance for a hyd roller cam, it says this:

".... ported and set up for hyd. Roller, Crane 99893 springs set up at 1.780"-1.790" intake & 1.810"-1.815" exhaust installed height, titanium retainers."

These heads were bought with the intention of running solid roller lifters on a hydraulic roller lobe. After the engines dyno session a set of springs were removed and measured. Keeping in mind that valvesprings can 'settle in' and lose some pressure after run-in. The actual installed height was 1.785" and it had 145 lbs. seat pressure. Rate for that spring is 391 and the net lift was about 0.602". Running apparantly with no issues, but based on my consulting of various professional cam designers and tech people around the country on the subject this in my opinion is margional for the application with the valvetrain mass involved. When in doubt, run slightly more seat pressure... NOT LESS. The extra amount of pressure may save you from issues and that extra amount of pressure WILL NOT shorten the life of the springs enough to worry about, nor will it cost enough power to even bother with.

[Larry Navarro]

Originally Posted by Cliff R

We have settled on .005" lash, dead cold. Working fantastic and these engines are very quiet. Something I'm not used to, as every single engine I've every owned that had a hydraulic cam in it, had one or two "clickers" someplace.

Yep....sure is nice.

[440GP69]

FWIW Ive found a properly setup a Hyd roller valvetrane will be quiet and race right to and past 6500 Usually untill it hits the rev limiter LOL

[Cliff R]

Probably true for in a small block Chevy where all the parts on each side of the rocker arm are lighter. For a Pontiac engine, I'd want to use a much lighter retainer, bee-hive springs, light rockers, pushrods, etc to try to get those kind of rpms out of the HR set-ups.

Ken seems to be able to do it without any issues. I've been at the dyno and have observed quite a few HR set-ups "nose-dive" up around 5800-6000rpm's, even when the cam and head flow was adequate to make power further into the rpm range.

I just took all that out of the equation using the Crower solid rollers instead of HR's. My engine revs clean and quick right past 6000rpm's without a hint of valve float or lifter "crash"......Cliff

[Steve C.]

"An interesting question surfaced during this testing relative to how much spring pressure a hydraulic roller cam combination could withstand. Keeping this explanation short and simple, too much spring pressure does not really force the hydraulic lifter piston down, as is commonly thought. What really happens is that higher spring pressures tend to deflect the pushrod, which causes valvetrain separation at higher engine speeds when the pushrod pole vaults the valve past the nose of the cam. This clearance in the valvetrain allows the lifter piston to pump up. When the cam lobe returns to the base circle, the pumped-up lifter holds the intake valve open and causes the engine to lose power. Reducing hydraulic roller valvespring pressures to more manageable levels reduces pushrod flex and minimizes lifter pump-up."

http://www.carcraft.com/techarticles...s_and_cam.html

Also interesting to note, and somewhat related, one of the three cams tested in the article was the infamous Comp 284XE hyd flat tappet cam that won't rev up in a "Pontiac" according to some. But here in this short stroke sbc application it goes to 6200 peak rpm with no issues. Using 153 lbs seat pressure. And yes, as noted it is a sbc. But in this piticular application with the valvetrain mass involved in conjunction with the aftermarket cylinder heads and bigger valves in use.... is the valvetrain mass really all that much off from a typical Pontiac... I personaly don't know but its worth considering.

[BruceWilkie]

Originally Posted by PONTIAC DUDE

I would say the smaller cam w/ smaller heads had more to with rpm range then the hyd rollers.

X2
I know you have been well beyond 7000 rpm with your hydraulic roller with no clicking and clatter at idle.

Choose the right cam for the application and the lifter designed for it.

I very much agree with Steve C about valve springs and seat pressure.

[stickboy]

I installed a solid roller before the SD old faithful craze...this was at least 6 years ago. Before the Cliff solid lifters on hyd cam deal. Steve C. helped me with the spring selection, at the time he was one of the few who had run them on the street.

solid roller, more spring than less..... I ended up with 200 seat and 500 open. I'm sure they have run down some as I have been running the car for over 5 years now. Couple of short road trips, lots of street miles and 1/4 mile runs...but all is good under the hood. ;-)

Dude has a nice setup goin on. Gotta pay attention to the little details if you wanna play the full hydraulic roller game.

[Steve C.]

Related. I went searching for a specific statement about 'valve float' that I recently read on another forium, Speed Talk I think, but couldn't find it. It was made by a gentlemen with experiance and a lot of authority in the area of valvetrain stability. I wanted to quote him directly so as to not screw it up or be misleading as I'm not a silver tounged devil. Anyway.........

In part, he mentioned that often the term 'valve float' could be mis leading and went on to address the issues of a valve bouncing off the seat as it closes, in part due to inadequate spring pressure to control the situation. My point here is not as much about the engine losing power and nosing over at rpm due to this situation, but he mentions that if the situation continues the valve springs will further degenerate. If so now distruction starts !

[PONTIAC DUDE]

Building quite a few SBC abd BBC's for roundy round and drag. in the 7200 rpm range over 40 years with hyd lifters. Yes Steve. Never saw a "lifter" float but springs will.

Same deal with Pontiacs. Springs, springs, springs.

If I hear one more response about lifter weight of the hyd roller lifter, I'm gonna puke.

I posted the difference awhile back. I'd worry more about valvetrain load going to a 1.65 ratio before i worry about lifter weight difference of a 6200 rpm Pontiac engine.

But people can ASSUME whatever they want as to what works and what doesn't. Ya want a solid lifter on a hyd roller cam. go for it. Just more load on the valvetrain with higher rated springs for 'long term' mileage & relatively mild camshafts.

[Steve C.]

Here are some of the floating valve springs.....

http://www.youtube.com/watch?v=_REQ1PUM0rY

[440GP69]

Originally Posted by Cliff R

Probably true for in a small block Chevy where all the parts on each side of the rocker arm are lighter. For a Pontiac engine, I'd want to use a much lighter retainer, bee-hive springs, light rockers, pushrods, etc to try to get those kind of rpms out of the HR set-ups.

Ken seems to be able to do it without any issues. I've been at the dyno and have observed quite a few HR set-ups "nose-dive" up around 5800-6000rpm's, even when the cam and head flow was adequate to make power further into the rpm range.

I just took all that out of the equation using the Crower solid rollers instead of HR's. My engine revs clean and quick right past 6000rpm's without a hint of valve float or lifter "crash"......Cliff

Yeah NO, LOL Not Talking about SBC, FYI you don't need to use solid roller tappets for 6000 even 6500, and the weight difference between high performance Pontiac valvetrane and a Chevy Valvetrane is Miniscule, JMHO

[440GP69]

Originally Posted by PONTIAC DUDE

Building quite a few SBC abd BBC's for roundy round and drag. in the 7200 rpm range over 40 years with hyd lifters. Yes Steve. Never saw a "lifter" float but springs will.

Same deal with Pontiacs. Springs, springs, springs.

If I hear one more response about lifter weight of the hyd roller lifter, I'm gonna puke.

I posted the difference awhile back. I'd worry more about valvetrain load going to a 1.65 ratio before i worry about lifter weight difference of a 6200 rpm Pontiac engine.

But people can ASSUME whatever they want as to what works and what doesn't. Ya want a solid lifter on a hyd roller cam. go for it. Just more load on the valvetrain with higher rated springs for 'long term' mileage & relatively mild camshafts.

Bingo, thanks Dude, also one must understand The Lobe Profile plays into this a bunch, the valve side is the one you need to worry about weight with IMO