[TCSGTO]

On my 2nd year with the hybrid setup and all seems well. There are only about 1500 miles and 35 or so 1/4 mile passes but no problems to date. The highest RPM it's seen is 5800. I meant to inspect the lifters this winter but never got around to it. Lash hasn't changed and there are no strange noises.

I did check spring pressure with a Moroso on the head tester recently and it is the same as it was after a few break-in miles.

If I had to do it again I probably would have used the Scorpion limited travel hydraulics. They're a few bucks cheaper and I'm still a little nervous about having lash in the valvetrain with needle bearing lifters. Hopefully the .004-006" lash and mild valve springs will make things last a good while.

[grandville455]

Not sure on my miles ,750? but must be close to 100 passes , and just fired it yesterday after sitting all winter dead quiet! Getting it ready for test day in two weeks, with new conv and rear DA AFCO Shocks

[rtanner]

would you enlighten me about the details of a hybrid setup? i was away a couple years must of missed it. thanks

[ponjohn]

Originally Posted by rtanner

would you enlighten me about the details of a hybrid setup? i was away a couple years must of missed it. thanks

Solid rollers on hyd roller cam.

[wheelspin]

I have run SD's Old Faithful hyd. cam with Crower's Hippo solid lifters and 300cfm KRE heads for 3 years on my GTO, including around 50-11 second passes and 2,500 street/touring miles. Lash has not changed since setting at .007, however the valve springs lost almost 10#, requiring additional shimming to maintain proper pressures.

[Skip Fix]

So was the 10# loss causing any problems-float etc? IE does it need the 10# and what seat were you running?

[428RA4]

What solid lifters do you guys recommend?

[wheelspin]

Originally Posted by Skip Fix

So was the 10# loss causing any problems-float etc? IE does it need the 10# and what seat were you running?

Skip,
No evidence of harm in the GTO, but it may have been part of the failure in my last TA engine that lost two valve heads which migrated thru the intake ruining the block (3 cylinders and some lifter bores cracked) and cracked a very nice set of 250 cfm 4X-7H heads under the seats in the process. Dave/SD Performance favors lower spring pressures than Steve C., around 145 & 350 as I recall. Call me if you would like more details on the TA's failure .

[GTOLou]

What is the perceived gain in running the solid roller lifters?

Rev's faster?
Free's up a bit more hp? - lighter valve train components?

What does it do to idle/vacuum?

[Steve C.]

It's not just my opinion regarding low spring pressures on these 'hybrid' set ups.

Out of interest I contacted cam companies and independent cam design engineers on this very subject. Especially how it relates to adequate spring pressure involved. I've posted the information obtained on numerous occasions, probably been a pain in the ass on the subject. But all those I communicated with agree it NEEDS ADDITIONAL spring pressure over a hydrulic roller set up.

Again it's just opinion as I have no direct experiance, but I feel running a solid roller set up with only 145 lbs seat pressure is margional and asking for trouble. And so did the companies and designers I contacted. Below are comments from Cliff Ruggles within a previous thread on this subject and his spring pressure running Crower solid roller lifters on his Comp Magnum High Lift Hydraulic roller lobes, including a comment from Dave Bischopp:


The springs I'm using are set at 1.800", this yields about 150-160lbs on the seat, and 380-400 lbs over the nose at .627" lift.

Right from Dave at SD, and I'll quote him here:

"It doesn’t matter if it’s a hyd. lifter or solid lifter we set them up this way for the “bigger” cams that can carry the power to 6000+ rpm."

He goes on to say that he sets them up with a lighter retainer making them good to 6500rpm's. Beyond that, a much more expensive "beehive" spring and titanium retainer is used.

In other words, I'm using the SAME set-up SD sets the heads up for Hydraulic Roller camshafts. Also mentioned in the note I got back from Dave, is that the springs will loose a small amount of pressure in use, the exact words were "drop a bit once broken in".

So here we have it guys, straight from the guy who built the heads, same deal on HR and solid roller lifters for the rpm range I run my engine in. Hope this helps some?......Cliff



.

[ponjohn]

It would stand to reason that if the SR lifters were lighter you could get away with the HR prescribed pressures.

[Skip Fix]

My question is slightly rhetorical-how do we really know what pressures a motor needs unless it goes to failure(float etc)?

We get so picky about exactly the same pressure so we shim each individual spring when a 5 or 10 # difference between them as long as it is controlling the valves probably doesn't make a difference if they are already 20,30, 50lbs more than needed.

I swapped one motor in the car from FT springs to 200lb seat roller springs. I guarantee it got harder and harder to manually turn over the more heavy springs that were installed. So if it is harder to turn over be it from ring drag, or excess spring pressure you have to be loosing HP.

But better to have a little too much pressure and not float them vs too little, kind of like trying to run 10:1 on an iron headed pump gas motor

[Steve C.]

Right from the Crane catalog......

"Always run enough seat pressure to control the valve action as it returns to the seat. Heavier valves require more seat pressure. Strong, lightweight valves require less seat pressure. When in doubt, run slightly more seat pressure . . . not less."

Speaking of Crane... their 99893 valve spring seems to be very popular with some running solid roller lifters on a hydraulic roller lobes. Crane Cams Valve Spring guide PP0203B states the 99893 spring is for "flat tappet racing use". But Pontiac Dude appropriatly pointed out that spring is a universal one size fits all depending on the lift and seat pressure set up. And on this subject if memory serves me right I believe Pontiac Dude also stated his opinion if you are running a hyd roller with solid roller lifters you need at least 160 seat and 450 open. But don't hold me to that.

It has been stated that Steve Crane actually rates the 99893 valve spring for 'small' solid roller use as well with a 1.750" installed height. That said if you look at the specifications within that publication it rates the spring at 167 lbs seat pressure at that 1.750" installed height. Personally I know of one set of Crane 99893 springs installed at 1.785" IH and after a dyno session two springs were pulled and measured, they were down to about 145 lbs seat pressure. But I didn't hear about of any failures.


.

[TCSGTO]

Those springs aren't made by Crane and are sold thru other sources like Trick Flow, Howards, etc. with a different label on the box. Circle track guys are known to run them on flat tappets. Match up the specs from other companies and you can usually find that same spring at quite a lower price without the Crane name on it. That probably holds true for most valve springs on the market.

[Cliff R]

Nothing has failed here to date, but I am replacing the PRW steel rocker arms this month. From day one they have had some minor "issues". Either the roller or the pin going thru it is out of round some, which makes valve lash adjustments a tad difficult.

If you set them at .006", then try to turn the roller, they get tight. Found the same thing out with another set used in a 455 when we had it on the dyno. Not sure what's going on there, and they haven't failed, but something isn't quite right with them so we're swapping them out......Cliff

[ponjohn]

Originally Posted by Cliff R

Nothing has failed here to date, but I am replacing the PRW steel rocker arms this month. From day one they have had some minor "issues". Either the roller or the pin going thru it is out of round some, which makes valve lash adjustments a tad difficult.

If you set them at .006", then try to turn the roller, they get tight. Found the same thing out with another set used in a 455 when we had it on the dyno. Not sure what's going on there, and they haven't failed, but something isn't quite right with them so we're swapping them out......Cliff

Cliff-

What brand are you using?
Same ratio?

[quicksilver97ta]

Originally Posted by GTOLou

What is the perceived gain in running the solid roller lifters?

Rev's faster?
Free's up a bit more hp? - lighter valve train components?

What does it do to idle/vacuum?

I wish somebody would answer all this but what I have read here are complaints about the hydraulic parts of the lifters not working properly and the solids eliminate that. Also, as a side benefit these hybrid set ups operate very quietly. I would think that all the advantages of a solid over a hydraulic still apply.

[428RA4]

This is an interesting thread read. Looking forward to more insight on the subject. I know it has been talked about a lot, but it would be great to hear the benefits.

[Steve C.]

From Hot Rod magazine: Solid Rollers On Hydraulic Cams

http://www.hotrod.com/techfaq/hrdp_0...#ixzz2Q4lPyvAR

"Comp said when you put the solid rollers on it to treat like a soild roller cam, MORE seat pressure. Lifter bounce is what will destroy the lifters."

http://speedtalk.com/forum/viewtopic.php?t=19578


Google.... "running solid roller lifters on hydraulic roller cam"... and you will get lots of opinions. A few examples:

http://www.chevelles.com/forums/showthread.php?t=299946

http://www.yellowbullet.com/forum/sh...d.php?t=141406


.

[Cliff R]

The "hybrid" set up basically puts a true "anti-pump up" lifter on the cam, and takes the hydraulic action of the lifters out of the equation.

Some folks pick the deal apart saying that the hydraulic lifter is required to provide a "cushion" for the ramp as they are quite aggressive on HR grinds.

The theory is that the solid lifter will beat up the rest of the valvetrain parts or at least be harder on them than a hydraulic roller lifter would be.

I've ran both set-ups, and had great success both ways. I did find that the hydraulic lifter was limited to apprx 5800rpm's with the weight of the valvetrain parts that I was using with my last engine.

The current engine with the Crower HIPPO solids will spin right past 5800rpm's without a grumble. This engine has seen past 6500rpm's a few times and never skipped a beat.

Even with the extended rpm potential, I still typically shift around 5000rpm's when drag racing, as there is no real need to "grind" up the engine just to take another .05-.08 seconds off the timeslip.

I actually use that deal for times when I slip some on the starting line, or it doesn't look like I'm going to get to the finish line first. I'll "buzz" the engine harder to get there first, or at least hard enough that my opponent never has a chance to let out of it, or tap the brakes, etc......Cliff