More questions about solid rollers, and going back to hyd rollers...

[750hp]

In the interest of not threadjacking Berm's question, but still considering less expensive solutions to fix my solid roller concerns...

I have a supercharged 9.5" SVO block stroker with a 660 lift solid roller cam and 320lb seat pressure springs.
It's out of the car at the moment, and I'm going to check bores/rings/bearings while it's out.
I've been worried about friends destroying their SBF motors from rollers breaking off and jamming sideways in the lifter bore, damaging the block, rods, etc, etc. Another had a complete failure of a new set of rollers in his 2000 mile old 351W
Can the solid roller cam stay, and just the solid roller lifters be replaced by hydraulic roller lifters?
Are pushrod lengths the same from solid to hyd rollers?
Are the springs too stiff for a hyd rollers?

If I can replace the lifters with hydraulic rollers without changing the entire valvetrain, I'm there!

Thanks for your help.

[vector1]

here's a pretty good discussion

http://speedtalk.com/forum/viewtopic.php?t=18182

[Jerry Clayton]

Going back to when hydraulic tappets appeared----you could put hydraulics on solid cams but couldn't put solids on hydraulic cams---reason-solid cams have a clearance ramp that gradually takes up the clearance and gentley lets it back on the seat that hydraulic don't have since the hyd is in contact all the way around

[bermblaster41]

Craig
Your question is right on. That is what I was considering. I checked and the expense would be too great. As it stands I have too much valve spring to switch. Hyd rollers lifters twice the price,new push rods and a new set of springs. Way too much for my budget. At this time. Still weighing my options at this point. Hope this helps. Berm

[blykins]

I think you guys are getting confused on spring pressures.

320lbs for a solid roller is nowhere enough.

Also, you can run up to 350-400 lbs on a hydraulic roller grind.

As I remember Berm, you don't have enough spring for a solid roller, but you could probably use your springs on a hydraulic roller cam. Plus you could always remove a shim or put a thinner spring locator on to lose some pressure.

I wouldn't run a hydraulic roller lifter on a solid roller cam myself.

I've ran some pretty stout hydraulic rollers and have had problems with losing control of the valve train, even with stout springs and titanium valvetrain components.

The ramps on a solid roller cam are much steeper and you take the chance of lofting the lifters.

You can run solid rollers on a hydraulic grind, but usually the lash is cut down extensively.

[blykins]

Also, pushrod lengths are not the same.

750, I would have no worries with a mild solid roller grind, a good set of pressure fed lifters, and enough spring pressure to keep things in control. If I were in your spot, that's what I would do.

[bermblaster41]

Brent
I am a little confused. The springs that are on my heads are the springs suggested by the cam designer. My cam is set up as a solid roller. Berm

[Jerry Clayton]

Gee Brent, I'm glad you explained that to me---hard to imagine that I've had it wrong all these years. By the way, what do you use for a spring compressor and how much pressure does those springs have on the nose of a .900+ lift cam????

[LMH]

What about using CompCams Endure-X solid rollers?
They are supposed to be engineered for street use or so I read.
Larry

[blykins]

Jerry, I don't understand what you're referring to. Of course we're all talking about roller cams here, where spring pressures are much, higher and ramps are much steeper. Some solid roller cams only have 28° between .050" duration and seat duration. That's open the valve REAL quick, holding it open for a long time, then slamming it down. Running a hydraulic lifter on that ramp with enough spring pressure to keep the valves from floating at high revs would probably collapse the lifter.

Berm, I don't know why a cam designer would recommend such wimpy springs on such a thumpy cam. If I remember your specs from the other thread, it's not exactly a street roller cam. The only caveat would be if he recommended a specific install height with those springs. You can take a 400lb spring and shim it enough to get 450lbs out of it, you know what I mean?

On a solid roller, I would never go under 250lbs seat and 500 lbs open and I wouldn't care to run a lot more than that on a billet core.

For a hydraulic roller, I usually aim for about 130-140lbs seat and 325-350 lbs open, depending on the grind.

Comp Cams Endure-X lifters are engineered for street use, yes. They are pressure fed lifters. There are better choices out there, but I've used the Comp lifters quite a bit.

The thing about running a solid roller on the street is that you keep enough spring pressure to keep the valvetrain under control, and you keep the idle up a little so that the cam/lifters get oil splash.

[vector1]

320 lbs on the seat......

[DAVID GAGNARD]

On a solid roller, I would never go under 250lbs seat and 500 lbs open and I wouldn't care to run a lot more than that on a billet core.

Brent:

Just asking, on my race car (331 stroker) I was running a solid roller Comp camshaft, 586 lift and 288 duration, on the cam card they recommended 215 lbs. on the seat, mine were set at 225 on the seat, don't remmeber off hand what the open pressure is...I have a 7,000 rpm chip in it and do run it up to the chip on track....on the dyno we did do a few pulls in the 7500 to 7700 rpm range....the actual hp peaked at 6400 rpms, so no need to rev it much more than that.....

Building a new engine as we speak, same 331 stroker, going with another solid roller, of 624 lift, can't remember the exact duration (haven't got the cam in yet), wanna say around 285 duration.....don't know what they recommend for seat pressure yet, but I'd think anything in the 200 to 225 range would suffice.....

Your thoughts???????

Thanks;
David

[blykins]

David,

Can you post all the cam specs?

I say you're on the right track with the spring pressures. If it's a race car, you're already of the mindset that you'll be doing maintenance. If it's a billet camshaft, I'd run some good pressure on it. It won't hurt it.

I just did a 347 for a 7.50 1/8th mile car. It peaked at 6500 as well with a solid roller...236/242 @ .050", .600" lift. I installed 250 seat and 600 open pressure on those heads and used the lightened steel retainers.

Of course the lighter the valvetrain, the more you can get away with on spring pressures. But I have minimums that I use with different cams.

Valve float is not your friend....and if you decide to stay in the gas a little longer before going through the lights, or before braking in a straight, I'd rather not worry about losing control of the valvetrain. It's not fun when that exhaust valve hangs open longer than it should.

[DAVID GAGNARD]

Brent;

The cam card for the Comp cam is the one I've been using for 4 years now...very pleased with it, peak hp was 472 @ 6400prms and torque was around 420 @ 5700 rpms, idles nicely at 900 rpms and if I remember correctly pulled about 12 to 14 inches of vacum @1000 rpms....

I'm building a "new" motor, using the new BOSS 302 block with t he same heads and rotating assy., was planning to go to a more aggresive camshaft, been looking at other solid rollers in the 600 to 625 lift range.....

This is the Lunati Voodo cam I'm currently looking at, not 100% sure I'll get this one, but the specs are in the ballpark for what I want...

I'd have to check my notes, but I think with the setup I have I have enough piston to valve clearance for a max lift of around 675, my springs are good for 725 lift.....I was gonna go with no more than 625 lift just to give some added clearance.......

not having any luck posting cam cards, but here is where you can veiw them........

http://www.lunatipower.com/CamSpecCa...rtNumber=63032

http://www.compcams.com/Cam_Specs/Ca...?csid=830&sb=2

David

[blykins]

David,

My little 347 that I did made 482hp @6500 and 430lb-ft with 10.3:1. The restriction was that the customer couldn't afford a new carb at the time, so we ended up using an old Demon 650 that he had. It wasn't a max effort as he didn't need that much horsepower to run the class he had, but he thought that at some point he would want to run a faster class. I used out of the box AFR 185cc heads and a Super Victor intake. It was a nice little motor.

If you don't have a cam yet, I can help you pick lobes. I rarely order off the shelf cams. But based on where you want the power to be and how often you want to do maintenance, I can help out.

There are some good lobes that make real good power, but they're harder on springs. I like the TK lobes for a solid roller, but they're pretty radical. However, if you want to make the power, they do a good job.

If you're planning on going a little wilder on the cam, I would go with a billet cam and up the spring pressure. If you think you have room, you can shim the spring up a little more, as long as you have good retainer/valve seal clearance and coil bind clearance.

Also, sometimes valve lift will fool you. You may have good piston/valve clearance with this cam, but a larger cam with different valve events may hold the valve open longer in a certain spot and it may get close.

When I assemble, I clay the piston up just to check radial clearances. For depth clearances, I use a dial indicator with checking springs and check it every 5 degrees.

[blykins]

David,

I looked at that Comp cam card. What heads are you using? It seems that you're making up for some milder head flow by using a larger cam.

A 246° @ .050" is a LOT of duration for 331ci...only to peak at 6400 rpm. It's possible that the heads aren't really matched well, or it's possible that you may have been losing control of your valvetrain at higher rpms.

You're also giving up some power by using the Magnum lobes.

Again, if you're cam-shopping, I would be happy to help. I'd just need some information (quite a bit actually) from you to make the best decision.

The 347 that I was referring to used a 236/242 duration camshaft to make 482 hp @ 6500.