Hydraulic cam with solid roller lifters?

[doogievlg]

The engine builder I used installed solid rollers on a hydraulic roller cam. I’ve done some digging on the forum and realized this is not unheard of. Where I am a bit lost is where to set the lash cold before getting it dialed in. Some details below:

360 .30 over
Edlebrock aluminum heads
273 rocker arms

 

[George Jets]

Hydraulic cams have a taper on the cam lobes so that they will spin the lifters to keep them from wearing out prematurely.

Roller lifters have a wheel that needs to be locked in position so the wheel runs straight on the camshaft, preferably a roller camshaft that does not have the taper on the cam lobes so that the wheel will run straight.

One other thought, it is better to use hydraulic roller lifters with the roller camshafts to maintain constant contact with the roller wheel and the cam lobes.


☆☆☆☆☆

 

[doogievlg]

Hydraulic cams have a taper on the cam lobes so that they will spin the lifters to keep them from wearing out prematurely.

Roller lifters have a wheel that needs to be locked in position so the wheel runs straight on the camshaft, preferably a roller camshaft that does not have the taper on the cam lobes so that the wheel will run straight.

One other thought, it is better to use hydraulic roller lifters with the roller camshafts to maintain constant contact with the roller wheel and the cam lobes.


☆☆☆☆☆

Lifters are locked into place. I could see the issue of running hydraulic lifters on a solid grind cam but it seems a bit better to be vice versa.

 

[RustyRatRod]

You can run solid rollers on a hydraulic roller cam, but they have to be tight lashed. Like .004-.006 hot. I'd trend toward .004.

 

[doogievlg]

You can run solid rollers on a hydraulic roller cam, but they have to be tight lashed. Like .004-.006 hot. I'd trend toward .004.

Any ideas on where to start cold? Obviously the builder did it before the dyno runs and I’ve been running it for a couple years now. Don’t hear any excessive noise but figured it would be good to get this sorted out so I can check it more often.

 

[RustyRatRod]

@

Any ideas on where to start cold? Obviously the builder did it before the dyno runs and I’ve been running it for a couple years now. Don’t hear any excessive noise but figured it would be good to get this sorted out so I can check it more often.

@Newbomb Turk is really good at this. I tagged him so maybe he'll chime in.

 

[Newbomb Turk]

If you have aluminum heads you can do .004 cold. If it’s summer you can do it as tight as .002, BUT as soon as it starts cooing off that will be too tight and it will hold some valves open on start up.

For the most part, .004 is where to set the cold unless you are anal like I am and you don’t mind setting the valves on the regular.

 

[RustyRatRod]

If you have aluminum heads you can do .004 cold. If it’s summer you can do it as tight as .002, BUT as soon as it starts cooing off that will be too tight and it will hold some valves open on start up.

For the most part, .004 is where to set the cold unless you are anal like I am and you don’t mind setting the valves on the regular.

I heard you like anal.

 

[Newbomb Turk]

I heard you like anal.

You know my wife lies like a rug. You can’t believe a word she says.

 

[crackedback]

I heard you like anal.

You pegged that one.

Yeah on the .004 or so.

 

[RustyRatRod]

You pegged that one.

Yeah on the .004 or so.

 

[doogievlg]

Thanks fellas

 

[GGress]

Yeah, I know, older thread, but I'm curious what you have to run for valve springs with solids on a hyd. roller cam?

 

[MOPAROFFICIAL]

/\Lighter than a solid roller...

 

[GGress]

But then the question becomes why? Less aggressive closing ramps?

 

[MOPAROFFICIAL]

But then the question becomes why? Less aggressive closing ramps?

Still better than a flat tappet,power n driveability

 

[GGress]

Still better than a flat tappet,power n driveability

Actually, I was wondering why it took less spring pressure, I'd like to try it!

 

[PRH]

If using SR lifters on a HR cam, you could run similar spring pressure with SR lifters as the cam grinder suggests for the HR lifters.
Which is generally considerably less than what is “typical” for an actual SR profile.

The HR profiles are designed to be smoother so as not to upset the hydraulic function of the internals, and to stave off the onset of lifter collapse at higher rpm.

Also, SR lifters are typically lighter than the HR lifters, so in theory…….. the same spring pressures would allow the valvetrain to go a bit higher before getting out of control with the lighter lifters.

 

[GGress]

Thanks, good explanation.

 

[33IMP]

/\Lighter than a solid roller...

Agree, but a bit more than hydraulics on a hydraulic roller. Imo, the idea is to get more stable at the top of the range, so a bit more than the hydraulic/hydraulic conbo would use.
Depending on the quality of the hydraulic roller lifter, Brule has said he's seen 30 hp at peak after a solid swap.

 

[PRH]

Personally, I can’t see myself intentionally building an engine around that idea.
Fundamentally I don’t care for the idea of adding clearance(lash) where there isn’t supposed to be any.

I understand it as kind of a band-aid to get away from a set of troublesome HR lifters.

“If” I found myself going down that path, I would add some spring pressure to give the combo some extra rpm headroom, since the hydraulics(and their shortcomings) have been removed from the equation.

 

[MOPAROFFICIAL]

Actually, I was wondering why it took less spring pressure, I'd like to try it!

Less aggressive ramp speed.

 

[MOPAROFFICIAL]

Personally, I can’t see myself intentionally building an engine around that idea.
Fundamentally I don’t care for the idea of adding clearance(lash) where there isn’t supposed to be any.

I understand it as kind of a band-aid to get away from a set of troublesome HR lifters.

“If” I found myself going down that path, I would add some spring pressure to give the combo some extra rpm headroom, since the hydraulics(and their shortcomings) have been removed from the equation.

Once you change the lifter like that..thats exactly what you need to do, up the spring psi. Typically 200-225 and 450-490 open to a point of lift of course.. but the idea is less aggressive hydraulic roller profile=less spring but no more hydraulic taking up the slack... so more than hyd psi but less than full blown solid roller. ..AkAka street solid roller. I like them for longevity per less dollar spent.
Not the best but a close 2nd.

 

[MOPAROFFICIAL]

Agree, but a bit more than hydraulics on a hydraulic roller. Imo, the idea is to get more stable at the top of the range, so a bit more than the hydraulic/hydraulic conbo would use.
Depending on the quality of the hydraulic roller lifter, Brule has said he's seen 30 hp at peak after a solid swap.

That what i was saying...

Example -You would use a spring like a k800
220 seat/480 open for around .580 lift