Here's a new one on me. I've a somewhat mild solid roller cam for my 496 I planned on installing; 0.642 lift / 242 dur @0.050. I've since decided to go with a hydraulic roller of similar grind. I called the manufacturer, Doug Herbert, about an exchange - they have the same grind in a hydraulic roller version. I was told no problem, I could just use my hydraulic roller lifters with the solid lifter cam.

Now, I don't have much experience with roller cams, but this sounds fishy to me.

Opinions?

 

You should use roller cams with roller lifters. The lobe design is totally different between cams.

 

It's all about spring pressure, if your solid roller springs aren't too stiff then you can go ahead. Compare the recommended spring pressures for the two cams

 

I understand that; I guess I wasn't clear. Hydraulic roller lifters on solid roller cam.

 

A lot of the "Boat People" (Performance "Boat people" that is) run the hydraulic roller cam w/ the solid roller lifters....But you're talking a completely different application for their logic. You should be alright- the lift is not to radical-and like Motor head said check out the spring pressures.

Whose lifters are you going to be running? Crane?

Richard

 

It works OK. The typical solid roller design has lash ramps to gradually take up clearance. Running the hyd lifter on it will work...BUT.....

Why would you do this? Two things are going to happen. First...the street manners of the hyd lifter on the solid roller cam...or on a similar hyd roller cam are going to be worse. The effective seat to seat..or advertised durtion will be a lot more with the hyd lifter and no lash. So we're going to have a much lumpier idle (which in reality on a 240'ish cam in a 496 will still be pretty tame) and less low speed power and manners.

Next, you just took a cam arrangement that can make really good rpm and power into the 6500+ rpm range. With solids you won't be floating the valves way early and now we've killed the one thing it can do well.

This stuff is all a compromise. If you are willing to keep RPM down and never want to worry about valves...then I suppose a hyd roller makes sense. But to get them to rev at all you will need some good spring pressure and now you're right back to the wear issues of the solid roller and still don't get the performance.


BTW,,,not sure what RPM range you're looking at...but a 242* cam is going to peak pretty early in a 496. The 244* one I had in my 427 peaked at 5850 rpm on the dyno.

JIM

 

Recently, a fellow CF member had problems (total failure) with street sbc hyd roller Doug Herbert brand from DH in NC. At no charge DH had a replacement shipped from Chet Herbert in CA.

Note: DH cam advertized as 8620 steel ... both delivered cams both DH & CH were NOT ... both were cast. I dunno what's the problem, even the cast should've held up just fine w/ mild hyd rlr springs.

DH offered no expanation ... not why the failure ... nor why advertizing billet while shipping cast. Another brand altogether (true billet steel) was installed in lieu of any DH/CH ... so far so good ... DH/CH shelved. This not my motor but I'm disappointed in & shy of DH.

 

Mild solid roller cams have milder ramp rates. So in actuality cam manufactures sell the exact same cam as both HR and Solid Roller. But in the cam list the H-roller will be given a slightly bigger .050 number because the h-roller has "ZERO" lash to take up before the valve starts lifting.

Using a HR cam on a mild solid would actually give you a performance gain if you motor required a little faster lift and a couple of more degrees of duration.

 

Jackson- Take another look at Doug herberts web site. all the solid
roller cams at the top in bold black lettering it says 8620 steel.
but under hydraulic roller cams there is no mention of 8620 steel.

 

Herbert told me personally they're the same cam if it's same grind # ... long ago I had a discussion w/ Herbert ... similar to above hyd:sld interchange. Also ...can't find my old herbert catalog ... seems like it showed 8620 no matter hyd/sld

moreover, I inquired of herbert about the specific hyd rlr cam the guy I mentioned was planning for ... herbert told me it was 8620 ... he rec'd cast ... that simple. Even though it was not my fault, I still feel crappy because what I told this fellow turned ou to be wrong ... everytime I think of herbert I think of this fellow's loss & that I'd recommended herbert's steel roller.

 

That is bad to recomend something and it not be what he told you it was. I just looked up there advertising on there web site. I have been thinking about doug herberts cams price is sure nice but now you have me wondering if thats such a good Idea.

 

Comp Cams Pro Magnum Series: 887X-16

 

I'm not a cam expert by any means, but I thought that the ramps on a solid roller were usually more aggressive than a hydraulic roller...as far as materials go, it should work ok, but unless the grind is exactly the same I don't think it would be optimal. I was told that the billet hydraulic roller I am using could be used with solid roller lifters (its a Gallant Technical Performance custom grind, not sure who does their grinding), because the ramps are less agressive.