[PONTIAC DUDE]

If you go to my website and look under Readers rides there is a 500 cu.in. Monti Carlo. Roller cam that has logged over 40,00 miles and run 11.60's on motor, 10.40's on Nitrous. This car weighs 3800lbs, has air and driven daily. It is well know on the West Coast of Florida and is driven 2 hrs to the track and home. Finally building hi a new ATI combo as after 5 years he wanted to retire it before the bottom end let go. This car had over 250 passes on it. Incuding a B & M blower for 6 months.
This was a solid roller.
Actual information that is available to anyone out there.
I have been running roller cams since the late 70's with no failures. Quite a few engine in that time too. Guess I'm lucky?

Current combo has a hyd roller as I felt I could make more power with a flatter power curve....... for the street . With more durability over a longer period of time. Ask Dave to post the hp Chassis dyno results. Figures to over 625hp with a hyd roller cam on pump gas? And no radical head porting either. 310/315 cfm 89 cc E-heads.
As time goes on people will see the advantages of the hyd roller.......but you might have to leave this Pontiac forum and check in the outside other world. LOL.

[Larry Navarro]

Congrats!!
I drive my 3875 lb. car "daily" and it runs 11.94@119, solid flat tappet of course.

[Bruce Meyer]

Larry-So your saying that you know more than David Reher??!! You must be a engine building god. You know lately Anderson has been dominating pro stock. Maybe some of the other teams will hire you to build thier motors so they can compete.

[Larry Navarro]

Oh yeah sure Bruce.....
I can't have an opinion, nor can I have personal experience?
I said I was an engine building god?! BWAAAAHAAAAA
But we all must heed Reher's opinions since he is a "god"?
Oh my gosh....I'll run right out an buy a roller setup so i can be one of his "apostles" too!!
Please, forgive me Bruce?

[Doug Christie]

This topic is getting "Religious". I'm sorry, but this topic is now "Locked".

[critter]

Well this got totally out of hand.

The original question was, given lobe profiles of similar specs (duration, lift and profile) which would make more power. There seems to be no definitive answer because no one has actually done any quantatative testing. Dyno numbers are good, track numbers are better. We have neither. Guess we'll wait until someone does it.

I also think we'd all be tilting windmills unless this was a test done on the same platform with nothing but a cam/lifter change and all other variables remaining the same. That would be a tough one to pull off in one day at the track.

[Steve C.]

The idea of testing a hyd flat tappet and a hyd roller with the same intake duration at .050-inch would be costly and one would have to ask why. If your going to upgrade to a roller most would add additional duration with a roller cam anyway, silly not to.

Example, toss the "041" or Comp XE274H flat tappet and move up to a hyd roller like a XE288HR or maybe the XE293HR.

I found this interesting...

"Cam companies are working hard to produce more and more streetable solid roller cam combinations because the tappet manufactures are slowly reducing production of flat tappets to the point of possible extention in another decade. By then, it'll be almost impossible to find a flat tappet cam. In fact, the only real reason flat tappet cams have lasted as long as they have is because of cost. They're much cheaper to run than any roller cam. But, just as the costs of our rides has increased by a factor of at least 10 in the last 30 years, so will the cost of building engines. Luckily, the aftermarket knows the value of affordable parts and is constantly looking at new sources for roller cam blanks and roller tappets that will be cheaper and more reliable on the street."
From the article "Rolling for Power"
June '04 PHR magazine

[77TA]

I just figured that one of the engine builders that come here that has a in house dyno may have at some point dynoed two cams one rolelr the other not of the same duration and would have this information. I agree with your logic though steve as in wondering why anyone would just go to the same duration in a differnt lifter type.

[Skip Fix]

A Dyno test migh be a time consuming thing. When racing NMCA Top Stock with a RAIV 400 in my TA I had 4 different cams and one at two different intake centerlines.From a 288/296 on a 108 lobe sep to a 304/312 on a 112 lobe sep, to a solid 288/292 on a 110. All the cams ran the the 100th of a second the same!

The problem with the combo was the large headers and running mufflers and the RAIV exhaust ports(85% intake flow.It took using smaller headers (1 3/4 vs 2") before the car improved.

So optimizing the combination may take some time to get a true comparison with just a cam change.

[Steve C.]

Interesting timing... I mentioned Comp Beehive springs in my post above. The new Hot Rod magazine has a bit about them.
Here is a passage from the material:
"Going a step further by comparing these springs with a set of high-performance hydraulic-roller lifters from Comp could easily produce a hydraulic-roller combo capable of pulling into the once unheard-of 7,500 rpm range."

[Junkyard Dog]

I don't believe anybody is making the beehive spring for Pontiacs, are they?

[Steve C.]

They are made in at least 3 and maybe 4 different sizes. Hopefully one of these will fit the cylinder head configuration with no or minimum modifications.
The article was using the cc26918 Beehive spring as an example, that's the sbc size with 1.290 O.D. and 140 seat pressure at 1.800" insalled height (I have also seen it listed 130 @ 1.800").

[Steve C.]

Yet another test of the Beehive valvespring...
In the new Sept'04 Hot Rod.

They used the 1.445-inch diameter Beehive at 1.850-inch installed height. It reduced the seat pressure from 210 to 160, open pressure from 405 to 360. Testing was done on a hydraulic-roller cam.
The RPM at valve float increased from 5,800 to 6,600-plus RPM.

[Junkyard Dog]

I read that. Does Comp recommend any of these for use with mechanical rollers yet?

I think they also needed to use a retainer to locate the spring in the pocket (because it was so much smaller in diameter).

[Steve C.]

JYD- I'd call Tim Cole at Comp and discuss it with him. I believe he is involved with the Beehive springs, if not he can refer you.

Seat pressures are determined by valve/retainer weight, engine RPM and life expectancy of the components before replacement is required. I have seen it written milder solid roller cams require 165 pounds on the seat as an absolute minimum. But 180-200 is most common for most modest performance applications.
Just remember much depends on the weight of the valvetrain parts involved. I suspect the typical Pontiac 2.110 valve might not be as heavy as some of the reccommended valve spring pressures in some catalogs might suggest. But that's opinion.