[Bruce Meyer]

You all might want to check out The lastest (June 25) edition of the National Dragster. David Reher talks about roller vs. flat tappet. Eye opening article. Here is a quote "For my money, flat tappets belong in the museum, not the racetrack."

[Steve C.]

6800 RPM with hyd roller lifters is impressive! Two years ago the magazines were touting that they were somewhat of a work in progress with premature valve float still an ongoing problem. The roller foot combined with the hyd mechanism makes for a hefty overall assy.
It's been a few years but when I spoke with Crane tech on the subject they left me with the impression they wern't too keen on applications way above 6000 RPM. They didn't say they wouldn't go there, just really implied a big concern.
I still think this is a good potential application for the Comp "Beehive" valve springs. Higher RPM with less spring, means more power and reliability. David Vizzards experiance to date indicates that they will run a typical street roller valve train to 2-300 rpm more while the seat load drops from 145 to 130 lbs. and over the nose from 345 to 310 lbs.

[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").

[69Goat1]

What is Hydralic? Is that some kind of fancy Arkansawyer spelling for Hydraulic

LOL - Just kidding

[PONTIAC DUDE]

If I understand your question right. Here ya go.
From what I have seen so far with my installs,research,etc. The hydraulic roller will have a flater power and torque curve with longer stroke engines. Especially in the mid range where most of the power ends up after your shift. Engine Dyno #'s for a motor might not show the E.T. difference........ for the gain.
Rhoades lifter is another ballgame. I call them the Pre-hyd roller set up. LOL.
Sorta a controlled variable cam deal to increase bottom end with a cam that is to big for certain combinations and the other parts used. Trying to give a cam street drivability, low end torque. Which is the purpose of the aftermarket competition hyd roller grinds.
Money spend is the issue currently being debated for the power gain.
I just had an e-mail conversation with a dude that had a milder combo worked out and wanted my opinion on the upgrade but keep the same cararcteristics. I told him he had his combo right on the money and for the money spent for the gain...stay with what he had. I guess he didn't like my answer. Wanted to go to a hyd roller and felt i would offer a cam that might or might fit his bill. Didn't want to say that changing cams along the same lines would be the best bang for the buck. Same deal here. Yes you will see a gain over a regular hyd cam if it get more agressive. Changing a regular hyd cam to 1.65 might give you the advantage, but would have to check the figures at .100 and thru the lift range.
If your starting from scratch and want a Street deal with more power and better pulling capability, then I like the hyd roller. If money is not the issue. And they have their limits as to ramp speed, etc. same as the hyd lifter. And the solid has it's limits.
It all depends on the application.

The engine your using. Compared to Rhoads and the solid lifter noise the customer has to live with and don't want when I talk to them. I'd recommend the hyd roller. Remember they are a compromise deal. No break-in deal. Work the same rpm range as a hyd cam. more power under the curve with a greater ramp speed.
Compared to a Rhoads lifter bigger cam and a higher ratio then the hyd roller? Then I would say the hyd cam would make more useable power throughout the entire range. And give almost the same idle and power deal
Did I miss anything or your point?

[PONTIAC DUDE]

Ok, I'll try. And this isn't gospel according to Luke. LOL.
Just observations and the results I have found in my personal Test car, customers comparing, etc. Still have more testing to do.

Will be tearing my IA engine apart this weekend to address some sealing issues. Ok Marty your turn. LOL.
However, have 40 passes since last done.

Peak would probably show the same #'s. lift is lift. Total duration is total duration. That's a given. However, given the newer unsymmetrical profile might not show a difference over a Hyd roller. A sorta loaded question that most people won't have those profile cams available too. Haven't looked at or tried their cams to make a comparison. The unsymmetrical cam is a totally different deal and depending on the aggressive ramps is hard on valve train components compared to a Hyd roller. That's the purpose of a hydraulic roller. To save cam wear/break-in and still make big power for the street. Not race. And I know you know that a basic Hyd cam compared to a Hyd roller won't make the same power.
But if you can bring on the early lift figures on quicker with a better flowing head, you have to see a hp increase in the upper low to mid rpm range. The Rhoades lifters work the opposite scenario. They take a bigger cam and tame it to run at lower rpms. So the same Hyd cam with stock lifters will not show as high an average figure.
Same deal as the flow figures for heads. I'm more concerned about mid then total figures. Companies are always bringing out new profiles and designs. Look at UltrDyna and the person that develop the unsymmetrical cam.

Third Question:
I don't see an issue with stock lifters and 6200/6600 rpm. It's the springs. The Rhoades are an advantage with that duration cam.
Like I said in the above post, I have had my current Comp Cam Hyd roller to 6800 at the track and even 7000 on the chassis dyno, the power just fell off with my heads and combo that's all. I run a 140 seat with 380 open. Sorta like a competition solid lifter/hydraulic cam spring. Anything over that that the plunger will fail.

[Steve C.]

Can you hear it ? Listen close. The Classical Pontiac ghosts are stiring and starting to moan and grown.... can you hear them over there ?
Ohhhhh, ohhhhh... "Don't waste your money"..... Ooooh... doooon't waste your money.

[PONTIAC DUDE]

How many people have wiped out hyd or solid cams and the damage sustained. I have read more about people wiping hyd cams on the PY forums in the last 2 years then I have seen in 35 years dealing with Chevy and Fords.

Most solid roller lifter deals with wiped rollers is due to the excessive pressures needed for high rpm and making hp. Or people not keeping a check on the increased lifter adjustemnt needed and then realizing that something must be happening.
This isn't the issue with a hyd roller to which this topic is about.

No high rpm break-in required.
I can change cams and use the <span class="ev_code_RED">Same</span> lifters over and over.

[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.

[PONTIAC DUDE]

Jim this could turn into a heavy discussion without actually going anywhere, LOL. Yes, peak can remain the same with either cam. However, from the chassis dyno pulls I have run, I see more mid to lower rpm hp #'s. And as we know peak isn't always where it's at. Same applies to heads and everyone wanted to know the peak flow #'s.
I would like to have the additional hp right where my rpm falls when I shift to pick it up.

Give me a set of heads with 10/15 cfm less peak and 15/20 more bottom and mid and I'll beat ya. LOL.

Question about those unsymmetrical Hyd cams? Wouldn't they be harder on the plunger/lifter? more so then a Hyd roller ramp with the roller absorbing the load on the quick dropping ramp with the right spring.
I would think you have more of a chance of spring bounce with a Hyd unsymmetrical cam over a Hyd roller with the same design.

Personally, I had a same design 068 cam made in a Hyd roller, but sold it as I went on to another project, so I can't tell ya. However, the dude in Hawaii might be able to give some info. Comparing specs, the quicker acceleration rate should have been worth a tenth or two. But then again speculation.

[al]

This is so ridiculous. Everyone knows that all you need to run fast is a wolverine cam,cast iron intake with a q-jet and a 4400 lb car

[69Goat1]

I really like the XE284H in my car and there is absolutely no cam/lifter noise under the hood. The car has over 170 drag strip passes on it and is like a Timex

I have heard all the CC XE horror stories but they seem unfounded as every comp cam I have used has turned out good as well as every one used by the Machine shops in our area...

[slowbird]

The hyd. roller that I was refering to idle with about 11 to 12 inch of vacuum in my 462. It has 242-252 dur. @.050. Its a very streetable cam. A friend of mine has the xe284 cam thats about the same duration @.050, it does have more lope than ours, not sure what his vacuum is though (all have to find out). To me the main advantage is the amount of lift that you can run compare to the duration, our is .594. It all about what you want and how much you want to spend. I personally would take a hyd. roller over a solid flat tappet any day if its a 455 or larger(if cost were equal). If its a 400 then go solid or solid roller so you can turn the rpms up.

[Junkyard Dog]

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

[77TA]

I ran a xe274 cam for a couple years no problems with it FWIW 12.70@108 and 20 mpg. I had some lifter noise but I think it may have been the cheap summit lifters I was running. Cam looked like new when it was removed for a custom ground Comp cam with a little more duration 236 vrs 230 intake @.050 and 244 vs 236 exh and a little more lift as well as a 112 lobe center. I also swaped to Summit boxed E-heads and single plane intake, bigger headers etc...
the car runs ok after fixing some fuel system problems that were probably holding the previous combo up too.

I guess its all clear as mud really. I wonder if the advantage of the hydraulic roller is not fully realized in our engines due to the poor head design ? I was thinking about this. the hyd roller once it starts to open the intake really yanks the valve open I wonder if the bowl volume and port shapes are able to feed this sudden draw as effectively as some other makes. Ive read some cam articals where they were very concerned about this yank effect on the port and the design of the lobe in relation to proper velocity. Its kinda over my head a bit maybe but maybe this is another variable to look at. I read something on a chevy thread about the under valve volume needing to be a certain volume to satisfy this intial draw on the port before flow through the entire port was established. Maybe pontiacs respond to a slower opening valve due to port shape better than a fast ramp or maybe its just the fast ramp does not show as much of an advantage on a pontiac. I'm just thinking out loud here.