[Jim Hand]

Dude,
Right On! I also will trade high lift flow for mid lift flow. And high RPM HP for mid range power. That is why I run conservative cams, small ports and great low and mid lift flow heads. And the proof is always in the results when the tires meet the drag strip!

Yes, I feel the same about the doctored up "modern" lobes. And that may be why the CC XE series has more noise and reliability problems.

Jim Hand

[PONTIAC DUDE]

Yes Jim, I'll agree on the noise with the XE series. A trade off for power that has to be explained to the customer. Same as when they want to run Rhoades lifters. Or a solid on the street.
Reliability problems? .......... none to date and have installed over 100 or so.
I hear other war stories, but have seen it also with regular street performance cams and others. Therefore, I take it with a grain of salt. LOL.

And your reasoning behind the dislike of the XE series? Curious.
You seem to like this Bullit cam with the unsymmetrical lobes? And noisy Rhoades lifters?
Or am I mis-reading it.
I'm always takin notes.

[Jim Hand]

Dude,
I like the great array of cam lobes (both duration and style) Bullit offers. It would be very easy to select exactly the cam anyone wishes to have built.

I believe the CC EE cams also have non symmetrical lobe design. That is the difference between the EE series and the older styles they offer. Yes, we have seen EE cams fail after proper break-in and use. CC made them good by replacing cam and lifters.

I like to have full control of my engine at all times, especially when staging at the track. So I use Rhoads to provide that increased vacuum and low end power. I can literally set the stage RPM to within 25 RPM to stage exactly where I want. And the car launches exactly the same each time. And they make normal street driving much easier and smoother. And the reasl bonus is that I can shift at any RPM for test purposes without any concern for lifter pump-up, as well as adding power through idle to 3000 RPM.

Jim Hand

[Steve C.]

http://www.bulletcams.com
As Jim noted they will do all types of grinds, including both symmrtrical and assymmetrical lobes.
Bud Lyons- your improvement in performence was a nice one. Did you make any other changes besides the cam and headers? And with about 10 degrees more duration added-in how was the driveability effected if any?
Thanks.

[Lloyd-TX]

I agree 100% with Jim H. on Bullet Cams. I had never heard of them, but my cylinder head porter picked a solid flat-tappet grind from their master lobe list because he likes their lobe designs and the fact they'll grind a cam any way you want.

On my 7F6 headed 467, he went with the following lobes, and had it ground on a 108 LSA and the intake lobe centerline @ 105 ATDC.

Lobe #: Adv @.050 @.200 lift lash type
I F262/327 262 232 144 .327" .016" CTA

E F265/333 265 235 145 .333" .012" CTA

Running 1.65 HS (1.72?) rockers my net valve lift is around .535" intake and .552" exhaust.

The engine idles so well @ 750 RPM in gear it's difficult to hear the lope at times. Made 530 CBTQ at as low as we could measure on the dyno - 3000 RPM. With an admittedly worn out stock suspension on my blue Formula and running a 3.08 gear it's tough to obtain consistent 60' times even after a long burnout due to the HEAPS of low end torque. My only reservation is that since the engine as installed runs out of breath at about 5500 RPM, I'm thinking we should have picked slightly longer duration lobes.

I've decided that once I test Tom Hand's other FullBore prototype crossflow muffler that I'll go to a pair of Ultra Flows and see how badly it it's being restricted by my current system. I'll wager some 12.50's @ 110!

Current perf in sig below.

[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...

[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

[critter]

No, what you need is education and track time. Sharing knowledge, learning from track experience and building on the mistakes, your own and others, is how we build our abilities and our speed.

I don't think you meant anything by your comments, al, just telling everyone that I'm enjoying this thread and the different viewpoints.

[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.

[Bud Lyons]

Steve, I had the heads cut .040 to give me about 10.25 to 1. Thats it. I already had the heads ported and the intake gasket matched. I have no idea what the heads flow. Half-Inch Stud ported them for me. We do know there are no restrictions in the runners. Proved that with a home made flow test. Vaccum and spray paint. This is in my 79 Sunbird drag car. Idle or floored, not much in-between.

[critter]

So I'll prove my ignorance and get in on this.

Everyone seems to agree that it's all about the low lift numbers on a traditional Pontiac head. If that's the case, it would seem that the roller profiles would be a perfect match for our application. The fast ramps would immediately bring the valve off the seat and allow that flow to be realized at a much quicker rate. Lifts could be kept to a minimum based of the upper end flow capabilities of the head in question, right?

[PONTIAC DUDE]

Critter, I agree. That's the reason 1.65 rockers were used back in the day when cam profiles were weak and computers weren't available to set up programs with cam designs.
Yesterdays cam grinds are todays RV and truck towing profiles. LOL.
Springs have also contributed to better cam profiles.

Example: Put a 1.6 rocker on an RV style cam for a 350 chevy and 9 times out of 10 it will slow down. Why the heads, etc flow with the grind and combo.
Put a 1.65 rocker on the Pontiac and it usually picks up........ why the port profile is weak and can use the help. faster ramps allow more charge into the chamber. I have stated this before 15 years ago. There is no bowl to hold the next charge, so ya fake the head into believing it's bigger then it is.

I like the Comp XE cams with the faster ramps and still use the 1.5 rocker as the lift is built right in.
Yes, I like 'some' of the hyd roller profiles.
I got one in my 76 500cu.in IA motor and works great. Sorta a good compromise between a roller and a hyd cam. I'm making the same power at a lot lower rpm then I did with a huge solid roller.
Why do you think hyd roller cams came about?
I remember when they first hit the market, a lot of weak RV type of grinds for daily useage. period. Times change and so do cams.
Are they for everyone. No.
If you pick up 1 to 2 tenths would you spend the difference for the upgrade....... your call.
What's is reasonable to spend for one is expensive to another for the gain. That's just the way it is.

And with the limited profiles available in a hyd roller, there isn't always a good choice.

Application and what ya want, determine if it's the right choice in cams.

Trying to compare a hyd roller to a hyd cam with Rhoades lifters and 1.65 rockers can't be done. To different theories.
But is a hyd roller stronger then a basic hyd cam with the same duration, C.L. and L.S. I feel Yes.

[Junkyard Dog]

Is there a downside to using 1.65 rockers with modern, high-lift cams if you run Edelbrock heads?

[77TA]

"Trying to compare a hyd roller to a hyd cam with Rhoades lifters and 1.65 rockers can't be done. To different theories.
But is a hyd roller stronger then a basic hyd cam with the same duration, C.L. and L.S. I feel Yes. "

WHy can't it be done ?
I realize the theory is different but bottom line ET/MPH at the track it seems you could or dyno test them. THey both are trying to accomplish the same thing and do to a degree. I guess a wider stronger power band. Why not take a hyd cam like a 041 with rhoades and compare it to like a XR288 Comp hyd roller both are in a few degrees at .050. ID like to see some test data not opinion, has anyone done something like this. I think until the test is done the question will remain. Good discussion by all. I also wonder can you get to much valve velocity for our engine ? Say use a 1.65 rocker on a hyd roller like the XR288 that would push the lift to about .610 with only 236 @.050 duration. Is this too fast even for a E-head topped motor even if th eheads were ported ?
I have a buddy with that combo.
Its kinda like some have said E-heads were bad for a street engine, but never actaully ran them but basing the commments on flowbench and theory. Sometimes a actual physical test in the real world is required to get to the bottom line.

[PONTIAC DUDE]

Why use a 041?
Why not compare milder grinds?
Why not a 068 with Rhoades and a simialr cam in a hyd roller. They aren't made for that application. Even Rhoades will tell you that.

The purpose of the Rhoades it to tame a wilder cam on the botton end but allow it to act like the 240 duration or so in the upper rpm range.

If you want the solid lifter type noise?

[77TA]

No reason just picked the 041 out of the air as its so widely used. I guess what I am asking is if I am running a 236/244 flat hydralic magnum profile lobes from comp cams lift with 1.65 is about .580. If I went to a XR288 from comp cams very simlar duration number 236/242 with about the same lift I think .600 with 1.65's would I see any improvements ? would it be a tenth or more ???

Has anyone did a dyno or track comparasons of any Hyd Cams to Hyd Rollers of similar durations in a Pontiac engine ?????
Just looking for hard Data here is all.

[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."

[slowbird]

Anyway you can post that article?

[Bruce Meyer]

Sorry I cant. I dont have a scanner.

[David Holmberg]

Come on Bruce, just type it all out...