MME Racing & Cam Spec

7K with a hydraulic's seems to be pushing it. The valve springs would need to be strong to reduce valve float at the top end. Too much spring pressure and you start to collapse the lifters.

Solid would fair the cycles better. But then trying to lash the valves with 180 headers could end up being a weekend long project.

Run down BJ in town. He was at C&I in Reno, might still be there. He is good with custom ground cams. I know he has build several custom profiles for various rides. He might help with the perfect top-end for your car.

Try CompCams #32-239-4. Solid lifter, 294 advertised duration, 248 @ .050, .605 lift.

It will idle around 1,000 rpm and will seem like it has no rev limit.

A little flat off of idle but it will be at 3000 before you can blink.

It has a very strong mid (3,500rpm and up) and the top end is like a Formula 1.

Solid lifters are easy. Set them once and they are good for 20,000 miles. Come on now. Are you going to put 20,000 on this car?

What are you building it for the Silver State? Perfect!

Julian,
Maybe I can help here?
I have a set of closed chamber heads I picked up from George with the intent of useing a hydralic roller cam!
I have Manley Severe Duty Stainless Valves with Chevrolet Big Block Beehive springs installed,
Some things these offer is less spring pressure, less harmonic's due to the different diameter's of the springs and less weight on the valve due to the keepers etc being a smaller diameter.
I'm looking at the Comp cams CCA-32-651-8
304 DURATION & .612" LIFT, I also have thoughts of running a hydralic lifter cam so I could take advantage of the Rhoads lifter, still trying to decide, I too would like to rev out to 7500 RPM

Mark

Julian & Mark (sick cat),

Crower has a solid roller lifter street grind power range 2500 to 6000 rpm, redline 7500 rpm. 110 degree lobe centers, 234 degrees @ 0.050" intake duration, 244 degrees @ 0.050" exhaust duration, 0.570" intake lift, 0.572" exhaust lift. The lift figures are relatively mild for a roller cam, this is why it has the redline it does, and this is why its a street cam. The part number is #15480.

The difference between a race cam and a street cam is the expected service life of the components. Race cams can only go a few thousand miles before the springs and lifters are trashed. Street cams are expected to go much further.

Mark McKeown has told me he can grind a solid roller cam that "needs no more adjustment than a hydraulic roller". I would imagine he's talking about a cam similar to this one.

Of course this is just a generic cam. Mark can grind a cam that is much more specific to your motor and will work better.

Mark McKeown has reported his web site is down temporarily. His telephone number is: (301) 246-9225. He's in Maryland.

(Hey Mark / sick cat, nice heads. You had the pedestals milled?)

cowboy from hell

Call Jay at Camshaft Innovations. He knows Ford cams better than anyone.

http://www.camshaftinnovations.com/

Aren't aftermarket roller camshafts considered competition componemts? (They sure are)
Aftermarket roller camshafts never had any kind of signifigant durabilaty.

They are heavy and require thicker pushrods and valve spring pressures.
They can also be pretty noisey.

The simplest way is the best way. Solid lifter camshaft.

It wouldn't be a bad idea to use titanium valves
either.

You just can't expect hydraulic lifters to perform well at those rpms. For one thing, you never get 100% lift because of the bleed down.
Rhodes lifters only help a little. They are just rapid bleed down lifters and give you a lot less lift at lower rpms.

With hydraulic lifters you are going to need more oil pressure, and spring pressure. How do you get more oil pressure to the lifters in a Cleveland when you are restricting oil to the lifters for bottom end durabilaty? As you heat up the oil and the pressure drops you get less lift.

I suppose if you ask ten different people about cams you will get ten different answers. Ultimately it is taste, sometimes experience. Bad experiences speak the loudest.

I wouldn't go to MME.

Get in touch with Dan Jones. He can help you spec a hydraulic roller valve train that can tolerate those rpms. My understanding is that the Crane Hydraulic lifters can be run to 7700 rpm.

Also you should look at a Comp Cams Beehive spring set up to increase the rpm potential of your valve train. There are many many articles in the hot rodding magazines such as Car Craft, Popular HotRodiing and Hot Rod about the ability of these springs to extend the rpm range of a hydraulic roller valve train.

Hi George,

Yes I had the rocker pedestals milled & tapped for 3/8' guide plates, Have the roller rockers.
Also had hard seats installed on the exhaust side with cast iron guides. Turned out real nice!
I looked at Crower and I like them but I set up for .625 lift and the only cam so far that I have been able to find that comes close to fitting my #'s is the Comp cams, CCA-32-651-8, very rowdy but streetable with a stroker. 1 down side is the vaccume at idle, but I may fix the brake vaccume problem with a hydro boost unit and use hydralics to assist the brakes.
My valve springs and parts are Isky's, they reduce the parasitic mass that is reciprocating thus allowing less spring pressure, and valve float, Isky say's they can give a special grind that would meet all the criteria's I need. Taking it slow and still open to any other vendors, idea's or grinds.
Rhoads lifter has the abilty to make a rowdy hydralic cam with little vaccume act more like a milder cam at an idle, with vaccume and then go to full lift characteristics at about 3500rpm, with anti pump up, they use to have a cam to go with there lifter's which I have in another rod. these were truely bitchen setups that satisfied mild and wild at the same time.
They don't sell the cam combo's any more so you have to put it together yourself.
Well more to look into!

Mark

I remember a old 302 I had that was fitted with a Crane Fireball camshaft with anti-pumpup lifters. I guess lifters have advanced since those days. That little 302 would go to 7200 RPM's and then the she would just float the valves. I always assumed that was because of the lifters releasing. A good friend of mine had a set of Rhodes in his Mustang. Sounded just like a solid set of lifters going off in her. Im sorry for this moment of memories...you may now go back to the previously interupted post.
Jeff

Julian, I should mention that normally when one runs 48ida's on an IR manifold reverberation of the intake pulses can be a problem.

Normally the treatment for this issue is to reduce the valve overlap as much as you can.

Even a street performance cam is going to be a problem for performance applications.
A street performance cam is normally around 72 degrees of overlap.

There are two cams that I can think of that I have used for the Webers. One is a CamTechniques solid lifter. I didn't like the sound of the exhausts at speed, i.e., the harmonics and it was trashed for that reason.

If you are getting a low rumble from the exhaust at speed, I feel the cam isn't working or the exhaust primaries are to big. My primaries are about right so I felt it was the cam. It should have had more of a GT40 whine/scream.

The second is a Lunati #41106. It is a solid lifter, .520 lift, advertised 290/300, actual 241/251 @ .050, and 30 of overlap.
It idles at around 800.

Neither were ever on the dyno so the butt dyno was the scientific method used.

It certainly falls into you criteria.

You can run a "normal" performance cam with Webers but the risk of carb fire is raised considerably since the more rpm you run then the more raw fuel plume you will blow out of the carb stacks.

I should mention too that open velocity stacks are the only safe way to run the Webers with a cam with a lot of overlap. Air cleaners normally will get soaked by the blow back and thus become fire hazards.

Once you are up an running with the Webers, give the neighborhood a treat. Invite everyone over in the dark and start the car.

Typically the carbs will flame back on cold startup. It is very visable in the dark. It is a little like the fuel dragster blowing flames out of the exhausts except here it is through the carbs.

I just wanted to remind you about this little detail.

George,
I originally started my inquires with Crower Cam's in San Diego, your post had me looking at them again.
I had went on to look at other cam grinders because the cam you pointed out did not have the lift, otherwise all the other requirements were the best suited for the heads,springs, dimensions, useable service from 2500rpm to 6000rpm, and the lifters are quite the setup!
Between your post and trying to find a clean roller setup I ended back up with Crower, Today I talked to Gerry at Crower and ended up with that cam but with a special Grind for a .600" lift! Perfect! Also with the extra lift I gain rpm's, so the Redline moves to 7500rpm plus.
Gerry did say not to use synthetic oil as the Zinc was an issue "ZDDP", Valvoline Racing oil seems to be the oil to use as it keeps coming up. The cost of the set up is approx $350 for the Cam & $550 for the lifter's, not cheap by any standards, but in comparison with other Exotic cars a deal.
One more part of the puzzle in place.
Mark

[QUOTE]Originally posted by Cowboy from Hell:
Julian & Mark (sick cat),

Crower has a solid roller lifter street grind power range 2500 to 6000 rpm, redline 7500 rpm. 110 degree lobe centers, 234 degrees @ 0.050" intake duration, 244 degrees @ 0.050" exhaust duration, 0.570" intake lift, 0.572" exhaust lift. The lift figures are relatively mild for a roller cam, this is why it has the redline it does, and this is why its a street cam. The part number is #15480.

quote:

Normally the treatment for this issue is to reduce the valve overlap as much as you can.

Even a street performance cam is going to be a problem for performance applications.
A street performance cam is normally around 72 degrees of overlap.

Doug,

Educate me please! I understand widening LCA reduces overlap, correct? I think I know how to calculate overlap from duration and LCA, but is it correct to use advertised duration or duration @0.05"?

e.g. I have a cam 274° @0.05" and LCA 105°, so the overlap is 274/2 = 137, 137-105 (LCA) = 32, 32*2 = 64° overlap correct?

What is the optimum then for running the Webers and can I still get a lot of lift from it?

What are the Webers good up to in terms of CFM, i.e. will they substitute for a 1,000CFM Holley and a motor spinning at 7,500 RPM?

Thanks,

I may get this backwards as of this moment but I believe that you add the intake closing point in degrees and the exhaust opening in degrees.
The overlap data I know is the theoretical and therfore the advertised.

Two points here 1)you can only reduce the amount of blowback by reducing the overlap, not eliminate it. I don't think anyone knows the safe number to run. I don't. The special "weber cams" I have seen have 25 to 35 degrees overlap. That is about what a factory cam has in Grandma's stationwagon.

The modern day term for copying what works as a guideline is modelling.
The GT40s and Comp Cobras didn't worry much about this and thus ran steady fuel plumes in competion. They ran open stacks so it reduces the risk of fire to your car and can be like spraying insectacide in the face of the guy on your bumper, so they ran a lot of overlap anyhow.
The GT40s had a plexiglass window over them so the I guess the fire was contained in the car not thrown on the competetors?
2) even if you go to IR FI, I don't know if in actuality you eliminiate the blowback. It is assumed that the fuel plume from the IDA's is because it is a carb with fuel in constant suspension and that the timing of the FI is perfect and the engine takes all of the fuel suspension in the intake port into the chamber.
Like I said, assumed.

I think the reality is that you will still have a percentage of blow back. How much? Beats me. That's why you have to test.

Engine chassis dynos are more common these days. Seems like everyone has one in the basement (I don't).

Looking at Quellas IR FI setups, they all run air cleaners, at least on the street. There aren't a lot of people that I would listen to about this subject. Dennis is.

Most don't even know WTF one is talking about but the fuel blowback isn't anything to mess around with. It soaks the air cleaner elements with fuel and it's only a matter of time before, gaboom.

This situation is absolutely the undeniable part of Webers being a "race" setup. Pay your money and take your chaces.

I saw a few of Inglese' set up catch fire under open track conditions.

Ask Quella for a cam to run with the Webers. It's your best bet.

Oh, somewhere in some Weber publication, each throat of a 48 IDA was stated to be 350 cfm. I presume that varies with the size of the auxiliary ventury which is changeable. If so I don't know if the 350 is for a 45mm or a 37mm, etc.

That nice chart that Holley did so you could pick the cfm of your carb doesn't apply to IR manifolds. Forget about it altogether.

The "desk top dyno's" tend to agree with this flow numbers as being required on an IR manifold. I think Dan Jones has confirmed that.

I have played extensively with the "desk top dyno" and once over .500 the lift doesn't seem to effect the hp or the torque much at all. Whether this is true on the real dyno I don't know.

If it is true then my thought would be to limit lift. A .600 lift cam is going to wear out the valve train a lot faster then a .500.

I suspect that on a Cleveland lift isn't as important as timing events.

Mark and Heather have moved to a new location. Their new web site is just now coming back on line.. http://www.mmeracing.com/ give them a call, 301- 932- 9292

I don't understand why you would want "Beehive" springs. If one breaks say good by to your engine. Beehives are a single spring, no dampener or smaller second spring to hold the valve up. Once the spring breaks the valve drops into the hole. Maybe it's just me but I don't by into all the "new" got to have hype.

Change is constant,
technology is funny, keep up with it or get left behind,
Roller cams for one,
these springs are being used in the new Corvette's with great success!
This new stuff is where all the big Horse Power is coming from on old engine designs.

This change is good,
Mark

quote:

Originally posted by DJEZC:
I wouldn't go to MME.

Get in touch with Dan Jones. He can help you spec a hydraulic roller valve train that can tolerate those rpms. My understanding is that the Crane Hydraulic lifters can be run to 7700 rpm.

Also you should look at a Comp Cams Beehive spring set up to increase the rpm potential of your valve train. There are many many articles in the hot rodding magazines such as Car Craft, Popular HotRodiing and Hot Rod about the ability of these springs to extend the rpm range of a hydraulic roller valve train.

How does one get in touch with Dan Jones? I'd be interested in contacting him about a cam selection. Does anyone have an email address for him? Thank you.

PM him on this board. Sometimes he's always here, sometimes he isn't around for months.

I would think that the tech people at someone like Crane Cams, etc, could do just as well? They do know how to make cams?