Hello everyone,
I need some advice about choosing a cam for my car. I have narrowed my selection to two Comp Cams Xtreme Energy Hydraulic Flat Tappet Camshafts.

Cam Grind # XE262H

Operating Range: 1400-5600 rpm

DURATION Valve Lift ( 1.73 Rocker) Lobe
Advertised @.050”
Intake : 262 218 0.513 110 deg
Exhaust : 270 224 0.520



Cam Grind # XE 274H

Operating range: 2000-6000 rpm

DURATION Valve Lift ( w 1.73 Rocker ) Lobe
Advertised @.050”
Intake: 274 230 0.562 110 degree
Exhaust: 286 236 0.565


Which of the above is a better camshaft for every day stop & go street driving at moderate rpms. I don’t track the car at all but, I do get into stop light drag race once in a while and, I want a noticeable idle. I don’t know much about the internals of the motor. It runs very strong with no smoke but has lifter noise. It has an aftermarket cam with a noticeable idle. I run a Holley 650 DP, Mind train headers & mufflers and 4.22:1 final drive. Any advice is highly appreciated.
Thanks
Shah
Original Post
I have always been in favor of the small incremental improvements in camshaft lobe grinding technology that have occurred over the last several decades. Higher lift for a given amount of duration equals more power with a 351C 4V. I thought the fast ramp rate of the lobes employed for the Comp extreme energy cams or Lunati voodoo cams were a cool way to use tighter lobe separation without incurring excessive overlap (overlap quickly diminishes the drivability of a 351C with 4V heads). True, there was less overlap for a given amount of lobe separation, but due to the lobes' short ramps (smaller hydraulic intensity numbers) it doesn't take as much overlap before the cam starts inhibiting the drivability of the motor. So there really is nothing to be gained in using such camshaft lobes.

There are several drawbacks however. The lobes are too aggressive for a flat tappet hydraulic cam; they increase the likelihood of developing hydraulic lifter problems, they increase the likelihood of developing valve train instability problems, and they will float the intake valve at lower rpm. Camshafts employing those lobes open the exhaust valves too late, putting a greater emphasis on the requirement for a low back pressure exhaust system, otherwise the motor's power band will flatten-out too early at upper rpm. In general the XE & VooDoo cams do not rev as high as the manufacturers claim. The lobe separation angles are generally too narrow for a motor equipped with 4V heads too.

So I stopped liking (or recommending) the Comp extreme energy cams or Lunati voodoo cams a few years ago and went back to what I know works. A cam with 112° to 114° lobe separation and about 60° of overlap (based on advertised duration) will give you the combination of drivability and lopey idle you're seeking. 112° lobe separation with 4V heads is equivalent to 108° lobe separation with a small valve motor. Look for a cam that opens the exhaust valve around 80° BBDC and closes the intake valve around 70° ABDC. The intake valve should close no later than 40° ABDC based on duration at 0.050".

Other criteria useful in judging street cams: the overlap based on advertised duration should not exceed the hydraulic intensity of the lobes; and centering the overlap period around top dead center is beneficial, especially with big valve (4V) heads.

These days the off-the-shelf cam I recommend most often for a motor with 4V heads is the Crane Cams Grind no. H-278-2 (part number 523801).
--------------------------------
278°/290° advertised duration
222°/234° duration at 0.050"
0.539"/0.534" theoretical valve lift
114° lobe separation angle
Hydraulic intensity 56°/56°
---------------------------------
Exhaust valve opening = 80° BBDC
Intake valve opening = 26° BTDC
56° overlap
Exhaust valve closing = 30° ATDC
Intake valve closing = 72° ABDC
---------------------------------

Of course, in sticky number 3 of this forum I've provided a whole bunch of info on the subject of cams and valve train.

-G
Helping someone pick a camshaft is always difficult and often risky of potential hard feelings.

It is almost impossible to predict that you will be satisfied with any that have wandered from stock.

There is a reason that Ford used certain style camshafts.

Driveability is their main concern.

I'm thinking that the one with the best drivability is going to be the original '70 351c 4v camshaft.

It certainly will be the most balanced under real world driving conditions, idle the smoothest and cleanest, and require the least maintenance.

George's spec is a good one for your application if you want a stock +1, so to speak.

For me it is way too mild, but I'm not you. Mine is not an everyday car.

The fact of the matter is that the stock Pantera is quite capable of cruising safely at speeds well over 100 mph by virtually any driver who has about 10 or 15 minutes to familiarize themselves to the car and can drive a manual transmission car.

So really, you don't even need more than the stock 4v hydarulic cam.

Aftermarket cams for the street don't really get picked for what people "need". They get picked more for what people fantasize about and sometimes that works out ok, if even for just a few minutes of driving once in a while?
I have the following,

21. Crane Roller Cam #529541 "Hydraulic Roller Custom"
Intake @ CAM 325 @ VALVE 562 Duration 278.0 deg
Exhaust @ CAM 339 @ VALVE 586 Duration 286.0 deg
22. Ford Racing steel dist drive gear #M 12390 J

Hear it at youtube

Good driveability.

The entire rebuild:
1. PI 10 qt baffled oil pan
2. Autolite plugs #3924
3. Jomar 100% no by-pass oil filter
4. Oil pump primer Moroso #62220
5. MSD 8577 Billet distributor
6. Holley Pro street Fuel Kit #641090
7. Thermostat Robertshaw #333-180
8. Holley Fuel Pump #12-854
9. Dist hold Down Moroso #26211
10.Edelbrock AIR-GAP Polished intake manifold
11.Holley 770 Vac Second street avenger
------------------------------------------------------------------------------

ENGINE
------------------------------------------------------------------------------
12. Edelbrock Aluminum heads #61629
13. ARP/Edelbrock Head Bolts #8560
14. Fel-Pro head gasket #1013
15. ARP header bolts #400-1202
16. Original #'s matching 4 Bolt Main Block bored .030 over
17. Original crank in perfet condition - polished journals original diameters
18. Balancer, Crank, rods & flywheel balanced
19. Intake gasket Edelbrock #7265
20. B & B oil pump drive shaft #65050
21. Crane Roller Cam #529541 "Hydraulic Roller Custom"
Intake @ CAM 325 @ VALVE 562 Duration 278.0 deg
Exhaust @ CAM 339 @ VALVE 586 Duration 286.0 deg
22. Ford Racing steel dist drive gear #M 12390 J
23. Keith Black Hypereutectic pistons #8-KB148+.030
24. Melling oil pump #M-84AHV
25. Clevite 77 Rod Bearings #CB-927 P
26. Clevite 77 Main Bearings #MS-1010P
27. Rear Main Seal Napa # BS 40042 JV614
28. Rings Hasting #2M 139 030
29. Comp Cams pushrods #7825-16
30. ARP Rod bolts #254-6403
31. Cloyes Timing Chain #9-3121
32. Crane Cams Gold Race Extruded Roller Rockers #27750-16
33. Jomar stud girdles #1135
34. Ford timing chain cover seal #E6DZ 6700A
35. Exhaust Gasket Remflex #RF3006 (these are great)
HTH
Curt
I think Panteradoug really nailed it with this:
Aftermarket cams for the street don't really get picked for what people "need". They get picked more for what people fantasize about and sometimes that works out ok, if even for just a few minutes of driving once in a while?

Read George's sticky #3 and also try and formulate what you want out of your motor ( and your car)in the long run. A wholistic approach if you will, trying to get all the bits to work together and work well. I have a 459" Windsor with a ton of head work and an aggressive roller cam - it's what I fantasized about and I love it, but I think most others would hate it. Whatever you choose, enjoy the ride!
This is how the car idles now and, I am looking for a similar idle sound with the new camshaft. Since I don't know any other Pantera owner close to my area, I cannot compare the idle sound & quality with another Pantera. I don't have much info about the internals of this motor either but, it seems to have an aftermarket camshaft.

http://www.youtube.com/watch?v...VWI&feature=youtu.be

Shah
“ That isn’t even close to a stock idle”. The plot thickens, what cam do I have? I wouldn’t want a milder cam, takes the fun away. Maybe, I should just change the noisy lifters and leave the cam alone. Car has very good power, runs good but, it always had slight lifter noise. There is info on Chuck Melton’s Pantera Place website where he successfully changed the lifters w/o changing the cam.
quote:
Originally posted by PANTERASHAH:
“ That isn’t even close to a stock idle”. The plot thickens, what cam do I have? I wouldn’t want a milder cam, takes the fun away. Maybe, I should just change the noisy lifters and leave the cam alone. Car has very good power, runs good but, it always had slight lifter noise. There is info on Chuck Melton’s Pantera Place website where he successfully changed the lifters w/o changing the cam.


I have a solid lifter Comp Cams presently installed. It is a 294s grind.

Yours sounds a lot like it.

This one.

http://www.compcams.com/Compan...s.aspx?csid=861&sb=2



This is the generic sound bite from Comp Cams for that series, but listen to this. You can hear the similarities.

http://www.compcams.com/Base/M...ytes/CompCams292.mp3



I can't tell from the video if your cam is solid or hydraulic lifters.

I will say that very hot hydraulic lifter cams with triple valve springs and anti-pump up lifters sound very much like solid lifter cams. The anti-pump-up hydraulic lifters click like solid lifters do.

They have a lot of valve train noise.

You should take the car to someone who is familiar with aftermarket cams and preferably with High Performance Ford engines and ask them to "look" at it.

There is little that anyone can do to specifically identify the manufacturer of the cam.

Many have ID numbers stamped or engraved on the face of the first bearing lobe, but you would have to disassemble the front of the engine to see it. Even if you did that, it may not be enough information to positively identify it?

I'm agreeing with ZR1 Pantera. You may have a solid lifter camshaft in there and if so, that valve train noise is probably normal for it.

We agree on something? My God! What is the World coming too? I hope this isn't one of the Seven Signs of The Apocalypse? Eeker



Someone who is very knowledgeable on camshafts needs to look at the car in person.

It probably is going to at least mean taking off one of the valve covers to see what that shows.

It should at least identify the type of valve train you have? You could in fact even have a solid roller cam profile in there? They sound similar.



Who did you buy this car from? Didn't you get any engine information on it?



Another observation from the video is that you have a lot of exhaust noise on this car.

On a Pantera with Ansa type mufflers and tube headers, this is absolutely normal.

Even with the stock engine the exhaust is not quiet.

Many people just equate the sound of the exhaust to loud valve train noise.

This could be what is going on here also.

Bottom line is your setup isn't close to stock.

Even the mufflers are louder.


I would also add that if that is a solid lifter engine, the valve train noise is very low, and whoever adjusted the lifters knows what they are doing because they are NICE AND QUIET at the valve covers.

Your engine is also idling around 700 rpm. Mine idles 650 to 700 rpm with the Webers.

The cam I am using, spec'd above, is quite capable of idling at that rpm.

I describe the idle on mine, "like a speed boat". I would describe yours that way as well.

I think you have the same Comp Cams grind that I do.


The biker guys like mine. It sounds a lot like a big bore Harley Davidson. They think it's "bitchin'".

I will also point out that mine is a bit louder with the 3" bore glass pack mufflers on the 180 headers. The cam overlap will knock the cap off of your head if you walk within 20 feet of the back of the car at idle. I hate that. Roll Eyes

You probably never thought of your car as "quiet", did you? Wink

Hum? Everything is relative? Cool
The exhaust is a Loud Mind Train system with no baffles. It sounds quite nasty at high rpms. Exhaust sound is different from valve train noise. The big cam explains the 11 inch vacuum at idle and mediocre brakes . Brakes don’t match the speed & performance potential of the car despite having F & R vented rotors, 4 piston F & R calipers, Porterfield R4S pads, GM master, braided lines and no brake proportioning valve. Again, its all relative mediocre to me may not be mediocre to someone else.
Idle speed varies between 650 and 800 rpms. It is slightly less lopey if idle speed is raised to 800 plus rpms.
Car was converted to GP4 specs and the motor was built by previous owners. I do not have any details but, I cannot complain about its performance. I’ve owned it for 6 years and as I mentioned earlier, it always had this valve train noise. I was told that it is probably lifter noise as it is mostly towards the front of the motor. With a solid lifter cam, the noise should be more consistent between the front and rear of the motor. Also, engine performance has not deteriorated a bit over time .
Whether or not it is a 294 grind solid lifter cam, I don’t know. However, there are similarities. Bottom line is that I either show it to a Ford high performance engine specialist to identify the cam etc or just drive it and enjoy it and not worry about noisy valve train.
Thanks all for your feedback.
quote:
Originally posted by PANTERASHAH:
The exhaust is a Loud Mind Train system with no baffles. It sounds quite nasty at high rpms. Exhaust sound is different from valve train noise. The big cam explains the 11 inch vacuum at idle and mediocre brakes . Brakes don’t match the speed & performance potential of the car despite having F & R vented rotors, 4 piston F & R calipers, Porterfield R4S pads, GM master, braided lines and no brake proportioning valve. Again, its all relative mediocre to me may not be mediocre to someone else.
Idle speed varies between 650 and 800 rpms. It is slightly less lopey if idle speed is raised to 800 plus rpms.
Car was converted to GP4 specs and the motor was built by previous owners. I do not have any details but, I cannot complain about its performance. I’ve owned it for 6 years and as I mentioned earlier, it always had this valve train noise. I was told that it is probably lifter noise as it is mostly towards the front of the motor. With a solid lifter cam, the noise should be more consistent between the front and rear of the motor. Also, engine performance has not deteriorated a bit over time .
Whether or not it is a 294 grind solid lifter cam, I don’t know. However, there are similarities. Bottom line is that I either show it to a Ford high performance engine specialist to identify the cam etc or just drive it and enjoy it and not worry about noisy valve train.
Thanks all for your feedback.


Mine whines in the front near the timing chain. It is quiet apparent if you listen for it there.



The brakes were good for their era. The issue is that even your standard family sedans now have 16 and 17 inch wheels and typically 14" front rotors.

Trucks are even bigger. In comparison 12 " rotors feel like there is something wrong with them.



11" is about what I have at idle also. That doesn't effect brake effect though. Just the feel of the pedal.



If you adjust the solids correctly, i.e., cold with the engine off, you won't hear the lifters very much. Certainly no more than anti-pump hydraulics.

There are hydraulic cams with close to that duration, lift and overlap as the Comp Cams profile I mentioned.

The solids just have more rpm in them since they don't pump up like hydraulics do.

Anti-pump hydraulics are generally good for 7,000rpm and the solids at least 500 rpm more.

I ran my hydraulic lifter cam to 7,200 and it would go more. Don't know what the limit of my valve train is at all. Probably well into the 8,000s?



The positive thing about Pantera exhaust systems is that largely you don't hear them from in the car because of their location.

Unless you are in a tunnel, you don't really notice mine at all from the cabin. From behind is another matter though.


When you have the opportunity you should remove one of the valve covers for exploration though. That will tell you much of what you need to know. Since there is nothing apparently wrong with it, drive it.

Keep in mind though that the clearances on solids need to be checked every 12,000 to 15,000 miles. Some profiles will need it more often.

It depends on how radical the timing is on the camshaft.


That camshaft is relatively mild these days considering what you could run. For 1970 it would be considered on the lunatic fringe.


There are those who think you are not enjoying life unless you live on the edge. Who am I to argue? Wink
Trying to pick a camshaft when you admittedly know nothing about the rest of the motor is fruitless. Adjustable rockers, or factory? Compression ratio? Carburetor? Intake manifold? Cylinder heads? Valve springs? Exhaust headers, tube & collector sizes and header type? Mufflers? It goes on and on. The camshaft is the heart of the motor, and it's configuration and components (springs, etc.) depends on MANY details. You need to know all of those things, then you can contact a competent cam grinder (not Comp Cams) and provide them with this information in order to make it all come together. A cutom ground camshaft matching your information is always the best route. If you don't know what all those details are, your just shooting in the dark and wasting your time and $$'s. Just my 2 cents on the matter.
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