Made it to the track, a little disappointed.

Haven't been to the track in 8 years and finally got out yesterday. It was a Mopar show and shine, test and tune day. Bunch of nice Mopars. Last time out the car ran 13.0 at 109. No wheel spin just gutless down low. 60' was in the 2.150 range. The car would get moving after 4500 rpm and pull nicely to 6500rpm.
At that time the car had:
750 Dominator
Weiand Team G single plane
Unknown cam with a wiped lobe

I wanted to improve the street drivability and pickup the low end torque, so I changed to:
850 Holley DP
Eddy Performer RPM intake
COMP Cams Xtreme Energy CCA-21-227-4
Advertised Duration:
275 int./287 exh.
Valve Lift with Factory Rocker Arm Ratio:
0.525 int./0.525 exh.
Lobe Separation (degrees):
110
Street manners are better and low end torque improved but it falls on its face at 5600-5700. I knew I was making a tradeoff for more bottom end and less top end but I didn't expect it to be as drastic as it was.
The car ran a best of 13.51 at 101 yesterday shifting at 5500rpm. Used to shift at 6300. Best 60' was 1.921 with a bit of wheel spin. I was hoping for about 12.7 at 108
Do you think the cam is solely to blame for the poor top end?

Is your engine the 383 mentioned in the .sig?
A .525" lift cam isn't much even for a 383... I can see that running out of breath at 5700.
Are the valve springs matched to the cam?

Yes, pretty much stock 383.
The lift is almost identical to the cam that I took out. Same valve springs.

IMO you just seeing real world street car 383 times. Id of even kept the older intake.



Cam specs tell a lot.



Brand:
COMP Cams
Manufacturer's Part Number:
21-227-4
Part Type:
Camshafts
Product Line:
COMP Cams Xtreme Energy Hi-Lift Camshafts
Summit Racing Part Number:
CCA-21-227-4
UPC:
036584078319
Cam Style:
Hydraulic flat tappet
Basic Operating RPM Range:
2,000-5,800
Intake Duration at 050 inch Lift:
231
Exhaust Duration at 050 inch Lift:
237
Duration at 050 inch Lift:
231 int./237 exh.
Advertised Intake Duration:
275
Advertised Exhaust Duration:
287
Advertised Duration:
275 int./287 exh.
Intake Valve Lift with Factory Rocker Arm Ratio:
0.525 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio:
0.525 in.
Valve Lift with Factory Rocker Arm Ratio:
0.525 int./0.525 exh.
Lobe Separation (degrees):
110
Camshaft Gear Attachment:
1-bolt
Computer-Controlled Compatible:
No
Grind Number:
CRB XE275HL-10
Valve Springs Required:
Yes
Quantity:
Sold individually.
Notes:
Single-bolt camshaft.

Sounds like the valve springs are dead. Same springs from 8 years ago? How many miles?

I dont think its that bad. Its more of a starting point. Im curious about the rest of your combination. Gear,converter,heads&car wieght. where your shifting at.

The springs are probably 20 years old. Might have 1000 miles on them total. 8 passes that I've done. When I changed the cam I had a shop look over the springs and they were good. The open pressure was at the upper end of what the cam calls for.

My expectations weren't very high. Just thought by improving the 60" by a few tenths would lead to a few more tenths off at the end.
4.88 gears
33" tire
3500 stall
Don't know what the weight is. Tubbed with a cage. Not much interior.
Shifted at 5500

https://youtu.be/8xeiaGZZCdc

I can see a stockksh 383 in a heavy car making 300 or so to the tire with that combo. The performer intake will definitely limit the power band in my experience. I would thinf the RPM would be good to at least 6500 on a stock stroke 383. While not 100% apples to apples my 451 with a comp 294h and 1.6's hits a wall at 5800 or so with a performer and stock 1968 bb a body manifolds with the exhaust corked or uncorked.. It acted the same with a performer RPM and headers on the dyno.

My advice would be a 125 or 150hp shot of nitrous. Keep the streetability 95% of the time. Change the timing and warm up that bottle and you are ready to party.

Since you do not have the old cams specs, hard to speculate, but first thing I would do is do a compression test and get an idea of how much cylinder pressure you have. If you don't have 135 to 140 on a cranking compression test, I would advance the camshaft and try it again. The big drop in MPH tells me you lost HP somewhere. My experience is mopars like a like of ignition timing, 38 to 40 degrees is where most big blocks wind up on the dyno. And of course what do the plugs look like? Is your fuel system up to feeding your combo at 6,000rpm? These are the things I would check first.

Stock manifolds or headers?

Fast rate hyd cam = won’t rev.
That’s your mechanical rev limiter.

Especially with what’s out there for hyd lifters these days.

A SFT is really a much better match for something that has the potential to run at higher rpm.

That cam would make decent power, up to the rpm limit imposed by the lifters.



Not so much the cam, as the lifters........ but the fast rate cam will find the limit of the lifters sooner than a cam with long slow lobes.

Pull a couple of springs, measure the installed height, and have them tested.
If they are 125-135 closed, 300-340 open...... they’re not your problem.

That same cam and lifters in my 383/432 Stroker is done by 5400 RPMs

I have tried just about everything

Street Car - 1971 Superbee / Auto / 3:91 Sure Grip

Edelbrock E Street 75cc Heads

10.5-1 Compression

Most everyone I have talked to say , ( Hydraulic Lifters ) and Fast Ramp Camshaft

That’s all she wrote

I did a compression test in the spring and the highest was 190 the lowest 175. The rest were all about 180-185. I don't remember what timing I had back then but I have it set at a total of 35 now.

Fast 68 beat me by 7 minutes

LOL

And he is one of the guys I talked to about Lifters with that Cam

1-7/8 Hooker long tube with 3" exhaust.

I am at 195 psi cold on all eight cylinders

34 Degrees Total


5400 RPMs Dead

Occasionally I read where someone has had success running a fast rate hyd cam with hyd lifters and carrying the power into the upper rpms.

Particularly in a BB application, in 31 years of dyno testing....... I have never experienced that.
In any brand of engine.

Usually in a BB, they’re “done” before 6k.

Success at high rpm with a fast rate hyd cam/hyd lifters in a BB would be the rare exception..... rather than the rule.

All that being said........ that’s not to say that curing the high rpm capability of your motor would.......without changing anything else...........make huge impact on the ET.

If you have an adjustable valvetrain already, the down and dirty test/solution would be to install solid lifters on that cam and run the lash at like .004-.005.
You’d need lifters and pushrods.
Provided the springs are good, that would buy you somewhere between 700-1000 extra rpm.

Thanks! I went with new but same lifters that the other cam used. Thought if it worked for that one then should work for the new cam.
I posted pictures of the old cam in an old thread and you thought it was an MP cam. The springs are a dual spring and open pressures were quite high. The shop said it was about as much as they would run.

Ok thanks! That answers that. More incentive to start collecting parts for the stroker.

Unparkerized cam....... probably MP.

The MP lobes are smooth and stable, which = more rpm before the lifters get upset.

I would absolutely expect the MP cam to rev higher before the valvetrain got unhappy than the XE275HL.

They let you run in shorts?

That makes sense.
Thanks!

That is what I would do, 400 stroker motor rule

One sure fire way to turn a 383 into a turd, install a fast rate hydraulic cam. Like PRH said, the lifters will not allow a 383 spin high enough to make use of the cam size. I agree with doing a swap to a solid lifter on the cam to simply check. But the valve springs need to be right too. My 383 is similar to yours. MP 280 cam. It will spin 7000 rpm (not that It should, but it is so much fun). If I had to shift it at 5500, it would be totally neutered..

You do seem to be going through the finish around what you shift at. But 4.88 gears, even with 33" tall tires, seems like a lot for a "stockish" 383.

Going to a bigger carb (750 to 850) to improve street drivability seems like the wrong direction to go.

Tuning the carb can sometimes provide surprising results. But it takes patience, tuning parts (jets, squirters, pump cams) and an understanding of how they interact. There are some good, old Holley tuning books out there that I learned a lot from.

If it was my car I'd put a SFT cam in there somewhere along the lines of a Mopar 0.528. I don't think I'd actually buy a Mopar cam anymore since they are super expensive and the the QC is spotty but just something in that range. With 4.88 gears you might want even more cam than the 528 but it is only 383 cubes and you mentioned that you wanted some bottom end torque. Actually I'm having a hard time figuring out your combination since you have a dual plane intake and 4.88 gears. Those two things usually don't work well with each other but I suppose the 33 inch tire kind of mellows out the steep gears.

I'm not positive what the issue is with your combo but it could very well be that the hyd lifters are heading home just when the rest of the combination is getting ready to party. All it takes is one part in the engine to quit early and the whole combo slows down. Of course you could also have some other issue such as fuel delivery, ignition, etc. Lots of things can kill the power.

Since the ignition and fuel delivery were good for 13.0@109 before, it’s unlikely they’re the problem now.
And that was with the cam going away.

109 was enough speed to run well under 12.50.
A converter swap alone would have had the OP reaching the performance goals, although it wouldn’t have done much for the drivability.

Since the OP states the lift on the old cam was close to the new cam, the old cam was probably a MP509 cam........ which would def make more HP up top than the XE275HL(248@.050 vs 231@.050).

The Moroso chart shows difference in speed between 109mph vs 101mph, at around 3600lbs to be roughly 85hp.
The question at this point is, how much of that speed gap would be made up by just having the valvetrain be stable for the full 1/4 mile run?

Couple of thoughts/questions

1) Something is off with your combo - you are not trapping much more than what a basically stock 383 should trap in a stock weight B body, with stock converter, 4.10 or less gear, etc. That would be a good running stock 383, but nonetheless its been done. With headers and good exhaust a stock cam would make the same MPH. You have more cam, a better intake system, and what must be a healthy short block with 175+ PSI. Sounds like this is not a low comp 383 either.

2) You may have too much converter - didn’t look like you came up on the converter much on the line but it looks like you’re only dropping to about 4500 on the shifts, I would think it should be coming down a bit more than that from only a 5500 RPM shift point (it looked like you pulled second at more like 5200). Are you sure the converter isn’t looser than 3500?

3) I wouldn’t condemn the cam yet, but if you want to go back to what you had if you had the 509 Mopar cam the Racer Brown SS-H-44 is supposed to be very close

4) Did you degree the cam? Did you make any change to the fuel system? Did you change the pushrods, or check your lifter pre-load? Your pushrods may be too short and causing additional issues.

I’m with Fast, cam and single plane intake. I had the 509 in my 383 and ran 117 mph but about 400 pounds lighter stock vert and 4.88s

I know this isn't that same but, I have a comp cams xe275hl in my stocker, 69 340 daily driver that I do randomly take to the track for fun as I'm a performance guy. Mine will not rev either, it's the cam. I've changed springs and shimmed until my hair falls out diff pre load etc etc and done everything you can try twice. 5,700 it's over with. Runs 12s but sucks. If I put my solid st21 in the exact combo it will rev up. . The xe275 is a killer daily slash low rpm deal. You fight the same issue I have as a 340 has zero torque. The cam works really good until it don't right where a 340 is wanting to go. Change cam to a solid and don't look back. Just my 3yr combo experience with the same cam.

I'll give a bit of a background on the car. My dad bought the car about 16 years ago pretty much the way it is. It was built to handle big power and the previous owner had planned to put a stout stroker in it. That never happened and he sold the car with the 383.I believe it was put together with spare parts that he had. For a variety of reasons my dad didn't get around to building another engine. I have the car now and have a 400 block to work with. I swapped out the cam because it had a rounded off lobe. Thought the new cam would help the lowend which it did but didn't expect the topend to drop off so much. Eventually the car will run as fast as it looks. Right now its all show and no go.

I agree with the above posts by Fast and Bee1971.

I had an XE cam in my 470. I'd heard people bash the XE line for years but, was one of the lucky ones that could get one to rev past 5500rpm or so. The car pulled clean to 6200 without issue. Put a set of ported heads on my car with different springs. Picked up around 40-50cfm in head flow and the car went no faster. With the new springs, the lifters were not happy starting around 5400-5500.

I did similar to what most have tried with these cams and thought I had an issue but, it's the cam. I've never seen anything like it in the past. When people say "hit the wall" or "it's done at x rpm", it's no lie with the XE cams. My car sounded like it had a rev limiter on it, it truly would not rev past 5500-5700 rpm. Can't remember where I saw it but, there was an article I found where they dyno'd one of the XE cams and ran into similar issues. Tried a whole bunch of different things with little success. It was interesting to see the curve when the cam get's unhappy.

Called Dwayne (Fast) earlier this year and had a SFT ground.

The XE cams, for the advertised power range, really work well but, they are done when they say they're done.

with a stock bottom end 383 in my charger, stock 906 heads including springs, DP4B intake, 850 T-quad carb, SSH-25 hydraulic cam installed straight up, 15% initial, 36% total timing, B&M hole shot converter 2600rpm, home brewed shift kit, 3.91 gear, 27" street tires, and 4000lbs plus, shifting at 6000, my charger runs 13.95-14.15 depending on the air.
just a comparison for the OP to consider for tuning upgrades.

But he hasn't had the car to the track in 8 years so lots of things could've changed. Fuel filters could be plugged, parts can fail, etc. The performance isn't there and it could very well be the fast rate cam blowing away the lifters but it could also be something simple like a bad coil wire.

Good point about the 8 year interval.

An ignition tester should be able to verify that system is up to snuff, along with flow testing the fuel system(electric pump) to make sure it’s keeping up.

At this point, it makes sense to perform those tests.
But the motor not wanting to get past 55-5700 or so is pretty much par for the course with those cams.
You’d basically be verifying you don’t also have another issue to contend with.

Frankly....... the drop in performance with the new cam/intake/carb is pretty ugly......imo.

I would hate to see a guy go to the effort of changing the cam when it was just something simple like a tank of bad gas or the gas tank vent is clogged. So I guess my advice is to verify all of the simple dumb stuff before tearing the engine apart.

I might be overly sensitive to the issue since lately I've had a bunch of customers come in for "EFI problems" and none of them turned out to be EFI problems. One guy had a broken valve spring, one guy had a loose connection on his coil wire, one guy had old gas in the tank, etc. In all cases the engines ran poorly and since the cars had EFI they just assumed that the "EFI system was acting up". And the last guy that came over to have me look at his EFI system had the timing retarded by 12 degrees. So not an EFI problem after all, just hadn't ever checked the timing.

Thanks for the input everyone! I'm certainly leaning towards the cam being the culprit. I've got a MSD 6AL ignition box (no rev limiter chip in it) with a MSD Pro Billet distributor. I have the fuel pressure regulator set at 6.5psi. It seems to bump up to 7.5 when I launch. The gauge is next to my right knee in the video. I used fresh 94 octane gas. The plug wires are old but I checked them out this spring and the all tested within spec.
I'm not trying to ring out every last tenth in the car. Probably won't be back at the track until next year. I won't change the cam. It drives around town well now and can do burnouts with a 21.5" wide tire. Couldn't do that before. Was a little disappointed because the car seemed faster. Hopefully someone else can benefit from this thread.

Thinking a little more on those lifters. Is there a possibility of them pumping up and lifting a valve or two off the seat at 5500. Reason being my 383 had the 509 with crane anti pump ups and I set them at zero lash. 4.88 gears 29,5 tire 117 mph, 11.65 you can figure the rpm out. Easily would have went faster with a high stall converter. (Had a Street Hemi vert)
Just looked at the Wallace calculater 6887 rpm. Never needed a tach, shifted by feel. It screamed they all thought I had a small block Chevy, were they supprised.

500 - I enjoy the camshaft around town , cruising and stoplight to stoplight

Idles awesome , great vacuum , torque off idle and just stabbing the go pedal at say 30mph and having the car sideways with an automatic
Will destroy the tires off idle just stabbing the pedal

Fun , YES

I went as far as taping a vacuum gauge to the windshield , checking fuel pressure
Tried every Mopar ignition module blah blah

Different carbs - Pulling plugs - Jetting

Timing - Distributors

Most on this thread commenting , helped me chase something in reality that wasn’t fuel or ignition related

I just couldn’t accept the fact a 383/432 Stroker was dead by 5400 RPMs - Again like a rev limiter honestly

Cudaman

This same 383 , before I turned it into a Stroker

Ran the 284 / 484 Mopar Camshaft for 20 years

Speed pro forged flattops

When I installed these same Edelbrock E Street heads that I am running now with that old camshaft

6,000 RPMs all day long if I wanted and higher , right up until I kissed some pistons with those same Eddy intake valves on the highway racing a Mustang


Hence , the new motor

New lifters? Adjustable rockers?

Ultimately, if you’re enjoying the car as-is, that’s all that really matters.

Just keep in mind, a nice solid cam would retain most of the good drivability you’re enjoying now, and get the performance back to what you’re looking for.

At the same time.......... it doesn’t sound like you’re at the track often enough to justify chasing the ET.

Maybe I missed the answer to Matt's question, but did you degree the cam when installing it?

This is why I vote spray a 125 or 150hp n20 kit when it goes to the track. With all of that tire you could leave on the nitrous and with a ring swap you could move towards the 175-250hp jets which is when things start to get really exciting. You won't wear out a bottle while it sits in the trunk and if you are into car shows look at it this way; nobody can see if it's a 383 or a 511" engine from the outside but some nitrous solenoids make for a pretty good ooh-ahh to the non-performance and street performance folks. Just one guy's opinion.

For extra cool points find a low deck fogger!

Do you have adjustable rocker arms? If so you could do one more easy check.