Technical does the thumpr cam make any power or not?

I have a Sunbeam Tiger with a 347 stroker in it want to change cams was thinking about the small thumpr cam but hear a lot of mixed feelings about it Summit ,Jegs and comp cams themselves all say they make sound no power but according to this they make more power than the other ones so witch is it do they or don't they? A Tale of Three Cams hot rod network
As no surprise, a quick call to COMP Cams’ Trent Goodwin confirmed that the most popular grinds in the SBF catalog are relatively mild designs that offer a great balance between sub-6,500 rpm power and low-speed driveability. The challenge was picking three cams that were different enough to show a measurable difference on the dyno, yet similar enough to where variations in horsepower and torque output could be pinpointed to specific differences in their lobe profiles. The smallest of the lot, which we’ll call Cam A for the sake of simplicity, is a 224/232-at-.050 unit with .555/.565-inch lift and a 112-degree lobe-separation angle. Cam B, the largest of the bunch, features 232/240 degrees of duration at .050, and .565/.574-inch lift, also with a 112-degree LSA. The wild card of the bunch is Cam C, which measures in at 227/241 degrees of duration at .050, with .531/.515-inch lift and a 107-degree LSA. As one of COMP’s Thumpr grinds, Cam C was designed with a lopey, aggressive-sounding idle in mind, and as such, it has a tighter LSA and an earlier exhaust valve opening
Two of COMP Cams’ most popular SBF camshafts are PN 35-518-8 and PN 35-522-8. Both are Xtreme Energy grinds, the former measuring in at 224/232 degrees of duration at .050, and the latter with 232/240 degrees at .050. The wild card of the bunch was the 227/241-at-.050 Thumpr, which proved to be the best all-around performer in our 347. All three grinds idled well at 900 rpm, with the Thumpr providing a noticeably choppier disposition.

Based on specs alone, Cam B would seem to have the advantage on paper since it packs the most duration and lift, but that’s not how things played out on the dyno. Cam A was good for 437 hp at 6,000 rpm, and 409 lb-ft of torque at 4,900 rpm. As expected, Cam B improved upon those figures dramatically, kicking out 464 hp at 6,200 rpm and 426 lb-ft of torque at 5,100 rpm. Longer-duration cams typically sacrifice low-end torque for top end power, and predictably, Cam A held an advantage of 5 to 10 lb-ft of torque from 3,600 to 4,200 rpm. After that point, Cam B pulls ahead big time, holding a 15-25hp advantage throughout the rest of the power curve. While the SAM crew slid Cam C into the block, since its duration specs fell in between Cams A and B, we expected horsepower output to fall somewhere in the middle as well. Boy, were we wrong. Cam C proved to be the most potent of them all despite giving up 5 degrees of intake duration to Cam B, and .034- and .059-inch of lift on the intake and exhaust valves, respectively. In fact, the Thumpr produced more torque down low than the smallest cam in the test, in addition to posting the highest peak output of 466 hp at 6,300 rpm. Peak output aside, the Thumpr trounced the 232/240-at-.050 grind by a large margin in the area-under-the-curve department, holding a 10-15 hp advantage throughout the majority of the power curve. The Thumpr proved to be the most rev-happy as well, pulling hard to 6,600 rpm, while Cam B was out of breath by 6,200 rpmCam A and Cam B both produced peak horsepower in the 6,100- to 6,200-rpm range, but the smaller grind falls off a table after peak while the larger cam does not. By 6,300 rpm, Cam A is down to 415 hp, while Cam B is still making 460 hp. That 45 hp difference is far greater than the 27hp gap posted by Cam B at peak power, proving once again that peak power is just part of the equation. The Thumpr (Cam C), on the other hand, clearly destroys the other two cams everywhere in the power and torque curve. can someone please help me out?

 

If you are looking for the rough idle, then thumper, but contact comp and tell them the engine spec's and car and what your use is going to be, they can recommend one that will be more efficient and prob make more power. I have had an overcammed motor, was not that fun, till got rpms up, then cuz didn't have the killer heads, it dropped off quick. But your doing it right, research and ask questions,

 

I have a model coupe, 383,turbo 350, 3300 stall, 4/11 gears and run 8 inch cheater slicks, I have the big mutha thumper and it makes a lot of power and the car flats ass scoots, of course the car is light and compression, heads, ect. all play a part in performance, and it sounds awesome

 

For actual street driving I always lean towards higher lift, shorter duration, and narrow LSA.

That said, there are WAY too many variables going on to make a clear choice.

You are only talking about an engine on a dyno here.

 

Your engine is a system of components.

The thumper cam obviously is well matched to your specific combination of heads, compression, carb & timing. Change any one component and one of the other cams *may* perform better.

 

Get a copy of "Desktop Dyno" from Comp and play with it yourself. You might be surprized.
http://www.proracingsim.com/desktopdyno.htm

 

You may find this old HAMB thread an interesting read.
Most say the Lemans cam is a bit cranky for the street, but oh boy the sound they make.
Kinda sounds like a small block cammer. I think you can pull it off with the extra cubes.
It sure would impress the boys around the local Ford bench racing session. Not that a 347 in a Tiger isn't enough!
My childhood buddies older brother bought a Tiger in about 1965-66, stock 260/2bbl.
That thing was scary fast bone stock.
http://www.jalopyjournal.com/forum//289-hipo-le-mans-camshaft.647624/

 

I want to say this about the thumper if you buy the run of the mill thumper and put it in a stockish mill it is going to do just as advertised, sound tough and run away when the big kids want to fight.

Now they do make big cams marketed under the thumper moniker that when shoved into the right mill will make some zot. Of course it is a synergy thing, the sum total of the whole is greater then the sum total of the parts. it take an entire package and not just one piece to fill out the equation.

I think that the poser cams are called a Thumper and the real cam shafts are called Big Muther Thumper.

 

The thumper destroys the other two cams you selected because the 112 LSA on both of them is WAY WRONG for a sbf, WAY too wide. Get a proper cam on a 104-106 LSA that doesn't have the ridiculous Thumpr exhaust event, and it will make more power than all of them, and be way better on the street that the thumpr. Talk to the guys at Bullet, they will want to know the intake port CSA/Flow numbers, as well as all the other usual stuff. Or Mike Jones.

 

The SBF in my '40 coupe is only a .030 over 302, has a "B303" Ford Motorsports hyd.roller, and for a cruiser, I like it.
Agree that over camming can make around town street use a bit tiresome on the low end in heavy, stop and go traffic jams, especially with manual trans.

 

LOL I had a Boss in '72. It was pretty much useless under about 4K and I was real glad I didn't live near a city.

We all want one that sounds mean and can still be driven. But sound I have learned comes from way more then cam shaft, and that cam shaft gets chosen by the rest of the build along with common usage.

 

I drove a guys '68 Firebird with a Thumper cam in a 400 cubic inch engine. On the dyno it made 505hp @ 6200, yet it couldn't spin the street tires with open differential. Above 4000 it pulled hard, below that, a stock engine would kill it!
Get a computer dyno, it's a fast way to kill a bunch of time and will answer a lot of questions if you enter the correct data.

 

Play with LSA. See what it does, even without changing any other variables.

 

The gist I get from multiple Thumpr threads (use the search function) is that while some guys like them (and that gets down to build specs and application) most seem to feel they are more hype and fairground effect than an across the board real world performance cam when compared with what else is available.

 

A 347 in a Sunbeam Tiger?? That thing must do wheelies all day long.

There's nothing "mild" about any of those cams in the article.

As others have stated, the cam needs to match the rest of the engine components to perform well.
On a small, lightweight car like a Sunbeam Tiger, unless you're going racing, why would you want anything that would have poor manners on the street?

I've gotten good performance in a 302 from a 215°/224° @ 050 and .470"/495" lift in a 2900 pound OT car. Of course the 347 has more stroke and can take more duration.

EDIT: with a 112° LSA

 

On board with this^ And even with track time included. For sure higher lift, shorter duration, and a lil tighter LSA....... Ide say the "thumper" is a marketing tool for too much overlap , and better have a looser converter.......Making useable power is above, "camming" like we used to say is the "thumper cam".

 

I have 302 X Grind roller , 1.7 roller rockers , Motorsport springs , GT40 heads ,pulls like a freight train and revs like a chain saw . It is a bit steep on the lope , open the headers , and sounds like a super stock . A roller grind is a bit more drivable , profile is greatly increased with a roller

 

I see all of these "cam-shootouts" with results showing nice high numbers at 5000, 5500, 6000, 6500, and even higher.

Aside from the 5-passes a month in the summer, and the occasional banzai run up an entrance ramp, when the hell are you going to be at those RPM's? Even then, you are going to only be there for a few seconds, total.

Where you are going to be is at low RPM, every damn time you pull off the line from having stopped the car. Every single stop sign. Every single stop light. Every stop, in stop-and-go traffic.

Unless you are building a race-only ride, you want an engine that works well with your car, in the low-end of the operating range.

High peak HP and torque numbers are useless if they are at an RPM where you never, or almost never operate the engine. Yeah, a "lesser" cam might have lower peaks, but better numbers where you actually use the car.

If you build an engine that makes 550lb.-ft. of torque at 5500RPM, and your cruise RPM is 2250, where the engine makes 210lb.-ft., you might not be too happy with you cam choice. You lose bragging rights if it only makes 475lb.-ft. at 5500RPM, but if it makes 310lb.-ft. at 2250, you will be a lot happier.

 

The Thumper cams are made and mostly for the radical idle , If you want the best performance , power then the correct ROLLER CAM for your ap. needs to be made. Do you want power at low RPM, high, middle, or just decent all around. GIMPY SAID IT BEST!!!!

 

Yep.

That's my theory. All the seat of the pants fun is from zero to the speed limit, whatever that happens to be in any given location. The shove you get off idle. And if it continues as you wind out if you have the space all the better. But what could happen at 5,500 rpm once you get there is pretty irrelevant in the real world.

 

Really...I have a 6800 chip in my shift light, it flashes on as I cross the second crosswalk thats on sticky tires...Benno, I have said it before, if I ever get this old, I expect you to come out here and shoot me...

 

I'm running a Ford Racing X303 cam in the 331 stroker in my 27 and love it. Rough idle, but I can lug it down to 1,000 rpms in high gear , step on the gas, and it smoothly pulls away. I have it redlined at 7,000 but have gone to 8,000 when I forgot to shift a couple of times. It normally idles right at 1,000.

I have a 351 that I will be building for some future unknown project and another X303 will go in that one too. Ford really did their homework on the entire X series of cams.

Don

 

Yeah, well I drive everywhere in first gear, local streets, freeway, everything. That way I get to use lots of rpm and never have to worry about wearing out the other gears. And that's with a 4:11 diff.

 

I built a 302 bored.030 about a year and a half ago. I can't remember if I put in the mutha thumper or the big mutha thumper, need to find my papers lol. But anyway, it sounds great and runs well. Haven't had the car on the road for long drives but it sure smokes the tires nice in the driveway. It did require larger heads, deep dish pistons, heaver springs and the sort. Im happy so far with the results. Like I said, don't know what times it will give me in the 1/4.

 

I had the B303 cam in my 302 for 5 years and loved every minute of it. Only rebuilt the motor cause I wanted more power. lol

 

Gee, I start out in first and shift. They even make these things, these "automatic transmissions" that can do that for you if you aren't capable of doing it yourself.

For those that are actually interested in learning how this shit actually works, rather than using worn out magazine bullshit and old wifes tales to flatter themselves as to how "smart and sophisticated" they are for building weak suck motors, take a good look at these two 383 chevy dyno tests. And yes, Gimpy has already seen this.
One makes peak torque at 3400 rpm, the other makes it at 5000. So according to Gimpys and X38's theory, the motor with the 5000 rpm torque peak shouldn't make more torque than the motor with the 3400 rpm torque peak until somewhere up around 5000 rpm, right?
Lets take a look. Oh, and by the way, these two engines were built in the same shop, and tested on the same dyno.




Hmmm, that doesn't appear to be whats happening here, does it. No, in fact, the engine with the 5000 rpm torque peak passes the "old lady Gimpy/X38" motor at 3500 rpm and never looks back. In fact, by 4000 rpm, its already up by close to 30 ft lbs.Even if you are in such an decrepit state as X38, where you cant manage to reach over and click the shifter down, they make these things called "kickdowns" so if you are in that sort of physical condition, you can use the aforementioned "automatic transmission" and it will do it for you!!
So if you put these engines in matching cars, with identical rear gears, and drive them down the road side by side at 40 mph, and go WOT, the impractical silly old motor with the 5000 rpm torque peak is going to flat out BURY the "old lady Gimpy/X38" motor right from the get-go. Now be forewarned, this may not be the best thing for you, depending on your driving habits and physical/emotional state. It may cause your walker to be flung rearward with some force, making an alarming rattling and banging, and causing some emotional trauma.
But again, and I already posted this on the "torque motor" thread, if you are building an the "old lady Gimpy/X38" style motor based on the delusion that its going to outperform the snarky, window rattling "Dons Rod Shop/FalconGeorge" motor at ANY meaningful point in the power curve, well good luck with that. If you race X38 or Gimpy, they will try to convince you that shifting at any rpm over 3500 rpm is unfair, and that to duplicate "real world" conditions, you should gently roll the throttle on at 1000 rpm in high gear, and step off at 3500. DONT do it. Do what I do, and what all REAL hot rodders have been doing since this thing began. Downshift, hammer the throttle, and shift when you see God.
Oh, and Gimpy, I have a dyno test I will be posting for you on the torque thread a little later, re: the whole brake fuel specific thing, and how it does or doesn't relate to part-throttle fuel economy.
Oh, and X38, I have 4.56's in my daily, not 4.11s. Its a "hot rod" thang...

 

One other thing I will mention here. As the cam in a given motor gets bigger, you can maintain cylinder pressure (and torque, all torque is is a measure of mean effective pressure in the cylinder at any given rpm, theres no black magic here) at low rpm by increasing the mechanical compression ratio. Contrary to popular internet forum myth and bullshit, this will not make your engine detonate at part throttle, because what you are doing is using the increased compression to compensate for the reduced cylinder pressure caused by the later intake closing point. On pump gas, its the octane rating of your fuel that pretty much dictates how much cylinder pressure you can run at peak torque, and its cylinder pressure that actually makes torque. I have actually run 12.7/1 compression on Chevron 94 pump gas with a really BIG cam (like 278@050). Oh, and of course, it made poor mid-range torque...Well, assuming you consider ripping 4 teeth off a 12 bolt crown gear going wot from a slow roll "poor torque"...

 

^^goddam crazy hot rodders...

 

The Thumper cam series is the Rodes lifters of the new millennium.

Ah common George Chinese gears don't count. Jeeeze

There was a guy once who wrote lots of Chebby tuning books, he owned The Best Damned Garage in Town or some silly shit like that. In one of his most popular books he wrote something that applies to most all engines and sounding cool. For some reason we have a tendency to equate poor idle with being cool. Anyway I digress, what he said and I paraphrase, was that if you want to sound cool and still be drivable on the street just pull your choke when you roll into the hot dog stand.

 

I had talked with someone at Comp Cams when I was cam shopping for my 355 Chevy. I mentioned the Thumpr series of cams and I was steered to an XH268 cam, which has better street manners. I did wind up with something comparable from Lunati.