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  #16 (permalink)  
Old 01-16-2012, 09:54 PM
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Quote:
Originally Posted by 1971BB427
I installed one of those Thumper cams in my friend's 350 Chevy last year. I was skeptical that anything designed to just sound good would really perform. His 350 is fairly stock, with just aftermarket intake, Edelbrock 650, and a set of headers.
On startup I was really impressed with how great the cam sounded, and they really did get that part right. After breakin we took the car for a spin, and it couldn't even break a pair of 275/60/15 tires loose. The car's stock cam would easily bust the tires loose before.
Headed home and tried all sorts of timing adjustments and test drives. Also tried some jetting changes, but Eddys aren't fun to change jets like a Holley is. We eventually got it to run good enough to get a litle ture spin, but it's still a dog.
I'm not sold on them, and they are just what I thought they might be; all bark and no bite.
was it the roller cam or the hyd flattappet cam? which cam grind was it? thumper/murtha thumper/big murtha thumper? i can only speak for the cam i have which is the "big murtha thumper" retro fit roller cam it ran like a wild beast in my setup/drivetrain i dont know bout the other grinds tho

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  #17 (permalink)  
Old 01-16-2012, 10:37 PM
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Quote:
Originally Posted by joelster
I just don't understand the hatred towards these camshafts. I race here and there but I also hit up our local cruise nights all the time. The Thumpr line of camshafts are tailored PERFECTLY for the cruise night crowd. They are for the guys who cruise their cars and want to rumble into the parking lot but have little interest of heading down the track. So many people want to nit-pick these camshafts and claim that a better cam would knock off .2 seconds, lol. So what? I'm sure I could nit-pick the ENTIRE build and swap parts here and there to shave some ET. So what if the cam isn't optimal for going down the 1/4 mile. That's not what it is intended for.

Funny thing is that they do make decent power!

Hate is a strong word for a simple opinion on a gimmick grind. The fact that every drive by narcissist wants one is proof the gimmick is working.

We are not talking apples to apples. Most guys actually want to drive the cars around and have an efficient engine to cruise with. It is the impractical part of the build/cam that is under fire/question not the person or ideal of building what you want, all the power to em either way.

Hmmm either at idle or WOT they are fine. Anywhere in between and you are sorry.
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Old 01-17-2012, 07:50 AM
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Quote:
Originally Posted by SBC DUDE
was it the roller cam or the hyd flattappet cam? which cam grind was it? thumper/murtha thumper/big murtha thumper? i can only speak for the cam i have which is the "big murtha thumper" retro fit roller cam it ran like a wild beast in my setup/drivetrain i dont know bout the other grinds tho
It was the flat tappet Thumper cam.
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Old 01-17-2012, 12:22 PM
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Quote:
Originally Posted by 1971BB427
I installed one of those Thumper cams in my friend's 350 Chevy last year. I was skeptical that anything designed to just sound good would really perform. His 350 is fairly stock, with just aftermarket intake, Edelbrock 650, and a set of headers.
On startup I was really impressed with how great the cam sounded, and they really did get that part right. After breakin we took the car for a spin, and it couldn't even break a pair of 275/60/15 tires loose. The car's stock cam would easily bust the tires loose before.
Headed home and tried all sorts of timing adjustments and test drives. Also tried some jetting changes, but Eddys aren't fun to change jets like a Holley is. We eventually got it to run good enough to get a litle ture spin, but it's still a dog.
I'm not sold on them, and they are just what I thought they might be; all bark and no bite.
IMHO: You install any cam the has choppy sound. You will loose low end torque.
If you do not have the gears for it or the cubes or compression, you will not break bicycle tires.
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  #20 (permalink)  
Old 01-18-2012, 07:00 AM
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Quote:
Originally Posted by 1971BB427
It was the flat tappet Thumper cam.
Oh ok yea see I never had the flattappet cam only the roller which is a great cam IMO
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  #21 (permalink)  
Old 01-18-2012, 10:26 AM
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The bigger thumper cams like any fairly big cam need higher than stock compression ratio, a high stall converter 3500stall ++ and big gears 4.10+++.

The distributor needs a totally different timing curve.
The big muther thumper needs locked out timing.

A stock motor with stock compression, stock gears, stock converter and a stock distributor will not work at all.

When the motor is set up right the thumper cams make very good power.
With any big cam,, You got to rev it up.

99% is the performance and drivability issues with the thumper cams is incorrect combo set up.
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  #22 (permalink)  
Old 01-18-2012, 07:59 PM
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Quote:
Originally Posted by F-BIRD'88
The bigger thumper cams like any fairly big cam need higher than stock compression ratio, a high stall converter 3500stall ++ and big gears 4.10+++.

The distributor needs a totally different timing curve.
The big muther thumper needs locked out timing.

A stock motor with stock compression, stock gears, stock converter and a stock distributor will not work at all.

When the motor is set up right the thumper cams make very good power.
With any big cam,, You got to rev it up.

99% is the performance and drivability issues with the thumper cams is incorrect combo set up.
U said it right on brother!!!! And when I ran my et with the big mutha I had bout 11:1 compression and 2800 stall with 373's and hit the 11's easy in the 1/4
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  #23 (permalink)  
Old 02-23-2012, 08:25 PM
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Quote:
Originally Posted by krooser
These Thumper-style cams are nothing new... Chet Herbert ground cams that sounded like that back in the 50's....

Didn't work then... don't work now. If you did an 11.70 WITH that cam you'd probably do an 11.50 with a real camshaft.

Just my over-rated opinion....
Well it has to be working a little Don't ya think? A 11.70 is a nice little ride. Its a Win/Win situation. He got the sound he wanted and the car runs good. Could it run better with a different camshaft?? Probably so! But the customer has what he want's. Thats all that matters.
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  #24 (permalink)  
Old 02-23-2012, 08:28 PM
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Quote:
Originally Posted by prostreet6t9
Well it has to be working a little Don't ya think? A 11.70 is a nice little ride. Its a Win/Win situation. He got the sound he wanted and the car runs good. Could it run better with a different camshaft?? Probably so! But the customer has what he want's. Thats all that matters.
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