• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

Comp Cams Mutha' Thumpr cam

Houle #382

Well-Known Member
Local time
12:15 PM
Joined
Jun 13, 2014
Messages
317
Reaction score
188
Location
Hastings NY
Anyone running the Comp Cams Mutha' Thumper cam 235/249 in their 440 ? Just wonder what kind of performance increases you got.
 
Just had a 355 SBC with one on the dyno here.
The criteria for the build was, over 400hp, rowdy idle.
The build was very bread and butter.
Flat top hypereutectic pistons, ootb E Street heads, RPM A/G, the middle Thumper cam.
Made over 425tq/425hp so far. The carb they were using was pretty lean and they’ve ordered a carb for the motor(which will get tuned to the motor), so there may be a few ponies left in it.

Idles at 6” vacuum(pretty rough).

Those lobes are pretty smooth and easy on parts.

I wouldn’t recommend it for power brakes or the FITech/Sniper type EFI.
 
Just had a 355 SBC with one on the dyno here.
The criteria for the build was, over 400hp, rowdy idle.
The build was very bread and butter.
Flat top hypereutectic pistons, ootb E Street heads, RPM A/G, the middle Thumper cam.
Made over 425tq/425hp so far. The carb they were using was pretty lean and they’ve ordered a carb for the motor(which will get tuned to the motor), so there may be a few ponies left in it.

Idles at 6” vacuum(pretty rough).

Those lobes are pretty smooth and easy on parts.

I wouldn’t recommend it for power brakes or the FITech/Sniper type EFI.

Interesting, do you have the specs on the comp cam, I do not have power brakes or EFI
 
Well, you asked about the Mutha Thumper, so I assumed you knew what the specs were.
This one is a HFT, part number 12-601-4

For the Chevy lifters the specs are:
287/[email protected]
235/[email protected]
.489/.476 w-1.5
107lsa

The Mopar version has a little more lift since it uses .904 specific lobes.
 
Well, you asked about the Mutha Thumper, so I assumed you knew what the specs were.
This one is a HFT, part number 12-601-4

For the Chevy lifters the specs are:
287/[email protected]
235/[email protected]
.489/.476 w-1.5
107lsa

The Mopar version has a little more lift since it uses .904 specific lobes.

I was just wondering how close that cam is to the one for BB Mopar as I'm sure it's not the same, it's close lift is .497 / 483 duration is pretty close
 
I have it in my stock 440, manual brakes, so vacuum wasn't an issue at idle. Rowdy idle, street performance feels about the same as my other GTX with original stock engine that has never been altered. It replaced a hemi grind purple shaft and I'm much happier with the current set up for street use.
 
Auto Transport Service
Back
Top