I am looking at the comp thumpr series camshafts, but they only make them in retro fit applications. Is it possible to put one of these cams in my origianlly equiped roller block, what would I need to do?

 

use a cam button instead of the thrust plate that bolts on the block. use a timing chain for and old model block. thats it.

 

Call Comp Cams and talk to them about this before just going with a retrofit package. There is a good chance they can grind the lobes for the cam you are looking for on a late model core.

 

fill out their cam form and they will tell you what cam you need for your engine.

 

And also consider very carefully if you really want a thumper series cam at all.

 

Yes, yes and yes!

I agree with all comments made.

I have put a retro comp cam in my roller ready 4 bolt main truck motor I used as the foundation for my build.

jeff

 

Why, what is wrong with the thumpr series camshafts, Ive only heard good things about them.

 

They are made for people who only care what their engine "sounds" like, and don't care what it runs like. Some of us have a word for people like that... starts with "L".

If al you're building is a "show" motor, then they're fine. That's what they're for. If you're building a motor that's supposed to RUN, you need something else. Even if you think somebody's motor "ran good" with one of those in it, you'd think otherwise if you saw how it ran with a cam optimized for RUNNING in it.

 

So these cams run like s**t, because the cam I have in it now makes the motor run like a raped ape, I just thought I could get a little more out of it with the more duration and 107 LSA and pick up some good sound, dont get me wrong, with the cam I have now it lopes pretty good, I was just looking for a little more umph. Thanks for letting me know this before I spent an unneccasry $300.

 

It's ground on a super narrow centerline to give it more of that "big cam" sound.

If you have a non-computer-controlled motor, and you don't mind the loss of high-end horsepower and idle vacuum and low-speed torque in exchange for a MUCH taller mid-range torque peak, it coud be OK. The combination of specs that those cams have, make their power curve real narrow and "peaky", and heavily non-computer-compatible. In other words, if you can somehow force your engine to always run between 3800 and 4400 RPM (or whatever the particualr cam produces), it could be OK; but it will run TERRIBLE outside of that range. It doesn't have the design features that make a cam run well across a wide RPM range and a variety of conditions.

I don't know what cam you have now; but odds are, it'll work better for whatever it's in, than that other kind.

 

The cam I have now is good for 2500 to 7000 and it works very good for my application, and no my motor is not computer controlled, and that cam only works in that RPM range well, why would anybody want a cam like that.

 

Marine application where the engine spends hours and hours at high cruise rpm. Or someone like Sofa said that starts with "L" that is after "show-only"...

 

well most people wouldnt... they just think they do... but sofa was just giving an example RPM range in the middle and very narrow is what he is saying... as in just to start a engine infront of a crowd and hear the oowwss and ahhhs

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nobody runs a marine engine that slow well except for the deisel guys or the cheapo people thinking they are saving gas but torque in a marine application is relativly useless as you only need to spin maybe a 18-19 inch prop so being able to spin that to 5500 off the line when the hull isnt going 5 knts just slows you down... not that marine racing is drag racing but you get the point

 

I know what you mean by the ooo's and awww's at the car shows, but at the track when I blow them away, we'll see who gets the ooo's and awww's then

 

Yep, that's what I was going to say. They advertise them as giving the muscle car sound, they don't even try to market them for power. That kinda tipped me off right there. The specs just looked weird, I don't think it'd be optimized for power. So yea, stick with your current cam.