Why is CC manipulating cam timing like they are b/c I would think they would need to use wider LCA's??

What's going on with them??

pdq67

Why is CC manipulating cam timing like they are b/c I would think they would need to use wider LCA's??

What's going on with them??

pdq67
=

Not Harold but here is my opinion,,
It is called marketing to the uninformed,,,
Or if we call it something really coooooooooool :cool:
Some bright spark will buy it. :D

Id say that they are marketing cams to the guys that are basically clueless , anbout engine mods,but who want a car to sound good at idle (LOPE) with few other considerations

Paul,
You might like this :D

http://www.chevelles.com/forums/showthread.php?t=153060

They will sell well. I wouldn't buy one.
Just look at how often there are posts by guys wanting to know what is the lumpiest cam they can get for their car.
I learned my lesson back when I was younger - had a 65 with a 327, stock stall Powerglide and 3.73's. Put a BIG cam in it - couldn't fall out of a tree! Great from 30mph on up, just took too long to get to 30.

Mike,

I guess even after going over that link again a couple of time's, I still don't get it b/c I figure any cam that sound's "knarly" really need's compression to do it..

I see how an old Crane 274H06 and Isky 270 Mega works, but not the new Thumpr's cam timing!!!!!!!!

So I can't see selling them to guys with low compressioned engines so how do they produce power like the old high compressioned needing cams of old do???

pdq67

Very similiar to the Comp N2O/blower cams. Added exhaust timing but the ICL stays is at 106-108. This allows the exhaust valve to open at a point of higher cylinder pressure. When I had the Comp NX279HR (230/242, 113LSA/108ICL) in the 402 motor, is had a lopey yet very crisp idle quality. Where it really came alive was WOT. You might have thought I went from the 9.5/1 402 motor to a 11/1 427 motor based on the exhaust note.

Id say that they are marketing cams to the guys that are basically clueless , anbout engine mods,but who want a car to sound good at idle (LOPE) with few other considerations

There are lots of guys out there that care about this one thing: "How it Sounds"

Really, lots of Street Rod Dudes like that. All Billet, Bling and Sound!

It is a differant mentality with the Muscle Car Dudes.

Well, here's the spec's on one of them, (hy-roller), from over at SGCOG....

291/235/311/249, 107/?, .521"/.507...

Now it seems to me that a 291 cam will need right at 11 to 1 CR!!

How far off am I here is why I'm wondering about this??

pdq67

Here's the theory: (courtesy of our old friend P.T. Barnum, hot rod parts marketing genius) There's a sucker born every minute!

I'm surprised they don't call em 3/4 race cams!

A typical conversation from the old days....or maybe even today?
You can tell which one I am in the conversation.

"what cam ya runnin...."
"It's a 3/4 race"
"so it only has 12 lobes?"
"huh"
"nevermind, hows it run?"
"pulls the front wheels 12" off the ground with street tires!"
"ok....what's it run in the 1/4?"
"well, this is our first time out but I'm sure it's way into the 11's"
"uh...ok, if you say so"

Said car ends up running 14's shooting ducks all the way down.

But hey, if they sell a ton of them, it will help the R&D budget for the real stuff.

Ron

A good cam for waxers

Ron454: "Said car ends up running 14's shooting ducks all the way down."

Sounds like you been around awhile.....

>>help the R&D budget for the real stuff.<<

The only R&D they have is in the Marketing Dept. IMHO, of course.

A good cam for waxers

The ones that wax-off????????? :D

Look, I'm trying to learn something here or I won't keep harping on it.................

pdq67

Look, I'm trying to learn something here or I won't keep harping on it.................

pdq67
=
Paul,
It is marketing plain & simple.
There is nothing magic about them
You have to look no further than their press release, it tells you all you need to know.
I don't think it can get any plainer than this
http://www.compcams.com/information/whatsnew/NewsDetails.asp?ListHistoryID=-1307765382 (http://www.compcams.com/information/whatsnew/NewsDetails.asp?ListHistoryID=-1307765382)

If after reading this you don't get the target audience,,, I give up :D

The "Thumper", the noisy gear drive, and the 3" exhaust system needs to be sold as a "Coordinated Kit" to take the guess work out of stupid.

Gottlieb Daimler and Carl Benz are spinning in their graves.

The "Thumper", the noisy gear drive, and the 3" exhaust system needs to be sold as a "Coordinated Kit" to take the guess work out of stupid.


Yeah.. and they should call it " The high school confidential package" :thumbsup:

What are they going to do with that pile of 305 magnums all of those guys used to put in their 8 to 1 smog motors :D

Well, all that said, please check out the three SIM's that CC ran for onna the guys over at SGCOG..

http://www.nastyz28.com/forum/showthread.php?t=75725

Doesn't look all that shabby to me, but I still don't get how they get by using them in lower CR. engines???

I do know that you start backing off on CR. and try to run a "knarly" cam and it get's soft in a hurry, so what's going on??

pdq67

Paul, I haven't looked at the cam card so I'm just guessing, but I'd think they get the "knarly sound" by messing with the events during overlap, but keep it low compression freindly by keeping an early intake close?

Kinda like using an intake lobe from a 270 magnum with a (somewhat shaved off) exhaust lobe from a 305?

Now that I can understand Jim!!

In other words, even though the advertised intake duration appears to be a whooper, they are closing the intake valve at a more normal time so it can handle average compression and then juggling numbers/centers so that it runs fine!

AND is old-school cam cackle noisy and not XE valve train noisy!!

Gotcha guys!!!!!!!!!!!!!!!!!!

Thanks,

pdq67

Not to vendor bash, but I have a legit question.

Seeing as we are already swapping from a flat tappet to a retrofit roller for the sake of a cool idle, when can we expect to see the Thumpr lifters hit the market? Cause certainly we cannot have ultimate thumpage with a standard retrofit roller lifter.