In the 15 or so years I ran a HP automotive machine shop I cant remember a bad CompCams camshaft. If one failed it was from improper break in, no lube, wrong springs etc. I found CC to be one of the better companies and I have used cams from pretty much all of the companies out there. Guys always wanted too big a cam for their applications cause they wanted "that sound" Thats why the Thumper came to be... to cater to a market no one else was. Just good business on CC's part.
Sad but true. Search the posts on cams: "I want it to lope" is #1 on 90% of the comments. As long as cams are part of posing, the mfgs. are going to use rilly kewl comic-book names to sell them.
What's funny is the thumper cams make power as demonstrated by the dyno results. Check the Hot Rod cam tests I previsouly mentioned, the Thumper cam produced the best power even compared to a cam with similar characteristics only it was an Extreme series cam.
I have run basically every cam on the market and some that were custom built for the application. Comp make a decent cam. These Thumpers are just for that... Thump. They make decent HP but no more or less than their run of the mill stuff. All they have done was closed up the lobe seperation. That's nothing new. If I wanted a big thump and power to go with it, I'd just put a decent sized roller in. That way you get both. Kevin Ooltewah Speed Shop
I have a 280H in my 9.5 to 1 350 in my 39 Willys with a Performer RPM intake and a 750 double pumper, 2800 stall converter, 4.86 gear and a 31 inch tall tire. Weights 2700 lbs with my in it. Got it to go 12.1's right off the street on pump gas. Has a decent idle and makes power. You might want to try a little bigger carb before you start going into the motor. Try a 750 double pumper. See if one of your buddies has one you can borrow. My car picked up 4 tenths going from a 750 vacuum carb to the 750 double pumper. Also how much timing are you running? That makes a big difference on the track.
By a crane and with the money you saved get a decent set of heads. Actually as has been mentioned Lunati makes a damned good cam for the money.
It may have been Chevy High Performance or Super Chevy - not hot rod. I'll have to look up the article from my stack - it was within the last 4 months I THINK. Comp Cams rocks. I think its BS to let a few comments deter you from trying them.
i seen the article too.... im thinking it is Hot Rod.... cause i dont get the other two (subscription)
The reason I went with the Vortec heads and the Edlebrock Air Gap intake manifold, was because of an article I read in Chevy Performance Magazine about a year ago. The article was about what bolt ons would give you the most bang for your buck. They started with a 350/290 hp Chevy crate motor, which was what I had. The article concluded that the Vortec heads and the Air Gap intake would give you the most bang for your buck, so I went with them. I guess it's the same as when I started this thread asking for opinions on the Thumpr cam, some will tell you they like them and some will tell you their crap, I asked for opinions and I appreciate the ones I got. I'm just going to have to pick one and see what happens, if my car runs 7 or 8 tenths faster with the new cam I'll be happy.
Engine displacement is a biggie, but so is engine compression. "You have to have a suitable compression ratio for what you're doing, Too little compression ratio-or too much duration-can lead to a drop in cylinder pressure and a corresponding drop in power. Too much compression- or too little duration-can create too much cylinder pressure, leading to detonation. I run a solid crane in my pontiac, wouldnt have it any other way.
The thumper closes up the lsa to 107 degrees, which is a performance, not an economy factor. The exhaust duration is way more than the intake, like 227 I, 242E @.050. The excessive exhaust duration creates most of the thump and the increased scavenging is probably what creates the power increase. Food for thought. The intake event probalby closes early enough to make low end power loss not noticable, and create a good street cam. Its all in the timing for sure. I'll bet that fuel economy is nothing to write home about, however.
Uh, Crane closed the doors a few months back. I got an auction paper where they were selling all the tooling and equipment.
they sold the company to S&S cycle. The cam sales is on hold for the time being until they get set . found my power max mechanical at swap meet new in box. 281241 [f-248/3334-2-12] 248/258 dur, 0.500/0.520 @.50, lsa 112 works great 3800-7000 range with my six rochester 2-g carbs, 10-1 compression had to perform some tricks /updates to the old 63 pontiac heads, springs pushrods, screw in studs, etc
a little more cam may help, 7 or 8 tenths is alot to ask for, what tires are you running slicks? does it hook? i have thought I was hooking with low gears and street tires and switched to slicks and got close to a second!!!! if you are hooking up that cam may get you what you want!!!
I'm running 28" M/T ET street drag radials, Cal Trac traction bars, and QA1 adjustable shocks and it hooks good but still only does 2.0 second 60's, it takes a lot to get my 3700 pounder going. It turns mid 14's now and I'm trying to get it into the 13's, which would put me closer to 13.00 which is the low end of the class I run in.
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