Technical Bootlegger vs voodoo cams

Call Clay Smith.

 

Let's take a look at the specs and what COMP is doing to create "lope" with the thumper cams. Comparing to extreme energy line as a typical performance cam.

Comp Thumpr 227/241 GK12-600-4
Dur 227/241 Lift .479/.465 LSA 107

Comp Thumpr 235/249 CL12-601-4
Dur 235/249 Lift .489/.476 LSA 107

Comp extreme energy 12-242-2
Dur 224/230 Lift .477/.480 LSA 110

Comp extreme energy 12-246-3
Dur 230/236 Lift .490/.490 LSA 110

Thumpr - - Less LSA, Double the duration split for exhaust - compared to extreme energy.
Interesting the exhaust Lift is less than intake on the thumper - performance cams typically use more lift on exhaust

Cam referenced earlier, specs align with performance cam, instead of "creating a lope". This is a lot of cam for a driver.
Lunati VOODOO 276/284
Dur 233/241 Lift .504/.525 LSA 110

 

I'll probably never run a thumpr cam, I choose cams for best engine / vehicle match for intended purpose. Extra lope to cruise the parkin lot has never on my radar.
I've seen dyno results or threads where the user is very happy with these cams.
Looking at the specs, I see what's going on.

 

Look at a Comp 12-243-3. I run this cam in my daily 70 Chevy K10. .060 350 with 10.3:1 comp., worked over 416 (305) heads, hedman headers with 2.5in exhaust, Edelbrock EPS manifold and 600 carb, HEI, ect..... truck has a 4speed, 205 t case, 3.07's in the axles. I wanted gobbs of torque and power, fuel mileage, decent vacuum, and a nice lopey idle, and thats exactly what I got. I can cruise the old logging roads all day, climb hills, pull trailers and heavy loads, drive it anywhere anytime. She pulls hard, climbs to 6000rpm with ease. At idle, it thumps and chops. It intimidates a lot of people when they realize its my old pickup. It is very well street mannered, rpm range is 1800-6000rpm, I idle mine at 700rpm, but when you wanna get out of your shadow, it goes. Yes i know this truck doesnt fit this group at all, BUT, i would not hesitate to run this cam in about anything, especially an old hot rod. It would be a great choice. 226int/234exh, 270/278, .480/.498 lift, 111 lobe seperation.

 

I posted an older video of it to my youtube, hope this helps your decision.

 

I think if you stick with a LSA 106-108 you will get what you are looking for. Crane has or maybe it had, saturday night circle track cams that I liked. I have a 238/244 at .05” and 106 lsa in a 406 and like it. Vacuum is marginal bit this cam is much bigger than I would suggest for your application. They offered some smaller cams too. The lunati you selected seems like a decent choice, just a little smaller than I think you could get and still be happy. However, if not sure erroring on the small side is the safest bet.

here is a size smaller which would be better for street

 

The Chevy 350 engine in my T Bucket is bone stock except for this camshaft. It has a quadrajet and a stock torque converter. It was originally in a low budget stock car. It definitely has a very lopey idle and I love it. It “almost” never stalls at stop lights. Occasionally I have to feather the gas pedal to keep in running. I have no vacuum accessories on it. I have 12,000 miles on it, and am very happy with the cam. I can easily squeal the tires right off of idle, but that doesn’t take much in a T Bucket with an open rear end. There is something to be said for driving a hot rod that sounds like a hot rod.

 

Vacuum most certainly will be an issue with an LSA of less than 110.

 

Driver 50X, unless you're using stock valve springs from the 50s/early 60s, why would you want a cam that has a net lift of less than .400?

 

If you don't have power brakes, and don't intend to install a power-brake booster, why don't you just convert your vacuum wipers to electric. Newport might have a kit for your application. I'm eliminating all of the vacuum accessories on my 55 Tbird and have bought a Newport electric wiper kit. I don't have power brakes.

 

I have the Newport unit on my car, my OG Trico wiper was a fossil. No power brakes either. I run a full manual Holley 700 with a manual choke. I went with the Voodoo cam over the Comp Cams XE268 based on reviews on how noisy the cam was under the valve covers. The Voodoo is as quiet as a mouse.

 

True, mine was marginal. Power brakes were good for a single shot but not double pump so I switched to manual brakes. However the cam and engine are pretty impressive for not being that large. Best et is 11.70 in a 3400 lb car with 8” converter

 

Malibu406, it sounds like you have the right tires and suspension to hook up, not to mention gearing.

 

I have been thinking about it. I will have disc all the way around, but thinking of using a manual master cylinder. I just might go electric on the wipers as well.

 

Well I'm hoping the heads will be done soon, really excited to get this thing together. I need to get focused on the rear end swap too. That's a big one, the leaf kit ain't cheap!

 

Because the rules in that racing class required a maximum of .400 lift.

 

That motor doesn't have a lot of compression, but you want the sound of a race engine. A big racey cam will give you the sound but be super lazy at low rpm. There is an older cam that works very well in that application, the Crane 274h06. Moderate duration with tight lobe centers. Google it for numerous reviews.

Crane is out of business but Summit sells the same grind. I think Melling also sells it.

 

I would not use less than 110 LSA. As you increase duration, the shape of the lobe changes and that gradually increases how much overlap a cam has. To get or keep a more gradual ramp for the lifter to ride up, you have to widen the number of degrees the lobe is active. As you widen both lobes, they overlap more.
I also would not believe all the glowing explanations the manufacturers put out on what their cams will do. Basically you give up something to get something. The cam that gives you the most HP never gives you the most torque. Usually the biggest mistake most beginners make is "over camming" an engine. I would look for a cam that gives you the best mid-range hp/Torq.
This is also where the gearing you select rears its ugly head. Not just the rear gear ratio, but the transmission ratios and the number of gears in the transmission of choice. Thats why an overdrive transmission makes a wise choice. You get a lower first gear to assist some of the torque you give up with a hotter camshaft.

All these things tie together. Thats what you have to learn, its about choosing the things that will give you the most/best advantages.........while still being enjoyable.

One of the neat things about modern fuel injection (EFI) that can't be run on a Hamb vehicle is the ability to load multiple "tunes" into the computer. Select the one for gas mileage and take a trip.........or select one that makes the engine run roughly and sound like its got a hot cam when cruzin. Sadly, not an option with a carb engine.

 

It's not likely you're going to use your 41 for road racing/autocrossing. Unless it's just for the "bling," I wouldn't spend the money on rear discs. Front brakes are responsible for 70-80 % of your stopping power.

The OEM brakes on my 1988 Mustang 5.0 (disc front/drums rear) were marginal. Initially, I replaced the stock calipers with larger Lincoln calipers, which were an improvement. I then replaced the rear drums with Stainless Steel Brake Corp rear discs. Any improvement in braking was negligible.

I have Wilwood Dynalite 4-piston calipers on my 55 Tbird, but the rear brakes are the stock 11-inch drums.

 

If you look on Summit, Jegs, or cam manufacturers' websites, you'll find that the majority of off-the-shelf flat-tappet cams have a 110 LSA.

 

The old number is Crane Cam 100172. The Summit Racing number 1785. I think this cam is close to the 327/350 Chevy cam which had a 222 degrees @ .050 and .447 lift but its ground with a tight lobe center. It is one of my go to cams.
Easy on the valve train due to a .450 lift. It has a nice Rumpty Rumpty Rumpty sound.

I remember in the eightys Crane cam out with that cam like it was an all new cam. It was advertised it as the "3/4 Cam" for SBC. It may have been a renamed "Fireball" cam.

Seems like the same basic specs were used for the Saturday Night Special cams at the dirt track in the 80s too. Maybe a Howard's grind?

 

Here are the numbers on that Summit cam:
Make - Summit Racing
Cam - SUM-1785
Type - hyd Flat Tappet
RPM Range - 1800 – 5200
Duration @ .05 – Int - 218
Duration @ .05 – Exh - 218
Valve Lift Intake - 0.450
Valve Lift Exhaust - 0.450
LSA - 106

https://www.summitracing.com/parts/sum-1785

notes: "The tight lobe separation will boost your torque, throttle response, and mid range power for exciting action at the track and on the road."

 

I'm running them on the rear since the explorer axle I got have them already. I feel the same way though, drums would have been fine but I got the 8.8 for free so I won't complain.

 

Study this and you can see what you get and what you lose. Take notice of "narrow power band" and "wider power band".