Springs for a thumpr cam

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stroker mike

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My new project has a 318 with 308 heads, and I'm gonna do the deal on it, and I am gonna swap out the cam for a 20-600-4 thumpr from comp cams. I don't wanna have to take these heads off to get them machined for a double spring, so I was wondering if an 1102 from hughes engines would work right? Any cam doctors out there? Thanks!
 
The comp cam is under 500 lift,and looking at the 1102 springs,you should be fine.I say use the comp cam with the correct new comp lifters,and run it.

My concern would be if this is to much cam for the "teen".
 
The lift should be good, but the spring rate at higher rpm is what concerns me, the whiplash series runs that 1102 but the rpm range on those cams is up to 5300. The thumpr should hang up to 5800, maybe 6000. Will a single spring be less effective at high rpm? The pressures seem right, I just aint sure about the rate. Am I even making sense? Ha!
 
what I did was run camquest and this was what came up first, I want 350 hp out of this 318, and it met the goal. I built a 360 last time, put a big ol cam in it, range was @2400-6000 and I know the 318 will rev much better, so I was hoping this little thumpr would work nice.
The other one that came up was a 275DEH which is a pretty beefy grind it seems, like a 318 whiplash but bigger. "Superior top end". I want something bigger than the 1326 hughes grind. Maaybe the thumpr is too big? I want it choppy but streetable and fun! I also want it to pull to 6!
 
A 260/260 comp cam in a 308 head 318 will pull to 6K.........
Ditch the Thumper, they are timed for a choppity idle......


I had ran the 275DEH before, it doesn't work well with a stock TC, so if you have one of those, you won't be very happy. The best running cam, with a stock TC I have found, for the 318, is the 268 voodoo, and the 270 Isky. Engle makes very nice cams too.

The Thumper, is for street rods, IMO, you know, look at me I am cool cars.
 
I was just lookin at the hp/tq curves on camquest.. I love that choppy sound but I love the 358 horses better....I want my new duster to sound good and run hard.
 
I would talk to the Hughes boys about your springs.What you can and cant do with them.

To much cam,and the wrong combination can make your 318 fall right on its face.

Make sure you have a good plan,before selecting your cam.

I was thinking the same thing about the Thumper cam,and figured performence is more important than sound. I would go with one of the Xtreme cams.
 
call mike at MRL performance...he will set you up with a cam you need and the springs
 
Mike Liston? Yep, he's a nice guy. Sure knows how to build a 318. BTW I took a close look at the Isky grind listed above, and you know what? That's a darn good grind! Very similar to the grind dusturb318 was running in his duster, but hydraulic. I'd like that, yessir!
 
One to take a look at,this is a very good cam series thats not real well known,Ive used the bigger one a few times and really like them,Im using one in my 340 build now.They compare with the comp xe cams as far as their agressive lobes,great way to get good power and a choppy idle. http://www.lunatipower.com/Product.aspx?id=1529&gid=277 Ive also used these springs with good results on cams in this range,the specs match up well,they are identical to the mopar performance springs ect. http://cgi.ebay.com/ebaymotors/NEW-...r_Truck_Parts_Accessories?hash=item439bb7dd46
 
dusterb318 is running nitrous..so i think its a cam that helps him with nitrous
 
Is the 1101 a single spring? Yeah Phil is running niitrous but that cam is a 220 single profile solid... usually a nitrous cam will have reduced overlap and significantly more exhaust duration, so it's hard to say what the design function was, but I know he is getting very respectable results!
 
stroker mike said:
My new project has a 318 with 308 heads, and I'm gonna do the deal on it, and I am gonna swap out the cam for a 20-600-4 thumpr from comp cams. I don't wanna have to take these heads off to get them machined for a double spring, so I was wondering if an 1102 from hughes engines would work right? Any cam doctors out there? Thanks!
Click to expand...

Hughes makes their own version of the Thumpr, called the Whiplash. It would list spring requirements for the cam
 
I was running a whiplash before, the 1326. I want the range to run into the 6000's. I didn't chose the thumpr for the sound, but because when I ran camquest it was the number one pick for my setup.
 
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