I have a 72 mach1 with a 351 cleveland h code. I have a edelbrock 4 barrel intake and 600 carb for it. I also picked up a comps cam thumper series camshaft. Using stock exhaust manifolds but switching to dual exhaust from single. I know its not the best cam i can pick but im just makin a cruiser out of it not lookin for high horse power. But was wondering if anyone may know about how much horse power gains i can expect outta this setup. Any help would be appriciated. Thanks.
Okay, so I went to Comp Cams on their on-line chat and spoke with an agent.
At first all I got was that they cannot give out estimates of horsepower and torque but Comp Cams is #1 .... He finally did state that in a SBC the Thumper Series cam produced about 10% increase in horsepower over the stock GM performance cam.
So other than their promotion of the "sound" of the Thumper Series cam an increase should be seen. Of course couple that with the new intake, a 600 CFM carb, and dual exhaust - the increase should be noticeable in the seat of the pants department test and should sound good. I don't think you would be looking at 350 HP but an increase of the stock under 200 HP to the higher 200's is a possibility.
Let's hope that someone else will jump in that has personal experience with real numbers.
Go to the comp cams website and download there CamQuest helper. Put in your specs, it will have everything from carb, intake, heads, exhaust, etc. After you add all the info it will give you a very close estimate of what kind of power you can expect. Great tool I've played with it on real engines and ones I'm gonna build, it's great. JTS 71 Mach1
(04-18-2012, 04:35 AM)JTS71 Mach1 Wrote: Go to the comp cams website and download there CamQuest helper. Put in your specs, it will have everything from carb, intake, heads, exhaust, etc. After you add all the info it will give you a very close estimate of what kind of power you can expect. Great tool I've played with it on real engines and ones I'm gonna build, it's great. JTS 71 Mach1
Wow, didnt know about that. According to camquest i should be around 275 hp and 305 ft lb of torque. I can live with that out of a basically stock motor. Thats more than i figured.
Yeah if you change things such as your carb size, say to a 750 with the other specs staying the same it will make a noticeable difference. Gives you lots of variables to play with. JTS71 Mach1
It is very important that you check for push rod length when you put an aftermarket cam in. Most all will have a different base circle which can effect the valve train geometry amoung other things, making the rocker not sweep the valve tip in the center. I can pretty much guarantee you the lifter preload will not be right as well. You want to keep the preload in the .020-.040 range IMO. Some people just throw them in and "get away with it" but it's not right and they don't even know it. Even if it runs ok you will most likely be leaving power on the table. I highly recommend degreeing it in to be sure you are getting the most power you can get. If thats out of the ? then at least get a good quality chain & gears and set it in the zero slot. It is also important to get the springs the mfgr recommends and put them in at the right height and check for coil bind, rocker to fulcrum bind, retainer to guide clearance, stem seal clearance, piston to valve clearance, etc then you will get the most from your new cam.