SOHC 482 cam selection.

[nitro98red]

Hi. Having trouble deciding cam selection for project. Looking to make the motor streetable along with reliable and still hit the 700 hp and 550-600 ft lb range. Starting off with what I have.
-Pond block aluminum 4.25 bore
-Stroker 4.25 crank.
-10:1 pistons
-Pond aluminum sohc heads.
-Pond aluminium dual four manifold.
-Munro rockers
-2.300 Intake valves
-1.900 exhaust valves.
Car weights in the 3500lb range / TKO 600 / 3:50 gears.
Was thinking of a cam similar characteristics to comp 308R cam.

[jayb]

I think you are on the right track with a cam similar to the 308R to get the performance that you want.  A friend of mine, thatdarncat on this forum, is doing a very similar build.  He just got a pair of Comp cams for his engine that use the 8594 Comp lobe on intake and exhaust, with 114 LSA.  This is a .708" lift, 277@.050" cam.  The duration sounds like a lot, but remember with the very low 1.3:1 rocker ratio of the SOHC you need more duration at .050" lobe lift to get the same valve action as a standard FE with 1.76:1 rockers.  Comp actually provides that data in their spec sheet; they call it " check dur tappet @.050 ", and for this cam it is 266 degrees.  So, you can expect this cam to behave duration wise about the same as a 266 @ .050" standard FE cam.

I'd expect a cam like this to idle around 1000 RPM with carbs, and make 700-730 HP with your setup, assuming you have decent compression.  What have you set up the compression at?  You will need some good compression, like 11.5:1 or higher. 

Edit:  Oops, just saw that you are running 10:1 compression.  That will cost you some power, and maybe the next step down on the cam would be better.  This is the 8592 lobe, with .702" lift, 269@.050", and that check dur tappet @ .050" number is 257@.050".  I'll email you some data on the cams so you can take a look at the options...

[nitro98red]

Thanks Jay.Starting understand the duration part. I am surprised at the amount of lift. It seems a lot when you compare to the stock cams that ford supplied for these engines.Or I am reading the cam cards of the stock cams wrong. Can the valve train be reliable with that much lift? By stroking these motors can you do more with the durations and lift of these motors? Appreciate any info as it has being difficult to find info on cams for these motors or for that matter try comparing them to the wedge cams.

[jayb]

Any time you increase cubic inches you will need more cam, and the SOHC heads will use it.  The stock cams were just over .600" lift, but I think this was mostly due to the valvespring technology of the time.  With decent springs .700" lift is no problem.  Also, factory cams were something like 325 degrees advertised duration, 280 @ .050"; this was what was needed to get over 600 HP from the original 427s.  (One of the offerings from Comp is a cam that is similar to the factory grind; did you get the email I sent with the cam specs?  That cam is labeled as the "retro series").  In your case, with an additional 55 cubes, if you stuck with similar duration to the stock cams and more lift, you should be able to hit your horsepower target.  Of course, the original cammers used a lot more compression.

As far as reliability goes, I've been running over .700" lift on my SOHCs for years with no reliability issues, except for some faulty rocker arms.  I don't have any experience with Munro's rockers, but I do have a couple of them, and they look pretty stout.  So, I don't think .700" lift will be an issue.  What valves are you running? You will want to give that some consideration before choosing valvesprings...

[nitro98red]

Thanks Jay, No I have not purchased the valve springs yet. I was gone to wait to I first purchase the cams and determine the springs . No have not received the email. Really interested in the 8592. My email is sleepyj5@live.com. Thanks for the info.