Well im starting to get parts for my 400 and was needing some help picking out a cam. Im not set on anything yet as far as the heads go, but i was thinking about using the dart pro1 aluminum heads with a 1.6 roller rocker on it. The intake that im going to use will be a hsr since its in my price range and good for letting the 400 breath up top. Thats one thing that im set on right now.
So for the cam i found a crower grind thats a hydraulic flat tappet that looks like itd work pretty good. It specs out at 288*/296* adv and 234*/246* @.050 with 497/504 lift with a 1.5 rocker. Do you think that this will work out pretty good with everything?
Also, does the stealth ram like a single pattern or a dual pattern cam? if it likes a single pattern, what would be a good cam to work in the 2000-6000 range thats a hydraulic flat tappet? need some help from the 400 gurus running round here.
Thanks for all the help
chris

 

ne one at all?

 

Okay, here's my take on some of it.

Whether or not you should go with a dual patter or single pattern cam depends on the head intake to exhaust flow ratio.

Anything below 70% calls for a dual pattern cam with longer exhaust duration.

There are a couple of way to address this.

You'll need the flow numbers of the heads, from at least .100 to .600 valve lift. Add all the intake flow numbers together and divide by the number of data points to get the average. Do the same thing for the exhaust.

Now divide the larger into the smaller - exhaust into intake; that will give you the average flow ratio intake to exhaust.

Another way is to use just the .400 flow numbers of intake and exhaust and determine their ratio. I prefer the former though.

The absolute best way is to flow the complete intake/exhaust track - TB/carb through the ports with everything bolted together as a unit; just as it would run on the engine. Not many want to spend the time and $ to do this though.

Choose your profile accordingly.

234/246 is a pretty healthy camshaft and will make excellent power, but the engine may not come on the cam til a bit higher that the 2000 you're looking for - perhaps 300 to 500 RPMs or more higher. It'll probably need higher compression too.

You didn't mention street manners, so I don't know what you expect in that area. Vacuum may be a concern too for the power brakes.

Aside from that, give close consideration to the LSA and the ramps the cam is ground with. Cams like CompCams Xtreme Energy series and Crane's PowerMax series have very aggressive ramps which work well in the RPM range you're looking at.

Keeping the LSA on the wide side helps with idle/vacuum quality too.

Hope this helps.

Jake