[mylittle307]

here is the deal, redoing my 400. It now will have 062 vortecs, mild cleanup, performer rpm air gap intake,9.5 cr, 750 holley vac, 2500 stall th 350, and 3.73 gears. I currently have a magnum 280 cam. Irt pulls good but doesnt have the rumpity rump, that i need. What is a good cam that will sound tuff without needing to get new converter and gears? The compcams help guy suggested an extreme energy with 240, 246 @.30 and .507, .510 lift. When i dd it, it makes less torque and 30 less horsepower than my cam. Is this righjt? Suggestions greatly apprteciated thanks guys

[pdq67]

D2K can't input cams other than single pattern cams!! Sure wish they would let us input dual pattern cams into it tho b/c it would a lot more accurate, but probably would cost a lot more!!

I'd consider an Isky 270 Mega hy-cam b/c at 9.5 to 1 CR., you aren't high enough to run a knarly cam like their Z-30 solid that needs at least 11 to 1!! It should cackle a good bit b/c of being ground on 108 centers!!

AND imho, a 280 needs at least 10.5 to 1 AND preferrably 11 to 1 to run it's best!!

I know a 292 needs 11 to 1!!!

pdq67

[72Tugboat]

Why can't you do dual pattern cams in Dyno 2000? I do it all the time.

Duration at .050 us more important than advertised duration. Advertised duration isn't even a standard spec, different companies measure it differently. I've run a Comp 280 with 230@.050, a Clevite 282 (RV) with 204/214@.050 and a Energizer 266 with 210@.050. The last two were about the same, the first one was much different. All these were in 454s in the same vehicle, a station wagon.

A 270 won't have a rough idle because of tight lobe centers. Don't worry about the overlap, worry about the intake closing point.

230@.050 is a little much for a 2500 converter as it is, I wouldn't go any higher on that. But there are some cams with long ramps that have a long advertised duration to get a rough idle, something like this:
http://www.cranecams.com/?show=brows...tType=camshaft

GL

[travis]

Crane makes a cam that would be perfect for you. I dont have a catalog handy, but its 228/234@.050, .480/.494 lift, 106 lsa, on a 102 ica. It would definately have some "rumpity rump" to it. The XE284 that comp reccomended would also work very well if you had a bit looser convertor, and also has a good thump to it.

[pdq67]

I'm probably all wet and just confued is all?????????????????

pdq67

[72Tugboat]

Along the top of the D2K window there are buttons for new file, open file, save file, then in the next group the center one is "cam math" which lets you enter specs. Or if you know the opening and closing points you can enter them in the camshaft section. Using .050 durations seems to come close to the cam makers power ranges.

GL

[Silver69Camaro]

As Travis mentioned, a tight LDA is the way to go. You get the bad-boy idle sound, AND a killer midrange pull. I went with a 106LDA on my roller, and WOW...it pulls hard. The idle isn't too bad, it can idle at 800-850RPM.

Your 400 will really like the tight LDA, because those heads are a bit small for the motor. The more the engine is "under-valved", the tighter the LDA should be. And we're talkin' about 30 lb-ft or more on the table...

[pdq67]

Back again, I'm thinking of inputting both advertised and duration at .050" values into D2K is all. NOT dual pattern cams....

The Extreme type cams with their aggressive hydraulic intensity numbers doesn't work very well in it is all when compared to the older, regular cams made before they came out.

pdq67

[DOUG G]

I have the Compcam 280H in my 400 +.030 with now 10.17:1 and I think it sounds fine also my motor is even balanced which takes some sound out of it, IMO.

My next step might be a solid or a huge hydraulic, still looking.

[72Tugboat]

Originally Posted by pdq67

Back again, I'm thinking of inputting both advertised and duration at .050" values into D2K is all. NOT dual pattern cams....

The Extreme type cams with their aggressive hydraulic intensity numbers doesn't work very well in it is all when compared to the older, regular cams made before they came out.

pdq67

Well, you said:
"D2K can't input cams other than single pattern cams!! Sure wish they would let us input dual pattern cams into it tho b/c it would a lot more accurate, but probably would cost a lot more!!"

Somehow I got the idea you were talking about dual pattern cams...

To be really accurate, you'd have to input the lift at a lot of degree points. The expensive programs do that, but then you have to get the data. The expensive programs will also model torque loss from ports that are too big, which D2K doesn't.

GL

[pdq67]

Sorry 72!! My bad...

I had a brain fart!!

pdq67

[camgrinder]

I would go with a 234/234 on a 110 lobe sep. Install at 106. The vortec heads flow enough air on the exhaust side you should not need a dual pattern cam.
If you go with more duration tighten the lobe centers another 2 degrees.
400 cubic inches is a lot to feed with a set of vortec heads, and by closing the seperation angle beyond 108 without adding a bunch of duration is going to kill the engine beyond 5500 rpms.