I posted earlier about needing a cam for a new 400 build

posted 10-10-2004 12:32 PM
--------------------------------------------------------------------------------
400sbc, .030 over 2 bolt block, decked to .005
Scat 9000 crank, scat 4340 5.7 rods
Wiseco 20cc dish forged pistons
Vortec heads, will upgrade to required springs etc.
Compression 9.8-1
Rpm airgap intake, holley 3310 750vs
Hooker super comps, full 2 1/2" flowmaster exhaust
TH350, 3.73 c/w eaton posi rear
The Beaumont is approx 3600lbs.(guessing)
I am looking for good performance but with reasonable street manors. Vacuum needed for brakes. I am thinking maybe a f.t solid cam
I currently have a 2000 stall convertor but can change if needed.
UDHarold , you out there

I called a few and come up with these choices. Any comments

Comp xe286s 280/280, 232@.05, 487 lift 108lsa

Howards(custom grind) 246/254 @ .05, 510 lift 110 lsa

Crower #00322 , 282/292, 248/254, 508/528, 112 lsa

Isky 272/272, 238/238 @ .05, 480/480 lift, 112 lsa

Lunati #40155, 280/280, 232/232 @.05, 487 lift, 108 lsa

Crane (hyd) 284/290, 228,234, 480/494 lift, 106 lsa

Elgin #mft68512-15, 274/274, 238/238 @.050, .502 lift

I am hoping to actually talk to Mr Brookshire for his thoughts.


Jerry

I would call Cam Motion, let them grind you a cam of unknown (to you) proportions and just run the darn thing. It will run as hard or harder than anything above and save on your long distance phone bill. LOL

Don't be suprised if they don't ask you what DCR you are going for. ;)

One thing to consider - typical density altitude is 5000 feet where we are so you will need either less cam or more compression to run up here.

Are CamMotion grinds pretty good? You mean they did not give you the detailed specs? That would bother me. I like to know what I am buying before forking over hard earned cash! smile.gif

They are as good as any - of course they give you the specs - I mean to say don't get carried away overanalysing it - just TRUST that they know what they are doing.

Phoning some camhelp lines is the equivalent of asking the teenage kid at the McDonalds drivethrough which burger will lower your cholesterol. Many are just sitting on the other end reading the same catalog you are.

MMM...Burger...

with your motor combo, i like the lsa at 108. check out pat kelley's dynamic compression ratio calculator for some interesting info. i built a 350 with 10.2 c.r. & a comp cams 270h and found it to be at 8.23 dynamic c.r. worked 4 me.

Jerry,
I think what 283 (?) is trying to say is that you can get real carried away in over engineering a cam selection. It was not that long ago (or it doesn't seem to be smile.gif ) that there were only 5 or 6 different grinds available and we still managed to go fast. I will go way out on the limb and bet that if you built the same exact engine and tried every one of the cams you listed, there probably would not be a difference that you could actually "feel" in the performance of the car. Yup .. there might be a one or two tenths difference in 1/4 mile performance from the best to the worst, but I dare anyone to tell me they can "feel" a tenth or two, especially in a street car. If you are really concerned about real performance numbers, you would do better channeling your energy towards suspension setup. Most street cars will spin at least 5 tenths, if not more.
So bottom line is, pick a manufacturer, tell them to suggest a cam, buy it and go on with life smile.gif

Just my opinion,

Bill, I thought about it after 66283 posted and I have to agree. With this being my first complete build and with not enough knowledge to pick my own cam, I thought getting a recommend from as many as possible would be the way to go, but now I see it isn't. I am going to pick 1 manufacturer and supply them with as much info as possible and fly with it.
I guess I was just wanting to ensure I was getting the best possible cam for my intentions.

Lesson learned ;)

I would question why any cams were suggested in a single pattern with those heads.
Try and get a cam with 8 maybe 10 degrees more on the exh side vs int.
Hyd cam with anywhere from 230-239 @.050 .480-.530 lift 108 sep would work fine.

I didn't mean to be an a$$ about it but it came across that way. I've been there - spent a lot of time picking my cams and always found that I wanted to change it afterwards.

Lately a bunch of my friends have gone with cam motion - some strange numbers on some of them that might not pass the communal sniff test here but they WORK! Have your cylinder head flow numbers ready for when you talk to them. Oh, and your desired DCR too :rolleyes: :D

If you don't like the cam they grind you, I will buy you a two-four of Molson Canadian and bring it over to your garage and console you.

If I was to pull a number out of my a$$ I would say 245/255 @ .050" on a 110 (high altitude, you want vacuum) and as much velocity and lift that they say a solid lifter can tolerate on a daily driver type car. (not sure what the .200" dur limits are on flat tappets).

(I am either going with cam motion or Lunati - the latter have been really good to me with my crankshaft repairs so I am willing to give them a try because they have provided great service to me.)

Here's some advice.

1) Be realistic with what you do with the car. Weekend driver? Daily driver?

2) HOw often are you going to go 6500?


The point of those questions is that it is likely you want to go milder and won't regret it, unless you want the most average power from 4000-6500, otherwise stick to a smaller cam.


I think the biggest mistake most make is they overcam for their real needs.


If you have a 4000 flash converter, slicks, don't care about gas mileage, etc, go bigger, otherwise stay conservative.


A true racecar or dedicated weekend strip car is anothe story, but it sounds like you have a nice driver.

Jerry,

I would use either a 401AA3LUN, 272/282@.020, 238/248@.050, .485"/.503" valve lift and 112 LSA, or else, as the biggest, the 401A6LUN, 276/284@.020, 243/251@.050, .518"/.530" valve lift, and 110 LSA. The 401A6 has about .500"/.510" NET lift, and has always worked fine in the Vortecs. Both have lots of low end torque, and peak power around 6000 to 6200.
The 401A3 normally goes a year between valve lash settings, both cams have gone over 100,000 miles on the street. I recommend a good high-volume Holley or Carter mech pump and 1/2" fuel line.
A 406 with a 2000 stall converter should work with these 2, and particularly the 401A3. The 401A6 may need a 2500 stall converter. The 3.73 is just fine.
If you order either of these 2 from Lunati, make sure they know it is a 406 with 5.7" rods---You need a small-base-circle cam.....

UDHarold

Jerry, I use the bbc version of that A6 cam in a 440 and it KICKS! Very nice cam. Great mph from a heavy street car.

I have the 401A6 in my 10:1 406. I like it. It really wakes up around 2200 rpms. The sound changes and it just goes. Good Idle too. I have this in my 1980 camaro daily driver and the brakes work fine.

MaTt

Couldnt be happier with my Lunati/UD cam...
Just wish I had gone a little bigger!
Should have told Harold my true intentions for the motor graemlins/clonk.gif

graemlins/thumbsup.gif

Geez, that's funny, I awlays think Harold goes really big on his recommendations, bigger than I would think in most all cases.... I think he would have put me into a different lobe somewhere between the two on the A6. Was worried about pump gas and 10.5:1 with the 276 intake I guess.

Yeah, I hear you now Mr. Brookshire! graemlins/clonk.gif