HeaderDesign.com

The long runners are what limit your horsepower. I ran a few calcs with the info you gave me, plus the AFR flow data. The 21" runner brings the torque curve in very early and strong. Peak horsepower RPM is coincident with the timing of the second return wave in the intake runner. This occurs fairly early. I would like to see your Dyno plots.

If I add 30degrees to your cam the torque curve shifts up about 400RPM, and power goes up by about 40HP over the entire power curve. If I use an 11" runner and the 250ish degree cam, it shifts the entire torque curve up by 1000RPM over what you have now, and makes in excess of 550HP at 6000RPM at the flywheel with open headers. That's where the power potential is, but doesn't beat your setup until after 4500RPM.

Speedracer176

I just wanted you to see that the super ram is in favor with high lift cams with "mild" duration. For a 406 the duration is "mild" for an agressive performance cam.

Anyhoo, take care.

89gta383

I've played with Engine Analyzer with your combo.

Current cam: 431 hp@5K - 481 tq @ 4k
219 cam: 428 hp @5k - 474 tq @4k
CC306: 440 hp @5k - 496 tq @ 4k
XE236: 448 hp @5.5k - 495 tq @ 4k
Cartek: 450 hp @5k - 502 tq @ 4k
ZZX: 455 hp @5.5k - 500 tq @ 4k

I've been playing with combos on EA for a while now. It allows you to change intake runner length, width, flow restriction, etc., and is more intensive than DD2000.

I also had my heads and superram flowed a while ago. Go here for the flow tests: http://briefcase.yahoo.com/bc/micdoc...+tests&.view=l

Basically, my ported AFR 190's flowed 282 cfm @ .500 lift head only, and with the superram attached, flowed 244 @ .500. My superram was ported, welded and matched to a 1206 gasket, but was still a 13.5% restriction.

I think your biggest gains would be in fully porting the intake trying to increase the cross-sectional area as large as possible. I think the larger duration cams squeeze more air into the cylinder, and that's why they show more power on the simulation.

I think the biggest thing to remember with the superram is that it's not going to make the highest horsepower, but it makes gobs of torque thru a fairly broad range. Cartek's vette had 3.73's, a 2800 stall convertor, ported superram, ported AFR 190's, 11.8:1 comp, DFI, and the cam was 232-242 .602-.602 112lsa. The combo just worked well together. I talked to Cartek when I was getting my heads and superram ported, and they said not to look for big hp dyno numbers from the superram, look for torque. Call them, I have seen a couple of 230 duration, .600 lift 110 lsa cams from them that made decent power, but their cams are $400 bucks.

89vette

I have that program but I cannot get the numbers you do with it. They are alot lower. My HP is about what you have but my torque is alot more. I called CarTek and they never called me back. Thanks for the information

89gta383

You have to play with the runner lengths. The runner length for the stock TPI and superram in EA are incorrect. They are only the runner lengths of the runners only, not the runner + base.

89vette

Oh I see what you are saying. I went in and changed that. The only way I get close to my current numbers is to use open headers. If I do that , then the EA program comes out almost exactly like my current dyno graph. What's more, if I increase the intake duration to 30 degrees, and add about .040" more lift, I only gain about 15-20HP. I guess that is about right tough huh? Do you have any pictures of your ported heads and base?

LD85

http://www.lesport.8m.com/lesport2.html he's in PA

JUAN J SANCHEZ

89 vette I've probably didn't read all your replys and i'm asking a question that was probably answered, but why do you want to change your cam? How fast is your car now? What do you expect to gain? I built a 406 SR motor for a friend and I might be able to give you some help.

89vette

Juan, I'm just lookign for a winter project. I don't race my car so I don't know how fast it is. Its plenty fast for the street. Scary in fact. If I had any sense, I'd leave it alone.

69stingray

How about LPE 74219 cam? 219/219 duration @ 0.050 0.503/0.525 lift w/ 112 separation. Description from his book, "The 213 or 219 cams are intended for 383/406 cid engines in conjunction with the SuperRam intake. These cams have a choppier idle."

Jussi

Hmm... I have 420sbc with SLP T-ram (quite close to SR but flows 276cfm STOCK) and Crane Powermax hyd.roller with
Advertised duration: 284 intake/292 exhaust
* Duration at .050 in.: 222 intake/230 exhaust
* Gross Valve Lift: .509 in. intake/.528 in. exhaust
* Lobe separation: 112 degrees

And it feels too damn stock!
I don't want any race car but stroked sbc NEEDS duration...
what ever intake you choose to use...

I have ordered AFR 210s to replace mine Dart 2's and the cam I choosed to use is also Crane Powermax but one step bigger...
* Advertised duration: 292 intake/300 exhaust
* Duration at .050 in.: 230 intake/238 exhaust
* Gross Valve Lift: .539 in. intake/.558 in. exhaust
* Lobe separation: 112 degrees

this cam with 1.6 rockers will give you 0.575/0.595 if you need lift that is..

That earlier 222/230 cam REALLY worked well... idled at 700rpm smoothly and started to pull from 1600 rpm but was out off breath about 5000rpm... with the bigger cam it should work up to 5500rpms.

0ski_dwn_it

89vette,

That is true what you said about his HP he got at the last dyno he went to, but he and I have talked about this several times and there is ABSOLUTELY no way that dyno reading is correct. If you go to those HP calulators, like http://www.smokemup.com and calculate his HP from MPH or ET, he has to be putting out ~450-480RWHP. For a car that weights 3350#.

There are LT1 with just a hotcam and a few bolt ons putting out 360HP. There is just NO WAY his car only has that much power. Either the dyno was messed up or the tires were slipping on the roller, which is a very common thing with High HP motors.

Our Chevelle only runs 11.4@119MPH and that was Dynoed at over 540HP, its putting out ~450 RWHP, but in a slightly heavier car.

What you are trying to do is should prove to be VERY interesting. Not many 396 SR engines are out there, so you are sorta, like you said the gineu-pig :D

Air flow is what its all about and as Ralph said, they may look wimpy, but they flow good. That is what makes this stuff so hard. I have been throwing around the idea of building my own flow bench. There is tons of information on the new for DIY test benches. Without a device like that I wouldn';t even attempt to touch a set of heads, but then again, even with the bench tester, once the material is gone, you can't replace it.

Keep us posted on the progress, we will all be watching to see how you make out....perhaps some time a bunch of us PA boys can get together. And have a few :cheers:

SloRvette

If you use the Smokemup rwhp predictor, use the 1/4 mi MPH one. The ET one has too many variables that can apply for it to be accurate. I've found the MPH one to be within 2%, consistantly, on cars below 550 rwhp.