74vetteman

Well, I've ordered all the parts for my 406.

Rotating assembly includes: Scat 3.75" stroke cast steel internal balance for 6" rod crank, Eagle 4340 H-beam 6" rods, SRP forged flat top pistons, and a Crane hydraulic roller cam with 222 intake and 230 exhaust duration at .050. Lift with 1.6 rockers is .543 in. and .563 ex. Lobe separation is 112. Also ATI dampner and billet steel flywheel.

Block was 0 decked, bored and honed, line bored, 1/3 block filled, deck restrictors installed, and I ported the oil galleries in the block and the rear main cap.

Heads are AFR 210 race ready with 76cc combustion chambers. With my flat top pistons I will have 10.2:1 compression. Also, Crane 1.6 roller rockers, and Team G 7530 single plane intake.

I haven't ordered headers yet, but will probably get Hooker 1 3/4" super comps. As far as carburation, I have a 650 dbl. pumper and a 750 vacuum, but will probably get a 750 dbl pumper (Holley or Demon). I still need to get a oil pan as well. Any recommendations (Street, drag, and slalom use).

I hope this will be the right combination for the type of driving I do (95% street). I know I sacrificed some hp with the relatively small cam, but hope I will reach my goal of 475+ flywheel hp. The dyno will soon tell!

What do you guys think? Anyone with desk top dyno software willing to hazard a guess? :chevy


[Modified by 74vetteman, 9:41 PM 11/28/2001]

hogan64

Vetteman,

Pretty new to Dyno2000 but I'll give it a try. Had a heck of a time cutting and pasting info from DD2000 into a reply. Anyway, I got the flow numbers from AFR for your heads.

Engine Power Torque Int Man Vol IMEP FMEP BMEP
RPM (Fly) (Fly) Pressure
Eff % Pressure
Pressure
Pressure

2000 179 469 14.66 72.9 225.9 17.8 176.4
2500 231 484 14.64 76.3 223.2 19.3 182.0
3000 286 501 14.60 79.4 227.2 21.0 188.3
3500 344 517 14.56 83.5 230.6 22.8 194.3
4000 399 524 14.49 86.6 233.5 24.7 197.0
4500 446 520 14.42 88.1 234.2 26.7 195.7
5000 473 497 14.34 87.4 226.9 28.9 186.8
5500 475 454 14.27 84.5 212.1 31.2 170.7
6000 459 402 14.22 80.0 193.7 33.6 151.0
6500 432 349 14.20 75.3 175.4 36.2 131.3
7000 386 290 14.18 69.7 154.3 38.8 108.9
7500 339 237 14.19 64.4 136.1 41.6 89.1
8000 285 187 14.20 59.9 119.2 44.6 70.4
8500 225 139 14.22 55.0 102.9 47.6 52.1
9000 160 93 14.24 50.7 88.0 50.8 35.1
9500 89 49 14.27 46.6 73.7 54.1 18.4
10000 18 9 14.30 42.9 61.3 57.6 3.5
10500 0 0 14.32 39.7 49.3 61.2 -11.2
11000 0 0 14.34 36.2 37.3 64.9 -26.0


Used "Large tube headers with mufflers". Lifter type is "Roller"

Hope this helps,

Ted



[Modified by hogan64, 1:04 PM 11/29/2001]

The Dude

Couple things:

Your cam choice caught my eye immediately but you addressed that in your post.

You say your driving is 95% street. That means your built-for-7,000-RPM bottom end will rarely, if ever, see the big side of 5,000 RPM. If that's the case you might want to re-think the single plane manifold and go with a good dual-plane--I prefer Weiand products and you might want to look at the Stealth manifolds or similar. The dual plane intakes will make some more torque for you down low where you'll be using it.

The large tube headers might be killing some low-end torque, too. If you can, try both 1 5/8" primaries and the 1 3/4" Hookers when you do your dyno pulls. You may find you'll have a smidge more grunt in the "95 percent street" powerband with the smaller tubes.

750 CFM with vacuum secondaries on the carb sounds like a good choice for regular street driving.

Of course, your mileage may vary. Your bottom end sounds pretty similar to one I just picked up. I'm going a slightly different direction with it, though. Good luck and let us know how it pulls on the dyno.

11sec84

the Dude: Normally on a small block Chevy (383 and under) your suggestions would be true. However, the 406 is unlike any other small block. They need to be looked at as a big block in a small package. The 406 loves header diameter and with those heads and cam, 1 and 3/4 is really a minimun and the optimum ones would be 1 and 7/8. I'd also tighten the lobe cntr up to 108 and wouldn't go wider than 110. The team G is a good intake and literally loves 1 to 2 inch carb spacers. That combo is a great choice for the street and will also love the track as well as a little stop light action :yesnod:

drive it

Hmmm, so you don't have to deal with smog check crap; I'm jealous! :cry

74vetteman

Thanks all for replying!

Hogan 64, thanks for taking the time to run the numbers. Hmm, peak torque 520@4500 and peak hp 475@5500. Pretty close to what I was shooting for!

The Dude, since i will have both 1 5/8 and 1 3/4 headers I will try both on the dyno to see which works better. I will also use a two piece timing cover to enable easy cam swaps in the future if I am not satisfied. When I drive on the street I usually exceed 5000 rpm every time!

11sec84, I'm currently using the Team G 7530 on my 355 with good results and agree it gives up little torque to a dual plane. I wouldn't mind trying a 1 or 2 inch spacer, but lack the under hood clearance. If I could I would also like to test the plenum divider to see what difference that it might make.

Drive it, there are no smog checks where I live, so just about anything goes!! :chevy

I should be dynoing the engine in early January after a well deserved vacation in Hawaii, so I will post the results then. :cheers:


[Modified by 74vetteman, 10:38 PM 11/29/2001] :blueangel:


[Modified by 74vetteman, 10:43 PM 11/29/2001]

hogan64

Changing the Lobe Center Angle to 108 and the Intake Centerline to 108 gives the following (I used 112 for both values previously)

2000 180 471 14.66 71.5 226.9 17.8 177.2
2500 233 489 14.64 75.5 225.3 19.3 183.9
3000 289 505 14.60 78.6 229.0 21.0 190.0
3500 345 517 14.56 82.2 230.9 22.8 194.5
4000 400 525 14.50 85.4 233.9 24.7 197.4
4500 446 521 14.42 86.8 234.2 26.7 195.7
5000 475 498 14.35 86.4 227.6 28.9 187.4
5500 485 463 14.28 84.6 215.8 31.2 174.2
6000 471 412 14.22 80.5 197.8 33.6 154.9
6500 445 360 14.19 76.0 179.5 36.2 135.2
7000 400 300 14.17 70.6 158.4 38.8 112.8
7500 353 247 14.18 65.4 140.2 41.6 93.0
8000 303 199 14.19 60.9 123.7 44.6 74.6
8500 242 149 14.20 56.2 107.2 47.6 56.2
9000 186 108 14.22 52.6 94.1 50.8 40.8


Ted


[Modified by hogan64, 8:11 AM 11/30/2001]

The Dude

Right you are. Big engines like big parts. I was basing my suggestions on his driving style and the somewhat small-ish cam he's added. I suppose what I should have done instead of trying to match components to the driving style and the cam was to just go ahead and recommend that he dump the little cam and go to something somewhat more radical. I'm not up to speed on my hydraulic roller specs, but I do know that a MINIMUM for a hydraulic flat-tappet selection would be in the 230-235 duration @ .050" range and .510" lift. And with the AFRs, he could easily go somewhat bigger.



[Modified by The Dude, 2:05 PM 11/30/2001]

11sec84

I see and I agree :cool:

korvetkeith

Whatsup hogan, my last name would happen to be hogan FWIW.