CorvetteDave01

I am getting my 427 sb chassis dynoed tomorrow and thought I would post a poll of what ppl thought it would put out for peak hp. We are having some speed density/ignition signal interference that I will work on over the winter, so the tune will be in Alpha N, bank to bank mode. I'll probably go through and change plug wires, rewire the ignition box, run several extra ground straps to the block and check the alternator wiring among other things. Also, the Hamburger 1088 pan is leaking from a single bolt, so I will probably have to redo the pan gasket (grr).

Basically, my goal was to build a 600 hp efi motor that would run on pump gas and be faster than a Viper or Z06 in the 1/4, but after some compromises on the heads, intake and Throttle body, I am guessing I won't get there. Anyway, everyone see what you think.

Below are the motor specs.
427 sbc (Dart Little M block, 4.125" BORE, 4" Stroke, 6" rod length): 4340 Scat crank and rods with 7/16" bolts/polished beams.
10.5:1 CR
Hamburger, 1088 7 qu. pan with windage tray

AFR 210 Eliminator CNC ported heads with 2.08/1.6 valves, 295 cfm @ .600 lift; 299 @ .650; 301 cfm @ .700.

Comp cams solid roller, .900 base circle cam.
-Valve adjustment .020/.020
-Gross valve lift .631/.631
-Duration @ .020 286/294
-Valve Timing @ .050
Open Close
@ .050 Int: 18 BTDC: 52 ABDC
Exh: 64 BBDC: 14 ATDC

-107 Intake Center line
-Duration @ .050 250/258
-Lobe lift .4210/.4210
-LS 111

1.6 ratio comp cams roller rockers with stud girdles
1 7/8" Hooker headers to 4" Hooker sidepipes with STS baffles
Mechanical alumin water pump and mechanical flex fan.

Intake setup:
Victor Jr. single plane, ported
1000 cfm throttle body
48 lb High Imped, Venom injectors
50 psi fp regulator
A1000 Aeromotive efi pump with -8 feed and -6 return lines
FAST XFI computer
FAST dual sync distributor (to run in sequential)
MSD 6A box with Blaster 2 coil

Manual tranny, Tremec TKO 5-speed, with a 3.27 first gear, 4th=1:1. 3.08 rearend ratio. 11" SFI steel flywheel and centerforce dual friction clutch.

MotorHead

What is the duration @ .050 of the cam and how many pulls and how much tuning are going to do. A motor like that should make near 500RWHP however no one is ever happy with the results of their first dyno pull unless they are realistic and know exactly how well the motor was built.

I'm shooting for the new supercharged ZR1 Vette myself with the normally aspirated 427ci I am building in my basement

CorvetteDave01

The cam is a solid roller with about 670/670 lift and 250/258 duration; 111 LS, (with the 1.6 rockers).

Yeah, and assuming I don't have any ignition problems, I am hoping for 450 rwhp or so, but I am prepared to be disappointed somewhat. It better make at least 400, or I'm an idiot for spending what I did on the motor.

CorvetteDave01

Not sure on how many pulls, probably a few I guess? The point is to tune it on the dyno.

Gordonm

You should be well over 400 RWHP. I made 409 RWHP with my 385 with a large flat tappet solid cam. Smaller 195 heads. You should be around 550 to 600 flywheel HP with your combo. Tune is everything though. I was pretty stoked with my dyno pulls. I could probably tweak a few more HP out of mine but yours should be real fun!

CorvetteDave01

Someone is already killing me on the <400 hp vote! With any kind of ignition problems, they could be right though...

MotorHead

Take it to the dyno, don't expect the moon and try a few easy things to make more power such as timing and whatever you do with fuel injection.

The motor should make some good power when properly set up, in the 450-475 RWHP range, maybe more. Don't worry if it makes less, you will get it tuned properly and it will eventually make the power it is supposed to.

gkull

Well Dave, I'm hoping that it makes some power because we have about the same thing....................

I would be dissapointed as to why my big 12X27 GoodYear road racing slicks are just spinning with no horse power

I've had some good motors and with out a doubt the big inch small blocks really put out.

Keep the timing down to 32 -34 and get the A/F ratio right. Have all in in the 3000 -3200 rpm range. run 10W30 and keep the water temp below 180. You can make @ 20 hp difference below 180 and 200+

So it's best to run the motor up under load to get heat in the block and then cool it before a dyno run. You want lower end metal and oil heat - not inlet and head heat.

CorvetteDave01

Yeah George, ours are similar but you have better flowing heads and a bit more cam I think. It will be interesting. I'm still half expecting a problem of some sort with the ignition, but we will see. I'll get graphs and stuff as well he says, so I'm looking forward to it.

69 N.O.X. RATT

If it runs well with no ignition issues it should make at least 450 and probably close in on 500.

CorvetteDave01

Thanks for all the input thus far all. The next time I post tonight, I'm hoping to have some results.

I did fail to mention the prize didn't I. George indicated that he was going to donate his Vette to the winner since his wife wants him to get rid of it anyway.

63mako

468 RWHP 455 RWTQ. I want Georges car!

GrandSportC3

421 RWHP (I voted before I noticed that it will be on a chassis dyno)

I'd say that you have about 575 flywheel HP. IF you run with the STS baffles unplugged, you should get 421 RWHP and if they are plugged, I'd estimate 400 RWHP.
If you ditch the flex fan, it'll be 431 RWHP plugged and 410 RWHP unplugged

If you'd run the exhaust completely open and ditch the flex fan, you could get as much as 440 RWHP

TheSkunkWorks

Peaks at 460 RWHP / 410 RWTQ. What do I win?

68 NJConv 454

Hope you don't have to climb stairs to get out of your basement...that 427 will really screw up your back...lift with your knees

MotorHead

Oh yes up the stairs just like the 406ci in the Vette now, on a fridge cart with my brother on the bottom

GrandSportC3

any results yet?

MotorHead

GrandSportC3

hugie82

Dave, when you dial that 427 in you will be at your goal!!! I will vote and say 528hp at the rear wheels and 490tq at @4900 Rpms. DRIVE IT LIKE YOU STOLE IT