Guess The HP & Torque Contest

[AL427SBF]

How good are you? Guess the crank HP and Torque @ 6200 RPM and be the "expert" on this thread! I should have dyno results by the end of next week.

Bore & Stroke: 4.125" x 4.000" (427 CID)
Compression Ratio: 10.3:1
Cylinder Block: Dart 31345235 Aluminum, 9.500 Deck
Rotating Assembly: SCAT SuperLight
Heads: Edelbrock Victor Jr Heads 70CC
Bearings: Performance Clevite
Dampner: Innovators West Aluminum SFI
Oil Pump: Melling Hi-Vol
Pulleys: March, Aluminum Performance
Rockers: CompCam 1332-16 Pro-Magnum Roller
Lifters: CompCam 8931-16 Pro-Magnum Roller
Valves: Ferrea F6202 1.600 x 5.060 11/32 Exhaust, F6207 2.055 x 5.060 11/32 Intake
Camshaft: CompCam 35-426-8 (2200-6200 rpm)
Valve Springs: CompCam 928-16
Push Rods: CCA796016 7.650 5/16 Hi-Tech
Timing: ProGear Timing Set PG-4138
Distributor: MSD 8578
Pistons: Custom 70cc dish
Carburetion: 1 Willey's 4-barrel

[LMH]

Cam is 288/294 duration, .555/.576 lift.
Compression ratio?

Lots of variable though.
Rough stab in the dark... about 515 HP, 525 ft/lbs.
Sounds like a nice engine! Personally, I don't like HV oil pumps unless a huge pan is used but to each his own.
Larry

[charles roybal]

535ft/lbs 530hp

[AL427SBF]

CR is 10.3:1 (it was listed)
Oil pan, a big Aviaid
Does the builder matter? Gessford

[olddog]

The intake and port work on the heads do matter a lot.

I'll gamble on excellent port work and a good intake.

@6200 rpm 470 lb-ft, which is 555 Hp.

I believe that is what you asked @6200 --- not the peak numbers.

[AL427SBF]

Yes, the cam top end is spec'd at 6200 so I figure that's the practical redline = close on max HP anyways, torque is on the downhill slide by then - but I could live with 470 lb-ft

[blykins]

What intake?

If the heads are out of the box heads with a valve job, I don't think the cam will pull up that high. Comp Cam's notes are not for the particular cubic inch displacement that you're running, but for the smallest in that category. So if you look at their catalog, look at the cams for a 351W, and pick one that will peak at 6200, then it may be close to that for a 351. For a 427, it will be a lot lower.

I did a 425ci Windsor with those heads, a similar camshaft, and a Victor Jr. intake. Running about 10.25:1. It made about 485hp @5400.

I would expect this one to be a little higher, probably around 510-520hp, but then there are stingy dynos and there are liberal dynos...

[LMH]

Now I see the CR. Duh.. guess I should read it better before posting!
Larry

[AL427SBF]

All the gruesome details -

Work Performed
Honed bore of Innovators West Dampner
Intake port matched to heads
Measured bearing clearances, used standard bearings and X-Std bearings to get oil clearances perfect
Honed Big Ends of Rods
Dialed in Bell Housing
Pilot Bearing bored for TKO input shaft clearance
Engine Block Final Boring
Pistons Balanced
Checked Balance on Rods
Measured crankshaft journals, provided additional clearance work as needed

Parts List
Cylinder Block
Dart 31345235 Aluminum Block 9.500 Deck for 4.125 Bore 351C/351W
FP602S Deck Dowels For 351W Block Decks

Rotating Assembly
SuperLight Rotating Assembly 351C Mains 351W Rods 4.000" Stroke
6.250" Rods. Custom Pistons HN Rod Brgs and H Main Brgs
Additional Mallory for internal Balance HM1.00 x 1.000
Additional Mallory for internal Balance HM .875" x 1.000
99999-HM Installed Mallory Labor

Heads and Intake manifold
Edelbrock Victor JR Heads 70CC 77389
Edelbrock 2981 Victor JR 1x4 Manifold

Options/Requirements
Performance Rod Bearings clevite CB-663 HN std. with Rotating Assy
Performance Main Bearings MS 1010 H std. W/Rotating Assy
DuraBond Performance Cam Bearing set for Dart Block
260-1028 Base Felpro Gasket Rebuild Set
Felpro 1262 Intake gasket, 95110SG Victor
1022 & 1023 Felpro Head Gaskets (Aluminum EDE Victor Heads)
Felpro 2921 Rear Seal Kit Performance
Felpro 2331 Race Set remainder
Felpro OS34508R Pan Set
Victor 95177SG Exhaust Gasket Set
ARP Oil Pump Drive Shaft 154-7901
Innovator west Aluminum SFI Dampner 4 bolt ser # 32831 # 204
690-028 Brass Pilot Bushing 289 Bored ID to .668"
Melling Hi-Vol Oil Pump performance pump 10833
March 1610 Pulley Set Aluminum Performance
Custom RaceTek Pistons 70CC Dish (cr 10.3:1)

Roller Rocker Systems
Comp Cams 1332-16 pro magnum roller rockers

Cylinder Head Valve Train Components
Ferrea F6202 1.600 x 5.060 11/32 Exhaust Valves
Ferrea F6207 2.055 x 5.060 11/32 Intake Valves

Camshaft & Lifter
Comp 35-426-8 Camshaft
Comp Cams 8931-16 Pro magnum roller lifters
Comp 928-16 Valve Springs
614-16 +.050 & 611-16 Std Valve Keepers
Comp 4700 Spring Cup set
Comp 741-16 Steel retainers
4776-16 Comp Spring Seat Shims
38-532-55 Valve Stem Seal Positive
camshaft thrust plate
CCA796016 Push Rods 7.650 5/16 Hi-Tech
ProGear Timing Set PG-4138

Transmission/Bell Housing/Clutch
11" Clutch - 5/16" Bolts - TKO 600 Setup
360850 McLeod 11 Pressure Plate Clutch
260871R McLeod 11" Performance reverse Disc
16031 Throw out Brg McLeod
McLeod Flywheel Lt. Wt 463200 Neutral Balance 28-33# Steel SFI
TCET4617 TKO 600 .82 5th Road Race Transmission
ANR 2253 Trans Mount
Lakewood Bell Hsg 15202
Lakewood Alignment Dowel set .014" offset

Miscellaneous
7200-180 MCS Hi-Performance 180 Degree Thermostat
Hi Torque 351WStarter (Gear Reduction) CVR 5055 ProTorque
Alternator Bracket
Pioneer Aluminum Timing Cover 500302s
Spark Plugs 14MM 3/4" Reach flat gasket style
8585 brass dist gear for his 8352 Distributor
Water Pump Edelbrock 8843
Fuel Log & Fittings, Carb Willey's

Ignition Components
MSD 8578 Distributor for Dart Block and Victor Intake Clearances
MSD 8222 Blaster Coil Epoxy Filled
MSD 6420 6AL Ignition Box
MSD 8010 Dist Hold Down Bracket
FMS M012259-M302 Black Wire Set
Gessford Custom Wire Loom Setup - Side Mount

Fasteners For Engine Assembly
ARP Block Head Studs for DART as follows:
AR36201LB Stud 1/2 x 3.62 90# W/ARP Lube
AR54L Stud 1/2" x 5.4 LG
2008514 Washer 1/2x7/8x.120" no chamfer
3008304 Nut 1/2-20 12PT
ARP Head Stud Kit 154-4203 1/2" SBF
ARP 554-9503 Accessory Bolt Kit
ARP 612-2000 (2) 612-3500 (2) for Water Pump
ARP 612-2000 5/16-18 2.5
ARP 612-3500 5/16-18 3.5
ARP Dampner Bolt
ARP 454-2101 Intake Bolt set
ARP 334-7203 R/A Studs 7/16-2.12 chg to 1.90" 200-7201
255-1002 ARP cam bolt
100-2801 ARP flywheel bolts
200-8558 ARP Washer set
150-2201 ARP Pressure Plate Bolt Set
MRG 6087 Oil Pan Bolt Set
MRG 1516 Fuel Pump Block Off Plate
Aviaid Oil Pan 351W 55356
Aviaid Oil Dip Stick Setup Dart Block
Harrison Tank, mounts & straps

[Gaz64]

Originally Posted by AL427SBF

Yes, the cam top end is spec'd at 6200 so I figure that's the practical redline = close on max HP anyways, torque is on the downhill slide by then - but I could live with 470 lb-ft

That doesn't mean it will max out at 6200, the band given of 2200-6200 is the cam's best operating range.

It will probably peak at about 6500.

I'll guess 530 hp / 450 ftlbs at the flywheel at 6200.

[AL427SBF]

I was wondering if there was a little margin on that cam spec, nice to hear that confirmed. Also found out the Willy's carb is #62502 (650 CFM) with "race floats" for what it's worth.

[jdean]

650CFM seems a bit skinny for that much motor. What were the thoughts on going small on the carb? My guess is it will peak at 490HP at 5,000 or so and go down hill to 450 at 6,200. With an 850 CFM carb I would guess at 40-50 more horses to about 530 at 5,600 and then still be over 500 at 6,200.

[AL427SBF]

That is what Gessford decided for that motor, I was thinking 650 is a little skinny too.

[lovehamr]

Still show no head work. If any port work was done on the heads/intake do you have flow figures?

If none, then I'm with Brent; I think this big inch puppy will be under-cammed, under-headed and under-carbed to reach 6200 and still be gaining power. I look for it to basically sign off at about 5800 and be 500hp/450tq. I hope I'm wrong but with lots of inches breathing through unported heads (even Victors) I wouldn't expect the RPM. It'll be a monster down low though.

[AL427SBF]

I think I know why Gessford chose the Willy's 650 CFM carb size. When they were working through the engine build, some Comp Cam engineers were brought into the discussion. Gessford was working out the Comp Cam component set for a "spec motor". I didn't know what that meant at the time (and still don't), but the Willy's carb description below makes further reference to "spec motor" in the IMCA context.

Willy's HP Gas Carburetor
WCD62502 Holley HP 650 mainbody, gloss black powder coating, 750 baseplate w/stainless steel butterflies and Teflon bushed throttle shafts, 1.250" venturi, externally adjustable metering blocks. The new WCD62501 and WCD62502 are the most powerful carbs available for the IMCA SPEC motor. These new carbs offer instant throttle response and more torque for the open wheeled modified driver.

[jdean]

I believe you will indeed have instant throttle response. Not saying you wont be happy with it on the street. But that carb is apparently designed for a 360 cubic inch motor.

[rdorman]

500 square

[jdean]

While it is on the dyno, maybe you can try a larger carb and see what the difference is.

[AL427SBF]

I think I'll ask Gessford why the 650 CFM.

[AL427SBF]

Here's a calculator that says maybe 650 CFM is right for that motor -
Carburetor Size Calculator
Load in the data then run your cursor over the generated bar graphs, you'll get specific CFM for VE and RPM.