Don Terrill’s Speed-Talk

SBC various Vortec Dyno Tests and Flow Sheets

426.7 Peak HP at 6000 RPM

originally started out with out-the-box #062 Vortecs and aluminum GM Dual-Plane
SBC Mud Truck Engine 361.5 cid 4.060x3.490
Factory powdered metal rods ARP bolts .827 pins
Factory Crank
GM Chevy OEM cast iron Vortec Heads
GMPP Vortec Aluminum dual-plane + HVH 4-hole Super Sucker
Edelbrock Vortec Air Gap dual-plane + HVH 4-hole Super Sucker
Original 461 short block with CompCams Hyd Flat tappet 241/245 .360/.360 Lobes 0.5472/0.5472 Valve Lifts
1.52/1.52 Roller-Tip CC Rockers
33 btdc
Rhoads Lifters VMax
12.4 CR
VP C45 .739 SPG Oxygenated Race Fuel
LAT 20/50 Breakin Oil
Vaccum Pump
Dyno Headers= 1.875x33.0 3.500x16.0
------------------------
90/92 from 86/86 jets
raise float levels
93.5/96 from 90/92
.018 from .035 valve lash across hot

made : Peak HP all over the place .... Note: this is from one single Dyno test run
426.1 @ 5200 RPM
426.4 at 5400 RPM
426.7 at 6000 RPM
426.4 at 6200 RPM

500.4 to 501.0 Peak HP at 6400 RPM ( from 426.7 Peak HP at 6200 RPM )

next series of Dyno tests were those very same #062 Vortecs maxed-out only with custom modified Goodson 3d Cutter Bodies/Cutters
and with a 6-Angle Valve Job, along with more Engine Mods, etc.

4.060x3.490=361.5 cid
#062 Vortecs 2.055/1.600 5/16 Stems
Dyno Headers= 1.875x33.0 3.500x16.0
Factory powdered metal rods ARP bolts .827 pins
Factory Crank
Edelbrock Perf RPM Air-Gap dual plane 1.000" HVC SS 4-Hole spacer
13:1 CR Diamond Flat Tops Total Seal .027/.027/3mm Rings
Billet Fab alum pan
LAT Breakin Oil 8 qts.
Star Vac Pump
Q16 Race Gas SPG= .716
new CompCams CS 5980/5985 s118 Nitrided Rhoades Hyd Lifters
251/247 .36200/.3630 118 Centers 114.5 CL 0.5792/0.5808 Valve Lifts
CC 1.60/1.60 Roller Tip Rockers Welded-Oil Deflectors
Jesel Belt
ATI Balancer
-------------------------------
35 btdc from 32
190 cranking psi Cyl# 2

new ProMaxx Vortec Heads = 525.9 Peak HP at 6200 RPM ( from 500.4 Peak HP #062 Vortec Heads )

custom modified Goodson 3d Cutter Bodies/Cutters
and with a 6-Angle Valve Job, including Chambers Cutters + Bowl Blades

Mud Truck SBC 4.060x3.490=361.5 cid
ProMaxx 185cc Vortec Heads 2.055/1.600 5/16 Stems .600 Lift= 242/176 CFM
modified ProMaxx Heads with offset 7/16-NC Nutserts w/Green Epoxy Packets for new 1.72/1.72 Roller Tip Rockers Welded-Oil Deflectors
CompCams CS 5980/5985 s118 Nitrided Rhoades Hyd Lifters
251/247 .36300/.3630 118 Centers 116.0 CL 0.62436/0.62436 Valve Lifts
Dyno Headers= 1.875x33.0 3.500x16.0
Factory powdered metal rods ARP bolts .827 pins
Factory Crank
Edelbrock Perf RPM Air-Gap dual plane 1.000" HVC SS 4-Hole spacer
13:1 CR Diamond Flat Tops Total Seal .027/.027/3mm Rings
Billet Fab alum pan
larger Oil pan w/LAT 5/30 racing oil 8 qts
Star Vac Pump
Q16 Race Gas SPG= .716
Jesel Belt
ATI Balancer
-------------------------------
C45 Oxygenated Race Fuel Pink color .739 SPG from Q16
18.5 in Hg vacuum at 1000 RPM
35.0 btdc from 34.0
Cam on 117.0 IntCl from 116.0 IntCL

Good info as always Larry! Although you should probably read some of the recent threads and realize a 2.055 intake valve and 1.875" header won't work in a OEM Vortec head

cpmotors wrote: ↑Sun Dec 09, 2018 4:55 pm Good info as always Larry! Although you should probably read some of the recent threads and realize a 2.055 intake valve and 1.875" header won't work in a OEM Vortec head

Pete, That would be me. I did send Larry an e-mail and he confirmed the 2.050 -1.6 was a good combo. He has never seen cracks in a head that had the 2.050 valves and bowl worked.

Larry, Thanks for the e-mail reply and info here.