[trifive]

Chevy Engine Build

Engine = 406ci, 4.155 x 3.75

Power = 581 hp @ 6,300

Compression = 11.5.1 on 91 - octane pump gas

Ignition Timing = 36 Degrees

Block = Production Iron

Crankshaft = Callies 4340

Rods = Eagle 6.0

Pistons & Rings = JE Forged

Oil Pan & Pump = Moroso 5 qt.

Camshaft = Isky mechanical roller 264/274 degrees duration, 0.588, 0.588 - inch lift, 106 lobe seperation

Rocker Arms = 1.5:1, 0.020 - inch lash

Heads = AFR 220cc heads w/full CNC porting

Valve Sizes = 2.06 / 1.60- inch

Intake Manifold = Edelbrock Super Victor PN 2925

Carburetor = Holley 950 HP

Ignition = MSD-6AL

Headers = 1 3/4 inch dyno headers

 

[spike]

Let me know how that 11.5 to 1 compression on pump gas works for you. Thanks

 

[r66ss]

Heads = AFR 220cc heads w/full CNC porting
with these aluminium heads it should run fine on premium fuel:wavey:

 

[Old Buzzard]

@ 36* timing?????????

 

[Pro Fleetline]

My 406 i have at 36% aswell!
pretty similar build!

 

[finn210]

good chamber desing and plug position is key factor to keep advance low

 

[airbournein2001]

overheating?

How are you guys cooling this 406?

I have an aluminum radiator with an electirc fan on the way to hopefully cool this thing at low speeds. Think it will work?


72' 406ci cam dynamics 280/480, Holley 780, GM stock heads, and a few other things installed that are not remembered. :confused0024:

 

[BADD55]

Chevy Engine Build

Engine = 406ci, 4.155 x 3.75

Power = 581 hp @ 6,300

Compression = 11.5.1 on 91 - octane pump gas

Ignition Timing = 36 Degrees

Block = Production Iron

Crankshaft = Callies 4340

Rods = Eagle 6.0

Pistons & Rings = JE Forged

Oil Pan & Pump = Moroso 5 qt.

Camshaft = Isky mechanical roller 264/274 degrees duration, 0.588, 0.588 - inch lift, 106 lobe seperation

Rocker Arms = 1.5:1, 0.020 - inch lash

Heads = AFR 220cc heads w/full CNC porting

Valve Sizes = 2.06 / 1.60- inch

Intake Manifold = Edelbrock Super Victor PN 2925

Carburetor = Holley 950 HP

Ignition = MSD-6AL

Headers = 1 3/4 inch dyno headers

:driver: Hey, that all sounds about right for everything, with the exception of the 91 octance fue:confused0006:l!!!--- IMPO 93 would be the bare minimun with the 11.5 to 1 and 36 degrees!!--This wouldn't even be possible without the Aluminum heads to help dampen the detonation, and the 264 274 @.050 cam, and a real good cooling system!!---milton--- PS-- I like the cam choice!!:tu

 

[iveys57]

similar but different

In mine we dropped calculated compression to just under 11:1, used Dart aluminum heads, having seen the destruction from failed/brindled rollers from solid rollers went with hyd. roller cam. I am sure my HP and ft./lbs. are less than yours, I was upgrade copying a magazine build from back when Dart was launching their SHP blocks/shortblocks. Use 93 octane, 3.50:1 rear gear, 36 degrees total timing, mechanical only advance I consider mine a good weather daily driver, it does love fuel but it is so o o much fun to drive. Point is compression and timing listed in this example can work with right tune and cam timing.

 

[JT56]

Chevy Engine Build

Engine = 406ci, 4.155 x 3.75

Power = 581 hp @ 6,300

Compression = 11.5.1 on 91 - octane pump gas

Ignition Timing = 36 Degrees

Block = Production Iron

Crankshaft = Callies 4340

Rods = Eagle 6.0

Pistons & Rings = JE Forged

Oil Pan & Pump = Moroso 5 qt.

Camshaft = Isky mechanical roller 264/274 degrees duration, 0.588, 0.588 - inch lift, 106 lobe seperation

Rocker Arms = 1.5:1, 0.020 - inch lash

Heads = AFR 220cc heads w/full CNC porting

Valve Sizes = 2.06 / 1.60- inch

Intake Manifold = Edelbrock Super Victor PN 2925

Carburetor = Holley 950 HP

Ignition = MSD-6AL

Headers = 1 3/4 inch dyno headers

If those are the AFR Eliminator 220, they will have a 2.10 intake valve and AFR claims will support 700 n/a hp.

Sounds healthy build

 

[midnightrider]

This is also a very similar build to mine, except mine is a measured 11:1, with a solid roller by Bullet, @.050 254/264 .625 lift....no prob on 93 pump. 26* initial and 36* total. AFR 220 CNC ported...pulls like crazy, even down low.

 

[topdog]

sounds like a lot of horse power for a 406. I run 10:1 with dual quads and estimate 425 horse power. reworked large valve double hump heads

 

[Alf]

My guess is that narrow lobe separation (106 degrees) will let you get away w/ that much compression on pump gas. I doubt the heads have anything to do w/ it. Especially w/ today's gas the higher the compression the shorter the fuse.

 

[topdog]

406 is a torque monster

 

[JT56]

I doubt the heads have anything to do w/ it.

??? Heads have everything to do with power. That is why the LS stuff is such easy horsepower. Maybe I am misunderstood this.

 

[midnightrider]

Agreed jt56...my 220's are as important a component as any in my build.

 

[Alf]

You guys need to re-read my post. Of course heads have a huge influence on power. The issue at hand was: will an 11.5:1 engine survive w/ 91 octane gas?
The tightness of the lobe centers will mean the intake valve will stay open a few degrees after the completion of the intake stroke......this will reduce some of the cylinder pressure thus "forgiving" the low octane. I don't think the AFR heads themselves are going to prevent detonation.....squeeze is squeeze.

 

[topdog]

FRIEND RUNS 11:1 COMPRESSION WITH DART ALUMINUM HEADS ON SBC AND NEEDS TO SPIKE PREMIUM FUEL WITH RACE GAS. NOT SURE WHAT MIX HE USES

 

[Lilracr]

Detonation is base on cylinder pressure, but the piston/chamber design has a huge amount to do with it.
Steel heads, older factory chamber designs, dome pistons and too much quench are a recipe for detonation.

It must all work together to be efficient.

Nice 406 build you have there!

 

[midnightrider]

My understanding is that max quench will actually help avoid detonation...I built mine with a "0" deck and a .039 gasket to accomplish what most would consider max quench, or least acceptable piston to head clearance. I know some builders run them even tighter, but that was as tight as I wanted to go. No detonation, even loaded up in 6th gear with a T-56 with a .5 overdrive... I did have to tune the advance curve since I run 26* initial I did not want that extra 10* coming in too soon, like where I would be cruising in 5th or 6th at around 2200 rpm or less, here is the curve I run:
FBO 10* Advance bushing, 26* initial – 36* total
2 heavy silver springs …27*@2000…30*@2400…32*@2600…36*@3100