[GMC Main] [6066 GMC Club] [What's New] [Engines] [Support] [Memorabilia] [GMC Gallery]
[GMC ID] [VIN Numbers] [Contact] [ Discussion Group] [Lighting & Electrical] [V6 Performance]



1. BATTERY SAVING GENERATOR Delcotron alternating-current generator charges battery
even when engine idles. Battery stays more fully charged, gives super starts, & it lasts longer.

2. SIMPLIFIED CARBURETION Highly efficient two-barrel carburetor rations regular-grade
gasoline to the engine. Simple design means easy servicing -- & it's seldom required.

3. GIANT-CAPACITY WATER PUMP A V-6 water pump, with up to three times
the capacity of pumps in comparable engines, drives more water to cool more evenly.

4. PROTECTED IGNITION WIRING Wires are short & designed to remain trouble-free.
Instead of looping around & over the cylinder banks, they're neatly nested between the banks.

5. FREE-FLOW EXHAUST MANIFOLD Identical left & right exhaust manifolds of special
alloy iron & highly resistant to cracking & warping by extreme temperature changes. Large
individual ports for each cylinder & short, large diameter passages permit more complete
scavenging of exhaust gases. Result is better fuel economy, longer life, & better performance.

6. POSITIVE-ACTION STARTER There's no hit-or-miss starting with this powerful,
solenoid-shift starter. Before the pinion rotates, it-shifts forward into full mesh with the flywheel.

7. SHORT INTAKE MANIFOLD with individual ports for each cylinder are a special
feature of this engine. Individual ports permit faster intake & more uniform distribution of fuel-air
mixture to each cylinder. Because manifolds are short & have a minimum of bends & curves, too rich
or too lean fuel mixtures, usually found in longer in-line or V-8 engines are completely eliminated.
This results in much better fuel economy, cleaner, more complete combustion & greater engine efficiency.

8. LONG-REACH SPARK PLUGS New, long-reach spark plugs have greater surface area
in contact with cooling passages. These cooler running plugs stay cleaner so they last longer.
Spark plugs, located inside the "V", away from hot exhaust manifolds, run cooler,
have much shorter wires, & are easy to service.

9. FULLY-MATCHED COMBUSTION CHAMBERS Smooth, precision-machined combustion
chamber minimizes carbon deposits, hot spots & pre-ignition. & there is uniform combustion in all 6
cylinders for smoothest engine operation. 6 equally-spaced head bolts surround each cylinder to reduce
bore distortion, & guarantee gasket sealing for long engine service.

10. SELF-ADJUSTING BRACKETS Valves operate efficiently at any engine temperature,
The hardened steel rocker arm shaft is held firmly in place by 5 aluminum brackets. As valves warm up &
expand, brackets expand too, assuring proper valve clearance under all operating temperatures. The engine
runs quieter with fewer valve adjustments needed, valve life is extended. Brackets at both ends of the shaft,
& one bracket between each set of rockers arms holds shaft deflection in check.

11. RELIABLE TIMING LINKAGE V-6 roller timing chains are double-strand, for
double durability. They're quit, & positive in action, models 401 & up have a three-gear train.

12. POSITIVE CRANKCASE VENTILATION Blue arrows show how clean filtered air enters
crankcase, flushes harmful fumes up to combustion chambers where they burn. Fully enclosed system.

13. FREE-BREATHING INTAKE VALVES Forged from steels with high resistance to warping,
pitting, & wear, extra-large intake valves let the V-6 breath freely, for higher volumetric efficiency.

14. FREE-VENTING EXHAUST VALVES Compared with other engines of equal displacement,
V-6's have the largest exhaust valves of all -- to keep back pressure low, efficiency high.

15. HARD FACES & INSERTS Tough, Silchrome XB-steel exhaust valves, hard-faced
with Ni-Chrome--plus long-life valve seat inserts are standard on the model 351 V-6 & up.

16. EASY VALVE ADJUSTMENT Self-locking adjusting screws s-t-r-e-t-c-h the time
between valve adjustments -- & then lighten the work; it's a simple & inexpensive one wrench job.

17. COOL-RUNNING VALVES Torrent of water cool V-6 valves, valve seats & guides.
This preserves engine efficiency, lengthens valve life, cuts the cost of engine maintenance.

18. LEVEL-TEMP COOLING SYSTEM Here's uniform cooling efficiency & prevents
trouble -- coolant temperatures vary less than four degrees throughout the entire V-6 engine!

19. "SCUFFPROOFING"DIP Before pressure lubrication takes over on engine starts,
V-6 cam lobes dip into a special oil reservoir. No "dry scuffing" mare cam or valve-lifter faces!

20. HIGH-POWERED LUBRICATION A lot of steel is on the go inside a V-6 -- but it lasts
because the high-powered, 14 gpm oil pump films all hard-working metal with life-saving lubricant.

21. TAMPERPROOF GOVERNOR Exclusive hydraulic governor is in the oil pan. The shop
can easily make authorized re-settings. Optional at extra cost on 351. Standard on 401 & up.

22. POSITIVE VALVE ROTATION A positive ratchet action rotated every valve on each cycle.
Contact surfaces stay clean for positive seating. Standard, 305C & up -- optional on 305E.

23. M400 CONNECTING ROD BEARINGS Big, long-life M400 bearings are used in V-6
connecting rods. Low-friction tin & aluminum alloys are backed with a layer os steel for extra strength.

24. EXTRA-LARGE MAIN BEARINGS Huge, M400 main bearings provide solid support for
the crankshaft, & resist wear by spreading the load over extra square inches of bearing area.

25. SHORT STROKE DESIGN It takes less travel of the V-6 piston to produce each mile
of pulling power. The result -- less friction, less heat, less wear & less expense.

26. PRECISION-FITTED PISTONS In every V-6 the big, deep-skirt aluminum pistons are
weight-matched, & precision-fitted to the bores, a cast-in steel band controls heat expansion.

27. SHORT, RIGID CAMSHAFT Extra-wide camshaft lobes are flame hardened & phosphate
coated to resist wear. Four big bearings carry the shaft for precise valve operation.

28. RUGGED CONNECTING RODS Piston power flows smoothly to the crankshaft through
big, forged-steel, I-beam connecting rods -- all balanced to within the weight of a cigarette!

29. SHORT, STIFF CRANKSHAFT This husky crankshaft helps conserve engine power &
extends bearing life, because it has the strength & balance to minimize deflection & vibration.

30. RIGID, RUGGED BLOCK This block has strength to spare for resisting internal strain --
strength from it's super-tough iron alloy, staggered cylinders & short, deep-skirt design.

~ 6066 GMC Trucks ~ 6066 GMC Trucks ~ 6066 GMC Trucks ~ 6066 GMC Trucks ~ 6066 GMC Trucks ~ 6066 GMC Trucks ~ 6066 GMC Trucks ~ 6066 GMC Trucks ~

Information About GMC Truck Drive Trains

GMC Big Block V6

GMC Drive-Train
Data Pages

GMC Twin-Six V12

1960-1974 GMC V6 & V12 Engine Data

GMC's Twin-Six V-12 Engine!

1960-1966 GMC's Inline 6 Engines

GMC Twin-Six V12 Engines

GMC Diesel Engine Data Page

GMC Twin-Six V12 Myths

Carburator Data Page

1965 Article GMC Irrigation Engines

GMC Toro-Flow Diesels

Powered by GMC V6/V12 Engines

GMC Transmission Data

Known Good Part Numbers

GMC Drive Axle Data

Spicer 5831 Aux Transmission

~ 6066 GMC Trucks ~ 6066 GMC Trucks ~ 6066 GMC Trucks ~ 6066 GMC Trucks ~ 6066 GMC Trucks ~ 6066 GMC Trucks ~ 6066 GMC Trucks ~ 6066 GMC Trucks ~

Return to 6066 GMC Trucks

Contact the GMC Guy

© 2000-2008 6066 GMC Trucks. Last Updated July 28, 2008.