Can you run a V-8 engine on just 4?

Wild Turkey

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I think I remember some cases where they ran only half the cylinders -- did they use a V-8 crank?

How was balancing changed?

(I'm not talking about the "compressors" that have half the cylinders firing and half pumping air)
 

Everett2390

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Cadillac did it in the '80's, called it Fuel Mgmt.
Once up to speed, half the cylinders dropped off, every other cylinder in the firing order.

Speaking of half a V8, I remember one time adjusting hydraulic valves on a SBC.
Remove the whole side of plug wires, draped them over the carb, removed the cover,
started the engine, ran through the valve adjustment, turned engine off, replaced the cover.
Then I seen I had forgot to reconnect the plug wires before adjusting.
Always wondered why the engine was idling so very slow...
 

Philip

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I did that once to, had the cover off to replace the gasket and forgot to reconnect the wires before starting the engine, but it was a 340 Mopar engine. IIRC it has the same firing order as a Chevy V8
 

Everett2390

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In answering the OP's question, Pontiac did in the early '60's with the Tempest engine, a 4-cyl
Pontiac cut a V8 in half, and changed the crankshaft, all else stayed the same, including cylinder head.
 

Wild Turkey

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How different was the 4-cylinder crank from the 8?

Could a V-8 crank be lightened to run as a 4 (using only one bank) ?

I seem to remember some folks do it but can't find any references.
 

Everett2390

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Different crank as in less rods connected to it.
 

hurst01

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Mind if I ask what your reasoning is? My 2011 Chevy Silverado 5.3 runs on 4 cylinders while cruising. When I was a kid it was common practice among some back yard mechanics to remove a piston and rod from the old 6 cylinder Chevy engines and block off the cylinder should they burn out a rod bearing.
I have seen people remove 4 spark plug wires from the plugs and run the engines but i can't recall which cylinders.
 

Craig Hanson

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I ran a Insta-Tune shop back in the late 1970's. A friend comes in a 1956 Pontiac Safari station wagon(Think Nomad) and had a 389 GTO engine with 3 deuce set up. He wanted a tune up and have it Dynoed cuz we had a Dyno. I fired it up and ran the dyno, shut it down and pulled the plug, Points, condenser, cap, rotor. I ran a compression test....A, OK.... put in new points, cond, rotor, cap Then I screwed in 4 plugs on the passenger side, hooked up the wires and said fire it up. Vacuum gauge looked weird and it was lopping along, I thought it was the 3 carbs, grabbed a screwdriver and started to reach for the carb. Jim said would it run better if you put 4 plugs in over here and hook up these wires. I said yeah, prolly will and acted like I knew what I did was normal. Got it back together and ran it on the dyno....It ran like a scared Jackrabbit. True story.
 
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