The Mythical 7 Cylinder V8

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Ant

Ant

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Has anyone heard of this story? It's about a new Chevy(some say it was a corvette)that came in for repair because of a minor vibration. The mechanic working on it found that one of the 8 cylinders was misfiring because the piston and rod was not there, like it was not put in from the factory. Rumor has it that the customer never fixed the issue and continued driving the car for years, which would mean even with a connecting rod missing the engine still had good enough oil pressure.

This story has been told to me multiple times by multiple now old timers. Some say that one of the cylinders in the block was just blank and some say it was not. Another rumor is that it was a test from GM for the dealers to make sure that they are properly doing inspections on the cars before they are sold. I have heard multiple versions and ideas of this myth and it's definitely not modern, possibly from the 80's, which may be why it was never documented online.

What do yall think? Has anyone heard of anything like this before?
 
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The oil hole in the crank throw with no rod on it will bleed off oil pressure like a garden hose.
 
No, I haven't heard of this, But I can see how it could happen.
 
One of the Viper racing teams left out two pistons of their v10, and run it as a v8, in order to comply with rules of the series.
 
A friend of mine had a 79 Camaro with a 350 that threw a rod... he wanted to sell it I said "we can drop the pan disconnect the rod push it up in the bore or remove it out the top and run it on 7 cylinders, it will run like crap but it wont knock..." it was an idea no we never did it...:) I would think eventually gas would get in the oil through the intake? but eh ya never know till ya try it...
 
If they overlooked, or forgot a cylinder, maybe the crank wasn't even machined in bearing area?
 
Sounds like another "200 mpg carburetor" or "my step-uncle special ordered a Vega with a L-88" kinda story
 
Minercar said:
You would be dumping fuel into the sump constantly.
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Wouldn't it be the other way around? When the exhaust valves were open, they would be attempting to pressurize the crankcase.

When the intakes were open the crankcase pressure would be forcing oil vapor into the intake
 
Minercar said:
You would be dumping fuel into the sump constantly.
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Yes and no. If the valves are closed or the ports are blocked off then no fuel would be going in, but that's another mystery to the story If it was true, then how was it done?

The fact that the engine should should have low oil pressure and possibly fuel going into the oil would and should debunk this myth, but I have heard and know how it could be done with those issues fixed. That would mean it was a dealer inspection test car engineered by GM if it was true.
 
I've never heard of this happening from the factory, but...

Sometime in the late 70'/early 80's there was a magazine article written by a guy who a famous off-road/4X4 dude, and he was "way out in the middle of nowhere" when his engine took a dump on him. He was smart enough to carry tools whenever he went out, and turns out he burned-up or broke a piston....for whatever reason. Anyway, long story short: He and his dog (I remember his dog was with him) dropped the pan, and then the crank (partway), removed the offending piston and rod assy, and then he fashioned a wooden dowel to fill the bore and act as a seal of sorts (I don't recall the reasoning behind that). Regardless, he kept running it this way for quite some time after he got back, and I distinctly remember him saying that he got some weird looks when he would pull up to a gas pump, start the gas flowing, and then open-up the hood to pour some water into that bad cylinder (to swell-up that wooden "seal").

Sure wish I could remember the details better, as I'd like to read it again.
 
I can remember well maybe not very well back in the 70s friends dad blew a rod in his 6 cyl tractor He pushed the piston to the top. Cut the connecting rod off near the big end. Welded the block and went back about his business. Kim
 
I watched some racers put a hose clamp on a journal to stem the oil flow, THROUGH the new window in the block, once, so they could finish the race.

It was on TV, but I still saw it.
 
oldkimmer said:
I can remember well maybe not very well back in the 70s friends dad blew a rod in his 6 cyl tractor He pushed the piston to the top. Cut the connecting rod off near the big end. Welded the block and went back about his business. Kim
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its amazing what farmers do to keep the work going...
 
i coughed a rod in a /6 once and windowed the block. yoinked the offending bits out, threw a jubilee clip around the bearing shells, JB'd up the viewing port and kept that mutha truckin'

it ran a little funny, but was otherwise fine. i sold the car to a friend who continued to drive it for years like that until he sold the car to somebody that was "gonna put a big block in it".
 
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