Modern manufacturing is a new world compared to days of old

[Janderso]

I've been in the automotive repair business since 1976.
The technology has come a long way.
I was surprised to hear the factory maximum specification for cylinder wall taper is .0004"
We have an unusual situation with a small V-6 engine and had to tear it down to identify the causal component. (The engine has less than 10.000 miles on it). In the process the tech. found one cylinder had significant taper >.001. I said, "that's out of spec? what is the spec??" = < .0004"!!
I don't know what a 1971 V-8 engine maximum taper would be but I bet it was a higher tolerance than today.
That's pretty amazing when you think of the pace and quantity of cylinder blocks coming out of these modern plants. I would assume the manufacturing environment is climate controlled in laboratory conditions.

 

[benmychree]

I've been in the automotive repair business since 1976.
The technology has come a long way.
I was surprised to hear the factory maximum specification for cylinder wall taper is .0004"
We have an unusual situation with a small V-6 engine and had to tear it down to identify the causal component. (The engine has less than 10.000 miles on it). In the process the tech. found one cylinder had significant taper >.001. I said, "that's out of spec? what is the spec??" = < .0004"!!
I don't know what a 1971 V-8 engine maximum taper would be but I bet it was a higher tolerance than today.
That's pretty amazing when you think of the paceView attachment 307734View attachment 307735 and quantity of cylinder blocks coming out of these modern plants. I would assume the manufacturing environment is climate controlled in laboratory conditions.

Maybe with that one it was under lavatory conditions???

 

[Janderso]

Maybe with that one it was under lavatory conditions???

 

[f350ca]

Thats tight tolerances. The last Wisconsin 2 cylinder I rebuilt was still running, sort of with 20 thou taper.

Greg

 

[eeler1]

We see it in all manufacturing of everything. Even ****hole countries can keep tight tolerances now, if they have decent machine tools, cnc and all. We see airguns (my thing) now, out of the orient, that rival German airguns from the 1990’s in terms of fit and finish. And cheap too. Pretty amazing. Metallurgy may be suspect, though. Welcome to the new world order!

 

[Nutfarmer]

A thousand taper is not going to cause a problem in a cylinder even if it is out of specs. If the engine wasn't performing right the problem was some where else .

 

[Janderso]

The problem was in the cam shaft on one side. Processing warranty claims requires a causal part. When we find components out of range, it bolsters a case for fast payment without red tape.
In this case there were two causal components out of spec = short block and one cylinder head.
The taper was >.004.”