Measuring cylinder taper with feeler gauge and ring.

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Dartswinger70

Dartswinger70

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Has anyone here done this? what is the no go spec? i am thinking .010 (difference between top piston gap measurement and bottom measurement) is "too much" What say you?

Also to clarify , I what I mean by "done this" Is measure cylinder taper with a piston ring and feeler gauge. You put the ring in the bore just under where the ridge may be (where the ring actually contacts bore) take a measurement, record it, then measure at the bottom ,where the ring doesn't ride .subtract the bottom from top, and note the measurement. I am saying .010 is too much using this method. , then you should overbore. Of course bore gauges are more accurate but who has 4 inch bore gauges ? :)

This is purely just to tell if you can hone and ring or does it go to machine shop.
 
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Dartswinger70 said:
Has anyone here done this? what is the no go spec? i am thinking .010 (difference between top piston gap measurement and bottom measurement) is "too much" What say you?

Also to clarify , I what I mean by "done this" Is measure cylinder taper with a piston ring and feeler gauge. You put the ring in the bore just under where the ridge may be (where the ring actually contacts bore) take a measurement, record it, then measure at the bottom ,where the ring doesn't ride .subtract the bottom from top, and note the measurement. I am saying .010 is too much using this method. , then you should overbore. Of course bore gauges are more accurate but who has 4 inch bore gauges ? :)

This is purely just to tell if you can hone and ring or does it go to machine shop.
Click to expand...
0.010 change in circ would be around 0.003 in dia. Is that too much?

I got that using this...

Circle Calculator

Then using the output or the circ +0.010 as the input for circ.


Seems like a legit way to do it.
 
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All it is is "pi." 3.14x diameter= circumference

So other way around, circumference/3.14 = diameter
 
Yep. What I was getting at is just take the change you measure in ring gap, and divide that by pi. That will give you the averaged taper. Of course it won't measure out-of round.
 
Well, I measured my "extra" 340 block, using ring and feeler gauge method and my cylinders were avereaging .006 so I am thinking a honre and rering with standard size pistons would work. keep in mind most guys would say take it to a machine shop, but i am into low budget type 'any guy could do this at home" type things. The measurement as i described is purely to determine if an overbore is necessary. I am thinking I can hone and re ring. In worse case scenarios the engine may consume oil etc if the taper is too much. Nothing like adding a quart a month but you have no leaks LOL!
 
3.1415926, according to my son, who is working on his doctorate in physics. My son the rocket scientist. Who'd of thunk?
 
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