3.910 + a few lines

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Princess Valiant

A.K.A. Rainy Day Auto
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I think I'm reading this right and I think this teen needs bored out.

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Are you measuring the piston? You should be measuring the bore.
 
This is the area in the cylinder right below the ridge, where the finger nail caught

Cylinder 7 and 8 have a ridge and yet 6 others not so much so it makes me wonder if an oil passage clogged and starved those 2 cylinders to having a ridge
 
Probably should to make it right. It's only .005 but............
 
If you are measuring correctly, .0013 would not need to be bored. Unfortunately I feel the is an error in the equipment or technique. You should not be able to feel .0013". A hot shot Engineer should have her own dial bore gage and setting rings ;-)
 
One spot won't be enough, but if the cylinders are consistent up and down the bores then a .030 cleanup should suffice. And i would feel more comfortable with a rebuild.
 
If you are measuring correctly, .0013 would not need to be bored. Unfortunately I feel the is an error in the equipment or technique. You should not be able to feel .0013". A hot shot Engineer should have her own dial bore gage and setting rings ;-)
Shamefully, I have a bore gauge, used it once and forgot how to use it.

I started honing this 318 to see how it would clean up or not. Came out of my 73 valiant. Low miles car that had the middle name sludge. This engine had so much sludge inside and out, that it was nuts.

All the cylinders are nice except 7 and 8 ... more pics coming
 
I thought this would be easier but .....I suppose no time like the present to dig into this thing deeper.

I really don't remember how to use this and I should be mastering this.

Now it's a great time to read the instructions. LoL

20240203_173637.jpg
 
Many moons ago i had one very similar to that and talked myself into a cheap cleanup with a larger then normal hone job, ring spacers on the wore out cast slugs with cut down oversized rings. That along with knurled valve guides and a cam upgrade gave me a pretty hot running engine........for about 500 miles. lol.

I surely learned my lesson on that one.:(
 
It has been my understanding and experience the average human hand can feel 0.001"
.010 in my experience. I could read a scale to .010. but a dial bore gage should be good to .0001" and not everyone can do that. A man has to know his limitations.
 
I only did a couple quick measurements and since it's so off, I'm just going to stop and not waste anymore time on this.

Now to the machine shop
 
Help me out. Where are you coming up with 3.906"? I thought the standard bore for the 318 was 3.910. Then, the pistons are slightly under size to give the clearance.
 
Help me out. Where are you coming up with 3.906"? I thought the standard bore for the 318 was 3.910. Then, the pistons are slightly under size to give the clearance.
That would certainly change things if it is 3.910
 
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