Cylinder boring question

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gliderider06

gliderider06

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Sorry if this question is "boring" to you, but I just picked up a standard bore 340, that has a grove in one cyl from snap lock on the wrist pin coming loose. I stuck a feeler gauge to it and it seems about .030" deep in the wall. Now, to clear that up, would I need to take it .060" over or will a .030" bore clean it? My thought process is that, when a cylinder is bored that it is the overall circumference of the cylinder, not the debth of the cut. Right or wrong?
Thanks!
 
gliderider06 said:
Sorry if this question is "boring" to you, but I just picked up a standard bore 340, that has a grove in one cyl from snap lock on the wrist pin coming loose. I stuck a feeler gauge to it and it seems about .030" deep in the wall. Now, to clear that up, would I need to take it .060" over or will a .030" bore clean it? My thought process is that, when a cylinder is bored that it is the overall circumference of the cylinder, not the debth of the cut. Right or wrong?
Thanks!
Click to expand...

That is correct.

A .030" groove in one side, will be required to be bored out .060"
to clean it up.

Put a center-line through the top of the cylinder, and if it is bored out,
.030" will be removed from each side.
 
You could always sleeve the one cylinder and bore the cylinders .030. A good machine shop can do it.
 
Use a shop with a CNC mill and they can offset the bore to that side. The vast majority of blocks don't have the bores preciesly where they're supposed to be located anyway.
 
69 Cuda 440 said:
That is correct.

A .030" groove in one side, will be required to be bored out .060"
to clean it up.

Put a center-line through the top of the cylinder, and if it is bored out,
.030" will be removed from each side.
Click to expand...

my duster has been bored .060 and it runs okay--it will run a little hotter than normal--mine runs about 195 even in hot weather--would recommend a good radiator--as far as holding up i've had the car 14 years and have not been into the bottom half yet--of course it's strictly a street machine--no racing---good luck
 
Thank You! I will tear the block down and see what the machineist recommends at my machine shop.
 
How do you measure depth with a feeler gauge?
 
hi, put a sleeve in it, do not offset bore the cylinder!!!!! sleeve is correct way to repair it.
btw , boring is done with a boring bar!!!!
 
"btw , boring is done with a boring bar!!!!"

Um, yeah... But the bar can be driven by a fixture that self centers on the existing bore centerline, or it can be attached to a machining center that can locate the bore centerline where ever you need it. Correcting the factory mess to actual blueprint spec(if you haven't had it done on a block machining center you probably don't know how bad factory is...), or offsetting to increase wall thickness on major thrust, or to avoid sleeving. It's MUCH more accurate. Offsetting .015 will not hurt anything, and costs nothing more. Sleeving will repair it properly and permanently, for another $100 or so.
 
moper said:
"btw , boring is done with a boring bar!!!!"

Um, yeah... But the bar can be driven by a fixture that self centers on the existing bore centerline, or it can be attached to a machining center that can locate the bore centerline where ever you need it. Correcting the factory mess to actual blueprint spec(if you haven't had it done on a block machining center you probably don't know how bad factory is...), or offsetting to increase wall thickness on major thrust, or to avoid sleeving. It's MUCH more accurate. Offsetting .015 will not hurt anything, and costs nothing more. Sleeving will repair it properly and permanently, for another $100 or so.
Click to expand...

Exactly. Last machine shop where I worked was a small mom and pop one. BUT, we had a brand new state of the art for that time Kwik Way boring bar. Computerized floating head. It would bore between two cylinders if that's what you wanted to do. You could literally set the bar up anywhere in relation to the crank center line. It was nice.
 
Sleeving an Engine Block

Should only be performed as a last resort.

An off-set bore on an +.060" Piston, you can get away with a .015" off-set
to one side from the center-line.

Meaning, .045" off one side, and .015" off the other.

That is as far as I have gone on our Rottler Boring Bar.
 
moper said:
Use a shop with a CNC mill and they can offset the bore to that side. The vast majority of blocks don't have the bores preciesly where they're supposed to be located anyway.
Click to expand...

Man, I learn something new every day. If this keeps on I will break 100 on the IQ test in 20 years or so............................:blob:
 
Just sleeve the thing and be done with it.

If done compentently, you won't even know its there, and if you use a high strength sleeve it will be stronger than OEM.
 
I did use feeler gauges to get a guestimate on how deep the groove is. I had to work all weekend, so I hadn't been able to tear it down and take to machine shop. I will be able to do that this week and see what they say. I do believe a sleeve is the best solution. I hate to bore the snot out of an otherwise good block that most likely not need to be bored.
Thanks for all the great information!
 
Put a sleeve in it. It will last the life of the block. I use sleeves to repair race blocks when they crack and they work just fine for and its cheaper than starting over with a new block.
 
69 Cuda 440 said:
Sleeve Installation

Cost ......... $200 plus the cost of the Sleeve.
Click to expand...

Wow, I just had three sleeves done on my block and it was 195 to bore and sleeve all three with the cost of the sleeves being 40 bucks. A little cheaper in Texas, I guess.
Rod
 
rklein383 said:
Wow, I just had three sleeves done on my block and it was 195 to bore and sleeve all three with the cost of the sleeves being 40 bucks. A little cheaper in Texas, I guess.
Rod
Click to expand...

also depends on the quality of the sleeve.......
 
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