Cylinder Bore

Glenn C.

Glenn C.

Well-known member
Is machining the cylinder bores to .125" oversize, taking to much of a chance that the remaining cylinder wall is too close to the water jacket ?
The pistons would be champhered back, to prevent hitting on the head gasket, if they are close.
This engine has a 5.5 Snyder head. "B" cam - touring grind. Porting and lightening of the flywheel would not be done at this time.
 
Hi Glenn, You certainly CAN do it, but you might ask yourself: SHOULD I do it. You are taking a risk with casting cavities and voids, etc. If you are already up over 0.060 in your cylinder bore, this conservative would advise sleeving and return to original bore. Happy motoring!
 
My coupe is bored to 1.25 and is running fine, with no ill effects on the water jacket or cooling. Many others in the club have done the same and most advise you can alway resleeve to original bore later. JM2Cents
 
.125 over is no problem. I am running one at that size and one that is .100 over with no heating problems. I have seen them in racing engines that are .187" over. I prefer to run without sleeves if possible although I wouldn't bore it more than needed to clean the bore. A bigger bore will result in more cubic inches and a little more power. Use pistons with thinner than stock rings if you can find them.
 
Glenn C. said:
Is machining the cylinder bores to .125" oversize, taking to much of a chance that the remaining cylinder wall is too close to the water jacket ?
The pistons would be champhered back, to prevent hitting on the head gasket, if they are close.
This engine has a 5.5 Snyder head. "B" cam - touring grind. Porting and lightening of the flywheel would not be done at this time.
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There should be no problems with water jacket. The main concern will be the reduced distance between the number one and number two, three and four cylinders and head gasket problems. You will need to use the Felpro 7013 head gasket, so as not to have gasket hanging over the pistons. I really don't see anymore chance of head gasket problems with .125 overbore than any other A engine that uses the 7013 gasket. The problem with sleeving back to standard size is heat transfer. Sleeves don't transfer heat to the water jacket the same because they are not part of the block. Sleeved engines will generally run higher temperatures. I would only consider re sleeving as a last resort to save a numbers matching engine.
 
With big bores I offset the bore to keep the deck between the cylinders as wide as possible.
Sleeves are a last resort to save a block.
 
Jim Brierley;70837.............. Use pistons with thinner than stock rings if you can find them.[/QUOTE said:
Egge is supplying balanced sets of Model A pistons, pins, and rings in all of the common oversizes. They have an online catalog. These "newer" assemblies use Chevy small block rings which are very thin as compared to the original rings. Two of my cars have these pistons installed and I believe they broke in quicker and run cleaner that the original style. Gar Williams
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Chris in CT said:
Hi Glenn, You certainly CAN do it, but you might ask yourself: SHOULD I do it. You are taking a risk with casting cavities and voids, etc. If you are already up over 0.060 in your cylinder bore, this conservative would advise sleeving and return to original bore. Happy motoring!
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Chris, with all due respect, why would there be any more chance of a void or casting cavity at .125 than there would be at .080 or even at .010?
 
Since the sleeves are of a high grade of cast iron, (possibly mehonite), and installed correctly, why would there be a problem with heat transfer ?
 
Glenn C. said:
Since the sleeves are of a high grade of cast iron, (possibly mehonite), and installed correctly, why would there be a problem with heat transfer ?
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It has nothing to do with the sleeve itself, it is the discontinuous interface between the outer surface of the sleeve and the block bore.
 
Sound plausible, about the heat transfer. But these engine were sleeved for many years and ran and still run just fine. I think we are trying to get to technical.
 
fordfixer said:
Sound plausible, about the heat transfer. But these engine were sleeved for many years and ran and still run just fine. I think we are trying to get to technical.
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The engines will run but will run hotter. Not only that if the sleeves are not properly installed they can drop down and cause catastrofic engine failure. I world prefer a large overbore to a sleeved engine any day for those reasons. You will gain cubic inches and compression with large pistons, I appreciate the extra power no matter how minute.
 
I lay a piece of .020 copper wire about 2" long between 1 and 2 and another piece between 3 and 4. I lay it on the block and hold it in place with a dab of grease. This is on my block with a 4" bore.
 
Purdy Swoft said:
The engines will run but will run hotter. Not only that if the sleeves are not properly installed they can drop down and cause catastrofic engine failure. I world prefer a large overbore to a sleeved engine any day for those reasons. You will gain cubic inches and compression with large pistons, I appreciate the extra power no matter how minute.
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I have an engine that was sleeved in the 50's and I ran the snot out of it back then. I never had a problem with it overheating. I now have an engine with a 4" bore and I place a piece of .020 copper wire about 2" long between 1 and 2 and another piece between 3 and 4. Haven't blown a gasket in that area. Once ran 9.5 to 1 with a plain fiber gasket, no fire rings, and it didn't blow where I had the wires. Don't recommend it. Just telling of my experience
 
Purdy Swoft said:
Sounds good, are you using the Felpro 7013 copper gasket?
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No, I use a Best Gasket on both "A" and "B" engines. I have nothing against the Felpro gaskets but the local auto parts would only order the entire Felpro gasket sets. I found the Best "B" head gasket worked better with aftermarket heads. Again, my engines are not stock so it is probably Apples and Oranges. Just wanted to share my experience with gaskets and sleeves.
 
just plain bill said:
No, I use a Best Gasket on both "A" and "B" engines. I have nothing against the Felpro gaskets but the local auto parts would only order the entire Felpro gasket sets. I found the Best "B" head gasket worked better with aftermarket heads. Again, my engines are not stock so it is probably Apples and Oranges. Just wanted to share my experience with gaskets and sleeves.
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Thanks Bill, This is all GOOD information and should be helpful to others who may be considering a .125 or 4 inch over bore. I hope that you don't mind my questions. I don't necessarily have a preferance to brand. I have used the Felpro 7013 copper gasket and it has a large opening that doesn't overhang the pistons on a 4 inch bore. I know that Specialty auto parts in Rosemead handled a big bore head gasket that was steel clad. Is the BEST gasket copper or steel clad and who handles them, Thanks for your knoledgeable information.
 
Purdy Swoft said:
Thanks Bill, This is all GOOD information and should be helpful to others who may be considering a .125 or 4 inch over bore. I hope that you don't mind my questions. I don't necessarily have a preferance to brand. I have used the Felpro 7013 copper gasket and it has a large opening that doesn't overhang the pistons on a 4 inch bore. I know that Specialty auto parts in Rosemead handled a big bore head gasket that was steel clad. Is the BEST gasket copper or steel clad and who handles them, Thanks for your knoledgeable information.
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Best makes both steel and copper clad, google Best gaskets. Or contact Taylor Engine in Whittier both are on the internet and can be googled. Best does not sell direct but has a dealer list available. I have used their Riley 2 port head gaskets successfully on my original Riley head. I'm not sure and don't know if their head gasket will work on a C Yapp 2 port. And you are welcome.
 
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