The Ford Barn

Wagga A'er · 05-29-2011, 08:38 AM

I want to rebuild my current engine as its number matches the firewall date. It has been previously bored out to .060 oversized. However it has two cylinders that are sloppy. I have bored it out to .080 and it still has marks in the bore. Would you bore it out more or put cylinder sleeves in the cylinder and go back to standard? I am worried about overheating problems. Your thoughts would be greatly appreciated.

John Stone · 05-29-2011, 09:21 AM

Not sure why an engine would overheat. Engines are bored to .125 over without any problems.

tuneman · 05-29-2011, 09:24 AM

I have one at 125 over no problem. Run it abt 5,000 miles a year on average.

Jim Brierley · 05-31-2011, 01:22 PM

I am running one at +.100" and one at +.125", neither have heating problems. I also race on the Bonneville salt flats with one that is 4" (+.125") and have no problems with it either. I've seen them raced at 4.060" without heating problems too. .100" over would be no problem. Where and how bad (deep) are the marks at .080"? It may be OK to run it like that? I would rather run a large bore than put sleeves in. If it has no sleeves, they will not ever cause a problem!

James Rogers · 05-31-2011, 01:39 PM

Bore it to .100 and let her rip. I have customers that want their motors bored to .125 no matter what the starting bore is.

James Rogers · 05-31-2011, 01:40 PM

Sponsored Links (Register now to hide all advertisements)

There is your coast to coast answer! Bore it, right Jim.

Peter J · 05-31-2011, 07:58 PM

While we're on the subject of scored cylinders, I have one that has one score mark almost the length of the bore but not to the top. I put new rings in. With the rings, will the score smooth out to some extent? Do any of you guys forsee any problems in the future?
Thanks,
Pete

J and M Machine · 05-31-2011, 09:47 PM

I would recommend that you sleeve them back to standard. The reason being that we have seen the core shift in the model A blocks from boring them oversize"for sleeves"
Where I have seen the blocks being thin is in the center cylinders.

The other thing that no one has mentioned is the erosion from rust in the water jacket. That reduces the original thickness of metal.
We don't go over .080"

05-29-2011, 08:38 AM	#1
Wagga A'er Member Join Date: Jul 2010 Location: Wagga Wagga - Australia Posts: 78	Engine rebore I want to rebuild my current engine as its number matches the firewall date. It has been previously bored out to .060 oversized. However it has two cylinders that are sloppy. I have bored it out to .080 and it still has marks in the bore. Would you bore it out more or put cylinder sleeves in the cylinder and go back to standard? I am worried about overheating problems. Your thoughts would be greatly appreciated.

05-29-2011, 09:21 AM	#2
John Stone Senior Member Join Date: May 2010 Location: Wichita, Kansas Posts: 710	Re: Engine rebore Not sure why an engine would overheat. Engines are bored to .125 over without any problems. Last edited by John Stone; 05-29-2011 at 09:22 AM. Reason: corrected english

05-29-2011, 09:24 AM	#3
tuneman Senior Member Join Date: May 2010 Posts: 264	Re: Engine rebore I have one at 125 over no problem. Run it abt 5,000 miles a year on average.

05-31-2011, 01:22 PM	#4
Jim Brierley Senior Member Join Date: Jun 2010 Location: Temecula, CA Posts: 4,084	Re: Engine rebore I am running one at +.100" and one at +.125", neither have heating problems. I also race on the Bonneville salt flats with one that is 4" (+.125") and have no problems with it either. I've seen them raced at 4.060" without heating problems too. .100" over would be no problem. Where and how bad (deep) are the marks at .080"? It may be OK to run it like that? I would rather run a large bore than put sleeves in. If it has no sleeves, they will not ever cause a problem!

05-31-2011, 01:39 PM	#5
James Rogers Senior Member Join Date: May 2010 Location: Asheville,NC Posts: 3,104	Re: Engine rebore Bore it to .100 and let her rip. I have customers that want their motors bored to .125 no matter what the starting bore is.

05-31-2011, 01:40 PM	#6
James Rogers Senior Member Join Date: May 2010 Location: Asheville,NC Posts: 3,104	Re: Engine rebore Sponsored Links (Register now to hide all advertisements) There is your coast to coast answer! Bore it, right Jim.

05-31-2011, 07:58 PM	#7
Peter J Senior Member Join Date: Jul 2010 Location: Olympia, WA Posts: 691	Re: Engine rebore While we're on the subject of scored cylinders, I have one that has one score mark almost the length of the bore but not to the top. I put new rings in. With the rings, will the score smooth out to some extent? Do any of you guys forsee any problems in the future? Thanks, Pete

05-31-2011, 09:47 PM	#8
J and M Machine Senior Member Join Date: Oct 2010 Location: 40 Mt.Vickery Rd. Southborough,MA 508-460-0733 Posts: 352	Re: Engine rebore I would recommend that you sleeve them back to standard. The reason being that we have seen the core shift in the model A blocks from boring them oversize"for sleeves" Where I have seen the blocks being thin is in the center cylinders. The other thing that no one has mentioned is the erosion from rust in the water jacket. That reduces the original thickness of metal. We don't go over .080"

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