Topic: Boring

vacaville john	-- 06-04-2012 @ 3:11 PM
	I have an original 1940 block that has never been bored. It's the 221 ci. motor, no sleeves. The block has freeze plugs in the pan rail. I'd like to know how far it can be safely bored and is 1940 the only year there were freeze plugs in the pan rail.
Stroker	-- 06-04-2012 @ 4:24 PM
	Vacaville: Guess we could use a little more info as to what your objectives are. Most flatheads will tolerate a .030 overbore, but unless you have a major bore issue with your existing block, that much is seldom necessary. If you are looking to increase displacement, then a better choice would be a 59 series (239 cu.in. block). Back "in the day", we would scrounge the junkyards for 59 series blocks, and then bore them .375 over. Today, if one is seeking horsepower, there are many more options, most of which are not embraced by this sage group of preservationists to which we ascribe to. Today we also have the technology to determine cylinder wall thickness via ultrasonic testing. A good race shop may be able to perform this inspection for you. If your objective is to simply "clean-up" the motor, then I'd bore as little as it takes to accomplish that.
mdurhan	-- 06-23-2012 @ 5:02 PM
	I know my 60 hp '37 had freeze plugs in the pan rail. I can't say I have ever seen an 85 hp with freeze plugs there. Mike
mdurhan	-- 06-23-2012 @ 5:04 PM
	I know my 60 hp '37 had freeze plugs in the pan rail. I can't say I have ever seen an 85 hp with freeze plugs there. Mike
supereal	-- 06-24-2012 @ 4:19 AM
	Bore and hone only enough to remove taper and clean up the cylinders. Then you can use standard sized pistons and rings. There is little to be gained by going big, and you run the risk of hitting a sand hole and either ruining the block or having to sleeve the cylinder. This message was edited by supereal on 6-24-12 @ 4:21 AM

EFV-8 Club Forum :	https://www.earlyfordv8.org/forum
Topic:	https://www.earlyfordv8.org/forum/viewmessages.cfm?Forum=18&Topic=4744