Boring a flathead

No, Ron, I have not seen the gator in my pond this year. Hope he moved. I think he did a good job on the snakes because I have seen only one in the pond.

Now, let's get back to the reason the valve locations are different from bank to bank-----do you understand my explanation?
 
Yes, but I never understand why they did it. I do understand why they offset the crank and wondered why modern engines don't do that. Are off set pistons still popular? When I built my Hemi, reversing the pistons was one of the first things I did. The engine was stock except for a Crane 292H cam and would turn 6500 with dual quads. scary mother. Back to the flathead, the ports are different side to side as well. Thanks
 
On the offset...I have an ancient Ford produced engineering text with an explanation from the horse's mouth...the book is moderately common, and likely your local library could get a copy via interlibrary loan. I just replaced my copy because Flatdog had the old one and was reading it about the time of his death. Did not want to bug the family at such a time!
Anyway, the offset crank is referred to as the "Desaxe principle", which might help in hunting patents or early papers.
I can understand about 50% of the book until it moves into heavy math, it would be a much better read for someone like JWL!
Some excerpts: "...the axis of the cylinder is offset from the centre line of the crankshaft...The principle object of this offset is to diminish the obliquity of the connecting rod during the power stroke. so that the mean thrust of the piston on the cylinder walls during this stroke when the bearing loads are greatest, is reduced."
This moves on into the differences between upward and downward movement vs pin position, influence on real stroke, etc., moving into math that takes me into screaming nightmares of analytical algebra and geometry in the 10th grade.
It also gets into determination and definition of TDC in these things, really explaining why it is not nearly as simple as a dial indicator topping out...
For those who read such stuff:

"An Elementary Text Book of Automobile Engineering", 1935, Facilities department, Ford Motor Company Limited, Dagenham/Essex.
Note that the A&B Fords and the little four banger made in England all also were offset.
 
I just pulled my flathead and it ended up being a 1941-42 that has a 3 3/16 bore but it's not a mercury. Is there still life in her? How much can you go on that year a motor and be safe?
 
I just pulled my flathead and it ended up being a 1941-42 that has a 3 3/16 bore but it's not a mercury. Is there still life in her? How much can you go on that year a motor and be safe?

If I recall correctly they will generaly go 0.060" over 3 3/16". I think Walt has taken some of these out to 3 5/16".
Just to clarify, were talking 21A here, no round water hole in the middle?
I'd have thought, if you bore just enough necessary for a good bore, you should be fine. Have you measured to see whats needed?
Martin.
 
If I recall correctly they will generaly go 0.060" over 3 3/16". I think Walt has taken some of these out to 3 5/16".
Just to clarify, were talking 21A here, no round water hole in the middle?
I'd have thought, if you bore just enough necessary for a good bore, you should be fine. Have you measured to see whats needed?
Martin.

Those 40-42 221 engines with the tin can .040 wall sleeves, I remove the sleeves so now you have an ,080 over bore, I bore them another .045 to 3-3/16 and use std. 8BA pistons. I wouldn't go to 3-5/16 that's 1/4.in oversize. BUT, if I had one that was already 3-3/16 and needs a little clean up I'd probably go another .030 or might get brave and go .040 Walt
 
Thank you for clarification Walt, I obviously didn't recall correctly. Early stage CRS.
Sorry for wonky info.
 
Yeah there is practically zero ridge but for some reason they look like crap. They're smooth just look bad. Hard to explain. I'm hoping just a hone will do them justice
 

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This has to be the most informative piece I've ever seen here by the "Masters" of the Ford flathead. Much of it beyond my level of comprehension, but never the less, spell binding in its content. I have a 276 that I thought was the "cats meow" but now realize I haven't even scratched the surface in what is possible.
 
The 276 is a very nice engine and properly tuned can be a great performer, with excellent fuel economy. So don't sell them short, I have one in my truck.
 
The 276 is a very nice engine and properly tuned can be a great performer, with excellent fuel economy. So don't sell them short, I have one in my truck.
Ol'Ron, am very pleased with the way it now runs, thanks to (Richard in Florida) and your help while I was putting it together.
 

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Yeah there is practically zero ridge but for some reason they look like crap. They're smooth just look bad. Hard to explain. I'm hoping just a hone will do them justice

You got a bore gauge? Or something to measure the bore down in the hole?
Its entirely possible that even with a tiny ridge at the top, the bore can bellow out further down the bore. These measurements will tell you if you'll get away with a hone.
Measure the ring groove clearance, tween the top or bottom of the ring to the groove. This will tell you if you need pistons.
All this depends on how far you want to go, and what sort of engine your after.
Martin.
 
This is my my flathead runs 85% fuel, theres a couple in the younger generation that love a gnarly flathead:D
 

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Does this have anything to do with boring an engine out? This is a fairly old thread. It looks like it hasn't been run yet unless that's an old photo. Running 4 carbs makes for an interesting generator/fan installation.
 
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