How Close to (Over)Square In V-8 Bore/Stroke?
 

Bored and Stroked is common in the old Ford lingo. In the interest of preserving the incredible knowledge in our Members history, I inquire; can you share your experience with square/oversquare vs. just stroked vs. just bored?

I know Ol' Ron will have something here as well as many others.

I ask because the Ford V8 is/was a torque "beast" in it's day and I know all sorts of bores/strokes/compression ratios/and cams have been used. Is there a "sweet spot" for the stocker/mild engine? In my case the 8BA.

Might be a fun thread. This should be fun.

Cheers, S

Re: How Close to (Over)Square In V-8 Bore/Stroke?
 

Square/oversquare relates to the ratio of piston size to stroke. It would take a very short stroke crankshaft to achieve either in a flathead Ford V8.

Re: How Close to (Over)Square In V-8 Bore/Stroke?
 

Square is square. That's just the way it is. Same with round.

Re: How Close to (Over)Square In V-8 Bore/Stroke?
 

Is this like what goes up must come down? All kidding aside.

Experience as to bored compared to stroke compared to square/over square can anyone really give their experience with all of that?
What you need to do is put together an engine masters type of competition if there were individuals interested in entering the results/discovery's could then be preserved. The rules would need to have a cubic inch limit then how you go about getting to the chosen size would be the entry's choice.

Just deciding the cubes limit would be an interesting challenge for whoever is chosen to be the competition committee. This could be a costly endeavor for anyone interested in competing. It could be interesting none the less.
Ronnieroadster

Re: How Close to (Over)Square In V-8 Bore/Stroke?
 

It wouldn't be to hard to test a square vs a under square combo. You could even test a over square but, the cranks would expensive.

The combo's would be:
3.202 x 3.750 = 241.58
3.375 x 3.375 = 241.55
3.440 x 3.250 = 241.65

Or
3.19 x 4.00 = 255.75
3.44 x 3.438 = 255.63

I don't think there would be any difference in HP for the last two but, there might be some slight difference over the 3.75 stroke, in reduction of friction.

The friction reduction is why Ford came out with the short stroke OHV engines, in '52 & '54 and they advertised it, in their adds. They continued on with it in '60 & '62 with the Falcon 6 and Fairlaine V8.

The Mobil Economy Run was important in those days and I think that might have, had something to do with it.

Re: How Close to (Over)Square In V-8 Bore/Stroke?
 

The 2nd and 3rd motors in my '41 pickup were fairly close in spec.
#2....3 3/4" crank ,bored .06 and a set of slightly milled EAB heads..I had to down shift to second 1/2 way up my test hill
#3.....4" crank, bored.08 and set of EAB heads that I spent hours on matching the comb chambers to the actual piston crown ending up with .040 clearance (with head gasket installed) between the crown and the chamber. No down shifting required on my test hill. Interesting here ,this motor labored some 1/2 way up but as the grade
level slightly it began to accelerate and pull to the top.
Ron Halloran and John Lawrence will have invaluable insight here. Things like piston speed and rod angularity begin to influence the bottom line ,which escapes me.
Charlie ny

Re: How Close to (Over)Square In V-8 Bore/Stroke?
 

The closes I came to having a "Square" engine was a 3 5/8 de-stroked crank and 3 3/8 pistons Sold them before I had a chance to run it. However, the only ay to compare it would be on a dyno run with a similar size engine. The short stroke "MIGHT" rev alittle higher, so the torque curve might shift a little.

Re: How Close to (Over)Square In V-8 Bore/Stroke?
 

Well, thanks everyone who responded with knowledge and wisdom.

I grew up up reading 40's and 50's (B&W and early color) HRMs that I bought at some expense for teenager at flea markets. Still have'em. Now I am careful with "hot rod" posts here...but as stocker flatheads will in future need at least boring, and frankly you can hide anything in a "stocker" my post hoped to initiate conversation and coax out opinions from the pros as to the possibilities towards preserving and enhancing drivability. And learn while having fun listening to positive folks.

Thanks Ronnieroadster, Frnkeore, Charlie ny (PM'd you about my Mallory) and Ol' Ron...who inspired my thought process on the de-stroked V8's.

Wonder what the madmen short-trackers did with the very oversquare little V8-60?

Cheers, S

Re: How Close to (Over)Square In V-8 Bore/Stroke?
 

The Ford flathead was designed as a very under square motor, square and over square go against it's nature and kill the cubic inch potential.

Re: How Close to (Over)Square In V-8 Bore/Stroke?
 

To get a Ford flathead to "square" requires the crank shaft to be "de-stroked" by more than 1/4". I cannot think of a more futile (not to mention expensive) undertaking.

Re: How Close to (Over)Square In V-8 Bore/Stroke?
 

Please do not say anything unless it is constructive. i would prefer my posts not to be disrespected nor spoiled by any insulting comments.

This is a forum by definition; a place, meeting, or medium where ideas and views on a particular issue can be exchanged.

This place should be enjoyable. If you don't like what I say, change the channel.

Bye bye

Re: How Close to (Over)Square In V-8 Bore/Stroke?
 

This is exactly what is happening here. Just because you don't like it doesn't make it wrong.

Re: How Close to (Over)Square In V-8 Bore/Stroke?
 

I have often wondered about performance difference in a 258 (239 .125 over) and a stock 255 cube Mercury ( 4 inch stroke standard bore) I have a Mercury but never driven or rode in a 258. I think tubman has had both if my memory is correct.