I went to a car show the other day and there were quite a few older trucks there with flat-head motors. I have a couple of questions about these. Where is the valve-train? You can't see any valve train on the outside of the motor. If the valves are up inside the motor, there are probably rocker arms driven right off of the camshaft. Isn't this more mechanically efficient than pushrods? Is the camshaft directly driven (versus a belt or chain)? This would also be more efficient. I wonder if you made a flathead today with modern metalurgy if it would make more power than a comparable pushrod engine?

Bill Jeffreys

 

flat heads dont have a camshaft, they have crank shafts.
if you got your hands on some they could be worth some money if it turns and will pop.
hope i kinda help some.
swanny

 

Um, I beg to differ. Flatheads do have a crankshaft just like every engine, but they also most certainly have a camshaft as well. It is gear driven off of the crank. The valvetrain is all in the block. The camshaft actuates solid lifters which open the valves directly. The valve springs are in the intake galley. With modern casting techniques, I'm quite sure that it is very possible to design and produce a flathead engine that does not have the tendencies of overheating and cracking the block like good 'ole Henry's does, and it may be more mechanically efficient from a friction standpoint than a pushrod motor, too. However, the inherent design problem with any flathead engine is that the fuel and air are drawn around a bend to get into the cylinder and the exhaust has to travel around a bend to get back out. In an overhead valve engine, the intake charge is drawn directly in and the exhaust is pushed directly out. This difference in flow efficiency makes up for frictional losses in the pushrod valvetrain tenfold. That is why the flathead has gone the way of the dinosaur.

 

I can picture a good flowing flathead. It would be somewhat of a 'side valve' engine. If you raised the camshaft into the lifter valley and then raised the angle of the valves, incoming air would have a straight shot into the cylinder without having to flow around the valve. Even overhead valve V8's have 90 degree turns in their ports so this would improve on that. But routing the exhaust ports is still a problem. Chamber shape would be compact and spark plug location could be optimized.

 

There is a brand new flathead on the horizon. Seems a few of the big names have worked out a new and efficient design and are in the prototype testing stage now. Rumor has it that it will even look like a Henry but be aluminum, etc.

 

"Um, I beg to differ........That is why the
flathead has gone the way of the dinosaur."


Haw haw haw, now Rage that's funny! Everybody knows the OHV phenomenon is just a fad and the fuss over it will fade shortly.

You guys should hang out with flat owners a bit and you'll realize they're anything but extinct. Click any of these links to expand your horizons

[http://www.fordbarn.com/]

[http://groups.msn.com/FordFlathead1932to1953/messageboard.msnw?pgmarket=en-us]

[http://www.btc-bci.com/~billben/flathead.htm]

Check the links on these pages for more info. That should keep you busy for a couple of weeks

 

Best answer I ever heard was, its a big lawn mower engine, and they are not that hard to work on. Especially if you are over 50 years old!

 

When most of us use of the term "flathead", we're referring to the arrangement of the cylinder and valves where the valve stems point in generally the same direction as a line from the piston to the crankshaft. A classic flathead head is flat - literally (except for some gas transport pockets, coolant holes, etc. An OHV head, on the other hand, has valve springs, rocker arms, and all the associated hardware sticking up on top.

One of the inherent problems with the classic flathead is that it's very hard to reduce the minimum chamber volume (the volume with the piston at TDC) and still leave enough room for the inlet and exhaust gasses to get in and out. This limits the maximum compression ratio and gas flow possibilities, as several previous posts have noted.

It seems to me that the term "flathead" applied to the new non-OHV designs refers more to the fact that they are getting away from the extra hardware (rocker arms, push rods, etc.) in a typical OHV engine than to the fact that the head will be flat, as in a classic flathead. As several previous posts have noted, these new designs will like have substantially different cylinder/valve geometries than the classic flatheads and their heads will not be nearly as "flat" geometrically. The will, however, be substantially more efficient, powerful, lightweight, and durable than the classic flatheads simply because we now have better materials and design tools. They probably will, in fact, be better than the OHV units in some applications because they won't have the extra hardware needed for an OHV arrangement. This extra hardware has to be very carefully designed to perform at high speed, has to have additional coolant/oil provisions, and is simply one more set of parts that can break or wear out.

My next project will be a classic flathead just because I think they look so ... classy!

George

 

Ohhhh, now wait just a cotton pickin' minute there, MT!!!! "I" AM one of those flathead nuts that you're referring to!! I've got more cars and trucks with their valves in the block around here than with them in the heads.:P By "gone the way of the dinosaur", I only was referring to what comes under the hood in new tin. As you said, the flathead and it's legacy will live on - but I don't think we'll be seeing any new ones in production vehicles again.

 

As my handle indicates Im a flatty man from way back.

The Flatfire broke 300 mph at Bonneville this year so the engine is far from dead. In fact production of new speed equipment is at an all time high. New head designs, new stroker cranks, rods...you name it.

My latest project is a blown 276 incher.

 

Hey Rage, I wasn't trying to dance on yer toes, honest!! I was just a bit slow on the uptake, but I get it now......yer just keepin' them flatties and hoping the newcomers will figure they're old junk and we can save them sweethearts for ourselves. I gotcha' now and it'll be our secret, I promise.



You youngsters readin' this will want to run and hide from any flatty you see and find yourself an engine that doesn't overheat all the time, that doesn't have breathing problems and can take all the rpms you throw at it without any maintenance at all. You sure don't wanta have to mess with points and condensers, repolarizing generators, etc. all on a motor that only puts out 100 bhp.

How'd I do?

 

Hello The flathead is extict in production cars but it's not alone in the list of the dearly departed. Here is a list of other so called dinosaurs never to be produced by the big 3 again. The Y block, FE big blocks, Ford Cleavlands,Ford Modifieds,Ford Inline 6s 240-4.9, SMALL BLOCK FORDS 221-351-5.0-5.8 ,Big Block Fords 429-460,SMALL BLOCK CHEVYS 265-400,Big Block Chevys,Chrystler smallblocks 318-360,Slant 6s,Buik,Oldsmobile,Pontiac and Cadillac went to the GM corporate V8 (aka)305-350 Chevy in the early 80s.The list goes on. As you can see a lot of us with so called new or modern engines are in the same boat with flathead owners . We work on and modify out of production obsolete by 2002 standard powerplants.One thing about the flathead vs overhead valve engines,The way the camshaft and lifter arangement is on a flathead the cam wear and break in are not as critical as is the case with an overhead valve motor with the lifters, rockerarms and overhead valve springs.Cams can be swapped from one engine to another if the old lifters are not worn too bad. I know the best practice would be new everything but with an engine 50 years out of production sometimes you haft to do things like that. It worked fine on my 1950 239.

 

[updated:LAST EDITED ON 10-Nov-02 AT 02:36 PM (EST)]I disagree Ford should remake the I6's they have good power, good mileage and are dependable.

Nathan

 

the flathead will be around for always atlest all of my life. i love my flathead 6 at it is starting to look good to.
https://www.ford-trucks.com/user_gallery/sizeimage.php?&photoid=9559&.jpg

grant
49 f1

 

sweet engine grant.

- JT