Recent content by maineSS

Many OHV engines do not use all the valve curtain area due to port angle- the flow goes out sideways, just like the flathead. I think a lot of people miss that fact and intuitively think this is a major flathead problem. Ricardo's flathead contribution was to lower the head in the chamber to...

Ricardo developed his flathead mod in the early 1920's- by bringing the top of the chamber down to the piston crown, he solved the detonation problems with 65-70 Octane gasoline. This assured the flathead's place in surface transport for the next 30+ years. Aircraft started going OHV in WW 1, by...

Here's another post from the "Siamesed Intake Ports" thread that does a good job explaining the balance between flow and compression in flatheads- http://forum.olskoolrodz.com/showthread.php?t=33527&page=5&pp=10&highlight=Dodge=flathead (start at Post 42). Unfortunately, Hudsonater's pics got...

Vergil- Outstanding job with the directory- it has stuff I've not seen before. I downloaded some material on siamesed intakes, will look at it tonite. For those interested in the flowbench, check out Porting School #2,3 &4. There's also good stuff concerning Turbulence & Combustion Dynamics...

As a general rule, anything within 1/2" of the valve will affect flow. Another interesting thing is that low valve openings have high depressions-(as low as 100 in water @ .070 for SBC), and high valve openings have low depressions (around 10-12 in water at .650 for SBC. This will definitely...

Here's an interesting series of photos from www.diyporting.com/thread.html - check out the low-lift valve flow pics, especially from .1-.300". For those who persist in thinking flathead flow thru the valve area is somehow "different", the Ford GT40P OHV head was well-regarded in its day (now...

I got a rimflow valve from APT to test along with my stock valves and the popular Street Flow Manley SBC valve. It's slightly bigger in dia, and shorter in length, so it'll never be a drop in replacement- I'll have to copy it if it turns out to be a winner. They are available as an exhaust...

Something that will always retard progress is a preconceived notion that things will always act a certain way. A classically trained aerodynamic engineer can mathematically "prove" that bumblebees can't fly- their wings are too small to generate the required lift. If you were to accept that...

From what I've read so far, block relieving will always be controversial. In my case, the Dodge valves wouldn't really benefit. I think I'd look very carefully at where the flow wants to go thru a transparent head before cutting on increasingly rare parts. I found another post on Speed Talk...

I wasn't able to get into GFN, either- hopefully they haven't vanished into Hyperspace. I did download a lot of good stuff from there. On page 2 of the pistonhead thread (www.pistonheads.com/gassing/topic.asp?h=0&t=1087429&d=0&nmt= ), Pumaracing weighs in with Parts 2 & 3 of valve seat theory...

I have most of Vizard's books, they're quite good. He's also done some articles on the Go Fast News site that are excellent reading, I'll try to post the links. He's just published a book on porting that's due out Feb 13, available thru Amazon. Raising compression is certainly helpful, I'm...

An excellent book I use quite frequently is David Vizard's "Tuning the A Series Engine"- 581 pages of info that goes far beyond an early Brit OHV engine. It's available for ~$35 from Advanced Performance Technology in Riverside, CA (www.aptfast.com (951) 686-0260), and worth every penny...

I read JWL's book, it was interesting to see what mods gave the most return on time and money. The reason valves and seat angles interest me is that (a) they are the most restrictive area in the engine, and (b) they are the last chance to atomize liquid fuel flowing along the port walls...

What is Bill's contact info? I did order Mr. Lawson's book. What I'm after is getting more torque in the 1800-2000 rpm range so I can use an overdrive effectively. The early 230 cam developed peak torque ~ 1300 rpm, and about 94 Hp, later on better carburetion allowed a different grind that...

Has any one seen any flathead flow work concerning valve shape and seat angles for better flow? Especially interesting would be wet-flowbench work, if anyone has tackled the problem of making a transparent cylinder for a flathead. I'm presently working on a Dodge 230 6 for my Power Wagon, and...