french flathead stock valves and hot cam?

hi all,,some of you have put a race camshaft on stock valve train french flathead?is a good way to go or they are shit?thanks

 

Since many of the French block flatties are factory relieved, it indeed is a good way to go by using a performance cam shaft. My French block engine, purchased just as a block and main caps, was built with all American parts. The French flatheads did have two different sets of valves for sale according to Halibrand's documentation when they first introduced these engines here in the states. Basically it was because of two different lifter heights, the taller Halibrand lifter using a shorter valve. The longer valve is the same as the American version as well as the matching lifter.

That all being said, the first performance item, IMHO, to wake up a flattie should be multiple carbs - a good dual or triple manifold should be your first performance upgrade, followed by a hotter ignition, then dual exhaust (mostly for the sound), and then finally a camshaft. The French blocks are a great, meaty block, with many of the features a hot rodder loves in a flattie.

Where are you in Italy? I just visited last summer, staying in an agriturismo in Pienza, Italy called Cretaiole - we had a great time.

 

The real problem isn't the valves, it's the ports. The French military engines have very reduced ports - probably to help with the low-velocity flow of a low-revving military engine. These ports have a serious restriction in them...you really need to open the ports before adding a camshaft - it probably can't flow what the stock cam could allow....

I believe there were two types of valves & lifters - one set was what we'd recognize, the other had longer/taller lifters and shorter valve assemblies.

Just like some of the engines used shorter rods with 4" stroke applications (used same pistons as 3-3/4" stroke engines for logistics).

 

first thanks for youe help...i have 2 holley 94 with weiand intake and msd distrib.and coil,so i don't really need to change the valve set....i need a good porting job......that's what i was thinking first but i was no secure for the valve set......my cam choice is a potvin 3/8, you think stock valves works good?one issue i think is from the valve springs.....they work well?thanks

 

If you open up the ports then the Potvin 3/8 should work fine. My son has a 40 merk engine in his roadster all stock other than racing style valves with a 3 angle valve job and a Potvin 3/8 cam and duel 97's. The engine runs like a champ. Do the ports and you should be fine.--TV

 

Hi,
do you have the big 255ci (4,2L) engine?
They have adjustible lifters, but weak springs and short valves and most of them have
very small ports.
If you choose a cam with a gentle ramp (WInfield SU1A for example) you will be fine
if you shim the springs to get more preasure.

You need to port the block before step up in the cam.

239ci(3,9L) have bigger ports but non adjustible lifters.


Michael

 

No rules on those rod lenghts, and adjustable lifters, both 239 or 255ci can have long or short rods, adjustable or non adjustable lifters, all depense on when they where rebuilt...

Porting is the First thing to do!
Cam
Dual carb and exhaust
Distrib!


good luck

 

not sure that's true for all French flatties, they tend to vary quite a bit
so better check before

 

Sure it is better to check.

I had my hands on 239 with adjustible lifters and once a 255 with HUGE ports from the
factory that didn`t need porting at all....

my statement was more of what i found is common....

 

I ran a French flattie, ported with a schneider 3/4 cam and the stock valve train, it worked well and no sign of valve bounce and I ran it in the UK Flathead meltdown in that guise a few seasons.
Don't think a flattie needs high spring pressures, just creates extra friction, with a streetable cam you are not going to be winding it up to 5K plus very often.
But I'm no expert.
Rich

 

I ran a 286 engine with a 400jr. cam and three carbs with a progressive linkage all through stock 1 1/2 inch factory valves. The four corner exhaust ports were cleaned up at the exit, and the center ones opened up some too. I ran the intakes as they came. The motor ran great.

 

thanks all...i think to stay with stock valve train ....i do the best port job some other tricks that many have done,,,and go with this way....

 

For springs, the Lincoln Zephyr springs (or Isky singles) are the ticket...the Iskys are probably borderline overkill on most engines. The Lincolns are relatively inexpensive and readily available from most rebuilders....

Here's the only pic I could find of the ports...

 

Like Ernie says, the stock ports are the problem to getting the most out of a cam, higher compression, and increased carburetion.

Here's a stock French block. Not only is there a thick ledge in both the intake and exhaust bowls, in most blocks the exhaust outlets from the bowls also include a restrictive ridge at the top.



The ledges in the bowls and the ridge in the exhaust bowl outlet have been roughed out in this view.


Here's another before-and-after illustration of the amount of material removed from the bowls and from the intake runners which, in the second photo, have been opened up to the shape of a FelPro 8903 intake gasket.





This finished block has had the relief finessed. It's been opened to match the head gasket shape, and radiused at the bowls and polished.



If you're starting with a bare block it would be a shame not to port it, including port matching to the intake manifold. Otherwise, you'll never realize the potential of all your spendy modifications. And you can do it yourself with an affordable die grinder and less than $50 worth of porting stones and sanding roles.

Mike

 

Somebody post the AV8 porting link! I don't have it here. One of the best tech posts of all time.
And, on almost any stock valves, get a roughly 20 degree back cut to get excess metal away from there. I believe flow across the back of the valve is extremely important in a flathead. This is a quick and easy job for anyone with a valve grinding machine, and if valves are already finished at the seats this job does not damage them...just cut up to the edge of the last angle.

 

I'm honored by your comment, Bruce. Thank you so much.

Since I wrote that porting post some years ago I've learned a great deal more about the subject and the process.I've recently been working on a rather lengthy piece on flathead porting, aimed at a magazine-reader market, but it continues to grow to the point that I'm beginning to wonder if it wouldn't be better understood on a board like the HAMB where the words/pictures elements can be better controlled for the best possible presentation.

Mike

 

Consider that, and also consider publishing it as a free-standing book. I think it would be a bestseller, and you could control it yourself without the problems of getting in updates and such with a "real" publisher...book could link to a web page for updates and clarifications, like in the modern world!
I don't know of a magazine that wouldn't reduce it the 3 pages and have a Ford illiterate editor insert some fatal mistakes in whatever wasn't cut. This stuff is hard core.
You are historically and technically connected with Binggelli, too. MAJOR< but not one of the 2 or so flathead names a magazine would consider important.
I think you would sella zillion copies here and on Fordbarn (and it should have a conspicuous separate chapter on guides and actual valve job, so it would be valuable to non-rodders rebuilding).
Further sales would come from conspicuos displaying at Hershey, Roadster show, and other such venues...most people would buy one to get dirty in the garage, one to stack in the nitrogen filled freezer with RJ, and 10 for Chrismas presents.

 

Hear! Hear!

 

Hi Mike,

print it like the little how to books that you do with Vern.

I think it will sell very good.

Michael

 

I'd buy it
What a great little book that would be.
Rich

 

"print it like the little how to books..."

Yes, but BIG. This topic demands big, sharp pictures to show what's going on down there in Hollow Earth. Think like an air molecule with a camera.

 

I'm in full agreement and that's my big concern with doing the subject as a magazine article which is space-limited. I have a similar concern with small-format booklets, clever and traditional looking though they may be. The little books I did for Vern Tardel -- steering and transmission -- were done to look like the booklets Ford created for dealership techs after WWII. I think the information could have been better served in a larger format.

The best magazine how-to's back in the day left many readers (me for instance) wanting to know -- and see -- more, but the specific wisdom wasn't to be found on the printed pages; you needed a teacher, a savant, a guru to demonstrate to you to what you must learn about the subject before you had any hope of putting it all into practice.

So, all that being said, it looks like I'm gonna do a flathead porting book. A place where I can share some illustrations like a simple before and after . . .

 

"...better served in a larger format"
Steal some format from the BIG Petersen books that came out about 1960, comtemporaneous with the little Spotlight series but much fatter and full magazine dimensions...the stuff that permanently warped me, "How to Build a Hotrod", "transmissions and Clutches", lots more. Something like the Engine one, which had color cover photo of a machinest boring a block.

 

Wow!!!!
What a nice porting, Mike !!!!!!!!!!!!!!!!!!!!!

 

This is a powerful format...that single picture teaches more about FH porting than about 90% of what has been published so far. Only approaches have been Ron H's wonderful book (hurt by poor picture quality) and a few snippets released by Flatdog, who was not about to release more than a few tidbits since he pretty clearly had the most powerful street driven flathead on the planet. Flatdog, by the way, kept the HRM article on Bingelli's gasser on the breakfast table, and spent hours trying to decode the scant clues in there. And trying to account for that car's entirely unreasonable performance.
My main texts have been Vizard, who is very good on usable theory even though his book is on SBC heads...I have to hold the pictures upside down to make sense of them! and Yunick, who released a few clues.
A book FULL of info like that picture would be a real gift to the world!

 

av8.....really good pictures!! maybe not imagine the potential doing this kool work...
i hope to do my best....

 

save for me

 

This is a fortuitous and timely resurrection of an old thread; I'm very close to finishing my book on flathead porting! I lost about a year's worth of time, thanks to a medical problem -- successfully dealt with -- and have been having a great time developing the book, and more recently, a website that will promote it and serve to keep the information dynamic.

I hope to have details -- time and cost -- available in a few weeks, and will post them here, on the HAMB.

In the meantime, I want to repost the before-and-after picture Bruce referred to; I hadn't realized I'd eliminated it from my picture-hosting site.




I'm also including some 'teasers' from the book . . . what can be done with those neglected exhaust bowls that some tuners ignore.









Mike Bishop

 

Cant wait to order a book

 

wow that's some beautiful work on the flatty block , good info