Flathead Tech

Here's the site Mac1 is referring to:

http://www.midstateantiquestockcarclub.com/flat_heads1.html

 

I have ported maybe 30 of those things and never worried about getting in the water p***age. A little silver solder and you are good to go.

Just made them as big as possible, and only had one go through into the floor p***age.

Used to do them for $35 including relieving the block.

1946-47 in San Diego.

TraderJack

 

This post by Flatdog has been on my mind for a while. I think his post was in response to a thread about offset in the PM-7 intake manifold found here:

http://www.jalopyjournal.com/forum/showthread.php?t=246519

Anyhow I thought I’d take some time and do some work with his photos he posted as to Flathead intake runners. Both photos scanned together below indicate to me that the photos were taken with no valve seats in the block. A PM to our good flathead friend Bruce Lancaster yielded the OD of a stock Ford Valve Seat OD at 1.625". I then used a vernier caliper to measure both right and left sides with individual print copies of each photo until the throat seat openings were the close to the same dimension. I then pasted the two photos to one piece of paper. I have a spare block that I measured @ 2.500" between the inboard sides of the inlet runners on the intake deck. As can be seen on the attached scan they are spaced ~2.500" apart as if they were in the block.
I then drew up some rulers in CAD, scaled to the ratio of the actual photos seat OD to the 1.6250" dimension from Bruce. I’m not implying that the dimensions are dead nuts on, but they are close.
Flatdog didn’t mention in his post whether these photos are of pre-59AB or post-59AB generation and I guess we’ll never know for sure but from the dimensions I’m thinking they were of a post-59AB block. The first thing I noticed was that both runners were indeed different lengths, the right side being shorter than the left. The second thing I noticed was that the left valve guide appears to have the top turned down but the right one doesn’t. Mike Davidson suggests in his "How to build a High Performance Street Flathead" book that flow tests he has done indicates that flow can be improved if the top of the guide is "tuliped" (sp).
The third thing I noticed is that the left runner really necks down near the valve guide top compared to the right intake runner. This seems contrary to what I think it should be as the velocity of the fuel mix to the intake valves would be unequal on the two sides. (Note: if this contributes to the wonderful sound we love in our flatheads perhaps we should leave it alone!) but appears there is enough thickness in this area to do a little porting near the valve guide.
I believe Flatdog would be happy to see someone contributing to his post in this manner and God knows we surely do miss his input.

http://pic4.picturetrail.com/VOL755/2598819/5779043/350400399.jpg

Anyhow I thought I’d take some time and do some work with his photos he posted as to Flathead intake runners. Both photos scanned together below indicate to me that the photos were taken with no valve seats in the block. A PM to our good flathead friend Bruce Lancaster yielded the OD of a stock Ford Valve Seat OD at 1.625". I then used a vernier caliper to measure both right and left sides with individual print copies of each photo until the throat seat openings were the close to the same dimension. I then pasted the two photos to one piece of paper. I have a spare block that I measured @ 2.500" between the inboard sides of the inlet runners on the intake deck. As can be seen on the attached scan they are spaced ~2.500" apart as if they were in the block.
I then drew up some rulers in CAD, scaled to the ratio of the actual photos seat OD to the 1.6250" dimension from Bruce. I’m not implying that the dimensions are dead nuts on, but they are close.

Flatdog didn’t mention in his post whether these photos are of pre-59AB or post-59AB generation and I guess we’ll never know for sure but from the dimensions I’m thinking they were of a post-59AB block and Bruce commented he thought it was post-59AB . The first thing I noticed was that both runners were indeed different lengths, the right side being shorter than the left. The second thing I noticed was that the left valve guide appears to have the top turned down but the right one doesn’t. Mike Davidson suggests in his "How to build a High Performance Street Flathead" book that flow tests he has done indicates that flow can be improved if the top of the guide is "tuliped" (sp).

My ruler dimensions are linear and not actual runner effective lengths

The third thing I noticed is that the left runner really necks down near the valve guide top compared to the right intake runner. This seems contrary to what I think it should be as the velocity of the fuel mix to the intake valves would be unequal on the two sides. Flatdog noted this in his post as well as possibly filling in some of the "belly" area. (Note: if this contributes to the wonderful sound we love in our flatheads perhaps we should leave it alone!) but appears there is enough thickness in this area to do a little porting near the valve guide.
I believe Flatdog would be happy to see someone contributing to his post in this manner and God knows we surely do miss his input.



Jim

 

Kevin his flathead knowledge was seemingly unlimited. He could really think outside of the box. Wish you still had the photo too.

Jim

 

The offset discussion is a separate one...very interesting, and hard to grasp even as you look at the iron. The shaft offsets (crank and cam are off-center, and by slightly different amounts!) are easy to see in the Service Bulletin drawings, the further subtleties are more difficult. I'm still set-up for that discussion...I went down and set an also offset old Thickstun manifold on a 59 block, using a long rod set into FP pushrod hole to mark cam centerline and just stared at everything.
Blown 49 has a wonderful set of cross section drawings...have you thought of overlaying that onto the port photos so centerlines can be seen together with ports?? I believe that I am correct in saying that all important flathead geometry '32-53 is about the same, except for the little change in valve angle in about 1945.

 

Here you go Bruce....cut and paste hope this helps




I have some other thoughts on that offset. I'll prolly be PM you next week sometme with them.

 

Everybody needs that poster...ever think of making it as wallpaper??

 

Just right click and select Set as background

 

I tried it; whole damn office is still industrial beige.

 

Damn the bad luck. I'll e-mail the pic to you tomorrw along with some other info.

Jim

 

Just in case you guys have never seen this, here's what I consider to be the ULTIMATE flathead porting job....ever!

I'ts the engine in Ron Main's 'Flatfire" Bonneville streamliner. World's Fastest Flathead Ford powered vehicle. 302.674 MPH with a single blown flathead Ford!

JG