Yellow Wing: Thanks. I've had them on a flow bench and they tested to 159-160CFM per port. So, I'm really excited as well. Not to bad for my first crack at porting eh?



I can't wait to put a header and an exhaust and see how they RUMBLE!

Heber City, UT (15 mins outside of Park City- basically it's in the mountains)

55 Effie

Good job. It will be interesting to hear how they perform when you get it back together. Mike

1956 Fairlane Victoria (ORREO)

 

Overlooking Beautiful Rimrock AZ

So, I finished all of the porting. I'm going to finish cc-ing the chambers and modifying them until they are all the exact same. At that time I'll go through the ports one last time to clean out any final burs, and rough out the intakes one last time. But otherwise I appreciate all your guys help. Here are some pics.



















Heber City, UT (15 mins outside of Park City- basically it's in the mountains)

55 Effie

"D" port has the flat on the bottom and curved on top, the gasses natually flow to the top.

   God Bless.   Tim                           http://yblockguy.com/

350ci Y-Block FED "Elwood", 301ci Y-Block Unibody LSR "Jake", 312ci Y-Block '58 F-100, 338ci Y-Block powered Model A Tudor

tim@yblockguy.com  Visalia, California    Just west of the Sequoias

One more quickie post on the same thread...







So, you're saying two things that are news to me. The first: That a flat roof flows better. Of a D port, with the flat side of the D on the top of the port, or bottom of the port?



Second: That you like to radius the port side into a circular shape to match the circular shape of the exhaust tubing coming out of the flange? (Did I catch that right?)



My intuition about the second point is that might lead to more reversion without having some disparity between the square exhaust ports and the circular exhaust tubing. But, I'm still a total newb!

Heber City, UT (15 mins outside of Park City- basically it's in the mountains)

55 Effie

Thanks Ted. I can patiently wait for the results. I do appreciate all of the knowledge you share!

Heber City, UT (15 mins outside of Park City- basically it's in the mountains)

55 Effie

Is Doug a Cyclops??? I wonder if we can measure the difference in efficiency/performance of cycloptic head porting, verses the more traditional two-eyed approach!



If one eye works better I'll need to fashion an eye-patch of sorts to block out vision in one eye. I'm sure there's a pirate forum somewhere that I can ask about building an eye-patch in my garage... I just need to make sure it's a "TRADITIONAL PIRATES ONLY FORUM." I can't have any of this non-traditional crap....

Heber City, UT (15 mins outside of Park City- basically it's in the mountains)

55 Effie

LOL!  Nice Doug!

   God Bless.   Tim                           http://yblockguy.com/

350ci Y-Block FED "Elwood", 301ci Y-Block Unibody LSR "Jake", 312ci Y-Block '58 F-100, 338ci Y-Block powered Model A Tudor

tim@yblockguy.com  Visalia, California    Just west of the Sequoias

Re Exhaust porting, I don't think there is much disagreement to the idea that the exhaust port is undersized in the G heads. I.60"dia exhaust valves are definitely a help. For porting my preference is to do it like the old heads that Ted has pictured so well: that is with an arched or curved roof. Flow testing on a bench will show that a flat roof will flow more but in all instances there needs to be a square to round transition for the header tube some place between the flange of such a port and the tube that will speed up the flow causing an increase pressure. I like very smooooth flow paths with a flow reversion as the only change in cross section until well beyond the exhaust flange. Therefore I make the transition as part of the port itself.

In any case be sure to use the proper safety goggles when you start to port the intake side!

Doug T

The Highlands, Louisville, Ky.

The Cain intake manifold is completely runnerless; both at the carb flange and the ports. Testing on two different engines has this particular intake design down on both torque and horsepower as compared to modern dual plane intake manifolds (Mummert and Blue Thunder). This testing gives an idea of what the horsepower and torque does if removing the dividers from an intake that originally had divided ports. Removing the dividers in the heads should have similar results as removing the dividers from the intakes. I have heard the stories of the dividers being removed in the heads and lowend performance always suffered but performance above 5000 rpms tries to come back. Based on what I saw with the Cain intake testing, topend performance is still going to be weaker with the runners being removed than with a good modified stock intake or an aftermarket manifold. Here are a couple of past threads showing dyno results on two different engines with the runnerless design Cain intake manifold.

http://forums.y-blocksforever.com/Topic29068.aspx

http://forums.y-blocksforever.com/Topic46008.aspx

Lorena, Texas (South of Waco)