My question re puting a divider in a single plane intake, was not intended to denigrate Geoff Mummert's new racing intake. It's obviously a well thought out facinating design, with great results!  It was based in part on observations of a recently tested (in Y-Blk mag) Hogan tunnel ram, which was bested by both a ported Blue Thunder & a ported Mummert intake. And also the results Ted Eaton got testing a Cain open plenum, common runners intake. Below 4200 rpm the Cain was well behind 4 other intakes in H.P. & it's torque curve was terrible. My post was just an idea for discussion.. And Ted brings up a point that didn't occur to me, about # 2 firing right before #1, when the firing order starts again. Things to kick around...  


Paul

I know that Paul. Just trying to identify the intent of the design. This is the first really successful single plane intake I've ever seen on a Y block. Pretty sure the volume of the plenum has something to do with that. Big enough to keep the runners full, but not so large as to loose velocity. seems to be an excellent balance.

Frank/Rebop

Bristol, In ( by Elkhart) 

Paul.  A divider placed in the plenum of a single plane intake makes it into what Offenhauser use to advertise as a 360° design.  Many of the older Mopar V8 engines used this design where the left side of the carburetor fed the left bank of cylinders and the right side of the carb fed the right bank.  On the FE and SBF engines this design typically makes for a lean cylinder condition on cylinder #8.  On the SBC, BBC, and Mopar engines, this same lean condition shows up on cylinder #7.  On the Y it would likely show up on cylinder #1.  Staggered carb jetting was the quick fix for this particular lean condition.

Part of the problem with the Hogan intake are the runners within the plenum being at different heights as observed from the base of the carburetor.  I’ve also tested a cast single plane intake for a Y engine that was built with the stacked ports within the plenum and it had some severe fuel distribution problems within it.  Here’s a picture of that intake.
  
The sheet metal intake for my roadster has all the entries to the intake runners at equal distance below the carburetor which is part of the key to making a successfully performing intake.

A properly designed single plane intake can outperform a dual plane design when everything is right.  I’ve seen this on some of the specialty intake manifolds where the single plane intake simply works better than the dual plane intake it replaced.  With many dual plane intakes designed for stock cubic inches and/or cylinder head flow, anytime the heads and exhaust system are upgraded to accommodate more flow, it’s not unusual for a properly designed single plane to make both increased low end torque and upper end horsepower.  The intake on my roadster is a single plane intake and it’s good for 520 lbs/ft torque which is about 35-40 more than I was getting with a highly modified dual plane intake.  Each engine combination will like its own particulars when it comes to runner lengths and plenum design.

Lorena, Texas (South of Waco)

Were working on a new dual quad Tunnel Ram , EFI combo manifold right now. Its a tunnel ram type base with a removable lid. It will be able to be fuel injection manifold for the street cars that will bring a modernizing feature that this motor hasn't seen yet. Or Drag race manifold with carburetors. Or it can be what ever anyone wants it to be. If a guy wants to make a new top lid and put 6 2's on it he can make it happen with basic fab skills.
     The  manifold has been underway prior to the creation of the recent single plain. Are opinion is that in racing conditions it will meet or exceed the single plain as well as be a street manifold in EFI trim and fit under all stock hoods.  
 We hope to have something to sell by summertime, sooner would better but you know how things go.

 Versatility is driving this Combo manifold.

 The single plain is a solid working part. In its current design stands 4" taller than our hi riser manifold. It is terminated to a 4500 Dominator flange in steel at +2" over the hi-riser manifold and then uses a 4160 to 4500 adapter that is 2" tall to get to our 850 carb.
 We would like to condense the height down a bit if we were to ever turn it into a production part to make it useable in more applications than just for cars with Hood scoops or race cars.   But it will take more development to see if we can make it happen and match the power numbers.

 We are excited about the new EFI / Tunnel Ram combo manifold and think it will get folks talking again.

On a side note FUEL DISTRIBUTION has been the plague of many custom manifold attempts.  
 I know that we have seen  the Hogan manifold and others not live up to expectations. As Ted pointed out are things about the runner layout more than plenum size that have doomed these other manifolds.
  
 

http://ford-y-block.com 

20 miles east of San Diego, 20 miles north of Mexico

I wonder your thoughts on allocating within the length of the runners louvred-perforated pipe at half the diameter.

"New dual quad Tunnel Ram intake". Now you have my attention! Any flow numbers yet, or pictures? I have a Big Stuff set up that needs to be on a Y!

  Vic Correnti

I'm excited about an EFI manifold.



Lawrenceville, GA

CK I wouldn't put something in the runner that would cause a restriction to the inward flow.

Reversion is caused mainly from running the engine at a lower speed than it was intended to be used at.  Most of this reversion comes from the exhaust system, and makes its way to the intake manifold via camshaft overlap.  Back pressure is one of the biggest killers of low speed power production..
DO NOT get confused.  Many people hear this and say I should put the biggest headers on I can.. NO NO.  Slow moving air is HIGH pressure, fast moving air is LOW pressure.  DO NOT get confused. Many people hear this and say well I should put the smallest headers on I can.   Once the air get moving to fast a stalling effect happens because the coefficient of friction rises through the conduit  and the motor refuses to produce the HP they want.  
 Proper sizing of all the components is a tough thing and wider rpm band you ask a motor run over the harder your job gets.  


http://ford-y-block.com 

20 miles east of San Diego, 20 miles north of Mexico

You would need to get a much taller scoop on that bird Vic! Either manifold in production would be great!

55 Vicky & customline

58 Rack Dump, 55 F350 yard truck, 57 F100

59 & 61 P 400's, 58 F100 custom cab, 69 F100, 79 F150, 82 F600 ramp truck, 90 mustang conv 7 up, 94 Mustang, Should I continue?

Thanks John
I ment for it to increase velocity and maintain atomisation in the intake runners.
Would there be much difference using a double pumper over a vac/mech. Secondary carb.

For example in my case I'm running a holley terminator which all 4 injectors run continually