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By PF Arcand - 9 Years Ago
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As posted here & featured in issue #125 of Y-Block magazine, I'm very impressed with the design of the single plain intake for the racing Falcon project, that the Mummert's & associates put together. Pulling 535 H.P out of approx 331 cu. in. thru a 4 Bbl, without power adders, is over the top!. Anyway, it got me to musing about it. If I understand correctly (?) single plain intakes are often effected by reversion issues, which is one of the reasons they are not usually street suitable . So, after kicking it around for a while, I've come up with a question, but first, we've never seen a birdseye view of the intake interior, so my question may be irrelevant. However, what if the plenum had a "divider" in it like a dual plain intake? Would that work & would it possibly be of any benefit? Just an idea..
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By babor - 9 Years Ago
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The only issue with running a single plane intake manifold on the street is the lack of low rpm vacuum signal and velocity. The single plane high rise intake is made for higher rpm use in marine and racing applications. The main difference is the runner design and length. A longer and more narrow runner creates more velocity at lower rpm levels where as the open lower velocity design of a single plane allows for much more air/fuel flow at a higher rpm range where you don't require the velocity. Basically the power band is higher and therefore should be properly matched with camshaft, heads and compression levels in order to operate properly. Hope this helps...
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By glrbird - 9 Years Ago
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PF
From what I have read on the www.jalopyjournal.com Jeff Mummert has been studying about manifold design and this is his design for the race y-block. Without looking inside, he would be the one with the answers. He post on the site as OHV4D, so you could ask him.
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By PF Arcand - 9 Years Ago
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babor: Interesting info on single plane intakes, however, my main interest was the possibility or not, of of using a plenum divider. Thanks anyway.
girbird; Thanks, but I couldn't figure a way to do a specific search on the jalopy journal site, so I never found Geoff Mummert.
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By babor - 9 Years Ago
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Why would you want to divide a single plane intake manifold? Some of your higher end pieces have either sort of a short separator, but not usually more than about 1/2" to 3/4" past the runner in the plenum opening and others use a ribbed bottom plate in the plenum for air/fuel atomization. I don't understand why you would want to separate the runners. This I think would just cause you problems, especially if you had a carburetor issue with a clogged jet or air bleed that could cause the carb to act in an un-predictable manner such as a lean out. Where this would just normally lean out the entire mixture a little bit if you separated the runners you could entirely melt down cylinders in this scenario. What exactly are you trying to accomplish? Not being cocky, just curious...
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By CK - 9 Years Ago
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So to clarify
A single plane has a common chamber shared by all runners
A dual plane has a divided chamber to seperate left and right banks.
I guess dividing the chamber would increase manifold vacuum. However I'm sure John put a lot of though into this particular manifold to suit the application. Runner length, diameter, etc.
Additional to the subject of dual or single plane. I have recently read about valve angles and the effects they can have on flow. In this it was noted that they had found by applying certain angles in sequence a reduction of reversion can be achieved. It can be manipulated to allow flow better in one direction or another, inlet or exhaust.
i thought this was interesting and fitting to share.
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By glrbird - 9 Years Ago
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http://www.jalopyjournal.com/forum/threads/y-block-dyno-day.938305/ Here you go paul.
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By CK - 9 Years Ago
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Awesome.
Wonder if it would perform on the street due to the long equal runner length?
Maybe the runners would need to be smaller dia.
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By pegleg - 9 Years Ago
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If you get the Yblock magazine you can read all about it. It was not designed for low end power. Geoff Mummert is an extremely talented young man. People send him cylinder heads from all over for his porting expertise. Dad's no dummy either.
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By Ted - 9 Years Ago
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Those longer runner lengths helps to make Geoff’s intake a good street manifold. From personal experience, using shorter intake runner lengths brings any reversion issues to the forefront with cylinders #1 and #2 being at the top of the list. An intake design that makes another 20HP over the best ported aluminum dual plane intakes is definitely a step in the right direction. I’m ready for the cast aluminum version of this intake.
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By PF Arcand - 9 Years Ago
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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...
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By pegleg - 9 Years Ago
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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.
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By Ted - 9 Years Ago
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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.
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By John Mummert - 9 Years Ago
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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.
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By CK - 9 Years Ago
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I wonder your thoughts on allocating within the length of the runners louvred-perforated pipe at half the diameter.
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By Vic Correnti - 9 Years Ago
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"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!
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By charliemccraney - 9 Years Ago
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I'm excited about an EFI manifold.
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By John Mummert - 9 Years Ago
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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.
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By Y block Billy - 9 Years Ago
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You would need to get a much taller scoop on that bird Vic! Either manifold in production would be great!
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By CK - 9 Years Ago
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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
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By John Mummert - 9 Years Ago
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Usually a good surface prep on the runners is enough to keep atomization up. A little bit of temperature goes along ways as far as vaporization is concerned.
One part of the story on the single plane manifold that has not been shared until now is that when we dynoed the engine we also tried it on E85.
Using 8 O2 sensors we were surprised that it has slightly better fuel distribution than the dual plane. We did our initial testing with vp110 on both manifolds.
After we felt like we had the motor pretty well tuned up we switched carburetors and fuel over to E85. That's when the party started. The a/f ratio variation between cylinders opened up a bunch. It went from having 1.5 points of AF from all 8 cylinders to about 5 points of variation. Oh yeah 10.0:1 on the richest and 15.0:1 on the leanest.
If you look at the Y block magazine article in one of the color pictures you can see if you look real close the readings of all 8 cylinders and you can see the kind of spread I'm talking about.
We tried 3 different E85 carburetors that day. None of them matched the power or distribution of the gasoline. My belief was that the tin manifold could not hold enough heat to get the E85 to vaporize.. I feel if the manifold had a cast piece and had a rougher surface texture the story would be different.
On another topic having your fuel injectors or fuel delivery farther away from the valves is a better deal than getting them too close. I know its not what you see on your wife's new car out in the drive way, but what OEM's are trying to accomplish and what performance oriented people are trying to accomplish are very different. It does help solve fuel distribution issues and that is good, it also however makes them very camshaft and header sensitive, and that is bad, especially in a sequential firing mode. Many times the OEM's can get the injector firing to close to the exhaust valve closing and it really limits what you can do for camshaft. Header scavenging, a thing that performance engines rely on can become a detriment.
OEM's have also struggled with injector targeting hitting the cylinder wall, washing the cylinder down and killing the rings and piston skirts.
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By RB - 9 Years Ago
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John Interesting Info..I have burned a fair amount of E-85 here are a couple observations.. I think your distribution issue would be similar if the manifold material is cast. Did you put your hand on the manifold after a pull? Ice cold.. Latent heat of vaporization sucks up all the heat, even if cast aluminum. So if the manifold relies on vaporization to get good distribution, the E-85 or Alky would not give good results.. I have not found that E-85 makes any more power than gasoline, either carb or injected.. They are about equal.. The advantages of E-85 are cost, octane rating, and wider tuning window. Were the A/F readings you mentioned from Lambda sensor calibrated for gasoline? Stoich for E-85 is around 9 to 1. Can't wait for the prototypes of that cast tunnel ram
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By pegleg - 9 Years Ago
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John Mummert (1/22/2015)
UOEM's have also struggled with injector targeting hitting the cylinder wall, washing the cylinder down and killing the rings and piston skirts.
Ford 2 valve 4.6's. The Crown Vic motor.
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By Ted - 9 Years Ago
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CK (1/21/2015)
.......... 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
If the carburetor is properly sized, then WOT performance will be the same with either a vacuum secondary or double pumper carburetor assuming tuning is optimal with each. The problem with a double pumper carb or being perfectly sized for a particular engine combination is it’s only properly sized in a given set of circumstances. If anything changes (put air density at the top of the list) then the double pumper carb is either too large or too small for a particular engine combination. Because the secondaries on a vacuum secondary carburetor open only as much as is in demand based on the primary bore air flow, then by design it’s easy to use a vacuum secondary carb that is intentionally oversized for a combination and always have a carburetor that will not be undersized. Likewise, it will not be oversized either by lieu of the secondary blades only opening the amount that’s needed.
The vacuum secondary carbs are capable of much stronger torque numbers in the lower rpm band where the secondaries are not open as much as would be seen on a double pumper carburetor that’s being run the same way. Faster air flow as a result of reduced secondary throttle opening enhances the torque. This is why I ran a vacuum secondary carb in the EMC competition. I had five similarly sized carbs to work with; four were double pumpers and one was a vacuum secondary model. After each carb was fine tuned, all were the same from 2800 rpms and above. It was that single vacuum secondary carb that was much stronger in the 2500-2800 rpm band than the others and based on this, that was the carb that was selected to run on the Y at the Engine Masters Challenge. That is also the same model carb that’s being used on my Y powered altered roadster.
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By pegleg - 9 Years Ago
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John Mummert (1/22/2015)
We tried 3 different E85 carburetors that day. None of them matched the power or distribution of the gasoline. My belief was that the tin manifold could not hold enough heat to get the E85 to vaporize.. I feel if the manifold had a cast piece and had a rougher surface texture the story would be different. Or a supercharger to warm up the charge............hmmm>
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By John Mummert - 9 Years Ago
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Royce the AF meter was gas calibrated. The stoich we were looking for was about 11.5:1 on the E-85. The motor did make some decent power and one of the carburetors had slightly better tq even with the distribution spread.
The E-85 was a real eye opener as to how the extra volumes could effect the distribution.
We ran the car with the manifold as dynoed for about 3 races. The manifold was pulled and floor was given the full cheese grater treatment and time was spent texturing the runners. The car picked up .04 et and 1.2 mph on the gasoline. The other thing we noticed was that it helped the pk rpm. Early on when we tried raising the shift point 200 rpm to 7400 it didn't pick up. After the manifold work it liked being revved.
It was interesting to see back to back I would have to say that anything could be done to improve the atomization or vaporization of the E-85 would help.
We discussed taking one of the water outlets and circulating it under the plenum before connecting back to the Y connection. But that is for a later date.
Vaccum Secondary carbs seem do a much better job of controlling AF ratio under initial loading on the dyno. We were dynoing a motor one time with a double pumper carb and it was down 15 ft/lbs initial loading. After we had done this a few times we decided to hold it there and see how long it took for the accelerator pump shots to clear out. It took 4 seconds best I can recall. The motor jumped up 15 ft/lbs .
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By LordMrFord - 9 Years Ago
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AFR 11.5 sounds like a little bit richer side.
We are using 12 to 12.5 but E85 seems to be quite forgiving for different mixtures.
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By Cliff - 9 Years Ago
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I've seen this manifold up close, I like it a lot, these guy's do a good jod.
Cliff
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By pegleg - 9 Years Ago
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John,
How would a cast iron, unported "B" intake work with e85? Mixture variation issues? Use a supercharger to create some heat and probably help atomize the fuel?
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By John Mummert - 9 Years Ago
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Sounds like a good place for it Frank. Maybe even a pressure activated solenoid that ran some through blower inlet under boost. May help regulate inlet temp a bit. Nothing like a high speed blender to get it all whipped up.
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