Intake manifold test

Old 05-23-2012, 02:56 PM
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Join Date: Dec 2007
Location: Morrison, Colorado
Posts: 120
Default Intake manifold test

Ok, so I've been working on an intake manifold test for a few weeks now, and I finally have enough info to post on it. What I've done is compared an Edelbrock Super Victor to a Merlin X on my car. It's been fun, and a lot of work, but the results speak for themselves. Please keep in mind when you read this that these are MY results, and were achieved with what I have. The times and DA info are legit, and I gave my honest opinion about what I ended up with. I do have pics, but I don't know how to post them, and there are a bunch. Hopefully I'll be able to figure that part out and add to this, but for now, here's a write up that I did for this test.

In the world of bracket racing, youíll find just about everything under the sun. Wagons, sedans, dragsters, imports, oddballs, you name it. Just about anything can make itís way down the drag strip, and in many cases does. If you donít believe me, just head to a drag strip sometime on your average summer weekend during a race. Youíll see cars stuffed with engines nearly as big as the cars themselves running up against state-of-the-art dragsters, and everything in between. Itís the one motorsport that can honestly say anyone with a car can compete. Show up at the track, pay your fee, pass a quick tech inspection and have the right safety gear for your class, and youíre off! All it takes is some practice and sometime a bit of tuning, and you can be a race winning driver in no time!

However, in the quest for the perfect combination, many racers find themselves in the ďI wish it was fasterĒ, or ďI wish it was more consistentĒ, or ďI wish I had more powerĒ loop, and thus the aftermarket was born. Literally millions of specialized parts that can improve your engineís durability, performance, and efficiency. Cars are getting more and more powerful, faster than ever before, and itís getting easier to accomplish this thanks to the aftermarket. In days past, a racer had to learn to work with what they had, and sometimes this led to limited performance, questionable reliability, and in some cases, custom, one off parts that couldnít be duplicated. But in todayís world, thatís not the case. Large cubic inch engines are very easy to come by, and very cost effective. Engine performance is at an almost unimaginable level, and keeps climbing every year as manufacturers develop and improve upon their offerings. A 500 cubic inch engine that made 800 hp used to be considered exotic, but now is considered an average ďsmaller sizeĒ street engine! Engines have already eclipsed the 1000 cubic inch mark, and exceeded 1200 hp on pump gas!! But even with all this technology, advanced design, and trick parts, there still exists something that will never go away. That is Joe Average racer, the guy or gal that races what they can, on what they can afford. There are far more ďAverage JoeĒ racers out there than any other kind, and itís that kind of racer that this test is targeting. Racers look for the best parts that they can afford, and sometimes what they end up with isnít always the best for what they have. Take for example the most common and simplest upgrade to an engine. The intake manifold. For years it has been one of the most cost effective upgrades that someone can do to their engine, and in some case is also the reason for the lack of expected performance. Many racers fall into the ďif heís running it then it must be goodĒ trap, and purchase parts that either werenít intended for what they have, or are just not properly matched. Additionally, what may be the most popular and common part may not be the best, despite what others may say. This is where my story begins.

World Castings, who make the intake, and Bill Mitchell Products who retails it have been around for quite some time now. World Castings, best known for itís heads, blocks, and intakes, they have something to offer for just about every application, and just about every make. While companies like Edelbrock, Brodix, Profiler, and others are well known and can be found at numerous tracks across the country, you donít always hear much about BMP. Whatís an issue here is that they produce literally THOUSANDS of these parts on a regular basis, and it seems no one wants to mention them because they just arenít the ďpopularĒ guys on the block, yet try to find a track where something produced by them isnít in use!!! It seems that they have been overshadowed by marketing and advertisements. Thatís ok though, because they are quietly making their products, and continue to sell them to dealers and individuals all across the country.

My part of the story begins on the internet. Yep, the world wide web of information. Maybe a better title is the world wide web of content. There is so much disinformation combined with good information out there, sometimes itís really hard to tell the difference. Internet based racing forums is what got this started, and is where this will continue, or at least thatís the goal. My mission here was to prove that one companies product can perform at least as well as if not better than the more popular ones, and on a stage that makes it not only fair for both, but honest as well. Honesty you say? Yep. No dyno runs here. Just plain and simple track time to determine the results. Why do it this way when so much emphasis is placed on how an engine performs on a dyno? Because a dyno can be manipulated by the operator to display what the operator wants, not what is really there. On track performance doesnít lie, it either does or it doesnít, and thatís what this is all about.

There was a thread on one of the internet forums that started talking about intake manifolds, and the subject of the Merlin X came up. A comment was made that it just doesnít perform as well as the Edelbrock Super Victor does, but when some of the people involved in the discussion were asked if they had ever ran one before, the answer was not surprising. Most of them had not, and they were basing their answers on what they had read or heard before. After seeing this, I contacted BMP and offered to test their manifold. My sell to them was that I had what could be referred to as an average bracket racerís combo, and the testing could be done in one of the hardest to tune in locations there is, Bandimere Speedway in Colorado. Because of the altitude and average DA at that track, making power and tuning there is a challenge in itself. I figured it would be a great place to test the manifold, because something that can affect the performance of an engine at sea level is amplified here. In other words, if it makes better power at sea level, then itís likely to do better here, but if it loses power at sea level, then the losses here are magnified because of the thin air. What better of a test to run then? Well, they agreed, and sent me a Merlin X manifold that would fit my motor, namely a tall deck Chevy. The manifold itís being tested against is an Edelbrock Super Victor that has been worked on quite a bit. Itís port matched, some cleanup work in the runners but not much more there, and substantial work to the plenum. Iíll get into more detail about that later. In itís best run on my car to date, the Edelbrock has gone 8.484 seconds in the 1/4 mile. To be as fair as possible, NO TUNING CHANGES are being made to the car until the testing is complete. The first part of the test was requested by Bill Mitchell himself, and that was that the intake was to be run as-is, out of the box, with absolutely no modifications whatsoever. Not a problem, Iíll do just as Iím asked. The second part of the test will be after the intake is modified in the same manner as the Edelbrock. In all of the testing, the configuration will be as close to the same each time so that the records are accurate. This will help to ensure that the test is both fair and impartial. Do I favor one intake over the other? Yes and no. The yes part is in what I see as far as out of the box quality is concerned, and I do have a favorite for that. But as far as performance is concerned, I could care less. The intake that performs the best on my combo is the one thatís staying on it, regardless of who made it. Period. Besides, why would I run a lesser performing part, even if it turned out to be the more popular one? What if itís the lesser popular one? Like I said, I donít care, I just care about performance.

That being said, hereís my disclaimer: As an Average Joe Racer, I do the majority of the engine work on my car myself, to include the porting work on the manifolds. I AM NOT A PROFESSIONAL PORTER, NOR DO I CLAIM TO BE. I can honestly say though, that I have NEVER failed to gain performance from any of the mods or porting work I have done. And again, that is the purpose of this test. I would imagine that professional porting would make even more gains than mine, and with either intake.

So, with all of that being said, letís get this underway!!!

The Car

The car used for this test is an older rear engine dragster. It has a 250Ē wheel base, and is fairly typical for what youíd see at your local track. Some will have wings, which this one does, some will not, but even despite itís age, itís not much different than the newer ones that are out there now. Big block chevy power and a th400 trans (yep, a three speed in a dragster) complete the package.

The Engine

As with the current trend in engines, my car follows suit, and runs a 600 cubic inch big block Chevrolet. Profiler 385cc CNC heads, Merlin Pro block with a 10.2Ē deck height, JE pistons (approx 14.5:1 compression), Total Seal Max seal rings, Crower stroker crank, Carrillo rods, and an Erson cam that is somewhat small for the combo. Jesel rocker arms and Manton pushrods complete the combo, and my current intake is an Edelbrock Super Victor. Carb is an 1190 cfm King Demon, and the tuneup was found by lots of on track testing and a bunch of help from people with a lot more carb knowledge than me!! Please note that no tuning changes will be made to the engine for the duration of the test. I not only felt this was the best way to compare the intakes, but also because there are a lot of cars out there that arenít perfectly tuned. Fine tuning info will come at a later date.

The Test

Itís simple, record the carís performance with one intake, swap them over, and do the same. After all testing is complete, Iíll post the actual numbers from the timeslips. Limited weather data will be included, such as temperature and DA during the tests, so that it can be figured into the performance numbers.

The first part of the test will be with the fully modified Edelbrock intake, and will consist of itís three best runs. The second part of the test will be with the Merlin X, and it will be ran out of the box, with the same setup the Edelbrock was run with prior to itís latest mods. The final test will be with the Merlin X after itís modified like the current Edelbrock is. Now letís get down to business.

Initial Impressions

From a consumerís perspective, appearance is everything, especially when you are looking at performance engine parts. Racerís dollars very often come from their own hard earned ones, and they want to spend their money on the best stuff for what they have to spend. Opening the box of a part and seeing something that looks like it was just thrown together or poorly made can really set the tone for how a part actually performs. When I opened the box for the Edelbrock manifold, I was quite surprised. I honestly expected a much better finished product than what I saw, mostly due to the high ratings this intake has received. There was considerable casting flash that had to be cleaned up, the edges of the dividers were odd sized and also had ridges, bumps, and edges that had to be cleaned up before it could be run. The area directly under the carb mounting pad had HUGE casting ridges that made the opening to the plenum smaller and looks like they would kill flow from the carb, as well as redirecting the flow towards the center of the intake. Iím not really sure how this would actually affect performance, but itís definately something I would not run as is. The ports were somewhat small, and thatís ok, but it did take quite a bit of material removal to match the ports to the gasket that I run (Fel-Pro 1275). The surface of the manifold both inside and out was quite smooth for a casting, so not a lot of smoothing would be needed on this manifold if a polished finish is desired. The Edelbrock also is not a ďheavyĒ intake, as itís relatively thin in some areas. For someone that is concerned about every pound, the Edelbrock definately comes in on the mark. There are some areas though that I would have prefered more ďmeatĒ in, but that is only my preference. Iím not aware of any situations where this would have or has been an issue. Lastly, two things that bothered me. One was the tapped bolt holes. In EVERY threaded hole, I had to chase the threads to get a bolt or stud to screw in easily. I always check this, but it was annoying to me that there was that much of an issue. A few burrs or some debris is one thing, but every hole is a problem. Second was a machined ridge on the bottom of the intake. It is cut back a bit from the sealing edges so that it will sit on the block, but in the case of my manifold I had to grind them back farther to get the manifold to sit down like it was supposed too. This is something that could cause an issue if itís not checked on assembly. In this case, I would not run the this manifold as is out of the box. I believe there are things that need to be addressed before this can be run on an engine.

When I opened the box for the Merlin X intake, I wasnít really sure what to expect. After dealing with the Edelbrock, and hearing all the bad press about World Products and their supposed quality issues, I wasnít expecting anything more than what I got with the Edelbrock. However, this wasnít the case. Out of the box the Merlin X intake was vastly superior to the Edelbrock in initial quality. To say I was surprised was an understatement. The overall appearance of the intake was very nice. Nearly every detail on the intake was different than the Edelbrock. The surface finish of the casting was a bit rougher than the Edelbrock, but thatís not an issue, just a cosmetic thing. The plenum area is MUCH better. There are no big bumps of material below the carb pad, and the runner dividers are much more uniform without the bumps and ridges of the other intake. Iím not sure how much of a difference it would make, but the dividers also extend all the way up to the carb pad. The surface finish inside the manifold is the same as the outside, and as in the case of the Edelbrock, needs a bit of touch up work to a few spots, but nothing major or anything like that. The ports are also sized small, but are larger than the Edelbrock manifold and didnít require nearly as much material removal to port match them. A nice feature of this intake that the Edelbrock didnít have was the spot faced and elongated bolt holes. Not only does this ensure that the bolt face sits flat and helps with even clamping, it also keeps you from having to do it yourself if there is an alignment issue. As a note, on my motor, the top edge of the bolt holes on the Edelbrock are right at the top edge of the bolt holes on the heads. If the manifold had to sit any farther down, Iíd have to elongate the holes to get them to line up. On the Merlin X, this issue doesnít exist. The holes in the heads are nearly centered in the holes in the manifold due to being already elongated. No alignment issues here unless there is a DRASTIC mismatch problem. The four center bolt holes are elongated but not spot faced, as the carb pad is in the way. All bolt holes are finished well, as no thread chasing was required. I was able to thread a bolt in every hole until it bottomed with minimal effort. While thatís a small detail, it counts. This manifold is somewhat heavier than the Edelbrock, and comparing them side by side it shows. It has cast in bosses for injection nozzles of two different styles. The ďwedgeĒ shaped ones would lend themselves to aftermarket fuel injection, and would save welding on bungs for the injectors to sit in. Not really needed in most applications, but a nice touch if you decide to change over at a later date. There is a mount next to the thermostat housing with a threaded hole on the Edelbrock that is cast in for a bracket or something that isnít on the Merlin X. Iíd like to see that on the Merlin as well, because if you have a bracket that needs a mount in that location youíll have to fab something to work, where the Edelbrock you wouldnít. Also, the upper flange above the intake ports on the Merlin X is machined down some, Iíd like to see more material left in this area, because if you have to raise the ports too much you could be in a situation where youíd have to add material in this area to ensure enough surface area to seal on the gasket. Something else that I like about this intake is the sealing flanges. They are somewhat thicker than the Edelbrock, and would likely be more resistant to warpage and cracking/breaking in cases where this could be an issue. Again, Iíve never known or seen this, but itís one less thing to ever have to worry about. The Merlin X also lacks a threaded port on the front of the manifold for a water bung or whatever that the Edelbrock does have. If used in an application that needs that port, youíll have to drill and tap it yourself. Not an issue for my setup, but it could be for someone elseís. There is a drilled and tapped hole right below the carb pad on the back of the intake though, that can be used for vacuum or whatever, and plugged if not needed. Pretty handy for some applications.

Overall, there are some things with both intakes that I would address, but my preference for an out of the box intake would be the Merlin X hands down. The initial quality out of the box I feel is much than the Edelbrock, and could be run as is without issues. For this test, it will be. When you look at cost vs. prep work, the few extra dollars the Merlin X costs over the Edelbrock is a moot point.

On the track, initial testing

This is where the meat of the test is. Just how does the Merlin X stack up against one of the most popular intakes on the market? How much are you giving up by running it, if anything? Can it compete with the ďbig boysĒ on the block? Weíre going to find out.

The first test is based on when I first ran the Edelbrock. My best pass then was an 8.54 et at 158 mph. The only mods done to the Edelbrock at that time was a port match, and the plenum was cleaned up. The big ridges below the carb pad were removed and the dividers were blended and smoothed. I used a nitrous plate for a spacer, but that was it. When that pass was made, the air temp at the track was in the mid 60ís, and the DA was approx 7000ft. However, I had some issues with both my tune up and my engine, and those were issues that needed to be dealt with before it would be run again. That finished out the season and over the winter those issues were fixed. When this season began, I had modified the Edelbrock even more. The plenum was cleaned up a bit more, and was opened up for use of a shear plate. I also added a 2Ē spacer based on some recommendations I had gotten during the off season. The tune up issues were addressed as well, and the best pass made then was an 8.484 at 158 mph. The 60í was a 1.16 and the car was very responsive. While that should be a better number and mph for what Iím running, you have to remember that Iím very under cammed for what I run. Thereís still more left in it though, but Iím leaving the tuning alone until this is done, as I want to eliminate it as a factor. More fine tuning will definately result in more gains. The temp for these runs was again in the mid 60ís, and the DA was approx 6500 ft.

The first runs with the Merlin X were done with the manifold as is, out of the box, per BMPís request. Not really expecting performance numbers to be close the Edelbrockís, what I found was this simply wasnít the case. The temps on this day were in the low 70ís. and the DA was at just over 7200 ft. The first run I made was not counted, as I had an issue staging the car on the starting line and the run was not clean. The next run however, was. And to my surprise, it was better than I expected it to be. I recorded an 8.507 at 157 mph! Not bad for an out of the box intake!!! I had the same NOS plate under the carb for a spacer, but that was it. No tuning changes were made on these runs. I didnít get a time slip for the next run, as I was fouled out on the start and the run was aborted. I was able to make three more runs the following day though, and those turned out quite good as well. The temp was a bit warmer, closer to 75 degrees, and the DA was a bit higher as well, approx 7800-7900 ft. First run was an 8.554 at 157, second run was an 8.555 at 156.72, and the final run for me was another 8.554 at 157. The last run would have been a win for me had I not redlit!!! What did happen was three good runs with the Merlin X out of the box, and they were impressive to say the least. With a best run of only .02 seconds and 1 mph, it was about as close to the Edelbrock as it could get!!! When you take into account the weather conditions, itís very likely that it would have ran as well or better than the Edelbrock! This shows a lot of potential for this part, and Iím excited to get to the second part of the test. For that, the Merlin X will be modified in the same manner as the Edelbrock, and again no tuning changes will be made until after completion of the tests. Iíll port match it, and open the plenum in the same manner to allow the use of the shear plate/spacer setup I now run.

On the track, final testing

Well, the final part of the testing with the Merlin X after porting work didnít happen as planned, as the track was closed due to weather. Too bad, the DA was down to the lower 5000ís and the temp was in the 40ís! I was looking forward to running in what we call in Denver mineshaft air! Since the goal of this was to compare the two intakes, what Iíve decided to do was run the next test and tune night, as the next race isnít until the end of the month for my class, and Iím curious as to what this is going to do after being worked on a bit! The forecasted weather for this test date is a high of 79, which will likely end up being in the low 80ís, and at that the DA will likely end up over 8000í. This is almost ideal though, because itís closer to what we really run in, and if my performance picks up, itís a win/win either way you look at it.

Gotta love Colorado!! If you donít like the weather, wait five minutes!!! As it turned out, I learned that the Night of Fire and Thunder had an ET class that I could run in, so I decided to enter. On the Wednesday test and tune, I had planned on making three runs to finish the test and so I could make tuning changes if needed for Saturday. Well, first run out of the box wasnít pretty. It had just rained and the track was cold and slick. Just so you know, they donít prep the track on Wednesday nights, so really good runs are usually a question mark, but Iíve been there before and had no trouble hooking up. Of course, this wasnít the case. The car spun hard in first, second, and third, and started fishtailing all over the track. I backed out somewhere around the 1000Ď mark, and ran through the traps at 8.69 seconds, 146 mph. Not bad considering, but still a useless run. I planned to try one more run, but it rained again and I called it a night. Friday night was a test night for Saturday, which was race day. So, on Friday night, I decided to make the three passes then to complete the testing. It was overcast and forecast for rain, but we were able to run. First run out of the trailer netted another crappy run, and something just didnít feel right with the car. I wrote off that run and got ready for run #2. This run was much better, but something was still wrong with the car. It was very delayed going into gear, the shifts were delayed and very soft, and the car would ďshudderĒ at the hit and each gear change. Nevertheless, I recorded an 8.57 @ 157 mph. Keep in mind, the temp for this run was at 78*, and the DA was 8500 ft, the worst air I have ran in yet this year. Humidity was approx 18%. If you do the math, that was actually a really good run, and the numbers were pretty impressive when you consider it. The funny, or not so funny part was something I didnít know. My transmission was slipping as well during that run, and that was why it felt so odd. The next run resulted in a complete trans failure, and ended my weekend.

So, with that being said, we are still trying to get three clean runs with the Merlin X intake in itís modified state! Weíll get the trans back together and address a couple of small issues with the motor, and head back out in a couple of weeks to try this again! Consider it a longer term test than originally planned, but also a very valid one, because racing is unpredictable, and that has certainly been the case here!! More info to come later!

In Conclusion

I should say, in conclusion for this part, but either way, several runs have been made, good data has been recorded, and even though the last part of the test really isnít complete yet, there is enough evidence to make a pretty accurate statement. On my car, with my current combo, the Merlin X outperformed the Edelbrock Super Victor hands down. Both out of the box and modified, the car was quicker and faster, and responded to the Merlin X better than the Edelbrock. So is it a better intake? In my opinion, it has features that set it apart from the Edelbrock. It doesnít lack performance in any way, and in the hands of a professional porter, can likely outperform some of the better offerings out there. Out of the box itís a no contest. The Merlin X pretty much sets itself apart from the Edelbrock in that it can genuinely be run as is, and not give up a ton of performance, where the Edelbrock needs some attention at least before I can be bolted on. Am I saying the Edelbrock isnít a good piece? Far from it. Itís track record speaks for itself. However, the Merlin X brings another option to the table that a lot of racers didnít consider before, one that has the potential to run with the best stuff out there and not have to compromise anything. For me, the Merlin X will remain on my engine, and Iíll either work on the Edelbrock some more, or sell it. I donít think you could go wrong with either intake, but I prefer something that I can use as is if needed, and the Merlin X is the only one of the two that offers that.

Itís been said numerous times on numerous forums that this intake canít compete with the other offerings out there. All I have to say about that is my test results are honest, accurate, and as complete as I can provide. The intake didnít disappoint, in fact it impressed. While every engine is different, and every combo will want what it wants, there is no good reason not to consider using this intake, especially if you have a larger cubic inch motor. Give one a try and you might be surprised at what itís capable of.

I want to extend my heartfelt thanks to Billy Mitchell Jr. and John Supino for letting me test this intake for them. Itís been fun, a lot of work, and exciting to say the least. Next time youíre in the market for an intake for your motor, take the time to see what BMP (World Castings) has to offer before you make a purchase. You might be money ahead

Well, that's it in a nutshell. I can't say for sure if anybody else would have the same results I did, but you never know until you try. I'm pretty pleased with the outcome, and will continue to tinker and test as the season progresses (and I get my trans back together)....
coloradoracerguy is offline  
Old 05-23-2012, 04:44 PM
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Mark were you using a older Super Victor ?
hammertime is offline  
Old 05-23-2012, 05:51 PM
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Great read!

Thank you for doing the comparison.

abodyaddict is offline  
Old 05-24-2012, 06:22 PM
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David, I'm not sure if it was an older version or not, it was purchased for me as a replacement for another intake I gave to another racer. Intake was brand new in the box when I got it............Can't remember the part number off my head though, but I think it's 29 or 27 is in the Edelbrock catalog......
coloradoracerguy is offline  
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