Sheet Metal Manifolds for the 5.0/5.8 Winsor

[skullandbones]

I've been contemplating a sheet metal intake for a long time especially since I saw this cool aluminator engine in a roadster at HB. But it goes much further back to my time as a drag racing fan. I like the performance of the folded tunnel ram manifolds like the one I have (Holley Systemax) but it is a major PITA. I've sort of gotten used to it as far as getting it off and on but it's still a pain. So I would like to fab a symmetrical one that clears all the working parts such as valve covers and fuel rails and only remove it when there is a major issue like changing cam and lifters, heads, etc......

So as with some of my other projects this will be a transitional approach where I start with a large plenum box on top of the existing Holley lower. I have a phenolic 1 inch spacer that I can use to create a smooth air passage to each runner. It isn't much of a edge anyway since the runners are so close together but I will do it just for kicks anyway. I'm curious to see if the plenum will perform well. I know there are tuning problems with various length runners and the size of the plenum but I will stay as close to the standards as I can for getting the components into the ball park range of the tune. I also am comparing with other manifolds runner lengths and diameters. There are some graphs on the web that give some data as well. Examples are like the length of the runner should be around 6.5 to 7 inches for my engine. Also, the top end of the runner should be at least 1.5 times the size of the ports then funneling in to the port size at the head. Those will be important for our second version which will be a full sheet metal manifold from flange to the box with a valley cover. I am excited about doing this to see if I can get some performance improvement but also to change the look of my engine. I want it to look NASCARish with the fabricated valve covers as well and machined fuel rails. It should be completely different from the present look which is sort of hot rod Mustang like. Eventually, I will change heads to something like Canfield which is my choice at this time but I will keep the GT40Ps for a while longer.

Here is what I have in mind except it will be EFI. http://www.swartzracingmanifolds.com...olds/index.htm

I'm curious to see if others have gone this route and if you got good, neutral, or bad results. I like that this will allow me to bolt things on and off without taking the whole thing apart and sitting for weeks. When we do the full sheet metal project, I will take an engine with heads on the little trailer to the machine shop and leave it with them so they can weld with the flanges bolted in place. These guys are racers so they like out of the ordinary projects anyway. I'll do some pics when we get started.

Thanks,

WEK.

[tirod]

Had the crazy idea of fabricating stack ITB and still researching. One link I found was this: http://www.mez.co.uk/ms12.html

Scrolling down most of what you mention is being done overseas. It's Good Ol' America who's a bit behind, we seem to be either plug a fourbarrel on it or spend big bucks for someone else to do it.

Having searched for alternate throttle bodies and finding some that only cost $40-50 at the salvage yard, I can see it being done for far less if more ingenuity is exercised.

As for plenum shapes one guy did run some stuff on the internal airflow here: http://www.mx6.com/forums/1g-mx6-oth...dy-swap-2.html

Having finished Dave Vizard's book on porting, seeing simulations like these graphs is beginning to make more sense: http://forum.e46fanatics.com/showthread.php?t=735897

The main difference is that with a plenum you get the advantage of a mass air method of metering, and some vacuum to utilize, with stacks you get all the flow and no robbing from another open valve - but having to use throttle geometry input.

Weber stacks didn't seem to have driveability issues, with EFI it seems quite feasible if you can wrest the proprietary hardware out of an existing vehicle for your own use. Lots use GSX or snowmobile throttles, one guy on the HAMB used one barrel throttle sections from old carbs. With a plenum a 95mm TB and some effort at internal flow should result in good power.

Looking forward to your pics, there are a lot of similarities and gas flow science is the same for both.

[skullandbones]

Hi Tirod,

I'm starting out pretty basic with the plenum box and mildly blended phenolic spacer. That's not the best way but when you are working with existing components, some compromises must happen. I have only contemplated multiple throttle bodies for one reason. I want to spread the air pattern more evenly between the four cylinders on each bank by using two side by side smaller throttle bodies instead of one. The same principle apples on tunnel rams where they use dual quads to feed the runners more evenly. I will do the single 75 mm one first. I'm not to anxious to get involved with complicated linkages and the like. I'm looking at a lot of different data. I like the flow charts on that one link. Thanks for that. In the next phase where the whole manifold will be changed, I think bell mouth ended runners would be more efficient. I'm working on getting those as I don't think I could fab those with the simple tools available to me at this time. I have a source for the flanges at a local machine shop. It should be fun watching it come together.

Thanks,

WEK.

[tirod]

Lots of parts like bells are on the internet, if you have a local source, great.

There's a thread on the forums where one owner milled his intake completely from billet - in his dad's shop where he works. It is at least an example of what could be done.

I'll mention Dave Vizard again, he's the acknowledged expert in intake and porting, with 40 years of work under his belt. His books are highly informative and worth the time to go thru.

For others interested, I'll fan the flames a bit more with links to sheetmetal makers:

http://treracingengines.com/treintakes.shtml
http://www.hogansracingmanifolds.com/
http://www.weinlemotorsports.com/pag...take-Manifolds
http://www.swartzracingmanifolds.com/

And a general look at what the ITB tuners are doing: https://www.google.com/search?q=ITB+...w=1024&bih=515

It's the next step up from just buying a cast manifold and bolting on another Holley. (Yawn.)

[skullandbones]

I hear what you are saying about the parts being out there but actually being available is another matter. If you commit to having a manifold built by one of the four you linked or another one is "Force", then I think you could get anything they have for a price. However, just buying these like you would a rod end or bolt is not likely. I did see a company called Revotec must be out of UK. They have bell mouths of various sizes on the shelf. I made an inquiry about flanges and bell mouths to one of the big manifold companies but no word yet. Some are very tight with their procedures in that they do not offer parts off the shelf but do everything custom. I did see one offering a kit of sorts for $1000. The bell mouths are definitely the most challenging component to recreate. I wouldn't even attempt it. If I can source those from Revotex, I will most likely. One of the complicating factors for me is the design being a cross ram will make it necessary to use very smooth entry points for the runners thus the bell mouths.

WEK.

[skullandbones]

During my sail making days I was a pattern maker out of necessity. I found it much easier to create a pattern on the fly or on site rather than taking tedious measurements only to have to adjust and revisit the site at times. So I'm falling back on that skill. I will start rather loosely as I am not sure of the shape and look of this initial plenum box. The first iteration is a ruff model with the maximum measurement limits. I will not use this as it is too large and definitely not the optimal shape but it gives me a reference point to hone in on. One goal is to remove any sharp corners and initiate curves for good flow whenever I can. But let's get the basic shape and work on refining it on the next model. Don't laugh. It's pretty primitive but the next one will look a lot better. Also, I used this mock up as a way to check the cutting and bending processes to see if there were any difficult steps. It turned out to be fairly straight forward this time around. There will be 6 panels plus the flange and a diverter on the inside across from the TB. Here are some pics. I can already tell, it's going to be narrower and have rounded corners sort of like the dual quad oval air cleaners.

Thanks,

WEK.

[Mike N]

Bill there are some details of the intake that you want to make sure are sized correctly or it won't work the way you want it to. Plenum volume being one of those. Spend an evening Googling intake manifold design and you will learn a ton. It's not easy designing an intake to work as well as some of the aftermarket ones. You get one shot, basically blind, and they spend hours and hours on development and testing to get it right. If you can find an intake that is similar to what you are trying to do and copy a lot of the volumes, lengths and cross sections you will have better luck.

I think it's great that you tinker with this stuff. It's exactly the reason I enjoy my FFR so much.

[skullandbones]

Hey Mike: here's a plenum volume that should blow your mind!

http://www.youtube.com/watch?v=Ujrdq...eature=related

I will be leaning heavily on other design parameters that are proven to get what I'm looking for for this first little project. I don't have a choice in the runner design since I am using the lower Holley manifold. I resembles a medium rise carburetor manifold which I've added a 1 inch phenolic spacer. You might say it's like many high risers you may have seen in the past but compared to today's high rise manifolds, it's not so high. The plenum volume will be the trick. I'm still working on the shape. I have some room to adjust the volume to a good starting point.

It's going to take a little more radiusing to get to the curve I want in each corner of the plenum but that's why I'm making a model to see what it will look like. The first real prototype will have a larger radius than this model. The added curvature should help reduce dams and turbulence in the box. Here are a couple of pics.


Thanks, WEK.

[OCCPete]

If you think you're having tuning problems now, adding that intake will double them. Nothing wrong with what you're doing, but a dyno tune and custom chip will be mandatory if you want it to run right. JMHO...

[Jeff Kleiner]

Bill,
Am I understanding correctly that your plan is to leave the plenum wide open like that then blend and mate it to the lower?

Jeff

[skullandbones]

Hi OCCPete,

I know, it's like jumping out of the frying pan into the fire, so to speak! I just can't help myself. I do plan on a baseline dyno pull to establish the "as is" condition of the engine but I hope I can work it out with the dyno guy to do some additional pulls for some experimentation (x number of pulls for a price). They do club days so I might be able to work something out like that. It's going to be a while before I change the manifold though. Of course, I always have the fall back plan of putting the Holley back on. It's running pretty good right now. Thx

Hi Jeff,

Yes, I think, if I understand your question. The base/flange of the box will be one hole open to the runners (app 3.25 x 12.75 inches). I have a phenolic spacer that I'm going to sacrifice and blend the runner openings to smooth the entry as much as I can. If you haven't seen the Holley configuration, there is very little to port or create a "bell mouth" for the flow. The runners are crowded very close together. The box will be sealed of course (not like the Viper demonstration). Hope that explains it better. Thx.

WEK.

[Jeff Kleiner]

OK. Frankly unless you are operating under boost with that gigantic volume and only one atmosphere to move it I'm afraid that at low to mid range RPMs the air is going to be lazy and stalled so putting your foot down may feel like sticking it in a bucket of $#!+. Don't let me discourage ya' though; maybe I'm talking out my arse! It'll be interesting to see how it works out.

Good luck,
Jeff

[skullandbones]

I'm so glad you said that! I was roughly calculating the volume after I "sized it" a little from the first model and came up with about 670 ci. So that is way too much. I believe they recommend about 80% of the volume of an 8 cylinder cycle but for EFI you can go as high as 100%. So That box is way too big. I did not think it was nearly that large but now that I've got the hind sight, it looks too large to me too. So I have to go back and revamp the box once again. I started out with what maximum space was available to me and didn't realize I would not need nearly that much to do the job. Thanks for looking, Jeff!

WEK.

[Dan Babb]

I wonder if you could try to find a used TrickFlow setup like this one:

http://www.cjponyparts.com/trick-flo...RzVhoCB27w_wcB

Then you could take the top off and make up a top that will mount whatever Throttle Bodies you want to use (and figure out how to block off the bottom of the throttle body mount that's there.

[skullandbones]

I wonder if you could try to find a used TrickFlow setup like this one:

http://www.cjponyparts.com/trick-flo...RzVhoCB27w_wcB

Then you could take the top off and make up a top that will mount whatever Throttle Bodies you want to use (and figure out how to block off the bottom of the throttle body mount that's there.

No I haven't Dan. I want the sheetmetal TIG welded look on the top EFI box along with some fabricated valve covers. I know it's silly but I just love that NASCAR one off looking stuff. I hope to mimic the volume of that manifold section but it will be a bit more rectangular looking. I am honing in on the volume and shape but it is a trial and error process since it is modeled and not in a CAD environment. I feel comfortable working with this hands on approach. As I get closer to the desired shape I will start adjusting the numbers on the volume. Can't do much about the runner lengths but it's eerily similar to the runner base that I have with my Holley and spacer configuration. It's almost exactly the same measurement! We will see how it works. Thanks, WEK.

[Mike N]

I made this one a few years back. Bolted onto a GT40 lower. Volumes, cross sections and lengths were all in the 'ball park' for a 331. Never did get it de bugged and in the end sold it to another forum member. Throttle body is from a supercharged Lightning.

GT40_ram.JPG

[skullandbones]

Mike,

I'm guessing that didn't fit under the hood! It probably could scare the heck out of the competition though. When I see the modern "folded" manifolds, I have a lot more respect for the R and D that went into the design not only from the performance aspect but the logistics of just getting it to fit in such a small space for that application. The Chinese are cranking out a lot of manifolds that are mostly knockoffs of existing American designs but I saw a couple that were pretty unique. At least, I haven't seen them in my searches. One was a split manifold so the machine guy can port the runners more easily. I did see a sheet metal manifold for a SBF that looked good but not EFI. Thanks, WEK.

[Mike N]

Bill.

This one fits under the hood and over the distributor that's why I used the Lightning throttle body as it was not as tall as the typical Mustang TB. I currently have a Victor Jnr lower with an Edelbrock cast elbow that does not fit under the hood. I am working on a custom elbow that will fit. More tinkering....... Perhaps when I retire I'll finally be able to make some decent progress on this stuff. Work definitely gets in the way.

[skullandbones]

Mike: BTW, what was your runner length overall? Was it close to 11 inches? Also, how did you calculate the volume of the plenum ? Was it around one eight cylinder cycle volume? Too bad you didn't get it tuned perfectly.

I got my new fuel rails today so I will be changing out the old OEM ones. They need to be in place for the new plenum so I can be sure of clearances.

It will clean up the engine bay some more, too.

Thanks,

WEK

[Mike N]

Bill. Pretty close to 11 inches to the valve from the plenum. The plenum was around 80% of the engine capacity. I designed in on a CAD system so the volume wasn't hard to calculate.

[tirod]

As for tuning once any manifold and gasoline emitter is bolted on it's a steep curve. That's why so many are attempting to discover which source programming and controller offer them the best interface.

When you limit yourself to a single four barrel it seems to be simple, but the reality is that most aren't ever fully sorted out, and all the claims of "they make more hp" don't stand up as the owner never even went so far as to use a vacuum gauge to set it up. Most are run right out of the box without any mods or component changes - which takes a wide band O2 sensor to measure.

Much less a set of Webers.

It's why the average guy just gives in and uses over the counter stuff and lets conventional thinking run the car. Tuning and sorting out never gets done, but the bragging does.

[skullandbones]

It's true that not a whole lot of R and D goes into the average hot rodder's setups but mimicking ones friends rod or even rivals can sometimes get you a good head start if they happen to have stumbled into a good combo or had a pro to set up their ride. I lucked up by finding a Hot Rod Mag series that involved sbf and a lot of after market components. Basically, they added and then swapped and ran every combination on the dyno to get a yea or nay on whether it was a real improvement. I was very happy when I found three components that I have on my setup in the mix: Holley Systemax intake, e303 cam, and GT40p heads. The increases were documented and pretty good for a rather low budget when it came to the components used. So I am working from a baseline that I can't claim to have dynode myself but it was done by someone else. So if I get an improvement with my little experimental sheetmetal plenum it will be something I can report.

I recently (2 days ago) got a vette. It's a '91 that needs a little love but will make a great minor project car compared to the roadster. I think I got out of the experience already was the intake manifold. I think I can use it as an inspiration and even glean some indirect data from it's size. I'm sure my finished plenum is going to look a lot more like Mike's and the vettes than the ones I began with. In my defense, those were for practice with the aluminum and the brake. Here's a pic of the vette manifold. Thanks, WEK.

[skullandbones]

I got back to the project "plenum chamber" on top of the Holley Systemax lower. I have gotten the volume down to where it comes close to the acceptable range. The first ones were practice anyway but they sure helped me with the fabrication of this smaller version by going thru the steps of each fab. Unfortunately, my buddy couldn't finish the TIG welding on the manifold so I am dead in the water until Monday. It's got enough done to mock it up on the engine and allows me to fit the rails and cold air system. I can't get over how little room there is to work with on these cars. Some measurements such as the vertical off the engine deck is the worst. I had to use a curved adaptor that I was using on the other system to clear the TB top from the hood. If I add a 1 inch spacer between the TB and plenum, I will be able to delete the adaptor but I will run it for now since I don't have the spacer yet.

I have several pieces that still have to be added to the plenum to create a mounting area for the top and a diverting double curve to split the TB air as it enters the plenum. It will help direct the air to the front and rear of the plenum where there are curves to carry it around and maybe create a vortex for the two sets of runners (that would be interesting). So Monday I should be finished with the welding and clean up (which will be substantial). I am testing the new fuel rails for pressure and leaks this weekend and finish running the modified cold air tube. Every time I change something I end up putting some of the parts back on that I took off for another application. So things get recycled. I have some pics of the old manifold (huge) and the new one mocked up on the engine.

The valve covers have to go I guess. The giant manifold covered up the Mustang logo but what the hey, they were free. So I have acquired some more appropriate "Cob**" ones.

Thanks,

WEK.

[skullandbones]

My first attempt for the new plenum didn't work so well. It ran but would not idle and run smoothly. I had multiple leaks and a leak I didn't even anticipate but discovered after removing the manifold. I had to basically go back to square one so to speak for the lid on the manifold. The one I initially made was the same thickness as the body. It was cut out with the metal sheers which distorted it slightly. So after trying it, I realized that I really needed to go thicker on the top. It also allowed me to counter sink the holes which looks a little more finished. So tomorrow I will remount the second version of the plenum and try it out (company tonight). So in summary, I will use a thicker gasket material which will take up any variation in the flange and the top of the manifold. I milled the flange and top with my belt sander and orbital to take out some variation. They are both nearly flat (less than 1/32 inch out of flat). I added some more supports for the top at each end of the box. Those will be sealed from the inside before placing the gasket. I also added some screws to support the rails and supports for the top. I will be sealing the gasket and adding an outside liquid gasket seal on the top which was left with a ledge for the added gasket sealant. I'm doing all of this to insure no leaks this time around. My unexpected leak was from an OEM hose that I had connected to the regulator. It has an outside shield that hides the plastic hose inside. I think the hose was cracked or maybe broken because when I removed it from the hose fitting, it fell apart.

Another thing I changed was to split an EGR plate I had with a ban saw to give the necessary spacing for the TB to the manifold. I had to sand that flat but it was just time consuming and turned out perfectly. I was able to get rid of an curved adaptor that I used before which takes out one more variable and cleans up the look of the top of the engine a little more. I'm learning more and more about working this metal (aluminum) with each operation. It is definitely different than any other metals I have utilized.

I polished the top and added another punch out of the snake image to give it a little personal touch. It's different than most of the ones I've seen. Wish me luck tomorrow.

Thanks,

WEK.

[Raceral]

I ran the old comp cams breadbox intake for years on a stock 5.0. It would do 1.80 60 ft with t/a's Didn't hurt my bottom end like many said it would at all.
My Cobra 009.jpg

[skullandbones]

I ran the old comp cams breadbox intake for years on a stock 5.0. It would do 1.80 60 ft with t/a's Didn't hurt my bottom end like many said it would at all.
My Cobra 009.jpg

That's very interesting. I have never seen that one before now. It looks very close in volume and runner length to mine. My wife calls this one the "toaster oven". Glad to hear about the performance. I was actually hoping for a change to bring the HP/torque band down to a more usable rpm range. The huge Holley one I had made power from about 4500 to 6000+ rpms. It was a little flat before that. Also, I will be able to do things like check my valve adjustment which I could not do without taking the upper off. We'll have to see if I get similar performance to yours.

Thanks,

WEK.

[skullandbones]

I used a much thicker cover for the plenum after my initial failure. It also has counter sunk holes and a new ornamental detail on the top.

The new gasket material is 1/8 inch with some cushion. I'm using Permatex Ultra Black Gasket Maker as well. I played it even safer by "machining" the top cover, flange, and modified EGR spacer with my belt sander for quite a while to get them nearly perfect. When I started the engine, it idled but was not set correctly for the new setup. That required a couple or three adjustments. I have found that when I change anything involving the throttle cable, TB springs, bracket, etc..... it requires a complete redo. It's finally idling at a stop without dying. The initial reaction I have is, of course, only a subjective observation but it does seem to have a distinctly different throttle response. So more driving time will help filter out the halo effect from having something new on your engine and just assuming it is better. I'm just happy that it's finally running again. Here are a few pics of the final setup. So in summary, I have new Cob** valve covers, the awl punched image on the top of the polished plenum, more polished tubes on the cold air system, and the new fuel rails and AN braided lines.

Thanks,

WEK.

[Jeff Kleiner]

Bill,
I see that you have a hose running from your modified EGR spacer to the fuel pressure regulator. That is not a vacuum source; those nipples on the spacer are for coolant to flow through to help cool the intake charge after it is heated by the introduction of exhaust gasses (when an operating EGR system is present obviously). Without vacuum to the regulator it is, well...not regulating and allowing full fuel pressure all the time no matter the engine load. Did you make any provisions to get a vacuum signal from the plenum?

You've done some nice fabrication work there

Jeff

[skullandbones]

Hi Jeff,

I should have thought that you or someone would have caught that (well you anyway). You don't miss any details or as I like to say, "no good thing goes unpunished". That's a step I forgot to mention. I drilled a hole into the TB opening articulating with the hollow area for the EGR coolant to create a vacuum source for the FPR. It was in such a nice location and I had just split the EGR block for the TB to clear the manifold (only needed a block about 1/2 inch thick). I was either going to have to use the other piece of the block with a mod to create a vacuum source or do that one or drill one directly into the manifold. It worked out pretty nicely. It was a lot of work to get this small project to work. There are so many small details that have to be addressed. I can see why people don't do this sort of thing as a routine. A buddy mentioned that I'm trying to recreate the wheel but I guess, at least for me, it's part of hot rodding. Thanks, for the nice comment.

If I do the full blown sheet metal manifold, it will require even more special operations like delivering the block and heads on a trailer to the fabrication shop so the flanges will be bolted to the "block template". It would be nice to have a milling machine. If and when I do this next project, the roadster is not going to be torn down during the process. It might take a while to get it tweeked just perfectly. Also, there are some critical measurements to be done to make it work right. Fortunately, there are some manifolds out there that are already set up for the Windsor and I have taken some direct measurements from them. I did one that was displayed at SEMA.

Thanks,

WEK.