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The 2.3L Ford engine that I'm using for my build came with a [Fatherless Child] electronically controlled carburettor, a short lived product of the 80's. I'm switching to fuel injection using a Megasquirt controller. The intake manifold that came with the ranger is not a particularly good design and is not worth modifying, so I want to make a new one. Parts that I have on hand include a compete 1.9L Escort off of which I'm grabbing the injectors, throttle body, wiring, sensors, and EDIS module.

My plan is to make a simple manifold with 1.375"-1.5" runners about 12"-15" long depending on where I want the torque peak to be. The runners would probably come straight out for a couple inches, make a 45 degree downward turn, then contiune on to a tubular plenum with a 1-2L volume (haven't decided yet) with a plate on one end for the throttle body.

How would you build this intake? Here are a few options I'm considering:

1. Welded mild steel. This is probably the simplest option since I can buy exhaust tubing of the appropriate size with a few bends and weld it up like a header. I would probably need to make an intake flange out of 1/4" or thicker steel to prevent warping and I'm not sure what is the best way to cut an intricate shape from thick(er) steel. Most of my cutting up till now has been with an angle grinder, hack saw, and a bit with a jig saw.

2. Aluminium. Same basic design as the steel, but lighter. The Escort intake manifold had 12" long, 1.375" ID aluminum runners bent into a U shape with a 1.5" inside radius. I could use these for my bends and join them to straight sections. The problem with this idea is that I've never welded aluminium before. My equipment options right now are stick welding (no good for aluminium) and oxy-fuel. Another option is bonding the tube sections together with an epoxy of some sort, or with a fiberglass wrap.

3. Fiberglass. I could make the runners and plenum out of foam, wax, or cardboard and use a lost medium modling technique. Fiberglass would be wrapped around the plug and then once set the plug could be melted out (wax), dissolved with a solvent (foam), or soaked in water and scraped out (cardboard). I'm not sure how easy it would be to get the right shape, espcially around the plenum to runner interface. This would probably still require a flange from steel or aluminium that the runners would have to be bonded to since I don't think I could make a flat, thick flange from fiberglass.

Your thoughts?

My first choice would probably be mild steel, using exhaust tube as you suggest with a few mandrel bends bought from wherever. For a thick flange I would find a local outfit that can water-jet plate. If you can draw in CAD, or have a friend who can, it's cheap. I had iceboat runner (skate) blanks cut out of 1/4 inch thick 316 stainless, and the 26 inch long blanks were 60 bucks Canadian a piece, materials included. (The runner stiffeners are a carbon-fiber reinforced Baltic birch core, and there is as much materials cost in the stiffener as there is in the stainless steel runner blade)

If coolness was my goal I'd go the lost foam/composite route and just do a wet lay-up (with carbon fibre for ultimate coolness). You might have greater design flexibility that way, although shaping the foam could be painful. Laying up a composite flange is not that big a deal in a simple press. But the composite route will likely be more expensive than the steel weldment, even if you water-jetted the intake flange.

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Warren
Isuzu Pickup/SR20DE, +401 COLD frame
Build Log: viewtopic.php?f=35&t=11601

Steel, using this stuff.
http://www.speedwaymotors.com/Shop/Spee ... -14.999000

I've made two intakes from this material and it is good quality and makes for easy fabrication. I used 1/4" steel for the flange. Intakes run cold, so the thin material is fine. I shaped the flange using a hole saw to cut the rough openings, then shaped to fit. That was necessary because the port opening was not round and the tube cut had to be made at the begining of the ell for clearance reasons. Used 1 7/8" O. D. pipe, about 13" long. It is for a 2.5 Duratec.

Used 3" exhaust pipe for the plenum. This is a cheap way to make an intake. I have about $75 in this one. The thing seems to perform quite well.


Bill

Hey Bill!
Nice color, too!

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JD, father of Quinn, Son of a... Build Log
Quinn the Slotus:Ford 302 Powered, Mallock-Inspired, Tube Frame, Hillclimb Special
"Gonzo and friends: Last night must have been quite a night. Camelot moments, mechanical marvels, Rustoleum launches, flying squirrels, fru-fru tea cuppers, V8 envy, Ensure catch cans -- and it wasn't even a full moon." -- SeattleTom

Hey JD. Yeah, nice color and cheap! Bought it about twenty years ago at Big Lots. Cost about a buck, but I just knew it would come in handy at some point down the road.

Posthumane, I would not use the 1.9 injectors. I think they are probably too small for the 2.3 engine, as Ford tends to design pretty close to engine demands. I have a set of Duratec 2.3 injectors I can give you a smoking deal on. They should be much better for your use. About 27 lb/hr (good for about 175 hp), better fuel pattern, high resistance and better response times. Also some other stuff laying around you might be able to use. PM me if interested.

Bill

If you are a DIY'er and based on your stated equipment, I'd suggest steel tube. This is something you can do. I built my Rotary manifold using the Factory Aluminum intake casting, cut it down and added aluminum runners and plenum. I had to outsource the welding for the same reasons you mention. Quotes were very $$ until I found a fellow Locoster who offered me a friends and family price. Yours will be more involved than mine was due to the needed injector bungs. Mine were in the part of the OEM manifold that I strategically kept.

Not sure that I would try fiber glassing one from scratch. I would be afraid of the glass warping with under hood heat soak. The steel tube fabrication is a more familiar process and a known entity. Get 'er done first. Then try the fancy stuff after it is on the road as product improvement.

Just my opinion from someone who has been there.

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Chuck.

“Any suspension will work if you don’t let it.” - Colin Chapman

Visit my ongoing MGB Rustoration log: over HERE

Or my Wankel powered Locost log : over HERE

And don't forget my Cushman Truckster resto Locostusa.com/forums/viewtopic.php?f=36&t=17766

Thanks for all the replies! Sounds like steel exhaust tubing is the way to go. Rx7locost and BBlue, both of your intakes look great, pretty much what I'm going for. What did you do for velocity stacks or radiusing the ends of the runners? Or are they just a sharp cutoff? I know you can buy pre-made flared ends for velocity stacks so that is an option, but usually getting stuff shipped from the states doubles the price of little items like that. I'll see if there is a local place that will sell mandrel bends. I not, I may go with a method I saw of cutting off very short 7.5 degree cut pieces off a straight pipe and welding them together.

BBlue, regarding the injectors, they are rated at 14 lb/hr which is probably only good to about 110 hp according to online calculators. This will be fine for the first go without any engine work, just to get it running. There is a pick-n-pull in Calgary where I go regularly and getting bigger injectors there is cheap, so it's probably not worth it to ship the ones you have. Thanks for the offer though!

Warren, thanks for the tip. There are a few fab shops near where I live and I will go get some quotes. Do you think plasma cut would be sufficient quality, or is water-jet definitely the way to go? I just reinstalled an older version of Solidworks that I had from my university days, which is a bit of a step up from the open-source cad packages I've been using lately.

The reason I was thinking of fiberglass is that I have a large roll of 6" wide cloth that I got for free, and a bunch of resin left over from fixing my sailboat. Btw, what kind of ice boat do you run? I was considering building one for the last few winters. There is a club that runs DNs on a lake near Calgary, though I thought I might start off with a simple small steel tube chassis. I build a small land-sailer last summer as a proof of concept but with a 3 square meter home made sail it needed some stiff winds to move at all.

That runner length makes me wonder about cutting the flange off of a shorty equal length exhaust header from a 5.0 and bending the pipes a bit to match the port spacing. ..

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"There are times when a broken tool is better than a sound one, or a twisted personality more useful than a whole one.
For instance, a whole beer bottle isn't half the weapon that half a beer bottle is ..." Randall Garrett

Here's a Toyota intake from a 4EFE as an example. ..

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"There are times when a broken tool is better than a sound one, or a twisted personality more useful than a whole one.
For instance, a whole beer bottle isn't half the weapon that half a beer bottle is ..." Randall Garrett

Unless all four EGTs or plug colors are checked, getting even air distribution to each cylinder can be a bit tricky.

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Midlana book: Build this mid-engine Locost!, http://midlana.com/stuff/book/
Kimini book: Designing mid-engine cars using FWD drivetrains
Both available from https://www.lulu.com/

I did no special treatment on the end of the tubes in the plenum. I thought about all the bellmouth stuff. But then I just ended up being a bit on the pragmatic side. I told myself, if I needed to, I could do it over again. So far, I have not found the need for it. I have a street car and it does very well for my needs as is. OEM's do not usually add an internal bellmouth either.

Look up David Vizard on the net, He did a lot of testing years ago on the various shapes of the venturi's. I think the best he found was around 6% improvement. I don't run that fast, don't race and don't "NEED" 6% more HP for the street. However, I did design and build a fiberglass venturi for my buddy's FV based on Vizard's testing. The same basic design has been tested on MGA's and shown about a 5% increase in HP. We ran out of time to test it on the Engine Dyno. It was never run on the track. The several-years' FV national champion's engine builder just sort of chuckled when he saw it. He doesn't run one at all. I really don't know what that really means. But it must mean something?

_________________
Chuck.

“Any suspension will work if you don’t let it.” - Colin Chapman

Visit my ongoing MGB Rustoration log: over HERE

Or my Wankel powered Locost log : over HERE

And don't forget my Cushman Truckster resto Locostusa.com/forums/viewtopic.php?f=36&t=17766

I did bell mouth my runners, at least to some extent. I figured it does no harm and probably does some good and cost was nil. Here is a series of photos.
I belled 4" lengths of the next size larger pipe. Here is on in the forming fixture, awaiting the assault.


Pretty much done.


And the finished product lined up, ready to be welded.


I took the belled stubs to a local muffler shop and had them expanded so the runners were a nice slip fit, then welded them in.

Here is a thread I posted way back when and it deals with my trials and tribulations of fabricating intake and exhaust manifolds. You might find some ideas there. Or least see something you'd never want to do!

viewtopic.php?f=4&t=6298

Bill

Posthumane,

Yes I sail DNs.

I used water-jet cutting for my DN runners, but laser or plasma cutting would probably give similar quality edge-finish. Water-jetting may be best from a heat input perspective, but when all is said and done, whatever technique is available locally is probably good enough. All will require some tidying up of the intake holes with a file or a dremel.

My 1/4 inch runner blanks had about a 1/32 inch (1mm?) or less roughness on the cut line. 3/16 inch thick blanks had a finer edge finish. My recollection is that shipyards are now getting something of the order of 1mm tolerance on NC water-jet or plasma-cut plates. It should be better on smaller parts like a manifold flange.

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Warren
Isuzu Pickup/SR20DE, +401 COLD frame
Build Log: viewtopic.php?f=35&t=11601

I have some pretty detailed logs of my engine swap over at SAOCA.org. Here is the main one, where I'm struggling with everything, including the intake. Spent a lot of time on the intake. Might want to review it. I'm sure it will be good for a few laughs.

http://www.sunbeamalpine.org/forum/show ... 00&page=17

By the way, my curent intake manifold is the third iteration. Still using the original flange. Everything else has been changed. Sort of like "my Grandfather's axe". It's had two heads and half a dozen handles, but it's still a good ole' ax.

Bill

BBlue, after going through your intake build/tune log I'm starting to second guess my decision to build one for my car, haha. Sounds like I might be in for some long hours of fiddling if I want to get it right. On the plus side, since I'm using a motor that makes almost no power to begin with and am only looking to improve it slightly, I may be able to settle for "good enough" at some point. The bellmouth idea looks easy enough. I saw another page where the guy made an end template on a lathe and then pushed it in to the runners with a press.

Warren, those finish tolerances sound more than adequate for me. A little bit of filing will take care of any imperfections. Although, I may be tempted to try the hole saw idea to see how that works out. The ports in the head are actually only 1.25" ID.

It's -20 here today so I doubt I'll be getting out to the garage to work on the intake, but I have my megasquirt kit to assemble now so that will keep me busy for a bit.