Making my own EFI intake... The First Casting

[Derek]

Hi Josh

The air filters will be a round disk of perforated metal that sits on a ledge inside the bell, then a chunk of air filter foam that is held in with a domed shaped piece of stainless steel wire cloth like this:

 

 

 

 

The holes are .295 or so. I'm making a set of simple dies to press the screens. Not sure how well this will work but that's where I'm at filter wise for now.

 

Derek

[josh817]

Maybe if you're intentions are to expand a bit, you could send your plans to a company thats fabricates stuff in bulk, then you sell it for profit or something like that. Perhaps sell them the info and they sell it under their name and you get part of the profit. Not too sure how it all works I just know that after Dad snapped several axles in his enduro years he designed a new set and head Summers Brothers or some place make them. He couldn't sell them by enough quantity so he wound up just giving them the patent and now they sell them under their name. Just a thought though.

 

I still LOVE the trumpeting look they have! I'm curious if one could get a manifold and then add a flare/horn at the end of each runner to make almost the same thing.

 

I'm keeping a close eye on you good sir. !

[Pharaohabq]

so if you plan on getting this going out for sale, I'm all for it. I like how you just have the runners/barrels all part of the same body instead of connecting to a manifold.

 

I guess you would use panty hose for filters? Not a big deal.

 

 

Hehe I got a kick outta your pict w/ your sunburn..

 

 

Back to Heat shields. Yeah I think that stuff you found should work just fine. maybe more than is needed, but way better than melting something.

 

So any idea on the moulds for the rear 3?

 

You said to watch out for guys who just melt down aluminum cans and scrap... Are the pours really that much worse in a case like that?

[josh817]

Haha thats not me. XD Thats some mug shot of a dude. I can believe the crappy aluminum thing... Forgot all about heat shields and yah I think one should definitely be used since everything being used is aluminum and its a conductor of heat... Stainless would be good. I think the ones Dad sells at his shop are stainless and some boo complained about weight and said make them out of aluminum and we were all like... that defeats the purpose...

[PalmettoZ]

Hi Josh

The air filters will be a round disk of perforated metal that sits on a ledge inside the bell, then a chunk of air filter foam that is held in with a domed shaped piece of stainless steel wire cloth like this:

 

 

 

 

The holes are .295 or so. I'm making a set of simple dies to press the screens. Not sure how well this will work but that's where I'm at filter wise for now.

 

Derek

 

Hey Derek-

I had Weber carbs on my Cobra and I used tea strainers as filters. They are made of stainless steel, were the perfect diameter, and had a very fine mesh.

I just snipped off the handle and made some rubber gaskets out 26" mountain bike tire tube about 1/2 wide. These slipped around the rim of the horn and the top of the rim of the strainer. Not sure of the diameter of your horns, but you could probably find some that are close.

They looked great when finished.

[Tony D]

I used a tea strainer on the inlet to my turbocharger for the longest time.

 

Really, it's kind of restrictive, and there are better alternatives. The larger you can make your filter area the better it will filter. The velocity across the single-stack style filters is sky high. They only catch 'the shark sh*t' as my old tech school instructor used to say...

"Strainer" more than "Filter" if you follow that meaning.

[Derek]

 

So any idea on the moulds for the rear 3?

 

You said to watch out for guys who just melt down aluminum cans and scrap... Are the pours really that much worse in a case like that?

 

I just finished the Hemi Manifold that was consuming most of my time. I'm hoping to start carving the core molds next week and hopefully the patterns right after that.

 

Scrap is ok if your making mail box parts but anything that requires machining has to be poured from ingot. The amount of inclusions you get in the casting goes way up when your pouring metal with a high scrap content.

 

Hey Derek-

I had Weber carbs on my Cobra and I used tea strainers as filters. They are made of stainless steel, were the perfect diameter, and had a very fine mesh.

I just snipped off the handle and made some rubber gaskets out 26" mountain bike tire tube about 1/2 wide. These slipped around the rim of the horn and the top of the rim of the strainer. Not sure of the diameter of your horns, but you could probably find some that are close.

They looked great when finished.

 

Tea strainers would work but I'm afraid they would be kind of restrictive. The only thing (in my mind) that the screens are there for is to hold the foam elements in place so I want as much open area as I can get. If I go into production I'll get a price on laser cutting some custom blanks out of stainless.

[Derek]

I used a tea strainer on the inlet to my turbocharger for the longest time.

 

Really, it's kind of restrictive, and there are better alternatives. The larger you can make your filter area the better it will filter. The velocity across the single-stack style filters is sky high. They only catch 'the shark sh*t' as my old tech school instructor used to say...

"Strainer" more than "Filter" if you follow that meaning.

 

 

Hi Tony

Any opinion on how thick the foam should be? I made provisions for a screen at the bottom of the bell and this would give me a filter thickness of 1.25". in hindsight this seems to be a bit thick and may be too restrictive.

 

Thanks

Derek

[Tony D]

Really, the only way to determine the thickness is by tapping the stack downstream and taking a water column restriction reading at WOT peak torque, and peak horsepower. If it's appreciably more than a few inches of water column you will really afffect the pumping efficiency of the engine's intake.

[Derek]

Well I decided to start designing the vacuum log. I wanted to incorporate the IAC and the main idle screw. Then I figured why not mount the balance needle valves on there as well. The individual lines will run over to each boss on the bottom of the throttle body. The lines will be hidden under the web of the manifold. This would make setting them a whole lot easier. It also looks pretty cool! The foot print is about 4.5 x 4.5" and fits right where the choke cables come out of the fire wall. The vacuum inlet is a direct shot over to the outlet on the manifold. It uses a Jeep 4.0 IAC

 

Here's a perspective shot:

 

 

Here is a view looking straight on at the firewall.

 

 

Here's a cutaway shot. You can see the shelf under the needle valves that will allow filtered air into the valves. As the IAC raises it will dump filtered air into the vacuum chamber.

The fresh air inlet and shelf area will be done with a core. The vacuum passages will be done as a machine op.

 

 

Am I missing anything?

Derek

[MONZTER]

Why do you need an idle screw if you are using an IAC unit? Wont you set the rough idle with the butterflies, and then let the IAC do it thing.

[Derek]

Why do you need an idle screw if you are using an IAC unit? Wont you set the rough idle with the butterflies, and then let the IAC do it thing.

 

Sensei Tony D (among others) Recommends using a separate Idle bleed screw as opposed to cracking the throttle plates or using the IAC. Apparently on ITBs you want the butterflies completely closed at idle. I like it because I can easily increase the idle without jumping into megasquirt.

 

Derek

[Careless]

i figure the screw is always good for fine tuning. can't hurt, can it?

[zguy36]

I tried making an air filter for a dirt bike when I was younger, just didn't work. I used a small bit of foam, similar to what you are doing on your intake. It took away half the power of the engine. Surface area is really where it's at. Unless the foam you plan on using is really open and really thin, it is going to restrict a lot. Better off just running a screen to catch the big stuff.

[Pharaohabq]

Well I decided to start designing the vacuum log. I wanted to incorporate the IAC and the main idle screw. Then I figured why not mount the balance needle valves on there as well. The individual lines will run over to each boss on the bottom of the throttle body. The lines will be hidden under the web of the manifold. This would make setting them a whole lot easier. It also looks pretty cool! The foot print is about 4.5 x 4.5" and fits right where the choke cables come out of the fire wall. The vacuum inlet is a direct shot over to the outlet on the manifold. It uses a Jeep 4.0 IAC

 

Here's a perspective shot:

 

 

Here is a view looking straight on at the firewall.

 

 

Here's a cutaway shot. You can see the shelf under the needle valves that will allow filtered air into the valves. As the IAC raises it will dump filtered air into the vacuum chamber.

The fresh air inlet and shelf area will be done with a core. The vacuum passages will be done as a machine op.

 

 

Am I missing anything?

Derek

 

hmm, have you already bought the IAC? mine looks a little different than that. I'm sure you've got it all set right though. I think it looks really good. I would gusset the mounting tabs, but that's a very small detail.

 

Phar

[Tony D]

People mistake the use of an IAC to think it actually controls idle speed. It does NOT! It compensates for loads on the idle speed like the alternator charging the battery, fast idle while cold, kicking up the speed when the A/C is on, stuff like that. Base hot no accessory idle speed is set using an idle speed screw, and then compensation is done with the IAC afterwards.

 

Actually, making those blocks would pay dividends...that looks a lot like the blocks that came out in the early-mid 80's in Japan when the first analog Fuel-Control Computers were being introduced. The ITBs were all set to run closed throttle, and idle synch and idle speed was all done using a separate manifold block with tubes to the manifold.

 

Didn't anybody ever wonder why the runners on some JDM manifolds have those 1/8 npt plugs in them? Now you know!

[Derek]

Hi Phar

Yea some gussets on the tabs would probably be a good idea. Thanks. The IAC is from a 1992 Jeep 4.0.

 

 

Actually, making those blocks would pay dividends...that looks a lot like the blocks that came out in the early-mid 80's in Japan when the first analog Fuel-Control Computers were being introduced. The ITBs were all set to run closed throttle, and idle synch and idle speed was all done using a separate manifold block with tubes to the manifold.

 

Didn't anybody ever wonder why the runners on some JDM manifolds have those 1/8 npt plugs in them? Now you know!

 

Hi Tony

 

I tried to design this as a universal style block so it could be adapted to other applications that wanted a stand alone IAC/Vacuum log.

 

 

Derek

[Tony D]

I just ran across something in a VW Magazine (probably from July, DB&HVW's) in their 'New Items' section there was a set of air cleaners like you proposed to make. There was something in there about new low-restriction filters for 48IDA's or 51.5 IDA's. It's back at the hotel...which doesn't have internet, and where I won't be for at least another7 hours...

 

They used what looked like a grey felt-looking compound in the screen sandwich. They also showed some smaller individual-stack K&N style filters that had air-trumpet clamps on them.

[Derek]

I just ran across something in a VW Magazine (probably from July, DB&HVW's) in their 'New Items' section there was a set of air cleaners like you proposed to make. There was something in there about new low-restriction filters for 48IDA's or 51.5 IDA's. It's back at the hotel...which doesn't have internet, and where I won't be for at least another7 hours...

 

They used what looked like a grey felt-looking compound in the screen sandwich. They also showed some smaller individual-stack K&N style filters that had air-trumpet clamps on them.

 

Let me know on that if you don't mind.

I found filter foam from UNI Filter.

They offer sheet foam that's .375" thick and 60 PPI density. They also offer 30 PPI as well. I think the idea is on dirt bike is to make a sandwich of the two. I'm going to call UNI and see if they have any suggestions on this.

 

I calculated the area of the filters and I'm going to be hard pressed just to get 60 square inches of surface.

 

As the filters start to plug will that change the AFR and will Megasguirt see it? Just thinking out loud here but it would be nice if there was a way to have Meggasquirt send an error when the condition reached a certain threshold. Something along the lines of "hey butwipe clean your filters!!!"

 

I'm planning on running a carputer so I'll have the ability to monitor the readings anyway.

 

If I try really hard I can complicate this enough to where I'll never get it done!!!!

 

Derek

[Tony D]

You will change the map signal compared to the barometric signal it gets when originally fired up. I think the foam dual layer in a larger oval filter on the extreme end of the trumpets would work well.

Herve Oulette had TWM ITB's on his 'Silver Elegance' and had a clamshell filter that clamped over his trumpets. He simply removed it when it was being shown.

 

Let's face it, when you're driving down the road, you want an effective filter. When you're showing the car, spend 3 minutes less polishing the rocker panels on each side and remove the filter and stow it under your sweater under the gas tank at the rear of the car. Stick Racquetballs connected with weedwhacker string in the trumpets like a real Hilborn Racer and just lie to the gawkers 'Sure, I run thataway all the time, just plug up the stacks when I park. Haven't had a problem in years!'