Hobbling together a fuel injection system

[josh817]

Mods, I'm not sure if this thread belongs here or in the projects section. Help me out, please.

Long story short, Don Potters widow was selling stuff off on ebay. I was talked into EFI and losing the triple carbs. Mommabear Potter had a Hilborn manifold that I suppose his intention was to chop and use the two ports on either end for an L4. Had 4 ram tubes, 4 butterflies, I didn't take the metering stuff since I didn't want mechanical fuel injection.

Bought a Palnet fuel rail I think it is? Supra 440CC injectors, MS2 PCB3.57, MS relay board, the MS2 auction also came with an MegaView 2 which I don't think I will be using. I also bought a ported E88 head from a user on here.

First thing I noticed was the ports on the head are 39mm and the ports on the manifold were like... 32mm or something. Sent the manifold to the machine shop to get bored which revealed a lot of casting imperfections. Nothing serious, just ugly.

Had shortened guides as well. Seems like whoever did it knew what they were doing, or did a good job to make it look so!






Alright so, first thing first. I had to consider my options on how to get injectors onto the manifold. Really didn't want to dish out a lot of money for welding, and I wanted to maintain a manifold that would be useful for mechanical or electronic injection if I were to sell it. Welding bungs onto it was out. Decided the easiest way to do things was to bolt the injectors to the manifold. I had heard of stand off injection before, helps atomize fuel, keeps the intake cool, that sort blah blah. Easy? Performance? Ok I'll bite.


After tormenting TonyD about EFI, what keeps the injectors in place, what seals them, will I get fuel reversion and burn my Z to the ground, I pulled some scrap aluminum and made an injector hold down plate. Mind you, my father doesn't have super precise tools. Would have helped.




I used this diagram and my eyeballs to get the holes lined up. Got it pretty close but 2 or 3 injectors don't sit nicely in the chamfer. There is a little bit of a gap which is annoying because when I set the distance from the plate to the fuel rail, I try to get all the injectors to fit so they can loosely rotate. I would get the middle ones fit nicely but then the end ones would be a little tight. I'm not sure how much it matters but.... I have a different idea.


Pressure testing. I questioned how loosely rotating o-rings could seal but they did. Ramped up the air pressure to 70PSI and sprayed some suds around the injectors. No leaks so far. I used aluminum bar stock, drilled and tapped holes in each end. Threaded a stud into the side that goes to the fuel rail so it could screw into the existing hold down holes. I don't like this, I will probably change to threaded rod so I can adjust the hold down. Right now I adjust it with washers, and that's lousy yah?






Now I had to mount the injectors to the manifold. Cue more threaded rod please. I trimmed down the hold down plate so there wasn't so much weight... Another concern of mine is that in other setups, they have this small individual hold downs, I have a big plate, and this big plate is going to sit close to the ram tubes. I believe David Vizard's book on MG engines(?) said you have to clear an area around the horn of 1.5 X the throat diameter which means I need to TRY to keep stuff about 2.5-3" away from the face of the horn unless I want to introduce restrictions.

More aluminum bar stock was used. to support each end. The ram tube bells are so big I had a hard time finding a place to bolt to. I ran the bar stock to the manifold flange. Chamfered a hole on the backside for a tapered headed screw (whatever you call it, the head is conical) to run threw and screw into the bar stock, the screw head fits nicely into the chamfer. Again, I don't like this bar stock, I can't adjust it; it being the height of the injectors. I'd like to use more threaded rod however I am out of ideas on how to keep it protruding from the sealing surface of the manifold.






Now comes the linkage. This manifold is usually cable operated. I hate cable linkages with a passion, it just seems dangerous knowing I can't pry the pedal up with my toe. Each his own though. I had one of those 280 manifolds with all the casting between the runners. Figured nobody wanted that type so I... chopped it. Sorry. Cut the linkage supports off of it and used a stock hard linkage. Rough placement of the supports.




So my Z buddy, a member on here who I won't mention because he'd embarrassed by his welds for some reason, was kind enough to weld the supports onto the manifold. That is the only thing I will weld to the manifold unless if I absolutely can't find a way to mount a TPS. I or a future buyer, can still use it as mechanical injection with the luxury of a solid linkage. And yes, my motor is being supported with clothes hanger lines because I have limited resources at my mothers house.


Actually... looking at it now, I may mount the TPS to the end of the linkage rather than the throttle shaft. Make a plate to bolt to the linkage support. Interesting. The holes for the mechnical injectors will either be linked together and sent to a MAP sensor. I don't know if it is proper to have them hooked to a PVC system AND to a MAP sensor, using a T connection. Will it read correctly? What if I have the manifold vacuum hooked to PVC, brake booster, and MAP? Still read correctly? I'll have to find out.

Also take this time to notice that the casting covers up the portion above 2-3-4-5 exhaust ports. I can only run a recirculation line from above #6 unless I want to cut the manifold more.

Alright so I guess you can pretty much run it how it is. I fear that at speed, the wind will blow the fuel around, ingesting dust, I have a lot of fears. This is where I'm getting stuck. I made a fiberglass airbox using a cardboard box wrapped with packaging tape and waxed lightly with..... yah bearing grease. Used a coffee can to get my air cleaner snout. For some reason I thought 4" diameter would be good, come to find out a lot of air cleaners are 3". The point was to have an air cleaner setup that would allow me to use an easily found air cleaner. After seeing one of PMC's 4 cylinder manifolds with top mount injection, I thought maybe I could use a stock oval air cleaner and squeeze it between two plates however to get all 6 air horns, you need a really long oval, or run two small ovals. Either way, you have to order it and its expensive compared to the generic types you see at the local store.

I hadn't quite thought out my fiberglass box though... I wanted the fuel rail and injectors on the outside of the box so I didn't have to run fuel lines and wires into it. I needed a way of mounting said box to the manifold. I need a way of mounting the injectors to the box. I thought I could use the current fuel rail supports, the magic of threaded rod, you can clamp things all down its length! Perhaps sandwich the hold down plate to the fuel rail with the side of the box in between. Problem: the box had two half dollar size bubbles on the mounting surfaces. The box is ugly. The box is strong and light but flexible. I made it a 5 sided box without the top, so I could make a top and screw it to the box; be able to remove the top to look in at the injectors or adjust... stuff. The lid would be sealed with like a bubble molded rubber AKA door seal molding.

Bigger problem, I made the box way too big. This is the problem with having the car away from the place you actually work. With fuel rail will hit the brake master. Doesn't look like there will be any room for the filter to fit. TonyD said consider flipping it and hiding the filter in the cowl area. Get that air pressure build up at speed maybe! Still to big, still very ugly. I haven't scrapped the idea yet; reluctant considering I spent $60 on fiberglass... I'm a cheap ass.

 

After perusing through the show off your engine bay thread, I saw someone on here has a valve cover as an airbox. I am seriously considering that idea however I worry about the weight hanging from the studs. If I did that, I either have the ribs/letters of the valve cover ground off, or flatten that whole area. Weld up the oil fill, weld on a 3" tube on the end for a generic filter. Use the top surface of the valve cover as my injector hold down. This way my injectors, fuel lines, wires, can be outside of the contained area. Use the stock hardware to screw it onto a back plate, with maybe even a standard cork gasket. Only complaints would be the weight and the fact that I would have to disconnect the injectors and fuel lines to open the box up. Then again, why would I be going in and out of there anyway?

An L4 valve cover is about an inch too short for what I need and an L6 cover seems absurdly long... If I'm trying to cut down on weight, and I'm going to have welding done, it would be tempting to cut an L4 cover in half and extend it so I can have it fit my needs. Seems overly complicated then.



I've been dragging my feet on the car now. I don't know which way I should commit for the air cleaner. Next on the to do list is to rewire her. I've already drawn up my schematic, bought my toggle switches. Even that simple task is turning into bigger dreams. While the interior is gutted, why not paint it? Before I paint, do I want a roll bar? Should I cut a hole for the fuel cell in the back? I should probably buy a fuel cell so I can fit it correctly.... Wait, I wanted to rewire the car though... Do I want to spend the time to install this setup on my existing motor which has been sitting for 2 years? Should I go ahead and rebuild the motor with all the mods I've learned? WAIT!!! I JUST WANTED FUEL INJECTION!!

I bought the remaining hardware to complete the manifold. Yes, the two new tubes are different lengths than the rest. I can cut them down, they're slip fit tubes. I am going to have to in order for it to fit. I am going to have to try to get the two new butterflies to fit better. The four old butterflies seal well against the walls of the runner when closed. The new ones have a big slit between them and the wall. I tried tapping them while the screws were loose to get them to seat but they're not moving enough. I had originally planned on using the mechanical injector holes for air bleeds so I could sync the runners like you would a carb. I'm not sure if I care too much about the idle to worry. If it runs like crap then maybe... Could very well be a casting flaw, having those two center runners shifted. Can always drill a small hole in the 4 other butterflies and hope your idle isn't way high.


TonyD provided this source in a thread long ago and far away, I think for its cooling systems article, can't remember:
http://mysite.verizon.net/vzezeqah/sitebuildercontent/sitebuilderfiles/inductionsystems.pdf

Parent site: http://mysite.verizon.net/vzezeqah/id1.html >>>>>>> induction systems

I don't really expect to tune the intake successfully but I will use the logic to make myself feel better about the length I decide. I don't know what cam I will run in the future motor, so I can't really begin to get a length. I figure around 10-12" of runner. The manifold itself is about 6-6.5", from the face of the port to the valve I'll guess 3-5", which means I could probably cut down the ram tubes as far as I can with them still being able to 'slip fit' into the manifold. Much more compact! Keep that weight closer to the stud so it doesn't see so much torque pulling on it as well.

Edited July 4, 2013 by josh817

[TimZ]

That's a very cool project you've got going there Josh!  Personally I would have put it under 

 Engine Components→ Fuel Delivery

 

Anyway, I'm thinking you should take a hard look at the airflow through your box - I haven't personally tried a setup like this but I think that you need to make sure that the airflow for the back cylinders isn't flowing between the injectors and the airhorns for the front cylinders.   I think that for this to work the way you intend, the air needs to be flowing straight into each throat by the time it gets to the injector in order to ensure that the fuel goes where you intend for it to go.  This means the airflow either has to be coming around the base plate or from the top and bottom, but not from the side of the airhorn, if that makes sense.  You might be able to achieve this by putting a couple of blocking plates between the #2, #3 horns and the #4, #5 horns for starters...

 

Also maybe take another look at MonZter's custom intake manifold thread here:

http://forums.hybridz.org/topic/61549-turbo-intake-plenum/

Edited July 4, 2013 by TimZ

[NewZed]

Is that plain old polyester resin you're using for the plenum?  It's probably not fuel resistant and if it catches on fire, it will burn hot and be difficult to extinguish.  Maybe you're just using it for mock-up, but with all of that fuel spraying around there could be a better choice of material.  Test burn a scrap and see what happens.

[josh817]

Is that plain old polyester resin you're using for the plenum?  It's probably not fuel resistant and if it catches on fire, it will burn hot and be difficult to extinguish.  Maybe you're just using it for mock-up, but with all of that fuel spraying around there could be a better choice of material.  Test burn a scrap and see what happens.

Yes it is. Good thinking. I didn't know fiberglass resin had problems with fuel contamination. I was even considering making an acrylic box until I read that acrylic doesn't like sustained periods with gas.

[madkaw]

I'm surprised you are going thru all this effort with the stand-off injection. And why don't you modify the injectors holes for electronic injectors?

I have an oppurtunity to get one of those mechanical FI TB setups and the first thing I thought was converting to electronic . I would think very few run a mechanical Hilbourne set up, but there would be a good demand for a converted ITBs.

 

And please contact my attorney in regards to using my patent for the air cleaner- LOL

[madkaw]

And as far as weight- my air box is pretty light, but I gutted all the webbing inside and I shortened the cover also. I've never weighed it though

[josh817]

I'm surprised you are going thru all this effort with the stand-off injection. And why don't you modify the injectors holes for electronic injectors?

I have an oppurtunity to get one of those mechanical FI TB setups and the first thing I thought was converting to electronic . I would think very few run a mechanical Hilbourne set up, but there would be a good demand for a converted ITBs.

 

And please contact my attorney in regards to using my patent for the air cleaner- LOL

I think Hilborn or Kinsler makes bungs or some sort of part specifically to convert the manifolds. I don't want to outsource expensive work and start welding up my manifold though. I feel like the direction I took is just as easy or easier, certainly cheaper, than paying someone to weld bungs. May not look as pretty. Even if I had used bungs, I would still need to address the airbox issue. The mounting of the injectors was really a days worth of work on a boring weekend. Also allows me to use the injector holes for vacuum stuff or air bleeds to sync the runners.

 

I'm glad to hear your idea is light! Care to link or post pictures of it, inside and out? If you cut yours to shorten, then I might as well look into what TimZ was saying too! Just have to be thoughtful of space and weight constraints. I will have to feel the weight of my carb setup compared to the new setup. I bet they're about the same... For what its worth, everything on the new setup is aluminum.

[Tony D]

Josh, you ever look at the TBI injector holders for a 5.0 Ford in the early 80's... You have a "robust" injector clamping setup there..... LOL

 

Nice manifold, you bastard!

 

Yet someone else using the 'anecdotes' on GrapeApeRacing... 

 

Edited July 20, 2013 by Tony D

[skirkland1980]

Only problem there is you need three cars for enough parts.

[josh817]

Only problem there is you need three cars for enough parts.

Manifold, 280z linkage, Supra injectors, megasquirt, TPS from some type of car, Palnet rail, any Z valve cover. I think the only thing that I would have to worry about sourcing are injectors and TPS, everything else "shouldn't" be things that wear out and need replacing. I don't see the problem, unless I wanted to make them and sell them, but I don't.

 

Josh, you ever look at the TBI injector holders for a 5.0 Ford in the early 80's... You have a "robust" injector clamping setup there..... LOL

 

Nice manifold, you bastard!

 

Yet someone else using the 'anecdotes' on GrapeApeRacing... 

 

Sorry if that makes you pissy, Tony. As I said, I use it to make me feel better about the length I choose. I don't know if the info they present is more for V8's or general for other motors. The equation they discuss already has some variables like subtracting 20-30º of duration from your intake duration, to allow time for the pressure wave to travel. They say 30º works well for high RPM solid cam drag motors. Just for shits and giggles I used 30º in my calculation.

 

Vel of sound: 1300 ft/s

Intake duration (pulled an Iske cam spec from internet): 304º

Runner diameter at throttle plates: 1-13/16" or 1.8125"

You can see the tuned length for reflective values changes quite a bit. I will go with 3rd or 4th reflection to say the least.

 

And about the injector hold downs, I know they're huge.   If you look at Madkaws valve cover air box, and imagine the injectors seating on the outside of the cover, so they're spraying into the cover, that's what I am wanting... Mayb if the price is right, he will make one for me?   Who knows! Quick sketch, only difference is that I will want the top of the valve cover to be completely smooth, no raised letters, so the injectors can seat nicely.

 

Sorry I haven't been updating. Not much has happened. I haven't touched the car... Too many expenditures this first half of the year, I need to back off. My original plans in the entire car project was to make negotiations with myself as to how I want things done, so I can get it on the road. Changed my mind, being so busy closer to graduation I might as well wait for when I have a real income supporting me, and do the job the way I want it the FIRST time.

 

I will still work on the manifold but I realistically won't have it on the car and running for a while. I will put it on my old motor, I just don't want to trash my rods or crank. The rest of the car will be completely gone through before I wire it. Roll bar, fuel cell, seats, belts, accusump, oil cooler, etc. I don't want to go back and find that I have to change everything up because I didn't put it in at the right time.

 

Edited August 17, 2013 by josh817

[Tony D]

I use it as a reference as well. Another board filled with morons referred to the Grape Ape Racing page as "anecdotal"!

 

I simply stated it was good to see someone else using this "anecdotal" set of formulas, etc...

[josh817]

I use it as a reference as well. Another board filled with morons referred to the Grape Ape Racing page as "anecdotal"!

 

I simply stated it was good to see someone else using this "anecdotal" set of formulas, etc...

I like that they explain why certain factors are in their formulas. Before you had posted those references many moons ago, I would visit different websites that had calculators, all gave me different answers, none would tell me what they were doing. I've downloaded all the GrapeApe articles, they're all great.

 

Currently reading through head cooling threads on this forum before I even think about drilling out a good head.

[skirkland1980]

I guess since you were running carbs before that you'll be running na now? I like this design. I'd like to build one like this for my turbo car. I just wonder if the turbo will blow the fuel away from the runner and cause a lean condition?

[skirkland1980]

On my post from yesterday I was talking about the ford 5.0 injector holders. There are only 2 per car so you need them from 3 cars.

[josh817]

That makes sense then, I was getting confused! I don't think I would do stand off injection on a turbo app. for that very reason. I would suck it up and pay to have someone weld bungs onto the runners. The guy who cut up 3 KA heads and bolted them together to get a twin cam head for a Z block, last I saw he was using one of the Hilborn manifolds for a turbo app. I don't know how far he got.

[Tony D]

It wasn't uncommon for early turbo L cars with the HKS Plenum to have standoff injection shooting into the carb bores...

 

Or if the ITBs had single injectors, and the HP was sufficient, the same deal.

 

Even when they used dual injector ITB's, there were injectors in the surge tank to shoot into the Center of the throat.

 

Really, inside the plenum the air should be diffused and static flow with the inertia of the fuel will carry into the bores easily.

 

During max flow, the airflow (if properly diffused into the plenum from the turbo pipe) will tend to draw fuel into the barrels.

 

In a stock plenum with air from the front blowing across the first three cylinders, it will blow fuel towards the back of the plenum, but with Center, Dual, or Diffused Top or Bottom Entry into the plenum it should not be an issue with stand-off injectors in a turbo application.

 

MSD once had screw-in injector bungs. Using a 1/8MNPT X 1/4FNPT brass pipe bushing reamed on the 1/4FNPT side to accept injectors worked well on several EFI from Carb conversion manifolds....

Edited August 25, 2013 by Tony D

[josh817]

I haven't mingled with the manifold lately... Life is getting busy.

 

But, I did just make this thread to better explain what I am looking for in my intake system:

http://forums.hybridz.org/topic/117954-a-better-explaination-to-exhaust-scavenging/

[Tony D]

I got martial law imposed, and then a military coup...what was your excuse again?

[TimZ]

I got martial law imposed, and then a military coup...what was your excuse again?

I wondered who was behind that...

Tony is now supreme leader of Thailand!

Edited May 24, 2014 by TimZ

[Tony D]

I have left the country and am in Kuala Lumpur, on the way to Singapore.

 

I had  nothing to do with the unrest. Really...