EFI Bung in head update

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pishta

I know I'm right....
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Well, pulled the trigger tonight and got the first 2 bung holes (haha) drilled in my /6 head. First one was a trial on what procedure to use, drill and lean, or drill at proper angle from the start. Drilling into cast iron is somewhat a challenge from AL. Slow and heavy pressure, get a good chip clave and keep going. Did the first with a 1/4 drill through the top, then leaned the 3/4 hole saw pilot over to 30 degrees and went to town. I dont know what happened but the hole saw went through at a greater angle and almost drilled parallel to the intake runner ceiling. I changed the angle to about 20 and completed the hole saw. Was a little sloppy so the second was a long 3/16 drill drilled all the way through top and runner ceiling at 20 degrees and followed that with the hole saw. That went off without a hitch, nailed the front side of the valve with the spray pattern. Both are equal but the second one is the best way to do it. Careful on the #4 as the casting is very thin on the back side of the runner as seen in the pic. I used the 4-4-2-4-4 inch measuring method to get them all equally centered in the ports and that will make drilling the fuel rail that much easier. One might wonder why bung the head? So you can hit the valve with the injector spray cone. More for emissions and smooth idle than anything. There is no chance with the bungs in the intake manifold or a very small window if that. Also it will allow you to run any aftermarket intake you want to add a TB to: Clifford, Typhoon, Aussiespeed, Hyper-pak, home grown (mine) etc. My intake is a straight 14" runner ram off a common plenum fed by a Windstar 3.8 TB off a 90 elbow. The TB sits between the plenum and the head and that is where the fuel rail would normally sit so I had to put the injectors in the head. Drilling them left a little step so they seat and Ill have to JB weld them in at both sides as they penetrate the water jacket (water cooled bungs!) so if I am successful in that, it should be good to go. The bungs need to be about 2" long and will be trimmed in the runner after I get them all sized. You can get them pre-made (tall ones) on Ebay for about $4 a piece in a 6 pack. Good deal if you cant make them (17/32 or 13.5mm drill bit into a 1/2 AL tube with a 3/4 OD, and them chamfer the top for the O-ring insertion)
 

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I so can not wait to see how this works out.
Not to mention you had my attention at "bung hole" :D
 
Interesting. I would be afraid of what happens if you get coolant leakage past the bung. Steam cleaned cylinders with a small leak and hydrolocking with a large leak. It is nice to see people trying new things I hope it works out cause you are much braver than I am.
 
Interesting. I would be afraid of what happens if you get coolant leakage past the bung. Steam cleaned cylinders with a small leak and hydrolocking with a large leak. It is nice to see people trying new things I hope it works out cause you are much braver than I am.
Water injection! I get your concern, its just a 6, not a 340...I got a repacement block and AAA...
 
One good thing is if you don't get it right the first time a slant six head is easy to replace for a very low cost.I'm impressed with the idea.Good job and good luck.
 
I am wondering if you make the holes larger, then press in a sleeve with the correct ID for injector, and OD for a press fit to seal water jacket. Whoops, read you post better, already using bung.

Not sure about efi you are using. I had a 85 BMW 528e that had a slant six of sorts. Only 2.7 liter, but 176 hp and got mileage in the mid 30s. The injection was Bosch Motronic, used a flap with potentiometer for MAF, and two sensors on ring gear. Later units used single gear tooth sensor at front pulley. I would think retrofit would be possible.
 
One good thing is if you don't get it right the first time a slant six head is easy to replace for a very low cost.I'm impressed with the idea.Good job and good luck.

I can't take all the credit, the idea was over 5 years old at slantsix.org. I think mine is just the most recent Guinea Pig and maybe the 3rd to get bungholed.....
 
More pics...JB weld is your friend....I JB'd them in and set the depth across all the bungs to let cure, then I flush cut the bung to the roof with a die grinder. Came out great if I can say so. I nailed the alignment too! After I cut the bungs, I put a final layer of JB on the seam both top and bottom and can assure they are sealed. Just how well JB will survive heat cycles, time will tell. I dont imagine heat higher than 250F MAX maybe after a hot run with post shutdown heatsoak. I have 2 different height injectors in there for comparison. Fuel rail next, either 4.6 Ford V8 rails cut into 2 3place pieces and joined (4" offset) or 24" of rail blank drilled and tapped. The inexpensive HF smooth cone vari-bit is a cool drill bit to have as it chamfers the top for O-ring insertion, and really cones the lower part of the bung to allow the 15 degree spray pattern to clear the bung.
 

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Megasquirt 2.2+ with MSnS firmware. Neon injectors, windstar TB. Custom ram intake. Will post with updates.
 
Megasquirt 2.2+ with MSnS firmware. Neon injectors, windstar TB. Custom ram intake. Will post with updates.
Cool project! Ever since I saw something on SS.org about what seemed to be a REALLY good idea for a back yard engineered fuel rail, I've been tossing around cheap EFI setups way in the back of my head but I've been struggling with computers.
 
Just seen this 8) Keep the info and tech advice coming Pishta
That /6 head and set up could be a great move for many of us.
Congratulations on having the gray matter (brain) and gonad's to
get this moving forward =D>..... subscribed.
 
I like what your doing, thinking outside the box and doing something different. If they don't make it, make it your self. That set up looks like it will work out real nice. and i will be following your progress.
 
Very creative. Just a question. Do you think the risk for coolant leaking is worth locating the injectors in the head? In other words, it would have been just as easy.....or even easier to locate then in each intake runner. Was there a specific reason for not doing so? It looks like maybe 2" back and you could have done that? Is there a real advantage to getting the injectors closer to the valves I guess is what I am getting at?
 
Ratrod, the reason for the injectors in the head was to hit the valve with the injector spray. The /6 runners are almost a right angle from the intake and there was no way I could angle the injectors from the intake runner itself to hit the valve, there is no line of sight or a very small window. Drilling the head was far easier than almost having to mill the runners to the correct angle and then having to make a fuel rail that would clear my TB runner that occupied the same space. I just got 4 more neon injectors so now I have 6 that are the same size. Assembly of the MS2 is next as well as mounting and sealing the plenum (valve cover) to the back plate and mounting the TB to the intake ram tube. Got a little sidetracked with about 8 other projects (Electric Razor scooter rebuild with a 3rd battery, 36V!, Mini truck rebuild, lawnmower rebuild, 2 laptops repaired, building 3 BMX bikes, etc) Not enough free time in the year!

PS> that JB weld is the bomb. just like liquid weld beads! Very hard and very EZ to work with when mixed properly. I have the utmost confidence in its ability to seal the water jacket as it was applied in 3 stages: on the bung during insertion, 2nd layer from the bottom in the intake runner after grinding flush, and the 3rd layer on the visible top.
 
Yes, I think the JB Weld will probably hold in that app. It's when people use it to try to hold an alternator on that it fails. lol I hope it works. Really nice work. Keep us posted.
 
If your JB weld doesn't hold up, try 3M's Dp420..I use it on my electric bikes.

[ame="http://www.youtube.com/watch?v=3NWzODqhSbw"]DP-420 3M EPOXY overlap shear test by Doctorbass PART 1 - YouTube[/ame]
 
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