No problem,i will get it out tommarow....and good luck.I have complete faith in what u r trying to do..

Sent from my SM-N910T using Tapatalk

There are three primary components in the fuel head that dictate fuel flow.

The piston or spool cartridge via the primary metering slots
The diaphragm and preload springs
The chamber outlet nozzles

the metering slots and outlet nozzles are the fixed mechanical restriction points for overall flow capability

The fuel pressure balance in the upper and lower chambers dictates the amount of diaphragm deflection and therefore the measured flow

Iron heads with the stainless steel diaphragm are operating on a fixed spring preload of 0.2 bar so are wholly dependent on the increase in fuel pressure between the two restriction points to deflect the diaphragm and allow fuel out

Iron Lambda heads alter the chamber balance via the frequency valve and trim the fuel flow, but have the same or very similar overall flow restrictions at the spool and outlet valve.

The later alloy heads have a synthetic rubber diaphragm and ceramic valve discs so have a greater range of movement for trim purposes but retain the two primary restriction points in the spool and outlet valves

The last gen CIS-E heads are inverted internally with the preload springs below the ceramic seats allowing a true fuel cut option via the electronic control but essentially operate on the same principals as the earlier designs.

the earlier spool comparison photos should also be considered in tandem with the below example of the outlet valve sizing

Excellent summary. I did not know about the different diaphragm materials. FYI, American Precision Machinery is a manufacturer of repair kits. Here is their repair instructions:

http://www.cis-jetronic.com/public_doc/07.3-0997-06.pdf

You will probably want to develop that ability in your own if you are going to do a lot of experimenting.

I probably have a 2.7 or 3.0L non-lambda head floating around. I might be willing to donate to the cause... No spare turbo fuel distributors, though.

The head went to the lab this morning. It is a 0 438 100 077 with Lamda. First off I gotta say for a car that has sat for most of its life, it was incredibly clean inside. No deposits, no varnish, nor foreign debris in the screen around the metering spool body.

What a precision device. I tore it apart before our meeting at 1pm today.

We had a meeting with the four partners in this business about a future development process. So today I have at my disposal the engineers that design the tooling, fixtures etc. all at the table in the conference room. Combined 150+ years of the EDM business. After the meeting we got to the big problem... The Bosch Fuel Head.

As luck would have it one of the engineers that does development work and trial burns was at that table and said "is that a bosch fuel injection part". I said how do you know. He took me to his toolbox and showed me a very similar barrel. He had done test cuts on this thing years ago, couldn't remember the specifics. Small world. There are not identifying numbers on this spool, only the letters ELO.

The shop supervisor told me in batches of at least 6 they can produce new barrels all together. He is going to get me a no margin price, approx. 500.00 each. I may have him make me 6. Most tolerances .001 is sufficient, except the id of the spool. Ground then honed to size matching the plunger. the rest is o-ringed.

They took a lot of other dimensions so I can calculate flows.

Waiting for the fluid guy to read some and look at all the pictures, cross porting, chamber volumes, diaphragm plate thickness (.004" on this head), spring pressures etc.

Then they examined the barrel. It has 6 small pockets 60 degrees apart that were milled in the barrel, with a shaped end mil creating rounded ends on the rectangular pocket and a flat for the surface to be EDM'ed. You can see the end mill swirl marks on the flat surface. The slot was cut with a shaped electrode plunging straight down. They know this because the slots are square on the ends. If it had been wire cut they would have been rounded. I thought maybe they wire cut it because you could burn straight thru on both sides and due to the fact there are 6 cylinders 180 degrees opposite is another slot. However their explanation was hard to dispute when zooming in and looking at the squared off corners. Not perfectly square due to electrode wear but certainly not rounded from the wire EDM process or shaped hole drilling method. They also said to wire this would mean constantly "rethreading" the wire for each slot. Hardly suitable in production.

The slot was approx. .125 MM (not inches) wide, 5.0 MM long. They will have better measurements for me. It wasn't critical today. I would love to see the blueprint on this....

Comparing the slots (look at picture 1 VS. picture 3) they didn't always get the slots exactly parallel to the milled slot. So they are not perfect......

In conclusion they said they can make an electrode that size or smaller and recut the slots. There will be approx. .001" overburn. so a .006 inch slot requires a .005" electrode. They said plenty of room to burn thru to minimize taper.

So its in the works, can it be modified? They say nothing they found today leads them to believe it cant be done. Examining other heads with other flow rates will help identify exactly what they changed, that can be crosschecked with the fluid engineer. I told him he doesn't get flow slot dimensions from head #2. I want to see if his math comes up with the flow rates I observed with this slot size and all the other variables for head number 1 the -077.

Working with this group on Pelican and the guys at the shop and lab on this attempt is a thrill. When I got into these cars years ago I wouldn't have touched this distributor. The more I see the more I am astonished at the quality of this assembly. Simply brilliant people designed this. And it is so reliable.

http://forums.pelicanparts.com/uploa...1462066380.jpg
http://forums.pelicanparts.com/uploa...1462066403.jpg
http://forums.pelicanparts.com/uploa...1462066413.jpg
http://forums.pelicanparts.com/uploa...1462066428.jpg

I cannot thank you enough. I will take good care of it. Notice the storage of the parts on this head....

Now this is what we are talking about...... Great information. I will print this and pass it on to the fluid engineer.

Best thread in a very long time. Cheers.

I can use any heads that offer potentially different flows. The same care will be taken with all. Packaged, labeled etc. Whatever you can do to help.

Good news here. They can buy this material already to thickness. They can stack them and wire cut 20+ at a time. They can also grind custom thicknesses. This surely plays an important part to the whole story. Mine was .004" thick. I ordered a kit, forget where from. Will be interesting to see if thickness is exactly the same.

Required reading -> Bosch K-Jetronic Fuel Injection - Technical Instruction

Got a call from the fluid guy and we discussed this diaphragm. I think I saw a rubber diaphragm in some heads. He's concerned about the role the diaphragm plays in fuel quantity. He said this this is very unique device, especially for its time.

Can anyone confirm a head with a rubber diaphragm. Possibly 930 heads or higher flow? Or did they just switch to steel because of the rubber deteriorating?

evolution is as follows

First
Iron head = Stainless Steel diaphragm (SS used directly as valve surface)

then later (until production stopped in the mid 90s)
Alloy Head = Synthetic rubber diaphragm and ceramic valve discs

As far as I'm aware
All SS diaphragms are paired with iron bodies
All Synth rubber/Ceramic are paired with alloy bodies

the diaphragm material itself plays no real role in the operation of the head other than range of movement.

your steel head with FV between 0v0 and 12v0 gave around a +18%/-18% trim range

Eddies 924/931 head is alloy and produced +50%/-25% range

^^^

Steve, I've read in the past that the move away from the stainless steel diaphragms was due in part to their tendency to become dented (such as with fuel pressure spikes); is that accurate?

So are all the stainless diaphragms the same thickness?

Switching to Alloy Heads with the rubber diaphragms had no affect on flow?

When they made the change were any of the orifices sizes changed? Example same displacement engine with alloy or Cast head.

I believe they are all the same thickness
As they just create a flexible barrier between the upper and lower chambers, changes in thickness would have absolutely no effect on the chamber volumes when static, but would impact on the pressure differential movement if too thick.
They just have to be thin enough to flex the correct amount for the pressure flow and thick enough to seal the outlet ports without deforming.

I doubt it, the move would more likely have been because of the change to alloy bodies and the introduction of electronic control of the FV.
The rubber gives additional range for trim control.
The alloy is less prone to corrosion and easier to manufacture/machine and isn't compatible with SS.

The two important measurements so we can model and compare the various part numbers are simply the spool orifice length and width and the outlet orifice diameter
Can you accurately measure the outlet diameter on the heads you have apart?

I have a number of units here I can do the same on
Non-lambda iron head 100-027 Porsche 928 (all markets)
Lambda alloy head 100-088 Mercedes 560 (USA)
CIS-E alloy head 101-018 Mercedes 560 (USA)
CIS-E alloy head 101-016 Mercedes 560 (rare rest of world or “Euro” AMG)

I'll second that. Really interesting and informative stuff. And huge props for sharing with the community. I can see this along with the great work Steve has done going along ways to help us CIS junkies get more HP out off our old sleds.

Not sure if you're interested in a Euro 930 FH (higher flow cast iron) but if so I can part with mine for awhile. My motor has been out far too long long and the reality is it won't be going back in for at least two more months.

So are you going to develop this as a product for sale?
Edelweiss and CISFlowTech already sell these. Now you understand why they did not want to share info? It's great to help a fellow enthusiast repair and maintain our old cars but this is WAY beyond the DIY home mechanic's abilities. Their fuel distributors support 700HP+, not too many folks building those engines.

What year is this head? What is the bosch #? does it have Lambda?

I'm not trying to sell anything. I could not get enough flow thru my head. I contacted CIS flowtech and didn't get a response.

Gavin contacted someone, and its my understanding he could not get specific flow information or a guarantee on what increase in flow was possible thru his head.

Statements were made anything is possible if you put enough money into it. If CISFlowtech and Eidelweiss haven't spent time on SC heads then they dropped the ball.

Looking at this now and getting a better understanding was the goal. Reaching 400HP with a SC head. Finding the limits on a SC head for guys like Gavin that build a 3.0 turbo. Put together properly how much HP can we get from a 3.0? Over and over on these threads I read 300HP from a SC head. Wheres Eidelweiss and CISFlowtwch in these discussisions offering solutions? If we can spend thousands on rods, valves, ARP fasteners, cylinder/piston sets, why can't we buy a head from someone with a guaranteed flow/HP limit. This doesn't make sense. This spool can be built from scratch. The nozzles as well. it seems if this is a business someone would be selling the DIY'ers a kit, consisting of the parts you need to increase flow. If the cast iron body itself needs modification then send it in. Not answering people when they have a dire need because your too busy, or you don't want to investigate limits of SC heads, simply opens the door for someone else. Making a statement like 700HP is possible with CIS and then not offering a solution. I would have paid for a head. Now its become a challenge. There are a lot of smart people in the world. To think someone wouldn't bust this door open and post how its done for all to understand seems a bit arrogant. So I'm asking anyone to help. My pictures posted clearly show I'm not going to keep anything to myself.

I'm not interested in a business doing this for guys. However if anyone that has the capability to do this learns how to when this post concludes, I would welcome them. Competition breeds ingenuity and lowers costs.

Maybe one of the shop employee's will offer to do this for people if they need it done on one of our demo machines. Maybe a pelican has access to an EDM machine. If we can understand it, modify it, and show everyone maybe 10 places will go into this business. when competition isn't there, prices skyrocket.

If I could buy a kit with a handful of parts for $1000.00 i would have done it in a second. Not that I wouldn't have paid for someone to do it, but this site is full of guys that want to do as much as they can on their cars. Not because they cant afford a shop. Many because they enjoy the feeling when it first starts, or that afternoon drive knowing they did it themselves.

Still nothing from CISFlowtech. No price, no input. You gotta ask yourself why not post a price if they can do it so easily?

I just don't see how EDM is cost effective? It's too slow.

We can accurately measure any of the orifices. They have pin gauges and a very accurate optical system. We made a machine years ago in the non-contact gauging department to measure EDM'ed holes. We can take some really good pictures as well. I caught them a bit off guard on Saturday, but the tools are there.

So far I only have the -077 head apart. I can take the -097 Euro *(non Lamda) head apart, but it flowed the exact amount as the -077 with the lamda valved connected to 12VDC.

A fellow Pelican shipped me a 930 head, so I will take that one apart next (when it arrives). I planned to flow it first and see the measured flow/volume difference.

I'm thinking flowing any one of the 6 or 8 ports (after I verify they are equal before dismantling) will be enough for future comparisons.

The more I see of this thing, the more intrigued I have become. In my world (software and hardware design) things are comparatively simpler to modify. I remember guys telling me EE's had tougher courses. I'm not so sure about that. God I wish I had paid better attention in the few fluid dynamics classes I took......

Any idea (anyone) who ELO is? Only identifying mark on this spool.

Tippy,

We made a lot of these machines. One I remember (my first programming job) for Rochester Products in NY. It was a large dial machine with multiple heads. Each head cut a specific hole. There were 12 stations. So 12 holes cut at the same time. It indexed. Then performed again. The pick and place took one off and put a new one on every index. Fuel injector machines cut holes one at a time. Most machines have multiple heads. Each nozzle is indexed a number of times and the hole cut. they are picked up and moved with tiny suction cups. Then every one is flow tested with column gauges. Bosch has hundreds of these machines. Our new fast drillers can cut an injector hole in 30 seconds or less, index four, five or six times and its done.

1981. No Lambda. I don't recall the #. I'll post it shortly.

I'm not tying to pee in anyone's Wheaties...... I needed help, that's why I started this thread.

So while I was at the shop I remembered this joke told by my bosses brother. My boss was the plant manager at this company. Also a brilliant Engineer and very hands on.

One day before United Technologies was coming in for a machine runoff, 15, 7-axis EDM machines for turbine blades. We had some problems, its Sunday Night/Monday morning at 2am. Shop is busy, I'm replacing a failed DC drive.

My boss has his tie flipped over his back, his Starret (Last Word indicator) on a spindle, and here comes Dick, His brother after a few beers with this joke for us....

A billionaire has three son's, first one reaches 16. He says son what do you want for your 16th birthday, anything in the world, name it, its yours. He replies dad, I want an Airplane. His dad buys him American Airlines.....

Second son a year later turns 16, Dad says son what do you want. The son replies I want a train. His dad bus him Chesapeake Union Railway.

Third son, a little bit simpler, kinda shy and quiet. Dad says son what do you want. He replies dad I want one of those Mickey Mouse Outfits. His day buys him Raycon Machine Tool Corporation. (our company).....

Sold to Charmilles EDM, my boss fired. I took a long vacation, couldn't drag myself back in. Never even cleaned my desk. Closed a few years later.... My old boss now running his own company, no corporate smuck to kick him out.....


Back to fuel heads.....

I used to work for Pratt & Whitney/UTC BTW.

Then you know the process. It is slow...the larger the hole the slower the cut....

It used to be done in dielectric oil. not sure when you worked there but I hope you didn't mess with that stuff....

"Any idea (anyone) who ELO is? Only identifying mark on this spool. "

ELO = Electric Light Orchestra

Sorry, couldn't help myself.
Very interesting thread. How many lbs/min of fuel are you shooting for? Beyond a certain HP if you have to get into new pumps, injectors, lines, etc you'll be pushing the cost of a basic EFI system or more and still have the same less than desirable CIS throttle response and it won't flow enough air to make the HP of an identical EFI engine because of the metering disc. I'm sure Flowtech hasn't responded because he doesn't want to help a potential competitor which is understandable. There would certainly be a market for it I 'd think for the street drivers who want more power from the CIS but don't want to get into EFI. The big dollar, big HP racers are going to go EFI because it will flow more air.

70'sbush, while it's out, just make sure you say no to the eventual certainty of ----> http://forums.pelicanparts.com/uploa...1441119271.jpg

:eek:

:D

[QUOTE=awjens;9101759]


him make me 6. Most tolerances .001 is sufficient, except the id of the spool. Ground then honed to size matching the plunger. the rest is o-ringed.

The more I see the more I am astonished at the quality of this assembly. Simply brilliant people designed this. And it is so reliable.

http://forums.pelicanparts.com/uploa...1462066380.jpg
http://forums.pelicanparts.com/uploa...1462066403.jpg

I am constantly amazed at what they did to create this device. I had to make a new metering piston for my 930 head - the metering edge was chipped which gave inconsistent tuning/flow results. (Took a long time to arrive at that finding).
I polished it down to a perfect fit in the chamber bore. I was struck by the fact this clearance is what seals the fuel pressure behind the piston from piddling out into the airbox. Who in their right mind would have sat down to design a moving part to seal fuel at pressure simply by the clearance tolerance between the moving parts? I guess one of the reasons I stick with CIS is the appreciation of the work and engineering quality that Bosch produced to make the system work. It is a piece of engineering art. Now, if only they had managed to make a better boost/fuel system for the 930 :-)
Alan

The market for CIS engines making 400HP using an SC fuel distributor is so ridiculously low that it makes little sense for anyone in business to spend time or money to develop such a thing. If they did it would HAVE to be expensive when only a handful of people on the planet would be paying for all the R&D and specialty machining equipment. It is common practice to switch to a 930 fuel distributor when building a high powered turbocharged SC engine. A less complicated mod would be adapting the 930 FD and injectors for use with your aluminum SC manifold and OEM runners.
That being said, the mod for SC normally aspirated race cars to 250HP is the normal stuff, increase the orifice size and turn up the set screws. The slit mod is reserved for the ultra-high HP 934 vintage race cars as they have the need and are willing to support the cost for R&D and high-end machining equipment.

[QUOTE=Alan L;9102583] I absolutely agree. I have never heard or seen fuel leaking into an airbox, even on cars over 200k miles.

How in the world did a metering piston get chipped? Previous owner drop it? I could see that spinning and causing random problems in random cylinders.

Did you grind it to size then polish it? I didn't have them mic. one, but it would be interesting to know the clearance between the piston and the metering body. I will know it soon as they are going to make some bodies.

It would also be interesting to know if the piston from one will fit another.

Some interesting information. I have found over the years its sometimes very helpful to read the patent application. Theory and operation must be very detailed in order to protect a patent from infringement. I haven't read all this yet, but I intend to tonight. Anything not in a manual will be in here.

Maybe while I'm working on my car (brakes and a 3.0 rebuild) somebody can read all this and explain it to me...... Joke


Patent US4193384 - Fuel injection system - Google Patente


http://forums.pelicanparts.com/uploa...1462135336.png

Anyone know what time it is ?

This thread is really heating up.

Re. the area of the fuel slots. That is only one part of the equation, like Edelweiss was saying. The other part is airflow across the disc, and dP (delta pressure or pressure drop) across the metering disc vs. engine airflow. Pressure drop across the disc is what moves it and the greater the airflow into the engine the greater the dP across the disc up to the max that disc/ring configuration can flow. Once the disc/ring reaches choke you are not going to make more power no matter how big the fuel slots are. Determining the req'd size and configuration of the disc/ring for the desired HP level (ie. air and fuel flow) is the hard part. The guys opening up the stock fuel slots must have determined what the choke point of the stock disc/ring is and set the fuel slot area to match it. Edelweiss's custom disc/ring allows the airflow necessary for over 700 HP of fuel flow thru the head. Then the control pressure has to be adjusted to counteract the plunger movement to get the right AFR across the RPM/boost (eg. airflow) range.

That's exactly right. If the plate and ring are not modified, not only will you reach the choke limit, but you will also reach the limit on barrel travel. This is important to them, because they have no electronic control of fuel pressure. You will, so the requirement is somewhat less demanding.

I see no reason to make tapered slots, if it is even possible. It might be interesting to try, since that would have some advantages, but just having wider slots with a properly modified metering plate/lever arm will work too.