[QUOTE=awjens;9102622] It was rotating, as you suggest, in the bore. So the chipped edge moved from cylinder to cylinder. I was trying to balance flows. And it was extremely frustrating to see the inconsistencies. But what got worse was they moved from cylinder to cylinder. I finally pulled the fuel head down. Several times in fact. Until I noticed the chip on the metering edge on the piston (the lower edge of the waist). I had those dimensions to work with, so spun one up in the lathe and finished it by polishing til clearance fit (just). I am sure I was Micing it, but can't remember exactly. The piston is hardened steel (like tool steel). So I then sent mine off for hardening. Which changed the dimensions again and some hours more polishing. I am guessing a piece of grit in the fuel head at some time previous. Don't know. The car came with a rats nest of issues like that. But having had to delve that far into the fuel head I came away blown away by what they managed to achieve. Hard to think you could design and fabricate something like that and believe it would work - and whats more - for 1000's of miles like you say. I guess some pistons will fit and others will be too tight if you interchange. Which is why they are paired items. Bosch must have had a large box of misfit pistons and metering cylinders at some point.
Good luck on your quest - lots of CIS addicts following this.
But I think Brians comments re -market for high HP SC type heads commercially would be limited.
Regards
Alan

100-027
outlet orifice diameter approximately 0.85mm
metering slit length 6.0 mm
metering slit width 0.100 mm

The 928 head correct? Do you know the flow in cc/min per cylinder?

Remember, more fuel flow means a higher control pressure is allowed, therefore less travel of the air plate for any given mixture point.

There were only ever 6 different air plate sizes, the cone addition on the 934/5 and the dome on the later CIS-E Mercedes V8s is the only change to those stock sizes I've ever seen.

Yes the 928 head, unfortunately I've not yet managed to measure the flow from these units

Ha! Fookin' hilarious right thar!:D

Butt to answer your question, I know of several, four-legged forum members (:eek:) that could tell you the exact time, any time!!!

Anyone have a boosted SC or a 911/930 turbo in Michigan willing to stick a camera in the car to watch the air sensor plate travel? Even a stock SC that they aren't afraid to wind up to redline?

I am curious how far the sensor plate/piston travels. My engine is on the stand and it rev's so quick with no load I can't see much....

While these fuel heads are impressive they are nothing compared to a Bosch VE diesel rotary injection pump in terms of mechanical marvel. The VE plunger not only develops the injection pressure (1150 bar) but also rotates at the same time to distribute the fuel to each injector. The plunger and the bore in the pressure head that it operates in are fitted with no seals or piston rings, just a high tolerance fit while allowing the plunger to both pump and rotate. The pump also controls injection timing based on engine temp, meters the correct amount of fuel based on throttle position and boost psi and governs maximum engine speed. They are an unbelievable mechanical device.

The mechanical fuel injection pumps on 1969-1973 911s, which preceded CIS, are marvels. Full sequential fuel injection at near DFI pressures in the 1960s.

Yes, I agree. Space cams!

Don't get off topic. This is a CIS thread, folks.

Let's really try keep it that way. ;)

Hoping to have some more parts today or tomorrow to measure. I have to say every day I am learning something. We are making a device to hold the spool so we can capture flow rates without it being in a head. The detail drawing of the SC spool is almost done. Then its off to MFG. We are going to do all the work here with the exception of the finish bore on the i.d. Luckily the Motor city has lots of places that can duplicate this fit and finish. It will be matched to the piston from that head.

The wire EDM program is done, so its ready to make diaphragms if we need to. I will probably make 10 or so, as well as order all the orings for these heads so we no longer need to order rebuild kits.

Still looking for more heads from anything....

Once you get the head done you will need to address the flow in the intake/intercooler, etc. I suggest EGTs on each header bank and then figure out how you are going to even the flow. The intake will flow inconstantly on the outer runners. If you are running a single 02 you are going to show that you are safe once you get to where you want to go...the reality is you are still leaning out cylinders and will break a ring or burn a hole. You will be running a cumulative AFR.

FWIW we did all this many years ago and supported the HP we wanted. Larry still does it and if you called him and said here are my AFRs and here is what I need he would build it. Larry is one of the best people I have ever known. That said the reason we started doing EFI is the cost of tooling up and covering every component that needed to be modified was far greater than then swapping to EFI. Not to mention driveablity and fuel economy was far better. I could lean an injector back at cruise (good injectors) and get 28MPG. In the end it was cheaper and when you wanted to add a new turbo or modify the car again it was a few hours on the dyno tuning.

Since the market has gone nuts (still Baffles me) few are touching these cars. In fact I have one in the garage right now the guy wants back to stock. From a business standpoint makes little to sense compared to 10 years ago.

What is your target for fuel mass flowrate and how did you come up with it? In other words, what is your HP objective?

400-450 hp, Boosted AFR 11.7 to 12.0.

I have a set of test pipes with 8 wideband o2's and gauges. Also 6 egt's adaptors for air pump holes. I ran this setup before with 2 injectors upstream of the airbox. It worked until on day.... backfire and end of the airbox. New design airbox with blow off valve. I don't want fuel in the airbox.

400-450 hp, Boosted AFR 11.7 to 12.0.

So I assume this is not a stock 3.0 with stock pistons? You'll need about 1 bar boost into 3L. Probably over 4 lbs/min of fuel.

You can do 1 BAR with 8.5, twin plugs and dead nuts tuning and/or knock control. SC cams wouldn't be the best choice...993SS or Evo. Nonetheless, doable even on CIS.

I thought they were 9.3 CR? I guess it depends on the year.

Depends. Usually 8.5. My SC has 9.8 Euros, but there were also 9.3 Euros. They went as high as 10.3 in euro spec.

This engine has JE pistons. 8.5 cr. It ran without twin plugs. It has, turbo oil pump, aftermarket rods/bolts, raceware fasteners, ssi, mile miglia exhaust, water/air intercooler. Large front oil cooler with fan, oil coolers in both rear fenders. With the additional injectors it ran 1.1 bar 11.7-12.5 AFR observed on all 8 o2 sensors. It has a ks-3 knock detection system. It weighs 2450. The problem was the fuel in the airbox.

I have a set of test pipes with 8 wideband o2's and gauges. Also 6 egt's adaptors for air pump holes. I ran this setup before with 2 injectors upstream of the airbox. It worked until on day.... backfire and end of the airbox. New design airbox with blow off valve. I don't want fuel in the airbox.

^ Sounds fantastic

That is a nice engine. Water /air IC? We need pics! So you've run it already as a turbo? Did you dyno it? What turbo? I am planning a 3.4 930 build if I ever finish up the present 3.3. I was going to run 8.0 with EFI but you guys say you can do 8.5 on CIS and not have it burn down?? And without twin plug? You are braver than I am.

It is supercharged, not turbo. I never had it on the dyno. I am looking to see if I can find an engine dyno in Saginaw Mi area. There is a place in northern MI that has a chassis dyno. The problem is all this testing and changing CIS parts is time consuming when the engine is in the car. Out of the car all the accessories intercooler, oil coolers etc. makes engine dyno tough. I have seen how much dyno tests change. The engine, oil temps. MAT temps all affect the dyno. First run looks good, second better, third even better..... the next day 40HP less. Different ambient, things not warm etc. I quickly learned dynos are only as good as the operator and repeating the environment. I have seen heaters on rear diff/transaxes, transmissions etc to maintain consistency.

I don't really care what it produces. If it reliably makes 350HP without risking damaging itself in any ambient temp, I'm happy. This is why I went with FrankenCIS and the MS. I want to keep CIS and I just need more fuel. If I learn how to get 700HP worth of fuel thru CIS then everyone on this board learns.

There is a shop in Saginaw that does ceramic coating and powder coating. This guy is also an engine wizard. He was teaching engine design at the local university. I went there to drop off my exhaust parts and spent two hours in his shop. He knows a lot of people in the design/racing arena in that area.

Currently Im getting about 245-250 CC/min thru the stock euro distributor. I need 360-400 cc/min. they say a stock CIS can flow enough to support 300HP. I don't see it in my flow tests on standard or Lamda heads, but I have not opened up the adjustments all the way. They also say theres 20% in there and if that's the case that comes close to 300HP worth of fuel.

I want 350-400 without opening the adjustment screws so I can attempt to balance AFR's on all 6 cylinders.

Currently the first limit is the nozzles, they are the deciding factor on the current flow. I am not going to open them up until I fully understand the relationship between the slits and the nozzles.

The shop has decided to make matching metering spools and pistons. They will blank them out at a cost of 450-500 each. I'm gonna start with 6. The nozzles are next. Much easier to make. They wont have holes so of the two pieces they are much cheaper to play with. Once the slit is EDM'ed I have committed to a 500.00 test. At that point if I don't get desired results I can try a variety of nozzles.

If all goes well and I can get it in the first attempt, I will have 5 spools left. I don't have a turbo spool yet, so before they start MFG I may make 3 SC and 3 turbo. If I don't locate a turbo spool soon I will make all SC spools. I only need one for this car. This wont be the last one I build, but I'm running out of time. My window for dedicating a lot of time to this project on this car is closing.

Does anyone know if the 930 metering body/spool is the same as the SC head. I need to get MFG going on these and I don't have a 930 spool yet. Looks like Tuesday. They are wanting to start machining today or tomorrow. I need to have them to EDM by next Friday. This leaves time for hardening and finish fit/lapping. If someone has one that they can dimension with Mic's it would be quick to see if they can use the same blanked spool/piston assy. I want to make some turbo spools for the 930 guys that are helping. If anyone has a junk SC head there is another test I want to try, modifying the slit on the high end and slightly opening up the nozzles. I could do this over the weekend and run it in the engine currently on the test stand. Before anyone goes negative on me, I just want to see the results on a running engine hoping for more up top, without affecting idle.

A blower, now this is getting really interesting, instant boost. Now I understand the SSI's, thought you may have made them into turbo headers. That will be a fun street engine. To make say 350 net HP you're going to need close to 400 gross, the blower will take 40 or so.

I did a significant amount of testing on the blower, running different ratios powered by an AC servo. At 1.5 bar it consumed <25HP. I have experimented with different crankshaft/blower ratios with a clutch, making variable boost. That clutch has horsepower limitations.

Anyone know if a 2.7 fuel distributer 438 100 006 has same internals as 3.0 units? A -077, 031 097?

Don't need to reply, I bought it on ebay, I will know next week. I can clean it, flow it and have more data either way.

Is it a Roots or a centrifugal?

roots

Eaton?

I have 3 different Whipple chargers. I'm putting the 2.1 on for this test. It is NLA.

Oh, screwcharger

Very cool, screw compressor. Adiabatic efficiency the same as or better than a centrifugal but w/o the lag. When you get the fueling right you need to get it on a dyno. Should be an almost flat torque curve, that car will be a ball to drive. OT, I started up a H2 plant once that had 11 Japanese screw compressors running at close to 14 bar. They were oil flooded though, no timing gears, one screw drives the other.

It amazes me the things I see pelicans have done to these cars. All kinds of creative thinking on here. Lots of ways to get the same results. If I was keeping this car, I would go way beyond what I am doing now. I want it right, and reliable. IfI dyno it it will most likely be on a chassis dyno. Too much complexity to take all this crap.

I am still looking for fuel heads or info anyone has on where I can get some "junk" ones. I bought two this week. I just want the internal parts. I may be able to get the fuel I need without using a newly MFG spool. If that's the case I will be selling the ones they make. I am in a time crunch on the engine. I was hoping not to destroy 3k worth of spools to get what I need on this car. But if that's what it takes......

You are not keeping the car??? That's a lot of work just to get rid of it!

Yes it is.... and it all started with a blown up airbox....

Anything new?