Supercharge M104.980 - Page 4 - PeachParts Mercedes-Benz Forum

Rital24 · #46 08-04-2019, 03:31 AM

I'm going on with order a set of side coated pistons from Woessner that costs about 1600$, the price is higher than Ross,Je and CP pistons that I've also contacted but it's more simple for me to follow this road...
I'm asking them to reduce CR to 9:1.
They need 8 weeks for build the pistons so I've much time and I would like to take advantage for rebuild my 722.5 trans and improve the gas supply system.
About that I would ask you if there are gas pumps with more pressure and flow for CIS.

SpartanV · #47 08-04-2019, 03:51 AM

As far as I know the pumps are good it's the distributor that is the limitation...

You could get a fuel distributor from a V8 CIS car and block off the extra two injector ports. That's what Mike from Dkubus told me to do.

Rital24 · #48 08-04-2019, 04:22 AM

Hello SpartanV!
Yes I know what Mike says about that but to find a good used distributor is not easy and You need to do other modifications over the flowmeter, I never seen this arrangement, the V8 distributor is bigger and it seems there isn't enough place on the cover head side.
I need not to much gas more, at full open throttle with 0,7 bar of boost Afr stays around 13.

97 SL320 · #49 08-04-2019, 09:01 AM

The shape of the air flow meter's cone dictates fuel mixture lean / rich over the air flow range so take that into account when swapping parts. The computer would compensate by using the oxygen sensor but the response may be slow and out of range for the computer.

Someone on e bay USA was selling diaphragm kits to rebuild fuel distributors.

SpartanV · #50 08-06-2019, 06:13 PM

Did Mike say to get just the fuel distributor or the air flow meter as well? I'm guessing just the fuel distributor... the question is, would the m117 distributor suffice or does one need the m119 fuel distributor. Are they same? I believe the fuel pressure regulator is the same for the m104.980, m117 and m119 CIS.

Rital24, were you saying the V8 fuel distributor would hit your fuel or oil line setup?

Rital24 · #51 08-07-2019, 03:10 PM

Steve (Frankencis) says that I could use 0 438 10 10 16 or 18 distributors .
Only fuel distributor, V8 airflowmeter has different connection points.

The fuel pressure regulators are the same on all KE.

And My fear is that V8 distributor could hit the idle mixture adjusting tower.

Anyway I still believe that the limit is not in the distributor but in the pumps.

I found a single pump (instead of our 2) from AEM that may do the job.

https://www.aemelectronics.com/products/fuel-delivery/high-flow-fuel-pumps/400lph-metric-inline-high-flow-fuel-pump

SpartanV · #52 08-07-2019, 04:46 PM

I don't think all CIS pressure regulators are the same... For example the 16valve M102 or even the 8 valve differ.

That AEM pump looks very nice, and in the 044 style, that's cool.

If you get that pump would you also need a new FPR that allows for higher fuel pressure?

Maybe ask the FrankenCIS guys what they say regarding a new pump rather than distributor.

97 SL320 · #53 08-07-2019, 06:30 PM

The dual ( in series ) pump system on a MB CIS car is to make high pressures required by CIS. I think MB used two pumps to lower noise, other lower end cars have only one pump.

There is an upper limit when using increased fuel pressure for more fuel flow. There comes a point where flow becomes so turbulent more pressure won't equal more flow.

I wonder if V8 internals could be placed in a 6 housing? The other question is, are the individual metering devices in the fuel distributor different between the 6 and 8 or is the fuel plunger different?

6 or 8 does not really matter , engine displacement per cylinder matters. I suspect that over some displacement per cylinder range, the same part is used and just adjusted for low or high flow.

SpartanV · #54 08-07-2019, 11:25 PM

I recall reading that the fuel metering screws within the fuel distributor can be adjusted for more flow. Perhaps you can mess with their height and get the extra fuel you need to keep AFRs where they need to be at your boost level.

Then with a new gasket rebuild kit your fuel distributor would be refreshed as well.

Also correct me if I'm wrong, but will less pressure yield more flow?

This picture from AEM illustrates my question, https://www.aemelectronics.com/sites/default/files/400lph_inline_Fuel-highflow_pump_vol-met-flow-current_vsPress_chart.jpg

Rital24 · #55 08-08-2019, 03:02 AM

I believe that's not a good idea to open a distributor and regulate the screws without checking with appropriate instruments what happens.
Also replacing the o-rings and gaskets when not needed.
When they was built at Mercedes-Benz, they were sealed at -50°C if I remember correctly.

Rital24 · #56 08-08-2019, 03:00 PM

And yes, when you increase the flow the pressure drops.

Rital24 · #57 12-05-2019, 01:20 PM

Hello!
Some updates:
I'm rebuilding the engine with a set of Woessner pistons reducing CR at 9.1.
The crankcase is rebored to 89 mm.
I'm reusing original rods, new bushings.

The trans remains the original 722.5 after replacing all the clutch plates and O-rings.
New timing chain and relatives guides, other new parts.

Don't found a solution for to increase fuel flow from CIS.
One solution could be to sent the fuel distributor to Alabama at "CIS flowtech" for rebuild and modify the internal cavities for about 600 US dollars but I'm not convinced...I don't need much more fuel, at full boost AFR stays on 13.
Maybe bigger pulley on the blower, we'll see...

Rital24 · #58 05-02-2020, 10:28 AM

Hi guys!
The baby is on the road again!
Done first 1000 Km with Amsoil break in oil, changed with Motul and filter, now 1500 Km on the tacho.
The engine round perfect, no noises, big power.
Put NGK BCP5ES spark plugs(maybe too cold?)
With overhouled transmission (722.5) it's very pleasant to drive.
I've tried some WOT but for the moment not more than 0.5 bar, AFR stays safely at 11.5/12, must see later at 0.7 what happens.
Many new parts as water pump, radiator, overhauled power steering, chain with all its parts and others.
This was the most difficult job, put engine and trans inside alone and without a hoist.

SpartanV · #59 05-04-2020, 02:54 AM

Badass!
would love to hear it

sm. pelle · #60 05-04-2020, 03:14 PM

Nice work, just ngk heat range is opposite, bigger number is colder, smaller is hotter. You should choose one step colder than stock.