Can a 3.5 IP and injectors function reasonably in a 3.0 603? Can I adjust the ALDA to compensate for 15% less displacement? If I have to go with a 3.0 IP, can I keep the 3.5 injectors?

Thanks,
Sixto
93 300SD

If I remember correctly, the injectors between the 3.0 and the 3.5 are identical. It's the prechamber angle that changes between certain version. FSM makes no distinction between 3.5 and 3.0...only 603 and 602.

as for IP, no clue. BC should be able to tell just by comparing part numbers in his stable

__________________
1982 300TD 210K miles ("The Replacement" aka "The Anvil") - SOLD
1979 300SD 245K miles (never ending project)
2007 Pinarello F3:13
1995 Ducati 916 (SOLD, sniff)
1999 Ducati 900SSie (SOLD)

If the IP from a 603 will bolt to a 606, I'd bet it will work between a 3.0-3.5

There's no fitment problem. I'm guessing the control rod sensor, idle actuator and throttle connections won't be a problem. What concerns me is the extra 15% of fuel the 3.5 IP thinks the engine needs.

Sixto
93 300SD

I know for certain that the IP of a 603.961 will work in a 603.971. The lifters too. And the camshaft. The IP seemed not to have the same pickup as the 603.971 pump, but actually made the car run much quieter and smoother. And for some reason, it seemed that the computer control functioned more precisely when the 603.961 pump was in the 3.5, i.e., the idle would raise up and settle back down, like on a gas powered car does, when the car is first started after sitting overnight.

The injectors would not fit in my car. The 3.5 injector threads are near the bottom of the injector body as opposed to the 3.0 threads being about a quarter of an inch higher toward the middle of the injector body, which made them not fit. Also, I believe the thread pitch is different, as well.

BenzDiesel

This must be related to the prechamber change between vertical and oblique injection and the 5 degree incline they put on the injector. FSM says oblique gives a smoother run, so maybe just transfer prechambers and injectors over. A little more work (ie. to the machine shop it goes) but get improved injection and better long term solution.

Maybe that's why the changed thread pitch, to make sure you couldn't mix and match the prechambers and injectors that would not work well together.

__________________
1982 300TD 210K miles ("The Replacement" aka "The Anvil") - SOLD
1979 300SD 245K miles (never ending project)
2007 Pinarello F3:13
1995 Ducati 916 (SOLD, sniff)
1999 Ducati 900SSie (SOLD)

Injectors are not a problem since I have the complete head off the 3.5. These injectors work with the IP from the same car (duh). I'm wondering if I'll leave a trail of unburned fuel because there's 15% less engine than the fuel system expects.

Sixto
93 300SD

maybe if you crank up the boost, and REALLY bend the rods! BLACK smoke WOOHOO, it sounds interesting.
John

__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

The 3.5L also revs lower too at WOT. I'm still going to ship it to ya when I get back.

__________________
I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]

It will take trial and error, but if you have too much fuel and are getting poor mpg, turn the fuel down (clockwise, I think). If not enough fuel, which means great mpg, but low top end power, turn the pump up (counter-clockwise, I think). If you want 35 mpg and don't mind going no faster than 75 mph, then set the pump to that through trial and error. If you want to go 125 mph and be satisfied with getting 20 mpg or maybe less, then turn the fuel up. I've found that at 28 mpg, you have good balance of power (can exceed 100 mph) and fuel efficiency (go over 500 miles to the tank).

DISCLAIMER: This information is for 603 Engines. I had a runaway on a 617 and I believe it had something to do with not putting that "fuel shutoff" component back on properly that allowed the engine to run (wide open and uncontrollably) until it threw a rod and busted out the side of the engine and busted the transmission too! So be careful when messing with that fuel control!!!! Like maybe have the driveshaft disconnected when experimenting on the OM617 fuel controls.

BenzDiesel

If I'm understanding this correctly, the pump in question is from a W140, so it's not the earlier lower HP output model (because the governor kicked in at an earlier rpm). This pump should work just fine; it has the same size plunger/barrel assemblies, so it's good to go. The IPs are interchangeable between .96 and .97

The h2o-pump housing is slightly different, as the .97 models have a second temp sensor built in. Other than that, most items should be a straight swap between the two.

There's no internal calibration for the greater displacement of the .97?

The heater lines are different too. The supply line doubles over the thermostat housing to make thermostat replacement really difficult then makes for the fender.

The front cover might be different since the .96 dipstick is at the front of the engine vs the .97 dipstick beside the IP.

I hope the archive chronicle these discussions for the next sap... uh... person who takes this path.

Sixto
93 300SD

I think if I were to locate a late model .97 car, I wouldn't hesitate to replace it with either a .96 or a 606 turbo, especially a W140.

15% more fuel is not a problem. If the 3.5 IP is in fact calibrated to deliver that 15% more fuel you will not realize it in normal driving. The extra fuel may only be a problem at idle (unlikely) and WOT. Fuel = power. An IP that delivers 15% more fuel, relatively, from the stock IP will simply develop slightly more power at a given rpm than the stock IP. In normal driving the result is needing slightly less accelerator pedal to maintain or accelerate RELATIVE to the amount of pedal needed with the stock IP. Does this make sense? Maybe not, but I can tell you from experience of having the IP fuel delivery turned up in other diesel vehicles that you won't notice it until you mash the pedal all the way down. RT

__________________
When all else fails, vote from the rooftops!
84' Mercedes Benz 300D Anthracite/black, 171K
03' Volkswagen Jetta TDI blue/black, 93K
93' Chevrolet C2500HD ExCab 6.5TD, Two-tone blue, 252K

My want to monitor your EGTs when using the larger IP. I'm sure you will have fun with the extra fuel.

__________________
1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

1982 300SD - 232K miles - Wife's Daily Driver

1986 560SL - Wife's red speed machine