I finally finished my 617.950 engine project. With the cylinder head porting, camshaft, turbo, injektor / ALDA upgrades, it churned out nearly 200 hp on the Dynojet. With the fully polished / enlarged oil passages, pressure with 15/40 Rotella is 40psi @ idle hot and quickly goes off the gauge once you blip the throttle. Pump is brand new, unmodified MBZ.

The engine doesn't shut off with the emergency stop, but stops immediately with the vacuum shutoff. The stop lever will drop the idle, but won't kill the engine. I am sure this is a calibration issue and I will address it later with an upgrade to the newer pump (617.952) in the near future.

The smoothness of this engine and the throttle response is indeed impressive. Once I got the engine in the car, I discovered a small problem with the glow plug circuit.

The engine starts quickly, even without the glow plugs connected, at our current ambient temperatures of 78 degrees Fahrenheit, although it does crank over 4 or 5 revolutions before starting.

With the glow plugs connected, the engine starts immediately. It doesn't even crank over. All you hear is the starter bendix (drive) engage and the engine is running.

However, the glow plug lamp stays on all the time the engine is running. I have never encountered this problem. I have seen no glow plug lamp, or one that goes off quickly, but never one that stays on all the time.

Additionally, my key buzzer sounds all the time the key is in the ignition. Any information on these two issues would be greatly appreciated.

Thank you very much for your time...Bert

Disconnect the buzzer if it's on all the time, I think it's under the footwell compartment on a W123, not sure where it is on a W116 though.
-Joe

__________________
'81 MB 300SD, '82 MB 300D Turbo (sold/RIP), '04 Lincoln Town Car Ultimate

Sooner or later every car falls apart, ours does it later!
-German Narrator in a MB Promotion Film about the then brand new W123.

Bert,

"The key is in the ignition", but isn't the ignition inside the engine? How did the key get in there?

P E H

True enough about the key...:-)

I would prefer to properly address the buzzer issue as opposed to simply disconnecting it. It could have something to do with my dome lamps not working.

After a first test drive, the difference in performance is truly amazing. I compared this in back-to-back test drives between my Dad's stock 1982 300SD and my 1978 300 SD with the modified 617.950 engine.

With the upgraded intake and exhaust turbine wheels, boost pressure comes up very, very quickly and the whine of the turbo is immediately evident; It has a distinctly different 'pitch' when compared to a stock Garret T-3.

There is no waiting for the boost pressure to come up and influence the acceleration curve. The throttle is very responsive and the car will leave 6-8 feet of acceleration marks on any smooth cement surface, such as the service department of your local MBZ dealer...:-)

Boost pressure is 12.8 psi at 4800 rpm.

I have made some small adjustments to the ALDA basic setting, but nothing near as drastic as I have read in this forum. I moved mine 1/2 turn CCW from the basic setting and the improvement was immediately recognizable.

I think the camshaft profile/timing, cylinder head/intake manifold porting and fuel delivery pressure are the biggest factors in the performance increase.

I have also seen very few of these engines that will start without glow plugs.

Further testing will resume on Friday with a 108 mile shakedown run to work and back near Coalinga, California.

I will post further observations at that time. Hope you find this interesting...Bert

Doctor Bert,

Your project is very interesting. I enjoy seeing what a turbo 617 can do in the hands of some one as capable and enthusiastic as you.

Please keep us posted and would love to see some photos.

__________________
Anders

1995 E300
2015 VW TDI Sportwagen 15K
1977 240D (197K)
2002 Subaru Legacy L Wagon (115k) (Wife's)
Gone but not forgotten:
2005 Buick LeSabre
1998 C230
1984 300D
1983 240D
1981 300SD
1974 240D
1974 Fiat 124 Spider
1968 Triumph TR250