I have both types of fans for 617.95* engines and was wondering which type will be better to use?

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DJ


84 300D Turbodiesel 190K with 4 speed manual sold in 03/2012

The plastic fan is the latest model with two additional blades. Presumably, it's the better choice.

The two sets of metal fans came from the SD engines and the plastic one is off my 300D. Better cooling would ideal. I never counted the blades on either type of fan.

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DJ


84 300D Turbodiesel 190K with 4 speed manual sold in 03/2012

But what does the extra blades mean? does that mean more air that is scooped up and thrown?

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1981 240d (engine donor 1983 240d) recently rebuilt engine hurray! - No more.. fought a tree and the tree won.

pearl black 1983 240d 4speed (Converted!@$$%) atleast the tranny was rebuilt.

yes. I would go for the plastic for sure.

more blades mean more cooling. the plastic is way lighter and therefore more fuel effecient too.

Tom W

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

The plastic one mated with it's smaller pulley will move more water and air.

The metal one might put more stress on the water pump shaft due to its weight.

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DJ


84 300D Turbodiesel 190K with 4 speed manual sold in 03/2012

Speedy used the 11-blade to replaced the 9-blade in his car and found that it works better.
OM603 fan + clutch upgrade. 1987 300D

The plastic one, it puts less stress on the water pumps bearings.

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

You think so?

Most of the "stress" on the bearings is due to the thrust load from the blades trying to pull the shaft out of the pump. It's probably close to 25 lb. at maximum horsepower of the fan.

The difference in weight between the two fans is probably 3 lb.

Three pounds could make a difference considering the size of the pump's bearings.

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DJ


84 300D Turbodiesel 190K with 4 speed manual sold in 03/2012

You must remember that when it's running the fan will also be working like a gyroscope. There won't be much weight on the shaft as the weight will be trying to move itself out in all directions.

True but a gyroscope is balanced, the water pump shaft is probably not.

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DJ


84 300D Turbodiesel 190K with 4 speed manual sold in 03/2012

Its a Mercedes! Of course its balanced! I replaced my (probably original) water pump at 215,500 miles due to a clattering sound and weeping from the weep hole. It cost $40 and took 2 hours....new one is still perfect, so I am not too worried.

I have the metal fan, and mine runs the same temp as my dad's, which has the plastic one. My shroud came loose once, fan chopped it to pieces, the plastic fan would have shattered and stranded me. Metal = better. Its also quieter, my dad's fan rev's up like crazy when its hot out and sounds like a hurricane.

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'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

I was thinking a metal fan would probably be quieter.

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DJ


84 300D Turbodiesel 190K with 4 speed manual sold in 03/2012