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Started by tondaz, 02 November 2005, 08:53 PM


Hi ya all, it's me again. Looking for alternator belt for my 79 350 se. Okay now, when I'm at the auto parts store (where my car does not exist, of course!) am I using the 450 se or sel as a crossover to get this part? Or would someone be able to give me the belt # so I can order this directly? No air conditioning on this car if that matters. You were so helpful on my previous posts I thought I might give it another shot. Thanks again!!

john skene

As far as I know the 350 was bored out to make the 450 engine, so there is a good chance that the fan belt is the same. The 450SE and SEL codes refer to the body size, standard or long wheel base, the engine is the same for both.


Hi guys

I think that the belts differ as a 450 is NOT a bored out 350 but a stroked 350 (by 20mm). This  makes the block deck height greater to get that stroke.

Remember that the 350 has a bit less than 66mm in stroke, which makes it a real revver. And the 3.5 and 2.8 cars could be had with a 4-speed manual in Europe, making them faster. I hate to say this but I used to own a 280SE with stick that had much more acceleration up to 80 kph than a 450SE in US trim that I briefly owned when I lived in canada for a while.

Denis (from rioting Paris)
with well hidden 350SE

john skene

Thanks for making this point, as you are absolutely right, it was a stroked 350 and was not bored out. That now proves to me that I should check things rather than go from memory.

I have a 76 450SEL, which is the first of the antipollution models, and the difference in performance between the 74 - 75 models and my 1976 model is amazing. Supposably there is only 20HP difference in output, but it feels more like 80 or 100HP in normal driving.


Two things make the W116 both a beautiful and a questionable car (no, not the 6.9) :
- the uglification for the US
- the destruction of performance in the M117.

The "American" 450SEL I had in canada was rated at 190 bhp (more like 175 hp DIN at best) while a Euro 450 has 225 hp DIN. that is a whopping 50 horse difference !

The uglification concerns those awful bumpers - no wonder people have mods to shore them up to teh bodywork. the truth is that the original bumpers are nice but merely decorative ;-)

Bye for now

Denis in sunny, quieter Paris

john skene

Tondaz, it has only just occured to me regarding your 1979 350SE.  Did Mercedes still make the 116 model with the 350 engine in 1979?
I thought that Mercedes changed to the 450 engine about 1975 or 1976 and stoped making the 350 model. You may have to ask for the details on the earlier years to get the fan belt you need.


The "350" M116 (3.5L V8) was made August 1972 - September 1980.
The "450" M117 (4.5L V8) was made December 1972 - June 1980.

The 350 was never never officially imported into North America.
1977 450SE [Brilliant Red]
2006 B200


Hi fellows

Back to the alternator belt,it is 9,5mm wide and 970mm long.

A belt that is 1000 mm long will NOT fit : the support bolt at the front of the casting supporting the alternator interferes >

Kenavo (bye in Britton)


Quimper, France
cold, lovely Britanny