Question for Mark DiSilvestro/any fintail users - PeachParts Mercedes-Benz Forum

joshhol · #1 03-26-2003, 10:42 PM

Just trying to get feedback on your driving style.

Basically the concern is to avoid lugging the engine. I think I lean more towards the babying side of things in my driving style, yet am aware that it can be more harmful to the engine after all.
I know these 6's like to rev.
How low is too slow for fourth. Going on level ground at about 40mph constant speed is probably fine but what if a slight incline approaches? Accelerating or adding load at that speed (or slower) in fourth makes me a bit uncomfortable. Seems okay to shift into third if going up a hill but if just accelerating from a constant 40 to get up to highway speeds doesn't make sense to downshift to for just 10mph more before upshifting again.
Am I making sense?
I guess I'm over analyzing it and know it is just something to get used to but want to ask anyways. (who doesn't want to talk about fintails?!)
When I take off from a stop, I go through first really quickly getting up to about 10 then shift to 2nd. From there I go about halfway between the marks for 1st and 2nd then shift to 3rd. Then go about halfway between the max marks for 2nd and 3rd on the speedo. If I'm trying to get going to highway speeds I'll go in third up to at least 50 or so before shifting.
Motor makes quite a bit of noise (although pretty good noise) but I guess I need to get over being afraid to rev it.
For example, if I shift from first to second at the hash mark for maximum speed in 1st, is that too soon?
Thanks for reading this rambling.

Mark DiSilvestro · #2 03-27-2003, 03:05 AM

As I understand it. the shift point markngs are the max allowable speeds permitted for each gear. You don't have to reach those speeds before you can shift. I don't see a problem with accelerating from 40 MPH in 4th gear, even up an incline, as long as the engine isn't laboring. Of course if the incline is TOO steep or you NEED the speed....

I have a set of reprints of original Mercedes roadtests, covering years 1949-1961, published in England by Brooklands Books. One of the things the original testers commented on was the flexibility of the 220 engine. Some even talked about being able to start off from rest in 2nd gear. While I wouldn't do it often, I've tried it on a level road and it seems to work out OK. Sometimes I need (or want) the power, but most times I try to to get up to 4th fairly quickly. I don't worry about the speedometer shift points and shift where I feel comfortable for that particular time, typically well before the max allowed. Maybe later, I'll note exactly what speeds I usually shift at and let you know.

Happy Motoring, Mark

300SDog · #3 03-29-2003, 01:55 PM

Somebody should try to explain what kinda damage lugging an engine can do - as opposed to racing and revving a high mileage machine.

Although not a professionally trained mechanic, I'll give it a shot...

How many miles are on your Heckflosse 220Sb? Am willing to bet the engine has racked up more than 100k out of an easy 190k life expectancy that assumes its been maintained at 110-125K with new sodium filled valves and guides, regular oil changes, etc.

Working in the lower RPM ranges can create carbon build up on pistons and valves from incomplete combustion - no big deal.

Pushing an older engine to its limits can cause worn out parts, valve guides especially, to literally destroy themselves. That's what happened to me when driving my 220Sb (95k miles on my first old Benz back in '76) cross country from New York to Boulder Colorado with pedal to the metal at 90mph in just 2 days returning to college from Xmass vacation.

When I rolled into town the car literally sounded like a WWI machine gun. Symptoms of valve problems, making a racket, began in Kansas City, but i was too young and stupid to slow down.... i began saying "ohhhh ssshhit" down the road 200 miles away from my destination, but the car did not let me down.

joshhol · #4 03-29-2003, 06:11 PM

As far as I can tell, the engine has 150,000 miles on it, it was rebuilt in '83. The whole car possibly has 436,000 K's.
I keep it around 70-75 on the freeway, 80 max. It idles smoothly and quietly.
I really doubt that the valves were replaced, I'll have to look into that. Is there a way to tell if they need replacing?
I think I have the hang of it now, I never max out the car to the shift points. Usually I go halfway between the previous mark and the max for that gear.
If I give it more pedal, It doesn't necessarily accelerate faster but it gets more gas. The engine 'digs' in more and pulls nicely and seems not to rev as high or sound as thin as if you just gave it enough pedal to accelerate at the same rate.
Thanks for all the feedback.

It really annoys me that California is one of the strongest economies in the world yet the roads are so crappy. It's taking a beating on the suspension, not like it was in Washington, its previous home. Oh I forgot, this state cant balance its checkbook.