need help on my 280 sl performance

[yehsf2003]

Hi All master,

I recently became the owner of a 1969 W113 4 speed manual 280 sl. I bought this car form a specialty  280 sl guy -Tony in Cherry Hill, NJ.  The engine compartment looks like had been done fully restoration job. After I drove this dream car few times later, it doesn't as perform as what I expect. I check with Tony and he said it is the same performance as back to 60s. Please see the follow questions. I understand it is more then 40 years old car. However, I hope someone can help me to improve it.


1. When I warming up it in the morning, I don't see the smoke but it is really smell. That means I can't warm my car inside of garage, people will die by the carbon monoxide. After 10 min. later, there is a big black oval mark on my garage floor. I feel it is more like oil rather carbon. 
2. It needs a lot of fuel. If I fill up my tank, it only runs under 105 mile. Is that normal?
3. The first gear is almost useless. I need to change to second gear right away.
4. When the RPM reach 3000, the speed only can reach 45mph. If I push the speed to 55mph, the RPM is almost at 4000. I can feel it is the higher speed for this car. i can't image if i wan to drive it more than 60mph.

Please advise.
Thanks

Frank

[graphic66]

Sounds like you are running way rich, your mileage should be above 15MPG, I regularly get 17-18MPG. These cars do rev higher than a big lumbering V-8, They almost run like a 2 stroke engine. The design is to attain peak torque and horsepower at about 5500RPM and the engine is made to handle the revs. I would get a GPS and check your speedometer for accuracy. It does sound like you are reving higher than normal, I get about 70MPH at about 3800RPM with the 3.97 differential ratio in my 66' 230SL.
   You should get the rich running problem corrected right away, you could wear out a set of rings very quickly as the extra fuel washes the oil off the pistons.
   You also will not ever really be impressed with the performance of these cars, most minivans are faster. These are comfortable touring cars made to run all day at high RPM's and get you where your going in style. My friend has the new 505HP Vette, My old beat up 230SL gets more attention when we are out together. I must say though, being able to smoke the tires on downshift at 50MPH is worth $75,000.00 all day long.
  Get your car tuned, sit back and enjoy your vintage ride. You will see what all of our excitement is about when you get comfortable with your car.

[jeffc280sl]

Hi Frank,

I agree you are running very rich.  There are lots of things to check out.  Try looking at the "linkage tour".  If the linkage isn't setup correctly you can run rich or lean. 

I know what you mean about first gear.  I have a 3,27 ratio rear axle which is perfect for our cars.  Makes first gear usable and reduces revs by 20%.  You can read up on that also if you like.

Let us know what you find.

[twistedtree]

With a manual transmission, the engine vs road speed is fixed regardless of how well the engine is running.  The only variable is the rear end ratio, and that will only change with a replacement.  A pungent, eye-burning exhaust smell means the engine is running way too rich, but don't mistake it for the stink of an older, non-catalytic converter car.  When an old car drives by, the smell is VERY noticeable, even if it's running correctly.  It brings back memories of being stuck in traffic on I-84 as a kid.

[ja17]

Hello,

Driving off from a stop your transmission should shift twice. If you floor it at a standing start, you will depress the kick-down switch on the floor under the gas pedal and the transmission should shift three times.



(Comment here is for automatic transmission)

[ja17]

OOPS ! Sorry forgot yours is a four speed !