Hi, Ive got a 1958 M. Benz 190 SL.... We have taken out the older carburators and put new webber carbs in the vehicle. The car was filled with 93 octane but it does not have much power. Does this car need higher octane?? thanks K
Octane isn't power, its ignition at a higher temperature to prevent preignition in a high compression ratio engine.
You don't say that the engine runs poorly - coughing and sputtering - only that it lacks (acceleration) power.
A carburetor works on the Bernoulli principle - that rushing air will draw a liquid into its stream. To that, an acceleration pump is added to kick extra fuel for acceleration, otherwise the air / fuel ratio would become too lean as the throttle is opened. The engine will cough and sputter if the air / fuel mixture is too lean (fuel starvation) which you don't cite.
These new carbs - do they have similar size venturis as the old ones?
I suggest you first check that they're the correct size for the engine.
Or, if the power reduction is not large, it could be that the old carbs were set too rich and, though nice to drive, were gross HC polluters that no longer could pass an emissions test. If that's why they were replaced then that's the answer to your post. This engine will run well with the proper air / fuel ratio but do so without the robust torque that you've become used to.
Are you in the Vancouver BC or northern Washington area? I know a guy who calibrates carburettors, his 1958 220 and 1967 200 run like new, people swear by this guy. If interested then reply.
cp
No.
no, im not located there- i guess recallibrating the carbs is the same thing as 'jetting' them?- a
Not necessarily. Carburetor adjustment is a black art. The technician need to be familiar with the particulars of the exact carb he is setting up to properly adjust things like choke setting and other linkage adjustment.
Sometimes bending the linkages is the adjustment mechanism.
Not a job for someone without expertise.
Look for an older guy :~)
Marty
Yeh, if in the northwest, I know of a real expert, 30 years experience (not too old), when the "pro" shops fail people come to him, he makes cars out of junkyards run like new, I seen it done. If you're in the area reply to cplas __AT__ telus __DOT__ net
cp
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