More horsepower?

[Cees Klumper]

It's a well known fact that US 280 SL (M130) engines had a lot less horsepower than European ones, after the introduction of a milder camshaft and emission control equipment (170 DIN HP for the European ones vs 155 for the US).
However ... Laurence Meredith, in his book 'The original Mercedes SL' states that, sometime in 1969, the European engines underwent the same emissions control treatment. However, the original 170 HP was nevertheless maintained through the use of a different intake manifold (shorter and taller). Now this would imply that ... provided a European engine is fitted with this intake manifold, but without the emission controls ... the horsepower would be MORE than 170 (more like 180?). Does anyone know whether there's anything to this?

Cees Klumper in Amsterdam
'69 white 280 SL automatic

[Ben]

I have definitely seen ratings for the 280SL as 185HP, though I cant reember where !

Also I have seen 230SL's rated as 170BHP !

I had assumed this was a difference between the ways of easurement e.g DIN and SAE !

Anyone clarify this ?

Regards,
Ben in Ireland.
'64 230SL 4sp.
'03 CLK Kompressor

[Benz Dr.]

I always thought that the length of the intake runners changes the tourque curve. This has to do with the ramming effect the air has as it speeds up. All engines are limited by how much air that can be drawn into the manifold or carb. There's a limit and the only way to go higher is to supper charge , turbo charge or VISA charge.

Dan c
SL Barn

Daniel G Caron

[Malc]

Hi,
Induction Manifold length influences both torque and economy, usual practice is that the longer the intake the more torque generated at a particular rpm. Also the economy is increased. BMW did this in the late 80's with an engine for the 5 series, which they simply put longer induction manifolds on, changed the valve timing and cam lift so that most "power" was generated at lower rpm
Though most european engines went through some form of emmisions control in the 70's and 80's it was never as radical as the requirements for the US market, such as air pumps, exhaust recirculation and of course the dreaded catalyst. In fact at the time most european manufactures, MB, BMW etc etc were developing "lean burn" engines which met all the proposed requirements without catalysts, pumps etc, but they were "killed off" for political reasons, mainly because the big three in the USA were so far behind in the technology race at the time the only way they could met the US standards were with all the smog control junk. Hence the US goverment decision to insist that catalyst technology was used.
Malc
Scotland