190E 2.5-16 help please - Page 2 - PeachParts Mercedes-Benz Forum

Racing · #16 06-08-2007, 03:49 PM

Being one of the few around that actualy is hands on as far as tuning these engines..
I´d say that within limits CB in on the money.

However..
I´ve taken quite a few apart by now and that the innards of the 16V would have all that much common with for instance its 8V counterpart is false.
They differ.A lot.

Stretching the envelope-power wise-of course also leads to the occasional failure.
In the case of the 16V and my behalf though these have been extremely few all things considered.
To tune the engine though..the following should be kept in mind;

1/Above 8 grand OR 400hp in SCd form the OEM conrods HAS to go as these will break.This pertains to the "late" style ones found in late 2,3s and 2.5s alike.

2/Valves are really to soft to rev to the sky.A lot can be found in the OEM manuals about how to quiet the engine down as the customer complains about racket and noises.Therefore..soft material valves et al is a biproduct of the streetworth of the engine i guess.
Anyways..above 8 grand-again-the valves NEEDS to be replaced by heavy duty ones.
The ones i´ve chosen to use is Ferreas,and then from the motorcycle listings.

3/For engines of high rev acceleration the OEM timing chain is also way to soft.This is easy to remedy for a high performance car though as the split of the gears are an industry standard 3/8".
I´ve personaly settled for a hardened chain from the japanese maker Tsubaki.

4/As is stated in the cossie article these engines have to be considered extremely sturdy.
I have never seen a block that from a tech standpoint needed deck cutting for instance.That we opt to do this anyway,and then by average 3/100mm to get it completely straight and true,is mainly to let the headgasket get a fresh surface to bite into
Likewise i´ve never opened one of these engine that needed attention in the main web area.

5/One design "flaw" or whatever you want to call it is the idea of putting the pressure relief valve for the oilpump out of stainless steel into a cast aluminium housing.THis is accessable from the outside,but none the less these DO gall over time,rendering a situation where the valve might get stuch leaving you with conrod bearings that go awol in a flash.
Therefore..ALWAYS take the front cover and give it a go over on overhaul.Better safe than sorry.

6/The KE-jetronic system.
Toss it the F out of the car and be done with it already for ANYTHING but a stock car.
I don´t CARE who is capable of what with it...
It is a dayum hazzle,and if nothing else delicate as well as extremely time consuming to work on.
I´ll take a shoot out on that standing any day of the week-and am currently converting KE cars by loads.

pentoman · #17 06-09-2007, 05:59 AM

Good info people

Quote:

Originally Posted by Cosworth Benz

It goes on that the original brief from Mercedes-Benz was for an output of 320bhp, hence the biggest valves that could be practicably fitted were fitted to the combustion chamber. Cosworth were then instructed to detune the engine to 185bhp for street use. 'Hall went back to the drawing board, but revisions required to bring the Cosworth head down to the required 185bhp were limited to reducing the inlet and exhaust port sizes and adjusting the camshaft profiles to milder settings. Gone was the necessity for the dry sump configuration, special conrods and the specialised Kugelfischer fuel injection gave way to the more everyday electronically-controlled mechanical Bosch K-Jetronic injection.'

Does this mean that increasing the inlet and exhaust port sizes again will bring power back up? Can that be done easily?

I took the head off my car just yesterday (see Head coming off - tuning?) and while I am there am continually having thoughts of tuning work etc.!

Quote:

Originally Posted by Cosworth Benz

Cams are and interesting proposition, as the aim would be to fatten the upper-mid range of the torque curve rather than shift it too much higher. From my motorcycling days one way of achieving this was almost grinding a 'cheater' cam profile. Essentially duration and overlap were left pretty much unchanged but the valves were accelerated open and closed more quickly to increase the duration at or near maximum lift. This type of modification can be hard on the valve train and valve springs may have to be uprated and great care be taken in the design of the ramp section of the profile (this eases the valve off and on to its seat).

I could get cams made by a friend of my dad's who used to do them for Cosworth back in the day... but I don't know if I would get much improvement? Does it require lots of calculations and stuff to come up with what you want? Because I don't know anything about that!

by the way I have this article too linked if anyone wants to read it here

Racing · #18 06-09-2007, 11:40 AM

Pento.
Again.
Numbers don´t lie.
A more or less stock 2.5 head on its 28mm ports will flow inxs of 350CFM.
Do the homework.350CFM is way beyond what you´ll ever encounter a need for with anything close to a streetable motor,so...again..port it...and chances are that you´ll toss driveability down the toilet.

320hp?
I seriously doubt that as the "klasse1" engines develop around that mark,and they´re not to be considered streetworthy in any way if you ask me..
Those are race engines.
It IS a fact that these engines can be had to pull to approx 12 grand these days with state of the art stuff,but be aware that we´re talking a thorough race horse in such a scenario.

pentoman · #19 06-10-2007, 06:00 AM

Sorry I forgot to upload the article I linked to.. it's there now

http://www.knapplane.plus.com/190e/16v/mag/

called "Flying flag"

From autocar magazine when the 2.3-16 was launched