I've found the last couple of days with the warmer weather mine is not only much easier to start but gets to that optimum temp quicker. But overall, when the engine is completely hot, it's really responsive. Now I don't know about my thermostat but I can feel the rad get hot up top when the engine gets to about 80degC, but remembering mine doesn't have a mechanical rad fan the engine keeps getting hotter until the dual electric fan comes on. The thing is the fans come on at about 100degC. I swear, whilst I thought that might be too high, the engine performs really well. The temp will drop to about 90 before the fans cut out. Of course this is all on petrol rather than LPG but goes to show how important "operating temp" is.
Back to tuning, couldn't agree more and rather than start another thread, one of you guys from Adelaide (Andreas or Bandolero) asked sometime ago about power and camshaft timing and using offset woodruff keys. The beauty of the M110 with DOHC being that intake and exhaust can be timed separately. So here's some food for thought. Is there still room for improvement on yours Craig.
From a
mercedesshop thread :
I have a 1981 w123 M110 280CE and I would like to share some performance mods with u guys, case anyone feels like trying them.
A few years back when this was my daily driver I needed to increase the engine’s top end pull, the M110 is a powerful unit considering it small capacity of 2.8L and since my car had rear end ratio of 3.58 I was in real need of top end revs.
So I ordered the offset cam pins from the dealer, those pins come in 2deg, 4 deg, and 5 deg offsets and they connect the cam gears to the cam.
Usually they r used when work is done on the head to reset the timing chain to specs, but in my case purpose was to shift the power band.
First attempt: I advanced both intake and exhaust cams by 4 degs, and boy did I get low end torque ok I lost even more top end as now revs hardly moved beyond 5800, but the low end was tremendous
I mean and I am sure of this, that any one will be stunned by the torque from 1000 to 4500 rpm range, flooring it in 3rd mid corner gives one big drift. First became almost useless as most of was spin.
Unfortunately it turned out that the small autobox on the w123 can’t handle all that torque, I broke a gearbox every 10 days, I swear I went thru three boxes in one month. In the end I had to change the setup. After all even with new internals the gearbox wouldn’t last more than 10 days.
Attempt 2: I retarded both cams by 4 deg. Now I had zero low down, I mean below 3000 u need to shift into first to see any movement, by 4500 u feel some power but at 5500 it feels like a turbo has kicked in and the power keeps coming all the way to 7400 (my cut out). Fromm 5500 on the engine is so smooth and so powerful, u don’t get spin as its HP and not torque but when overtaking cars once u go past 5500 u would think cars have braked as u don’t feel the push but see ur self moving a lot faster than the cars around u.
I know most of u would think I am exaggerating, but tell me how many m110 w123s u know of that can keep revving all the way to 7300 in fourth and clocking 235km/h?
?
I remember I once raced a w124 320 E from 150km/h on to max, we were equal from 150 to 170, then from there I pulled with ease all the way to my top speed of 230km/h.
in the end though, top end ended costing me lots of fuel as u always had to kick down to have the car moving, so i switched to a 2 degs retard setup, it was ok but not that gr8.
Also my engine had taken a beating with all that over reving from the original redline 6500 to my new 7400. oil consumption increased drastically in the end, and the fact that i ran the car with no filter during winter months didn’t help at all.
