There's not much going on right now on the forum so I thought I'd spark up a conversation on blend ratio differences between seasons and see if anyone would like to chat.
Southern hemisphere is coming on winter and I've been up early enough to see at least one frost so far. I notice the difference with the cool ambient temps in that the engine runs slightly noisier till it gets hot. I reason that this has to do with the fuel viscosity being heavier at the lower temperatures. The IP lift pressure at startup is showing up to 140psi at idle in frosty conditions. (For comparison, ordinarily 140psi is only at 100kph and hot running.) The heavy blends give more injection timing advance and consequently the diesel rattle we've all heard at some stage.
My fuel is normally mixed to a "whatever I can get away with" basis for the bought components. Normally this is petrol and diesel.
So, to explain, I add enough petro-diesel till my mix performs satisfactorily at the cold running temps. A max of 15 % petrol plus 10 % diesel. If I need more thinning, I add diesel till I get the sweet spot.
OK. Has anyone any comment? Or anything being done or trialled re season blends. Please remember the approach is from a blenders' point of view. Thanks.
Southern hemisphere is coming on winter and I've been up early enough to see at least one frost so far. I notice the difference with the cool ambient temps in that the engine runs slightly noisier till it gets hot. I reason that this has to do with the fuel viscosity being heavier at the lower temperatures. The IP lift pressure at startup is showing up to 140psi at idle in frosty conditions. (For comparison, ordinarily 140psi is only at 100kph and hot running.) The heavy blends give more injection timing advance and consequently the diesel rattle we've all heard at some stage.
My fuel is normally mixed to a "whatever I can get away with" basis for the bought components. Normally this is petrol and diesel.
So, to explain, I add enough petro-diesel till my mix performs satisfactorily at the cold running temps. A max of 15 % petrol plus 10 % diesel. If I need more thinning, I add diesel till I get the sweet spot.
OK. Has anyone any comment? Or anything being done or trialled re season blends. Please remember the approach is from a blenders' point of view. Thanks.
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