Petrol v diesel long and short term costs...

[Ty Korrigan]

I don't think anyone will have a sub 750 woodchippers with 35hp diesel soon enough. Diesel engines will get more complicated, very expensive and a load heavier with the new tier regs! We may all have to accept the smaller diesel units like the 26hp we already use or a petrol! We have already looked at 80hp Kubota petrol engines in chippers, gas conversions and hydrogen generators fitted to engines!

 

PeteB,

What about E85 engines?

Is there no-one pursuing the development of these?

Also, what model GM uses a 26hp diesel?

Regards

[Jase hutch]

The Arb 150 has the option of a 26hp Kubota diesel...

[Ian C]

Another option is to forget the 750k stuff and the young uns do a trailer test and just run bigger chippers.

 

Sent from my SM-N910F using Arbtalk mobile app

[Will C]

Bigger chipper means less snedding and less conifer timber left. The difference in fuel to tow extra 1/4 or 1/2 ton is more than made up for in my opinion.

[PeteB]

My recollection on high ethanol fuel burners or E85 units is that the are woefully underpowered for their size! I read an article about one in a car and it was truly awful!

[Ty Korrigan]

I understand now.

E85 being lower octane so less power.

Ty

[openspaceman]

I understand now.

E85 being lower octane so less power.

Ty

 

I doubt it.

 

E85 has a higher octane rating than unleaded but there is no advantage in a stock engine, it needs a higher compression ratio to get the advantage.

 

Alcohol fuels have lower energy density, because they are already partially oxidised (as wood is) so to get the same power you have to feed the engine 30% more fuel. This means the jets in the carburettor need to be bigger, else you wreck the engine by running it weak.

[Ty Korrigan]

Ah! Cheers for that. So E85 would mean a higher litre prr hour consumption and a very different engine.

Ty

[openspaceman]

Ah! Cheers for that. So E85 would mean a higher litre prr hour consumption and a very different engine.

Ty

 

Yes basically.

 

I know little about denatured ethyl alcohol but back in the day methanol fueled grasstrack bikes ran much higher compression ratios with 500cc JAP engines, probably over 12:1 and the carbs were able to accept bigger jets, also I think the jets were not brass as the fuel attacked brass.

 

Unleaded can probably only stand about 10:1 cr ( but maybe higher with a knock sensor which could retard the ignition, even so this would derate it) and power is in direct proportion to compression, all other things being equal. So to get the best out of E85 the engine needs to be higher compression and free of brass and some other metal bits in the fuel system plus no rubber or organic hoses or gaskets. Plus 30% bigger jets or preferably injectors.

 

Then the higher compression should go a small way toward addressing the 25% higher fuel consumption.

 

Much the same is true of LPG (propane) to get the best out of it needs a higher compression ratio to take the advantage of its higher octane rating (which means it resists detonation to higher pressures).

 

I've never seen E85 for sale in UK is it much cheaper in France?

[aspenarb]

Diesel all the way, torque ( the bit that matters) and more of it produced at a lower RPM, rebated fuel cost, end of.

 

 

 

Cars running ( diesel)

 

I`ll get my coat.

 

Bob