New Sawmill Build - what engine - gas or diesel?

[JohnnytheFish]

Hi Everyone - I am working on a new sawmill - It's a modifier version of one of Roy Nix's Crosswood sawmills - but I've gone with 4 legs. The previous 2 legged one, the head rig used to get stuck sliding up and down. I think the two legs would flex slightly in and out. I think this will work better. I have alsobmodified the tension system so that it tightens exactly parallel to the cutting portion of the blade. Before when you tightened the blade it caused the blade to track differently so it was difficult to set up.

I have attached a few pics.

Where I live basically I only have 2 engine choices ....

One is a diesel that claims to be 10 HP and produces 7.5 Kw at 3000 and 8.3 Kw at 3600 rpm. The brand is LiFan. I believe weight is 48kg.

Alternative is called Roto 420 petrol/ gas and claims 8.8Kw at 3600 and 26.5 N.m/2500 rpm. It says 17.5 HP on it. The whole engine is 30 kg.


Any thoughts on what will give better cutting power?





[/img]

[sawguy21]

The diesel will deliver more torque but you may not like the weight. For a small mill I would go gas but that's just me. Out of curiosity where are you? From your use of metric I assume Europe or Asia where gas can be very expensive and scarce so that may be a consideration

[JohnnytheFish]

I am in East Africa. Gas and diesel cost about the same here. The Diesel engine is about 450 USD equivalent and the Gas about 270 USD. I have a diesel on my other mill that produces 6.3 Kw at 3600 so either engine will be an upgrade  in power terms. I have no experience with gas. How will one notice the lower torque of a gas engine in usage?  

[JoshNZ]

In my experience any diesel engine that size is a real rattle gun. Need decompression lever on the valve to start and then runs like a jack hammer. Maybe they've come a way since the ones etc I've used but the ones I have I wouldn't want next to my ear on a mill all day. Not for a small gain in torque.

I don't think you'll notice one bog before the other in a cut, that's what it's about at the end of the day.