Daniel McCurdy
Full Access Member
When it comes to the actual engine design is the idi better at burning wmo than a di diesel. Im looking at the vw aaz idi and the alh tdi cant decide which one to use.
Daniel McCurdy
Full Access Member
So has this been covered before or does knowone really know.
NeverHave-I-Ether
Full Access Member
By DI do you mean direct injection with a common rail?
Never-Have-I-Ether
Never-Have-I-Ether
Daniel McCurdy
Full Access Member
I mean Direct injection in general like the cummins or the vw tdi
NeverHave-I-Ether
Full Access Member
I don't believe one is better than the other, though it does seem to be more popular with the Ford IDI community vs everyone else.
Never-Have-I-Ether
Mt_Man
Full Access Member
Idi have usually have higher compression ratios(22:1) then di engines(16ish:1). I think that might be part of it. I worry glow plugs can be erroded by wmo and difficult to replace. I also wonder if the pre-combustion chamber could get coked up. Never seen it, but have read about it online. Personally I feel like di is simpler design. But I have never tried an idi only di so far.
rreegg
Full Access Member
I’ve never run wmo just biodiesel - but have an 88 IDI in a Ford and a 02 tdi alh in a vw.
The common wisdom is they’re both great engines for alternatives fuels. it seems typically folks suggest you’d want to filter to 5 microns for the tdi engine and this is probably a little more relaxed for the IDI (filter to 10 microns). Additionally people running wmo seem to often have a fuel heater to make sure the injectors can handle the oil.
I believe Direct Injection engines are a bit more efficient than IDI.
Will post more details if I can find them, good luck
The common wisdom is they’re both great engines for alternatives fuels. it seems typically folks suggest you’d want to filter to 5 microns for the tdi engine and this is probably a little more relaxed for the IDI (filter to 10 microns). Additionally people running wmo seem to often have a fuel heater to make sure the injectors can handle the oil.
I believe Direct Injection engines are a bit more efficient than IDI.
Will post more details if I can find them, good luck
rreegg
Full Access Member
Am not familiar with the aaz engine but if the alh is turbo that may be a consideration for wmo?
rreegg
Full Access Member
This could be a relevant thread for vw engines https://forums.tdiclub.com/index.php?threads/vw-diesel-running-wmo-alternative-fuels.441704/
Imho, idi is better for 'heavier' fuel. Injector fouling is less of a problem since there is one spray hole, and the pre-cup design stays hotter.
On the DI side, i believe (from my experiences) an injector tip with fewer, larger holes performs better with wmo.
On the DI side, i believe (from my experiences) an injector tip with fewer, larger holes performs better with wmo.
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Booyah45828
Full Access Member
Agreed, I feel the IDI's pintle nozzle would have less of a chance of plugging or coking from the heavy fuel then a DI's multi-hole nozzle. Only time I've seen IDI's have issues with wmo is due to lack of filtration or too much idle/low load time. Keep it clean and get it hot and it will burn well.
Jesus Freak
Full Access Member
I was going to replace my glow plugs and put them on a switch a while back, but there's no getting them out, so I just keep on starting it on ether. My 7.3 TIDI is pretty tired and due for a rebuild maybe this winter. I'll be curious to see how it looks in there. Honestly I'd be glad to do a fummins if a used 12v 5.9 didn't cost as much as a new Harley.
Mt_Man
Full Access Member
Yep the 5.9 12 valves are very desirable. They are not that much to rebuild if you find one at a junkyard or needing rebuild. It's kinda nuts.
Jesus Freak
Full Access Member
But I have an edge. I drive rural areas for FedEx ground, I know where all sorts of stuff is. Eventually I'll find one, and they won't know what they got....but they'll be glad to have it gone! One day....one day.....
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