awaken dieselers...

[smithy010]

I dunno what it's like up in newy, but down here.. (UNSW), we would have so little time on the dyno (if we could even access) it, that a project like that would be impossible to get done in time.

I guess there is something to be said about smaller universities. Everyone out there, if you have a choice of unis to go to for engineering and you are torn between small and local, and the 'big name', i'd go for small any day. Speaking from the experience of a big university.

Aydan, will you be dropping the comp ratio to turbo it? or will you just pump what you can into it? I'm glad you found a way to turn diesels into a thesis project! i sorta stayed away from the thought because the lab is a **** to get into, and engine dynamics has too much thermo involved... I hate thermo.

Smithy

[gldgti]

" i hate thermo..." hahahaha, amen. thermo courses are hard, but i guess totally necessary!

if i drop compression ratio it will be only for the purposes of increasing the efficiency, which, stated by VW engineers, is maximised at about 18.5:1 with the VW indirect injection engine. (it is higher for ease of starting purposes). otherwise, i will be using high compression. this may also depend on my research for the best overall compression ratio depending on fuel type, should this have an effect...

cheers

aydan

[smithy010]

I did one of my thermo courses twice and got a concessional pass in another- that's how bad i am at thermo.... (i'm normally a ~65-70 student)

[gldgti]

head off

ok, so i spent the morning making up a locking plate, locking pin and pulling off the head.

it appears the oil way that takes oil up to the top has leaked badly through the broken rubber seal in the head gasket around this point (this is the one where the head bolt goes through.)



so far this is the only cause for failure i can find.

the bores are a bit rusty from coolant i guess, but it should be ok. there is a LOT of crap encrusted on the pistons/head/valves... more than i've ever seen in a vw diesel, including carbon, oily residues, strange coolant/oil burnt things etc.




the pistons appear unmarred by valves which is nice. there was a 4 notch head gasket on it, im thinking i might rebuild it with a 5 notch but my dads own special torquing sequence and torques.

given the extreme buildup of crap, i will likely dissemble/clean the entire engine/head.

there dont appear to be cracks between the valve seats, a rare thing, and also the valves appear to seat well.



so, it will be a full dissembly and clean, tolerance check and reassembly.

[gldgti]

the head, afer 4 or 5 sprayings with degreaser and rag wiping...

[gldgti]

apologies for the burryness...

[brackie]

Piston and head condition

The destroyed oilway seal on the head gasket is common. More commonly the large, circular drain hole at the front of the head lets oil into the coolant and this can have disastrous results. Pitting in the pistons is also common and usually results from over advanced start of injection timing. Direct injection diesels are more prone to this problem and I can remember when I was a young bloke having a BMC diesel that blew sparks of molten aluminium down the exhaust when the injection pump bolts worked loose causing the timing to slip. The head face especially around the valve seats is in remarkably good condition. As for putting in a 5 notch gasket instead of a 4 notch this will slightly decrease the compression ratio so you will need to adjust the injection timing accordingly.

Makes me want to get my hands dirty

[Edison]

apologies for the burryness...

I can still recognise my little engine, from the injector tubing 8-) my goodness it looks different all clean though, I never knew there was metal under all of that gunk, I wonder if the my other diesel engine is made of metal too (?)

Brackie, this one had a little oil in the water all it's life with me, and the previous owner also, it was such a slow leak it wasn't worth fixing. The head gasket failed recently though guys, the coolant would build up huge pressure after a downhill rollstart, so gas was getting past the gasket into the coolant methinks...

the bores are a bit rusty from coolant i guess, but it should be ok. there is a LOT of crap encrusted on the pistons/head/valves... more than i've ever seen in a vw diesel, including carbon, oily residues, strange coolant/oil burnt things etc.

It had the headbolts removed but the exaust manifold wouldn't come off for me, so It had sat on the roadside for a month or two with the head open, but not enough to see, the coolant that had leaked in would have exidised the bores/heads..

Other crap would include virgin cooking oil residues like canola and peanut, not a great sucess I'd say, I'm looking to clarify the oils first now. I need to find someone in driving distance who makes biodiesel and copy what they do., and make a small refinery too.

Makes me want to get my hands dirty

I'm enjoying this all immensely precisely because I don't get dirty from this distance 8-)
(maybe he can send you some grease in an envelope, good quality stuff from the cylinder heads)

[gldgti]

well, i fully dissembled the head on the weekend to find no apparent faults. its been fully degreased and awaits some more time from me to cleam up the valves and reassemble. bottom end is next.

on the project side, im trying to get together a test rig with variable speed drive for the injector pump run by an electric motor. the pump will be connected to a single injector, the other lines simply returning to the fuel supply. the injector will be mounted within a perspex chamber with an evacuation setup to catch diesel vapour and the nozzle sray will be watched by a high speed camera, so i can monitor visually what the injector is doing at various RPM.

the aim is to identify any problems with the spray pattern that may be caused by the pump at higher rpm and trace this to some part of the pump i can modify.

[brackie]

Advancement on the "old days"

In days gone by we had a Hartridge machine to check spray patterns and breaking pressures and a full mechanical test bench to test pumps. Your high speed camera idea should let you see just exactly what's happening but I reckon only at low revs. Once they rise all you'll see is a mist and it'll obscure the injector. Keep us informed... this is interesting stuff

[Edison]

well, i fully dissembled the head on the weekend to find no apparent faults. its been fully degreased and awaits some more time from me to cleam up the valves and reassemble. bottom end is next.

on the project side, im trying to get together a test rig with variable speed drive for the injector pump run by an electric motor. the pump will be connected to a single injector, the other lines simply returning to the fuel supply. the injector will be mounted within a perspex chamber with an evacuation setup to catch diesel vapour and the nozzle sray will be watched by a high speed camera, so i can monitor visually what the injector is doing at various RPM.

Crikey! and I thought I was loonie! 8-) cool stuff, so just testing to see what the power output difference between petro and blood free biodiesel looks rather simple now, is that something you'll do?
Also I'd love to know, but don't think you can risk, trying striaght canola and straight peanut oil can you? to see what it does to power ? although they aren't practical oils for fuel I am guessing because of the gunk you found inside from when I ran it that way..

[gldgti]

Crikey! and I thought I was loonie! 8-) cool stuff, so just testing to see what the power output difference between petro and blood free biodiesel looks rather simple now, is that something you'll do?
Also I'd love to know, but don't think you can risk, trying striaght canola and straight peanut oil can you? to see what it does to power ? although they aren't practical oils for fuel I am guessing because of the gunk you found inside from when I ran it that way..

i dont know if i want to really, just because of the amazing amount of crud that was in there....

i also pulled apart the injectors to find masses of carbon clogging up everyting....so im weary of SVO apart from maybe pre-heated.