1982 Volvo 244 D6 with 2383ccm diesel engine

[houseofdiesel]

I love the sound of those old inline 6's, like a mini transport truck! Consider upgrading your injector nozzles to the 1.9d size or GTD ones, I have found a larger injector helps overall. Replace your rear diff with the lowest number possible (I am far removed from Volvos and don't remember the lowest one anymore), the lower the rpm the better. For sure remove the engine driven fan and add an electric one or install a relay and use the a/c fan if strong enough. Play with your injection pump timing, if the factory spec is 0.95mm lift try 1.05mm, if that works try 1.1 or 1.15mm the more advance the more mpg to a point, then the engine gets noisy you will develop an "ear" for it overtime, and pumps wear a bit internally too it helps compensate. If your oil consumption is that high try a thicker synthetic like 20w50, the thicker the oil the less it will burn. On some I have even added Lucas oil stabilizer (very thick goey stuff) it does reduce consumption on really tired diesels. Cetane booster/fuel conditioners/two stroke oil mix all help a small amount to keep things lubricated and don't hurt mpg, although being in europe you have quality fuel to begin with. Consider a ram air set up to get air into the engine, I am no specialist to that effect but for sure it will help just not sure if you want cowl induction, a big ugly hood scoop or just duct work from the front grill. Go with skinny tires and low rolling resistance compounds. Remove your exhaust-straight pipe all the way, seriously there could be 10kg of soot trapped in your exhaust pull it and try no muffler, if you cannot live with the sound get a free flowing muffler only nothing more. I loved the sound of my 1.6 D jetta with no muffler, it was loud but not loudest on the road nor droaning on the highway, it was straight all the way out back.
I did these things to a 1987 Jetta non turbo diesel, top speed went from 125km/h to 160, fuel range went from 900 to 1400kms on 55L it was great until the drivers seat fell out at 450000kms. I did not have to drive terrible slow to get great range either, 120km/h would result in 1250kms to a tank, slow down to 95 and get 1400.
The basics are let the engine breath both in and out, tune it well (timing and nozzles), lower the rpms, free up the demands (fan, tires etc)

[mechman600]

+1 on timing. Advancing the timing a bit can do wonders for a diesel. JUST DON'T GO TOO FAR. If you hear crackling, you've gone too far, and holes in pistons are being made.

[houseofdiesel]

Also adjust the vavles, forgot about the old mechanical lifters. They use flat shims so be sure to source a bunch before tackling it.
The timing by ear is very evident, you will hear when your timing is set to far but if you adjust it in stages of 0.05mm it will not blow up the engine/mass destruction right away, holes in pistons occur when something is really wrong and more with the direct injection/high pressure diesels.

[Doni_99]

Houseofdiesel, Mechman600,

Thanks for your advice. They contain a lot of new and useful information for me.
But I have a lot of question, too.
At the moment I have no time, but I hope I will be able to write about 7 hour later

Better mpg!
Doni_99

[Doni_99]

Originally Posted by houseofdiesel

... Remove your exhaust-straight pipe all the way, seriously there could be 10kg of soot trapped in your exhaust pull it and try no muffler, if you cannot live with the sound get a free flowing muffler only nothing more. I loved the sound of my 1.6 D jetta with no muffler, it was loud but not loudest on the road nor droaning on the highway, it was straight all the way out back.
I did these things to a 1987 Jetta non turbo diesel, top speed went from 125km/h to 160, fuel range went from 900 to 1400kms on 55L it was great until the drivers seat fell out at 450000kms. I did not have to drive terrible slow to get great range either, 120km/h would result in 1250kms to a tank, slow down to 95 and get 1400.
The basics are let the engine breath both in and out, tune it well (timing and nozzles), lower the rpms, free up the demands (fan, tires etc)

This result's amazed me. So did you remove the whole exhaust system?
Where was the end of the pipe? Just behind the engine?
Perhaps the free flowing muffler will be the right solution for me because of the expected rise of noise. It would not disturbe me, but my wife and maybe policemen...
Is the free flowing muffler equal with a straight pipe? I must look after it.

Intake. I tried direct filter, but I felt no change in fc.

Diff: Currently I use diff with a 3,73 ratio. The "longest" is 3,31. It is very rare in Hungary, but I hunt for one.
There is another solution to drop rmp: one of my friend plans to make a 5+OD transmission.

Thanks once more!
Doni_99

[Doni_99]

Originally Posted by houseofdiesel

Also adjust the vavles, forgot about the old mechanical lifters. They use flat shims so be sure to source a bunch before tackling it.
The timing by ear is very evident, you will hear when your timing is set to far but if you adjust it in stages of 0.05mm it will not blow up the engine/mass destruction right away, holes in pistons occur when something is really wrong and more with the direct injection/high pressure diesels.

Sorry but for first reading it is 'Japanese for me'

[Doni_99]

Originally Posted by houseofdiesel

... Consider upgrading your injector nozzles to the 1.9d size or GTD ones, I have found a larger injector helps overall. ...

So will the changing of the nozzles for 1.9d size improve my mpg? What kind of nozzles? SDI (68PS) or TDI ones (90, 105, 110, 130PS) or rather GTD ones?
My main aim is the fuel consumption reduction, I'm looking for the best soulition with no demand for more power
What would be your choice?

Doni_99

[Doni_99]

Originally Posted by mechman600

+1 on timing. Advancing the timing a bit can do wonders for a diesel. JUST DON'T GO TOO FAR. If you hear crackling, you've gone too far, and holes in pistons are being made.

+1 on timing??
How did you mean it? 1mm instead of the factory 0,95mm?

[Doni_99]

Last weekend I made modifications on the the car for improved cw figure:

http://kepfeltoltes.hu/120502/SAM_00...toltes.hu_.jpg

http://kepfeltoltes.hu/120502/SAM_00...toltes.hu_.jpg

And my PCV jar:
http://kepfeltoltes.hu/120502/SAM_00...toltes.hu_.jpg

[Doni_99]

Originally Posted by euromodder

Thanks
I thought I had replied earlier but ... can't find the reply.


All I can say : I'm stunned
Even the 5.2 L/100km (45mpg US) is still very good.
....

Thanks, Euromodder!

But Jtbo might have said the reason for the extreme 4,6L figure. The main part of the reduction must have come from the foaming rate of the diesel fuel.
Honestly it came up my mind earlier, but I thought when I start the certain cca 270km long trip I filled the tank. It was almoust empty. I had clicked with the fuel pistol about 4-5 times before I stopped filling it. When I completed the trip I filled it again, but there was much smaller room for foaming (I could put less then 15 litre diesel into it.
In a nutshell: The measuring wasn't accurate.

Other thing: I tried to change (or boost?) the brick shape of my car. Just look at my pictures in my previous comment.

Best mpg!
Doni_99