Heads Up on Diesel Gas Conversions

Submitted: Saturday, Aug 19, 2006 at 15:12

ThreadID: 36912 Views:4906 Replies:6 FollowUps:10

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_gmd_pps

Guys,

just my opinion after researching my options and the future life of my new engine. I am getting a new truck and intend to drive it for a long time. Towing and high ambient temperatures are an issue for diesel engines.

EGRs, Cats and gas conversion play a role in increasing exhaust temperatures. High exhaust temperatures kill engines .. many examples .. just recently here the story with the Nissans 3.0 .. it is related to that problem.

So only a heads up, you make your own decision:

Get a EGT Gauge. At least you can see after a hot run when you need to run
the engine in idle before shutting off. Or you can see when to slow down in 50 Degrees heat towing your 24' trailer.

Additional things one can do against high exhaust temperatures:

Larger exhaust pipes or true dual exhausts with twin turbos.
Block EGR
Remove Cat

All above measures will affect your warranty, if you are worried about it.
And thats the tradeoff .. by the time you are out of warranty your engine
might already have suffered quite a bit ...

so suggestion one might be an option ...

there are also timers which run the engine in idle until a certain cut off
EGT is reached and then the engine switches off ... this is already common
in diesel trucks and delivery vans ...

Also I have read that some intend to convert to Diesel Gas with reasonably small tanks. Just think about it how much Gas you need and how much Diesel .. a small Gas tank is not worth the hasel and risking high EGT because in the country supply is limited anyway and when you go long distance you burn more gas than diesel. Whats the point ?

ok as I said .. just a heads up .. I do not advocate a specific position ..
it's your call in the end ...

No there are people telling me that LPG will run cooler but I just have not seen
any evidence ... anybody here has researched that and may have a curve of
EGT over %of LPG burnt ?

have fun
gmd

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Reply By: Member - andrew B (Kununurra) - Saturday, Aug 19, 2006 at 15:24

Saturday, Aug 19, 2006 at 15:24

The small gas tank is adequate as you generally only blend about 30% lpg with the diesel. The converters claim a lower EGT than straight Diesel as less unburnt diesel makes it out the valves. I'm sure I have read figures of a lower EGT under tests for this.

LPG fumigation, as I understand it, Will cool the EGT in the 30% or less blend due to this. I have also read somewhere that in some circumstances you gan get a lot more power if you wind up the LPG %, but at a point somewhere above 30% the curve goes the other way, and damage/accelerated wear occurs. I think truck racers do this, they don't want 500,000km from their engines, they want to win.

It will be interesting to find out some results in a few years time on the new generation of LPG fumigation, the long term info I have found is mixed, but from fairly crude systems.

Cheers Andrew

AnswerID: 189780

Follow Up By: _gmd_pps - Saturday, Aug 19, 2006 at 15:58

Saturday, Aug 19, 2006 at 15:58

Adrew,

the mixture is the key I guess here ... I have heard different stories about the mix
mix is load dependent and can go as high as 60% or more .. maybe thats just
theory ...

"from the dieselgas website"
Engine operating temperatures are not increased by running this system. Exhaust gas temperatures are reduced, since there is no longer fuel being burnt in the exhaust system. quote end ...

they don't say anything about the mixture .. and I have not seen any graphs
of EGT vs percentage of LPG at different loads ...

well .. will keep looking ...
thanks for answering
gmd

FollowupID: 447261

Follow Up By: _gmd_pps - Saturday, Aug 19, 2006 at 16:04

Saturday, Aug 19, 2006 at 16:04

well they say one thing .. 1l of LPG every 25-30KM
so thats 3.5 -4 every 100 .. that sounds much less 30% to me or maybe just
probably thats the reason they can claim lower EGT ...
I was always under the impression that the LPG % is much higher

I am really interested in some people here giving us real life results ...

gmd

FollowupID: 447262

Reply By: jaksun - Saturday, Aug 19, 2006 at 16:58

Saturday, Aug 19, 2006 at 16:58

Is there anywhere in Ballarat that does LPG Diesel thingy
Jaksun

AnswerID: 189786

Reply By: phil - Saturday, Aug 19, 2006 at 16:59

Saturday, Aug 19, 2006 at 16:59

Quote:
"Larger exhaust pipes or true dual exhausts with twin turbos.
Block EGR
Remove Cat

All above measures will affect your warranty"

And also can make the vehicle unroadworthy with implications for insurance etc.

Phil

AnswerID: 189787

Follow Up By: Exploder - Saturday, Aug 19, 2006 at 17:32

Saturday, Aug 19, 2006 at 17:32

Block EGR
Remove Cat

And lighten you wallet substantially if your caught. LOL

FollowupID: 447270

Reply By: PK Eildon (VIC) - Saturday, Aug 19, 2006 at 20:36

Saturday, Aug 19, 2006 at 20:36

I have a diesel/gas 4.2 Turbo I/C Patrol. Just returned tonight from trip up to Yowah then across Simpson to Alice to Coober Pedy and home over 3 week period. As expected gas not available all the way, but most of it. Haven't worked out consumption figures as yet. As far a EGT, I have pyro in front of turbo. Possibly a marginal drop on gas (You can turn it on/off at will) but near impossible to measure in real life as you would need same running conditions over a reasonable distance. My impression is a marginal decrease (maybe 25 degrees). Certainly does not increase it. Mine was running most of ther trip 400 - 550 @ 110kph, dependant on ambient temperatures.

AnswerID: 189822

Follow Up By: _gmd_pps - Saturday, Aug 19, 2006 at 21:17

Saturday, Aug 19, 2006 at 21:17

Great info thanks ...
I am not so much interested in the fuel consumption side of things.. thats nice but not essential .. cleaner burn (because my EGR will be blocked no matter what some say), and keeping the EGT at bay because mine runs much higher than 550 ...
so no increase in EGT is good news .. but you were not towing hard ? well not at 110kph :)) ... maybe you were :)) .. the engine of my truck is prone to EGR Valve/Filter problems and I don't need that ... Do you still do the same oil change intervals with the gas ? or do you extend a little now ?
thanks for posting that
gmd

FollowupID: 447305

Follow Up By: PK Eildon (VIC) - Saturday, Aug 19, 2006 at 22:06

Saturday, Aug 19, 2006 at 22:06

No, not towing, but certainly heavy. Oil takes longer to go dark black, but I still keep same oil change interval, and I think diesel/gas recommend no change.
As I understand it, gas injected is 0% at idle and up to 30% under load, so soot & carbon are less under load but the same at idle. Dependant on engine load 180l diesel = c. 50l gas. Does vary a bit. I imagine heavy towing may increase gas use.

You may find the extra 20%hp, extra 20% torque and torque starting 600 rpm or so lower allows the motor to operate easier without having to keep accelerator to the floor. One of the biggest things to notice is that your foot is a lot lighter on accelerator with gas.

FollowupID: 447314

Follow Up By: Member - Jeff H (QLD) - Saturday, Aug 19, 2006 at 22:28

Saturday, Aug 19, 2006 at 22:28

G'day PKE,
. Endorse your choice of vehicle (Nissan over Golden Tonsils' playthings; I'm happy with my third (diesel) Rodeo, so really should sit; stay.
. You mentioned 110 kph: while I realise that excludes the Simson, (where we averaged maybe around 30 kph), may I ask , what was your fuel consumption?
At 110kph, we use around 12l per 100km. Stay around 90kph, and we 10.
. The old 2.8L rodeo returned 8.7 over 280,000 km (no towing).
. At the edge of campfires(especially those written to this forum from a heated room) I've heard of some wonderful fuel consumption figures: so tell me, have I really bought a tiny, thin Oil Eater in disguise?
. Cheers mate,
. Jeff.

FollowupID: 447319

Follow Up By: PK Eildon (VIC) - Monday, Aug 21, 2006 at 00:24

Monday, Aug 21, 2006 at 00:24

GDay Jeff

Nothing wrong with a Rodeo IMHO. Horses for courses, depends what you are looking for.

Nearest I can work out on 6000km round trip is 17/100 (diesel/gas included as litres). Sure that could be shaved with economy driving. I certainly didn't drive to that. Didn't get gas all the way round but 21% gas use overall.

FollowupID: 447570

Reply By: Jimbo - Saturday, Aug 19, 2006 at 21:20

Saturday, Aug 19, 2006 at 21:20

I suppose it poses the question;

Will your "RV" run better with the LPG?

AnswerID: 189830

Follow Up By: BILL from Fitch Fuel Catalyst Australia Pty Ltd - Saturday, Aug 19, 2006 at 22:55

Saturday, Aug 19, 2006 at 22:55

Guys==You are ALL too sceptical to to believe real live results,and I suppose 2,000 vehicle owners are just dreaming that they drive up to 100klms further on each tank of fuel be it petrol-gas or diesel.Wake up SCEPTICS and save.

Regards BILLS

FollowupID: 447325

Follow Up By: Eddy - Sunday, Aug 20, 2006 at 19:28

Sunday, Aug 20, 2006 at 19:28

BILLS.

I fully realise you are now a protected species as a forum advertiser.
Hijacking threads in your own commercial interests still does not sit well with me.
Sensible input however is always highly regarded on this forum

Eddy

FollowupID: 447426

Reply By: TerraFirma - Monday, Aug 21, 2006 at 16:44

Monday, Aug 21, 2006 at 16:44

On the subject of Diesel Gas , fascinating, how does the $2000 grant come into play here..? Can you qualify with a Diesel Gas installation for the grant..? Diesel Gas, Biodiesel, alternative fuels etc etc etc, which bandwagon do you jump on.?

AnswerID: 190068