More Bio Diesel D3 scaremongering

[Latestarter1]

Really ? How does "blowpast" allow unburned fuel into the sump ?

"Blowpast" is when the pressure caused by the exploding fuel cannot be contained by the rings and escapes into the crank cases, causing crankcase compression. At this point the fuel has already ignited, so no fuel can enter the sump.

If the fuel is getting past the rings on the compression stroke, the rings/bores must be badly worn.

How does this fuel then get passed back into the combustion chamber from the sump ?

Hey guys don't fight probably my fault, let me expain,

Remember I mentioned injection system capable of up to five different injection events over just a few degrees of crank angle.

Nox is a characteristic of high combustion temperature and advanced timing. Stand next to the bonfire on Friday with bucket of diesel throw it all on in one go and ‘whoomph’ noise and pretty much instant heat.

If I split the same quantity of fuel up into say four containers of increasing size then get four people at the bonfire party to pour fuel on to the bonfire one after another, we burn the same amount of fuel but effect is far less dramatic, no huge ‘whoomph’ and heat release although the same is slower, called injector rate shaping. Benefit is reducing the peak temperature which reduces Nox as well as noise, se we get a double whammy.

Engineers can sit down and play tunes with the rate shaping by varying the actual quantities of fuel and the timing of the individual squirts, all this for just ONE lousy bang, well not a big bang cos we have tamed it some. Trying to design a quiet diesel engine is as difficult as inventing a quiet hand grenade.

Remember the EXTRA injection event, that is only turned on if the DPF says I am choked up. We now give a tiny squirt of fuel which is too late in the injection event to burn in the cylinder, however the small amount of fuel is sufficient to initiate combustion in the DPF together with the hot gases from the fuel combusted earlier and the grunge in the filter gets burned off unblocking the DPF and when back pressure is back to normal, life is good and the extra injection event is switched off.

If for any reason the DPF becomes poisoned or blinded the extra injection event continues, as engine is unsuccessfully attempting to light up the DPF. By this time cylinders awash with fuel some of which is finding its way into the oil pan, diluting the lube and increasing the oil level. The eventual damage to the bores results in blow by from crank case ending up in DPF causing it further damage with the engine still squirting the extra fuel in a vain attempt to set the now completely wrecked particulate filter alight to clear it.

Life as we know it goes down hill from here!

 

[ulyden]

Well it tells me several things. Diesel combustion is very hard to get clean. You always get sones that is rich and sones of lean. I was reading a article about a test with having a nozzletip in a porous material. Then is was thousands of small injektors. But any how you end up in the same way. You never get good combustion as long as the nozzel holes are the same at high load and low load. To get low fuel consumption at high load you needs a fast heat release to avoid nox(and soud) at part load small nozzle holes are the best. To split up the heat release by multiple injections is a vay to get aroud, but it has its price...

http://www.mbclub.co.uk/forums/engine/77050-blue-efficiency-injector-recall.html

Anyway im glad im just dealing with IMO tier 2 and WB(World Bank). For that you don't need CR EGR or SCR. Simple reliable mechanical engines does the job.

Lots of jurnalsts are focusing on fuel injektion part in better fuel economi of diesel engines. I do not fully agree about that. This is because the fuel consumtion on a automotive diesel engine havent been redused last 20 years. Remeber the Audi 100 2.5 (1990) diesel had a spesifik fuel consumption of 197g/kwh i best point. My old car BMW M47 from 1998 have a consumtion of 202g/kwh in best point and 235g/kwh at max power. The common rail version 2001 more or less the same values. And now the latest BMW 184hp version have the same numbers.

So why are the fuel consumption better these days? Easy fixes by start/stop
lower friction, tyres with lower rollingresistance, lower final drive ratio and so on.

But if you look at real fuel consumtion and compare you see no signifikant cange.

http://www.spritmonitor.de/en/overv...ower_s=80&power_e=140&minkm=10000&powerunit=2

http://www.spritmonitor.de/en/overv...ower_s=80&power_e=140&minkm=10000&powerunit=2

This page is nice!

(http://www.spritmonitor.de/en/)

 

[DAKA]

Road going Volvo D5 engine showing Volvo sticker recommending 2/3 dipstick level.

 

[Latestarter1]

Actually this thread has a really positve spin.

What we have today fpr Tier II in terms of engine technology for example current CMD QSB and Volvo D4/6 Bosch common rail is all tried and tested robust genertion 1 common rail. The automotive technology for used Euro 5 is just still a distant fear for us.

I have read though the links posted by ulyden, among some typical anecdotal garbage there is some very well informed technical comment. The bit I like is the fact that Mercedes have moved to Delphi generation 3 common rail injectors and suffered a bundle of problems. If MB had asked, Ford they would have told them not to go there as they diched Delphi a while back and are now using Nippon Denso!

As I have said before little knowledge of Green engines, however I saw old and revised D3's this week and was astounded by the general layout of the older D3. Volvopaul please tell me the couch engineer who put a water filter on the pressure side, or a raw water pump above the alternator was sacked long ago, he/she must have HATED boat owners!

 

[volvopaul]

Actually this thread has a really positve spin.

What we have today fpr Tier II in terms of engine technology for example current CMD QSB and Volvo D4/6 Bosch common rail is all tried and tested robust genertion 1 common rail. The automotive technology for used Euro 5 is just still a distant fear for us.

I have read though the links posted by ulyden, among some typical anecdotal garbage there is some very well informed technical comment. The bit I like is the fact that Mercedes have moved to Delphi generation 3 common rail injectors and suffered a bundle of problems. If MB had asked, Ford they would have told them not to go there as they diched Delphi a while back and are now using Nippon Denso!

As I have said before little knowledge of Green engines, however I saw old and revised D3's this week and was astounded by the general layout of the older D3. Volvopaul please tell me the couch engineer who put a water filter on the pressure side, or a raw water pump above the alternator was sacked long ago, he/she must have HATED boat owners!

yes as ive said many times beore on here, the d3 is a pile of poo, ive seen that many rusty lumps now ive lost count.

And yes ive changed a few alternators too, I just laughed my socks off too when I saw the d3 water filter, its cone shaped, when you clear it out water goes all over the place including its way down to the starter motor!

 

[ontheplane]

Ok Thread drift here I know but.....

I've watched these threads for a long time, and one (and I realise that it's only one) reason oft cited for buying diesel not petrol boats was that the diesels were so much simpler....

That's clearly no longer the case - and now we've lost the low price diesel, do people think a swing back to petrol will occur.

And yes yes I know petrol boats blow up every day, and most marinas have a permanent fire engine on standby because so many catch fire and who in their right mind would sit on a bomb....

But seriously, the only reason I'd buy a small (sub 25ft) diesel is that it's hard to get petrol in marinas, but if there is a big swing back to petrol, that may change.

 

[ulyden]

Actually this thread has a really positve spin.

What we have today fpr Tier II in terms of engine technology for example current CMD QSB and Volvo D4/6 Bosch common rail is all tried and tested robust genertion 1 common rail. The automotive technology for used Euro 5 is just still a distant fear for us.

I have read though the links posted by ulyden, among some typical anecdotal garbage there is some very well informed technical comment. The bit I like is the fact that Mercedes have moved to Delphi generation 3 common rail injectors and suffered a bundle of problems. If MB had asked, Ford they would have told them not to go there as they diched Delphi a while back and are now using Nippon Denso!

Well. Some comments

The new D3 and By will have these injectors. Hopefully made by bosch and hopefully better.

Were I live there have been problems with cr nozzles. Some of them have improved due to 2 micron filtration on fuel. MTU claims an improwment from 1000h to above 3000h with this solution. All pleasure boats are using MGO. (Tax free) think this contains some small particles. Lots of D3 D4 D6 have nozzles replaced before 500h.

But it is strange that yanmar BY and Mercruiser and some larger IVECO MAN don't seem to suffer same trouble. Maybe they are more quiet in dealing with this.

Volvo claim the oil companies don't have the correct diesel for their engines and recommend exstra additives. So all volvo owners have to buy this Statoil additive.

About delphi.
My sister have a 2006? Mondeo. 50 000miles. Smoking all the time. No errors.
One period it lost power aswell . No errors when visiting the work shop.
Had to look at it. By nearly burning the cluch trying to test the turbo actuator
i discover that air was leaking. The clever guys had skipped boost sensor. Propably they only had air mass flow. When i was looking i could see rail pipe was marked delphi. After replacing a hose its better but still it gives a lot of smoke and the sound is terrible. Some nozzle have to leak. The engine is knocking. No error codes. Its their first diesel car. They think its ok. Maybe its ok maybe not, no errors. I don't know what thes new engine can take, it's more than i can take!

I have been driving diesel cars in 20years now. From mercedes 220D 60hp 300D 88(OM 616 OM 617)hp to BMW 524td/ 525td/520d 2000model. in 2007 i was going to buy a new 520d. It was a nice car until i started it. Full of vibration and strange souds from the engine. Did not go for a test drive. Ended up with a petrol car.

So untill the running behavior on modern diesel engines does not improve. I don't buy.'
It does not help that repairing is complex and tecniologi is shaky. Even if the fuel consumption is 20% higher on petrol it will take me 15 years driving to pay back the exstra cost of a diesel engine.(Only fuel cost) (Got a good offer on the petrol car) I'm driving 18000miles a year. The modern petrol engine gives me 47-52 miles pr gallon in a 3 series BMW. The old 520d up to 55- 60miles pr gallon.

So maybe when the fuel pressure is 4000bar and you have 40 injections per sycle I come back. The only modern diesel i have liked is the HONDA engine. First type. Don't know how but the sound and running behaviour was not bad. Don't know the fuel system.

I think small diesel is going to be to expensive in future. To get it clean you need particle filters and scr katalyst. On a 100hp engine this is a huge cost.

I think otto engines have a future in boats and in cars. Where i live some ferries are running with big spark ignited otto engines.(15 000 hp)
25 000h in 4years. The emissions reduction correspond to emissions from 250 000 cars running 10 000 miles a year. Operating cost is low and the engines have a higher efficiency then diesels engines. Now ther are more ferryes are comming with otto engines. Fuel: Natural gas.

 

[Latestarter1]

Were I live there have been problems with cr nozzles. Some of them have improved due to 2 micron filtration on fuel. MTU claims an improwment from 1000h to above 3000h with this solution. All pleasure boats are using MGO. (Tax free) think this contains some small particles. Lots of D3 D4 D6 have nozzles replaced before 500h.

But it is strange that yanmar BY and Mercruiser and some larger IVECO MAN don't seem to suffer same trouble. Maybe they are more quiet in dealing with this.

Volvo claim the oil companies don't have the correct diesel for their engines and recommend exstra additives. So all volvo owners have to buy this Statoil additive.

500hr injector life is quite simply dirty fuel, not an additive issue. Why do BMW CMD IVECO and MAN generally not see injector issues, they use a rigid spec pre-filter.

For example CMD spec for last chance filter for the QSB's, QSC's and QSL's on-engine fuel filter is 2 mic high performance coalesing media with 19 grams of dirt holding capacity, .95" Hg pressure drop/100 GPM clean with a 203PSI burst pressure rating. To the non technical this is a gatekeeper that doesn't let much past it!

But it needs to be supplied with a specific quality of pre-filtered fuel. And I STILL hear of technicians pre-filling filters with fuel before installation and I have seen this practice openly discussed by owners doing DIY servicing on a motor home forum, fearing that the system will fail to prime. You MUST let the pre-filtered fuel from your off-engine fuel system do that for you through the priming mechanism built in the engine.

Reported on this forum that some Scandinavian builders are not even following Volvo minimum filter requirements.

I am looking at a forum members fuel system to do a fit for purpose set up for a Volvo D series right now. Is there a published technical spec for the Volvo fuel filter 3583443? The answer when I asked at the front door was sorry 'commercial in confidence'. I expect somebody who has been on a course has the filter spec. However I will eventually get the data by going in through the US where manufacturers are obliged to divulge such infomation.

Clean, clean, clean, equals zero issues.