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considering they're already based on diesel blocks but have lower compression ratios, then lower internal pressures, would them have a better durability?

i prefer to handle diesel than cng, and if i could avoid spark plugs i would, so i'm not against diesels, was just thinking about those gas engines...
 

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What is the compression ratio of these engines
 

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There are some natural gases that can run safely as a dual-fuel in a compression ignition diesel. MAN have a specification based on pressure. If you can compress the gas to x bars and no condensate forms then you're safe. I can't remember what X bars was but a bit of internet searching will reveal it.

All gases outside that spec (including propane and LPG) require a lower compression spark ignition engine.
 

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My understanding on the Westport engines is that they use the diesel injection for the ignition of the CNG. No giant spark plugs on this diesel engine! Quite a novel Idea in my opinion. Other than needing two fuel tanks. Emissions wise there is virtually no soot and fuel comsumption according to the website is = to straight diesel at a fraction of the price.... Hi hopes for this engine/company, but it will never sound like a 53 series detroit!!!
 

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My understanding on the Westport engines is that they use the diesel injection for the ignition of the CNG. No giant spark plugs on this diesel engine! Quite a novel Idea in my opinion. Other than needing two fuel tanks. Emissions wise there is virtually no soot and fuel comsumption according to the website is = to straight diesel at a fraction of the price.... Hi hopes for this engine/company, but it will never sound like a 53 series detroit!!!
Westport engines are spark ignition.
 

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Discussion Starter #6
My understanding on the Westport engines is that they use the diesel injection for the ignition of the CNG. No giant spark plugs on this diesel engine! Quite a novel Idea in my opinion. Other than needing two fuel tanks.
gm uses this system in the thai version of the colorado... but due to the bed-mounted cng cylinders it sacrifices cargo space, while its spark-ignited opponents have only cng cylinders assembled where a tank would be... but with the colorado running out of cng would still allow it to run as a regular diesel rig...
 

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they don't get nearly the fuel mileage of a diesel and are plagued with fuel system problems
 

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gm uses this system in the thai version of the colorado... but due to the bed-mounted cng cylinders it sacrifices cargo space, while its spark-ignited opponents have only cng cylinders assembled where a tank would be... but with the colorado running out of cng would still allow it to run as a regular diesel rig...
I can't find anything on the colorado. But I did find this Thai CNG ELF (NPR).
http://www.isuzu-tis.com/2011/catalog/truck/ELF-CNG.pdf

The engine is the 4HV1, Converting a PDF to text for a translation takes some time.
I found this Australian version:
http://s3.neisuzu.com.au.s3-ap-southeast-1.amazonaws.com/2010/10/08/NLR 200 CNG-0271bd8b.pdf

It talks about spark plug ignition.
 

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gm uses this system in the thai version of the colorado... but due to the bed-mounted cng cylinders it sacrifices cargo space, while its spark-ignited opponents have only cng cylinders assembled where a tank would be... but with the colorado running out of cng would still allow it to run as a regular diesel rig...
I can't find anything on the colorado. But I did find this Thai CNG ELF (NPR).
http://www.isuzu-tis.com/2011/catalog/truck/ELF-CNG.pdf

The engine is the 4HV1, Converting a PDF to text for a translation takes some time.
I found this Australian version:
http://s3.neisuzu.com.au.s3-ap-southeast-1.amazonaws.com/2010/10/08/NLR 200 CNG-0271bd8b.pdf

It talks about spark plug ignition.
 

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Westport engine clarification

My understanding on the Westport engines is that they use the diesel injection for the ignition of the CNG. No giant spark plugs on this diesel engine! Quite a novel Idea in my opinion. Other than needing two fuel tanks. Emissions wise there is virtually no soot and fuel comsumption according to the website is = to straight diesel at a fraction of the price.... Hi hopes for this engine/company, but it will never sound like a 53 series detroit!!!


OK Looks like I need to clarify. Wesport has many engines in it's line up. You are correct, Most of them are traditional spark ignition.

The Westport/cummins engines I was refering to is the 15 L truck engine. Obviously too big for a "swap" but very cool technology.

Go to the westport website and find the link ==> http://www.westport-hd.com/technology [link fixed by moderator]
 

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Discussion Starter #11
I can't find anything on the colorado. But I did find this Thai CNG ELF (NPR).
http://www.isuzu-tis.com/2011/catalog/truck/ELF-CNG.pdf

The engine is the 4HV1, Converting a PDF to text for a translation takes some time.
I found this Australian version:
http://s3.neisuzu.com.au.s3-ap-southeast-1.amazonaws.com/2010/10/08/NLR 200 CNG-0271bd8b.pdf

seems to be the same vehicle... as for the pictures, there are no diesel tanks on the thai market one...

It talks about spark plug ignition.
seems to be the same vehicle, and fitted with spark-plug ignition... the system used in the colorado, called "green box" due to the extra cng tanks on the pickup bed, was not so successful and then phased out - i wouldn't expect it to come back in the 2013 colorado, if it even offer a dedicated cng version it will probably have the cng tanks under the bed like the tata xenon...
 

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We have 15 of these Westport engines in a fleet that we service as we are the only dealer for LNG/CNG Westport in our Petes. They are 15 L Cummins based engine. Running a CM870 block and modified head, CM871 turbo and CM2250 control system. Yeah, three generation into one. The start on diesel and once they warm up, switch to natural gas. Use an additional hydraulic pump to compress the gas to high pressure for injection. Up north here, they do not fair so well. They hate the cold. Injector issues, harness issues and valving issues. Also, can sealing one of these trucks up is like sealing up a old 2 stroke detroit. Not so easy to do and constant. The fuel efficiency is better but not grand from what we have had feed back about. Can use for long hauling either. Fuel tank capacity is limited due to the size of the tanks compared to the amount they actually hold. Anything colder than 0 degrees C they usually are town in.
 

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We have 15 of these Westport engines in a fleet that we service as we are the only dealer for LNG/CNG Westport in our Petes. They are 15 L Cummins based engine. Running a CM870 block and modified head, CM871 turbo and CM2250 control system. Yeah, three generation into one. The start on diesel and once they warm up, switch to natural gas. Use an additional hydraulic pump to compress the gas to high pressure for injection. Up north here, they do not fair so well. They hate the cold. Injector issues, harness issues and valving issues. Also, can sealing one of these trucks up is like sealing up a old 2 stroke detroit. Not so easy to do and constant. The fuel efficiency is better but not grand from what we have had feed back about. Can use for long hauling either. Fuel tank capacity is limited due to the size of the tanks compared to the amount they actually hold. Anything colder than 0 degrees C they usually are town in.
The westport 15L engines are actually LNG not CNG, they run approximately 5% diesel and 95% LNG, the diesel is injected to provide a controlled ignition source for the gas. Also, the timing chamber in the injector uses diesel so instead of having a timing, return and metering diesel fuel rifles, you have timing and return diesel rails and the lower rifle is pressurised LNG. Down here they have to use cryogenic rated tanks so it doesn't boil off too fast.

I know that they won't run properly without LNG, because I worked on them a bit in the KW plant here. With diesel in the tank but no gas in the gas tanks, the engine won't rev past 1200 RPM- even at while stationary.

I can't speak much for their reliability, as I haven't done much with them on the service side, but I know they were a dead set bitch to dyno test, even when they were running properly.
 

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The westport 15L engines are actually LNG not CNG, they run approximately 5% diesel and 95% LNG, the diesel is injected to provide a controlled ignition source for the gas. Also, the timing chamber in the injector uses diesel so instead of having a timing, return and metering diesel fuel rifles, you have timing and return diesel rails and the lower rifle is pressurised LNG. Down here they have to use cryogenic rated tanks so it doesn't boil off too fast.

I know that they won't run properly without LNG, because I worked on them a bit in the KW plant here. With diesel in the tank but no gas in the gas tanks, the engine won't rev past 1200 RPM- even at while stationary.

I can't speak much for their reliability, as I haven't done much with them on the service side, but I know they were a dead set bitch to dyno test, even when they were running properly.

Sorry for the misleading info then. This is the understanding I have on them from what I have be told from our LNG techs. I get some more info exactly from one of their engineers. They are stationed at our dealer at the moment. We run the same tanks, as well. Also, yes these are 15L engines. They are Westport coverted engines using the Cummins based engine.

I stay away from working on these because of the consistent issues and how irritating they are to work on. I would like some more training on them but havent had the chance between all the other engine training yet.
 
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