I am considering doing a CNG conversion for my 5.3L 2004 Silverado, and was thinking if it worked out I'd drop in a 6.0L engine to make up for some of the lost power, maybe increase the compression ratio a bit as well.

Anyway, I was looking online (Used Auto Parts - Car Parts - Truck Parts - Body Parts - Engines - Wheels - Bumpers - Lights) at engines available from junk yards, and noticed there are actually some 2004 Silverado 1500 6.0L CNG engines up.

Does anyone know of that may have come from the factory, or if someone converted it after the fact? In anycase, the price of the engine is similar to the conversion - and was probably done professionally - so this is interesting.

Wonder how hard a swap would be... my understanding is a 5.3L to 6.0L swap is not too challenging, wonder what the added complications of 5.3L gasoline to 6.0L CNG swap would be....

Thoughts?

[URL="http://www.automotix.net/usedengines/2004-chevrolet-silverado_1500-inventory.html?fit_notes=d6a94fcd1eb8186b382f79fcc ce35aaf&seq_num=8"]

 

The 6.0L Vortec V8 CNG engine had a few enhancements for use with gaseous fuels, and as such were equipped with factory-installed hardened exhaust valves and intake/exhaust valve seats to resist wear from higher temperatures and the corrosive nature of propane and natural gas. They also had a dedicated fuel injection and engine control module. The LC8 was rated at 323hp @ 4600rpm / 373ft-lbs @ 4400rpm as installed in the vans.

 

Thanks for the info! I've been looking around since I made this post, and did find a few vehicles for sale... it appears they're CNG only and not bi-fuel which sucks... I need the bifuel capability so probably will go with the conversion.

I'm not sure where to start with trying to determine the correct compression ratio... but here are my thoughts, CNG is around 130 octane, so I could increase my performance and efficiency by increasing the compression ratio, however, since I want it to still be able to run on pump gas.. what is the highest compression ratio recommended for good drivability on premium pump gas on a 6.0L?

The other thought was adding some type of boost to the system...

hmm....

 

Im looking into this for my 2002 HD as well.

When it comes to 130 octane, compression is whatever the hell you want it to be.
If you can get the compression to 16:1, keep the factory timing and use that fuel, you'd have shitloads of torque and horsepower out the *** and not detonate.

As a "safety" thing, (you'll hear contradictions) I would shoot for 14:1, which would only be possible if you used a milled down 862/243/706 head with a flat top LQ9 piston. It would run beautifully and have MORE power than a gasoline counterpart. It will also run much longer. You will have to spend some money on good valves and valve seats, as the fuel is corrosive, and those engines require different bearings in the bottom end (or so I've heard).

Trying to find a factory HD truck with the cng stuff so I can convert (easiest way I would guess) while also raising the hell out of the compression, putting on headers, ported heads ect. You could have a 500hp CNG truck that gets the same gas mileage you get now, but cng is half the price of gasoline.

 

That would be pretty sweet, but I am going to keep it a bi-fuel vehicle - so I have to go with whatever will still run on premium.

BTW: I'm in Fort Worth, we're not too far apart. There is a station near here where CNG is $2.45 and has a 3600 PSI hookup. But, just across the border in OK it's 1.29. More trips to winstar I guess! haha

Check Canada, $0.50 - $0.75 per gallon. Can you imagine?

 

Try that price as per liter, not gallon. We have been using the metric system since the late seventies you know, lol. So if you convert a mean price of 70 cents a liter to your gallon we are about $2.65. In Edmonton right now it's 75 cents a liter, so $2.84 a gallon.

Canada is not the magical land of cheap CNG...... You are, lol

Cool project and I remember reading a lot about it years back. That said it's completely impractical for someone like me with the utter lack of fueling stations.

But hey, those dirty oil companies pay my gas bill anyhow, so why would I care, lol. They raise prices, I raise charge out. Simple.

 

ha! omg, I can't believe I made that mistake. I used to live near the border and have been to and driven in Canada many times. wow.

But hey I can still be jealous of Oklahoma, right?

 

Yes you can, as can I. Premium gas here is $4.76 a gallon whereas the average in Oklahoma is $3.62 a gallon. Bah. Oh and for insult Alberta's gas prices are the cheapest in Canada..... If you take Toronto as an example their average premium gas price for the area is $4.99 a gallon.....