Crazy conversion idea.

[karlhafen]

I have noticed that most dedicated CNG vehicles (honda excepted) use engine electronics very similar to thier gasoline counterparts.

Could one do a conversion by installing generic cng stuff (tank, lines ,regulator, ect) then install cng injectors (either using a factory cng fuel rail or modifying the gasoline rail.) and run it all with a factory pcm either by installing a cng pcm or reprogramming the gasoline pcm with the calibration from a cng vehicle?

Would the end result be epa legal? (assuming you were using the injectors and pcm calibration from the same engine family).

I do not have any particular model in mind. I'm just thinking.


Post moved to conversions by forum staff.

[Lakewood90712]

Re: Crazy conversion idea.

Not crazy at all, but costly.

Most oem dedicated engines also have a different cam, different pistons for higher compression, and somtimes different heads/valves and catalists.

Time for the engineers and wrenches to chime in here.

[cnghal]

Re: Crazy conversion idea.

Not to mention wideband A/F sensors instead of narrowband O2 sensors.
Different fuel pressure and temp. sensors. Different ignition map. No evap system to monitor and purge.
And on and on.....

[Techie]

Re: Crazy conversion idea.

Not to mention wideband A/F sensors instead of narrowband O2 sensors.
Different fuel pressure and temp. sensors. Different ignition map. No evap system to monitor and purge.
And on and on.....

Wide band A/F sensors are used in most modern fuel systems anyways. Narrow band o2 sensors are getting to be a thing of the past. It is true for the upstream positions.

Whether is is old o2 sensor or newer A/F, they measure content of oxygen in the exhaust gas by comparing exhaust gas sample to the outside air. In case of old o2, the large difference between the two of the above will cause higher voltage (rich mixture). When we burn fuel, we use oxygen. o2 and A/F both monitor oxygen content and not the fuel. In fact, blowing raw CNG into exhaust has no effect on o2 sensor but may overheat the Cat Converter if enough oxygen is present in the exhaust, which is true in case of a misfire.

You can relatively safely run LPG or CNG in the gasoline engine, you are likely to loose power and get poor fuel efficiency. Factory Bi-fuels mainly used a gasoline engine, they used an altered fuel/ignition control software to compensate for different fuel. Boosting compression, increasing cam duration and changing cam degree angles can be done with aftermarket performance parts. In case of Honda/Acura, start with VTEC - make it come on sooner. I will shut up now, I know this is not a tuner site.

[cnghal]

Re: Crazy conversion idea.

The wideband O2 comment was more about the fact that most narrowband O2 sensors and OEM A/F software are only seeing 14.5 - 15.0:1 A/F mixture since lambda or stoich for gasoline is 14.7:1. CNG's stoich is at 17.4:1 so most existing sensors and ECMs are incapable of maintaining the correct mix without some serious changes.

[karlhafen]

Re: Crazy conversion idea.

I did a little looking in service manuals. I looked at a 2000 ford and it uses a ngv module ( I would bet similar to the baytech injector driver module, to allow for wider pulsewidth) between the pcm injector output and the injectors.

I also looked at a 1995 dodge (the only dodge cng manual I have) I found that the pinouts of the dodge computer were identical to the gasoline counterpart except for two pins. The left o2 sensor pin(the cng only uses 1 o2) and the transmission temp pin are used for the cng sensors. The dodge uses the same regular old o2 sensor for both gas and cng. The cat is unique to cng. The only difference I could find in the engine is cng uses unique heads with hardened valve seats. The evap hardware is simply deleted.

[rkcarguy]

Re: Crazy conversion idea.

You need to flow far more CNG thru the injectors than regular gas injectors will flow. Then you start having problems with the injector size and their plunger weight, along with the amp draw being too much for the ecu. I researched this extensively thru the company that makes the injectors for the GX.
You have to get the specialized CNG injectors, or go with a mixer setup and a servo controlled adjustment for optimum performance. This is not a tuner site, but I think the higher factory compression ratios and aggressive cams found in Civic's and Integra's can perform quite well with increased timing curves and or turbocharged if needed.
I am exploring these possiblities right now.

[cnghal]

Re: Crazy conversion idea.

Crazy idea?
Man on the moon, a pingpong ball of plutonium the same power as 20 billion pounds of TNT, a TV in every house, an information super highway, science fiction becomes science fact, all crazy ideas.

Simple is simple, no matter how complicated it gets!

See, question, learn, try, see, question, learn, try....push the envelope!

The ball is rolling, keep it up. Just be smart, be safe and share with others.
And if you come up with a really crazy idea...please fuel it up, turn it on and launch it in the Nevada desert somewhere.
But above all.....take plenty of video!!!!!

[josch]

Re: Crazy conversion idea.

Problem is, this forum wont let you talk crazy things. It is a {profanity removed by moderators} forum here that is protecting its own interests by simply banning people for speaking their minds, if it might jeopardize their revenues. No free speech here

[Andy-Paul]

Re: Crazy conversion idea.

One might wish to be careful about what kind of gasket material one chooses: hydrogen can have very unexpected effects on crosslinked/rubberized materials.

[ajgiorgi]

Re: Crazy conversion idea.

1st amendment. dam it. The internet is not regulated by the fcc and niether should this site.

[cnghal]

Re: Crazy conversion idea.

A & J,
If you will read the entire thread, you'll notice that it was a positive and informative exchange of uncensored ideas and facts on what is involved in converting an engine to run on CNG (Wow, what is this doing in the conversions forum?).
If you would like to debate your first amendment rights or discuss moderator actions, which BTW violates the TOS

http://cngchat.com/index.php?pid=9#stayontopic

http://cngchat.com/index.php?pid=9#discussingspecific

that you agreed to follow as a member of this community forum.
Might I suggest another, unrestricted forum that I notice one of you already belongs to, where you can freely discuss whatever ideas are taboo here. But please be sure to tell your next of kin where you got the ideas so they will not persue the operators of this site and infringe on thier "first amendment rights" and right to provide a safe, legal and informative source for information.

Thank you for your support and understanding,
Your Friendly Nazi Moderator

[Lakewood90712]

Re: Crazy conversion idea.

Folks: This Forum is Service and Conversions. The debate can continue in "The Lounge".