Dodge Magnum 3.5V6 on Buthane/Propane

[Dutchneon]

Hey there,


Found your site some time ago and found it verry helpfull thus far!

Now i got a question for my Magnum i bought a month ago.
I put an "autogas" installation in it (gas is a little more expensive here)
And now i'd like to treat her as best as i can to extend the life of the 3.5V6

Manual says 10W30
ive seen people saying 5w30 (also on the board here)

as addition i'd like to add that the autogas compares to liquid gas like 110 octane, but the car is not tuned for that
in any way (looking into that) but its a fact that it burns alot hotter then the regular 91oct than she was used to drink the past 70k miles.
Curious on your thoughts on if this changes anything?

 

[JHZR2]

Running hotter means needing better oxidation resistance in the oil , driving to a group III/IV blend.

Not sure if running on those fuels effects acids in the oil, etc.

 

[AandPDan]

Hi,

In general, switching your vehicle to propane should improve the longevity of the engine and oil. Since it enters the engine as a gas it won't wash away oil on the cylinder walls or get past the rings and into the crankcase.

It's a good clean fuel. The higher octane is a plus as well. It will decrease any chance of detonation.

Any good 10w-30 or 5w-30 should be fine.

 

[Dutchneon]

Hmm sounds feasable about the higher oxidation

Also from what ive read the buthane burns cleaner and also results in less dirt in the oil...

Oh and i just found the autogas is around RON102 thats alot higher then the regular RON95 or the highest RON98 gas that i could get over here

 

[wiswind]

The only thing that I can think of that might be an issue on a vehicle that has been properly converted (and it sounds like yours has been) is the lack of Upper Cylinder Lubrication and maybe detergents.
The UCL would be my concern.
I am no expert on the subject so you would need to research this further to see if it is an issue and if so, how to address it.

Even though the fuel is burning much cleaner, you still have EGR and PCV junk coming in.
This has been an issue with Gasoline fueled direct injection vehicles as the intake valves don't get cleaned by the detergents in the fuel....but they still get the dirty stuff from the EGR/PCV

 

[Dutchneon]

I also got a valve lubrication unit installed with the lpg system, its from the company Flashlube and its basicly a lead additive that is injected with the lpg.
The company claims "to lubricate and clean the upper cylinder & create a protective barrier between the valve & valve seats to keeping valves & seats cool"

 

[Garak]

Originally Posted By: Dutchneon
as addition i'd like to add that the autogas compares to liquid gas like 110 octane, but the car is not tuned for that
in any way (looking into that) but its a fact that it burns alot hotter then the regular 91oct than she was used to drink the past 70k miles.
Curious on your thoughts on if this changes anything?


Not an issue at all. I've run fleet vehicles on propane for years. They were all on conventional with 6,000 mile OCIs. If the manual specifies 10w-30, run that. You could also go down to 5w-30 without any issues, assuming there are no warranty concerns.

With respect to upper cylinder lubrication, it's another non-issue. You're not going to be able to do anything about it and it's not going to blow your motor. Your oil and valves will stay nice and clean.

 

[Dutchneon]

Sounds convincing Garak!

What about this Pennzoil stuff? http://www.walmart.com/ip/Pennzoil-High-Mileage-Vehicle-10W30-Motor-Oil-5-Quart/14962319

i still have some jugs left from my old car, would this be any good? cause i think its only half synthetic right?

 

[Merkava_4]

Originally Posted By: Dutchneon

Also from what ive read the buthane burns cleaner and also results in less dirt in the oil...


Not dirt in the oil; combustion byproducts. Gasoline leaves a lot of combustion byproducts after being burned.

 

[mechtech2]

Dutch -
What is running hotter? the water temperatures? Oil temps?
Combustion?
One thing is for sure - you certainly can utilize a tune for the higher octane, with resultant benefits.

 

[Dutchneon]

@mech,

Combustion is hotter and thus probably also the oil?? ive read that tuning can do alot for it.... so far ive read that leaning out cruising can do alot for egt's and timing can be turned down compared to regular gasoline.

I'm going to hook up my Diablo Trinity that i have for my neon and see if i can do some logging and have my tuner look over it.

 

[A_Harman]

Originally Posted By: Dutchneon
I also got a valve lubrication unit installed with the lpg system, its from the company Flashlube and its basicly a lead additive that is injected with the lpg.
The company claims "to lubricate and clean the upper cylinder & create a protective barrier between the valve & valve seats to keeping valves & seats cool"


Since you have already installed a valve lubrication system, you have taken care of the major problem with gaseous fuel conversions. Intake valve seat wear is the major concern with such engines, and typically require Stellite seats and valve facings. Oils for dedicated gaseous fuel engines typically are low-ash or no-ash. Over time, ash deposits can build up in the combustion chambers and lead to detonation or preignition in heavily loaded engines. Since your car has not been retuned to take advantage of the higher octane, this is probably not a concern, since in a passenger car you will not be running close to the knock limit very often, or for very long.

 

[Jeff_in_VABch]

Running propane is very easy on engine oil. I ran a F-100 pickup truck on propane for about 30,000 miles and the oil always looked great.

My house backup generator runs on natural gas and it also has great looking oil.

The gasses are a great engine fuel. As for tuning, there is little you can do. An increased compression ratio would be beneficial, but probably too difficult to be worthwhile and would eliminate dual fuel capability, if you have it.

 

[Garak]

Originally Posted By: Dutchneon
i still have some jugs left from my old car, would this be any good? cause i think its only half synthetic right?


Yes, it's semi-synthetic. It isn't API or ILSAC speced, but aside from that, it should be quite fine. Realistically, you don't even need a semi-synthetic. The combustion heat will not give you any problems. Since you have it on hand, I'd use it.

We got 1,000,000 kms out of one propane fueled taxi. It had its cam replaced once (it was a Chevy small block and they were hard on cams, even with the higher ZDDP oils of the time). The valves were always beautifully clean. It, too, had 10,000 km OCIs on Quaker State conventional 10w-30 with Wix filters.

 

[mechtech2]

The good news is that no one will siphon gas from your tank!

 

[Garak]

Originally Posted By: mechtech2
The good news is that no one will siphon gas from your tank!


The bad news is don't run out. You can't put LPG in a jerry can.

 

[Dutchneon]

Thanks for sharing all ur knowledge guy's, I feel alot more comfortable now running the regular oil!

I will order me some wix filters and put that Pennzoil 10w30 in her.

They can still siphon me, i alway's keep half a tank of gas with me for if i run out, but stealing gas is not something that happens here regularly......

 

[fraso]

Originally Posted By: Garak
The bad news is don't run out. You can't put LPG in a jerry can.

LPG Gas Can

I would not say that LPG burns a lot hotter than gasoline. The energy content of Autogas (aka LPG) depends upon the constituent gases, which can vary greatly. Using information from the US DoE, LPG contains 20,038 BTU/lb LHV compared with reformulated gasoline's 18,211 BTU/lb LHV. According to the Streamline catalog, the peak flame temperature of propane is 3614°F (1990°C) vs 3591°F (1977°C) for gasoline.

If an engine runs hotter on LPG compared with gasoline, it usually means that the timing isn't optimal for LPG and/or the fuel mixture isn't optimal. Injection conversions of newer vehicles have good fuel mixture control because of the engine's feedback system. Since LPG has a higher octane number than gasoline, the engine will run the full programmed advance due to the absence of knock.

You are safe to use the OEM's recommended grades. My car (2003 Impala. 3.8L) is also an LPG conversion and I've been mostly using a 0W-30 HDEO rather than the recommended 10W-30.

As for intake valve fouling, injection conversions typically start on gasoline and automatically switch over when the engine reaches a programmed temperature. I've never heard of this being an issue even on older carburetor conversions.

 

[Garak]

I've seen that "jerry can" setup before. A local shop offer the service. Fortunately, I never needed it.

As for tuning and engine heat and oil, spot on. The same local shop sometimes would tweak the plug range, but that's only for being picky - he raced LPG vehicles. He ran a whack of cabs, too, and he used the recommended viscosities, and he ran only used CVPIs with loads of miles on them.

 

[fraso]

I ran the original plugs in my Impala until they started causing a CEL (@ ~194,000 km), which was about 90,000 km on propane. Because propane requires higher ignition energy than gasoline, the new (same heat range) plugs were regapped to 0.050" from the spec'd 0.060". Since the propane in this area is fairly clean, I haven't had the need to change vapor filters yet.