I am writing for an engineer friend in Mazatlan who restored a '56 and converted to dual fuel. He e mailed, asking me to research a problem he is having; i.e., that after smooth running for several months, he is now noticing an engine 'sound' change while operating via propane, and he is thinking his current is insufficient to completely burn 'all the propane' and wonders what options might be available to him.

 

His problem is that the valve seats are not made for propane... Like running unleaded gas.. propane is a very dry and cold fuel with no lubing acting at all.. most likly his valves and valve seats are starting to breaking up.. He needs to pull the head and have the valve and seat checked over.. I have done Duel fuel conversions before and on all the older cars and truck have had the valves and seats replaced first for Unleaded fuel.. thats will solved his problem and save him a major engine damage.

 

I run eveything on LPG (propane) because it is a third the price of petrol here

I agree that in theory you need stelite seats for LPG, but have seen numerous older cars converted that already had many thousand miles on the heads and had no problems doing many more on LPG

One of my mates who is big into LPG converted a V8 daily driver that had 350,000 KM (about 190,000 Miles) to LPG and did 400,000 more..........no valve problems

Heres what I reckon the problem might be:

If the US is anything like Australia the fuel companies vary the mix of gasses in propane depending on the time of year and ambient temp. More methane gas in Winter is the way I think it goes.

I find if you tune a car in summer it runs like crap in Winter, and visa versa
And we don't have anywhere near the temprature variation you guys have....wheres Mazatlan?? This could be his problem due to the change of season over the last few months.

If it is an impco mixer Give the mixture screw a SLIGHT twist to richen it up.
If it is any other brand consult a propane specialist with an exhaust sniffer.

Mark

PS Why do you guys call Petrol "Gas".....and LP Gas "Propane"

 

Mark,

Why do you guys down under call gas "petrol" and propane "LP Gas"?

Vern

 

That's easy

Petrolium extract
Liquified Propane Gas

Your shot........I'll make it easy for you.....Propane is a gimme

But why GAS.....it's a liquid for a start

And this of course leads to Gas station, Gas pedal, Gas pump.......non of which have anything remotely Gaseous about them......

Mark

 

Maybe we call it "Gas" because we burn it so fast <img>

 

Mark,

"Gas" is shorthand for gasoline just like "petrol" is short for petroleum. We yanks have a tendency to shorten things too.

Vern (short for Vernon)

 

Many thanks for your advice. Mazatlan is on the W coast of Mexico about 1 k miles S of The U.S. border.

I went to a local Ford dlr the other day, and a tech there told me his best guess re: the problem is that my friend needs to upgrade to an aftermarket, high performance, ignition system...maybe a MSD distributor & ignition box & coil. Your way would certainly be cheaper.

Also, I erred in my earlier posting: I thought the truck is a 1956 when, in fact, it is a 1979 F100.

Thanks, again.