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converting xb 302 to straight gas

7K views 23 replies 12 participants last post by  Evil XE 351 
#1 ·
gday there
i may be getting myself an XB ute GS 302

And i was wondering
what details can you guys give me on turning this into straight gas

What do i need to be aware of?
how much?
what needs to be replaced?

and most importantly, will there be a change in the note it gives?
 
#2 ·
A few pointers here:-
You will need a electronic HE ignition system recurved to suit LPG
Single plane manifolds work better than dual plane
Exhaust headers help but if your running fairly stock cam you dont need them.
Stock cams are OK.
Dont try to raise CR above about 9.5:1.
Impco make good LPG mixers and convertors.
You should hva "stellite" exhaust valve seats if you expect any valve seat life.
a7M
 
#3 ·
find out where you can buy it some areas not as gas friendly as people think? if you runout of fuel call a towtruck or a special freind who can downfill a gastank(rare). more tuning depending on system! scary gas backfires you will know it when it happens.
and talk in near future of a min 20cent excise tax and up to 40 cents. take all this into account. and how many kms do you do with it as gas is not half price as you actually burn more gas per km than petrol. still good though but these are facts.
 
#4 ·
reece1 said:
and talk in near future of a min 20cent excise tax and up to 40 cents. take all this into account. and how many kms do you do with it as gas is not half price as you actually burn more gas per km than petrol. still good though but these are facts.
you got the proof to backup your claims about excise tax on LPG? because what you say is not fact! It's BS.

An LPG excise will be introduced, but it is more like a 12c capped excise, which will be introduced on an incremental basis. I'll try and find the link if you doubt this.....

Engine note will be smoother and less crackly when compared directly to petrol, although the need to modify the timing between the two fuels does effect this somewhat.
 
#5 ·
Pilch said:
An LPG excise will be introduced, but it is more like a 12c capped excise, which will be introduced on an incremental basis. I'll try and find the link if you doubt this.....

QUOTE]

Call me a pessimistic prick if you like...but we are talking about beaurocrats here......given time they will see fit to make the excise match petrol....because they are self illuminating pricks
 
#6 ·
AS for the conversion....
there isn't much info out there (yer i know someone will correct me..and i hope they do)on the web as to manufacturer and componant choices.

My old mans 351 has an Impco 300A converter (too small), a holley 600cfm baseplate an adapater and a 425 horn mixer placed on top and upside down.
Works pretty good, but runs out of gas at higher RPM.
I'd reccomend it.

the biggest issue was bonnet clearance...remove insulation, and we had to shave some of the baseplate and the adapter.

The adapter is available off the shelf.


If you go straight gas, then don't muck with a regular carby, either use something like this, or a straight gas carby.. Sprint gas make some interesting items, like seperate twin throats that look really cool.

Given you have a ute, a dual bottle setup would be desirable...similar to my old mans ute. We have an under tray bottle and an inside tray bottle. Ok the inside bottle is about 80 litres, but theres nothing to say one of the bottles cannot be smaller..as a reserve if you like.

See pic below.

Jas

 

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#7 ·
Pilch said:
you got the proof to backup your claims about excise tax on LPG? because what you say is not fact! It's BS.

An LPG excise will be introduced, but it is more like a 12c capped excise, which will be introduced on an incremental basis. I'll try and find the link if you doubt this.....

Engine note will be smoother and less crackly when compared directly to petrol, although the need to modify the timing between the two fuels does effect this somewhat.
just trying to give a look into the downside of this product that gas salesmen fail to tell, sorry to be wrong on the excise but is what i heard from a reliable person. true i should have left the fact word out. but we all know what happens to excise. gas is good if you are doing huge kays but if your not it in my opinion its simply not worth the hassle
 
#8 ·
(thanks to Phildee for this info)

“On 1 July 2011 excise will begin to be introduced on LPG in five increments of 2.5cpl taking it to 12.5cpl by July 2015.”

http://www.fuelwatch.wa.gov.au/misc/dsp_faq.cfm#18
http://www.dpmc.gov.au/publications/energy_future/chapter4/8_alternative.htm
http://www.sdi.qld.gov.au/dsdweb/v3/guis/templates/content/gui_cue_cntnhtml.cfm?id=12800
.
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Regarding tips for LPG conversions, have a search thru this forum 'cos there's already heaps of useful info recorded.

I just noticed that you are a brand new member, so I’ll help you out with some links, just to get you started.

Welcome aboard Chunkz.

http://www.fordforums.com/showthread.php?t=115835
http://www.fordforums.com/showthread.php?t=119678
http://www.fordforums.com/showthread.php?t=107762
http://www.fordforums.com/showthread.php?t=101339
http://www.fordforums.com/showthread.php?t=73177
http://www.fordforums.com/showthread.php?t=70310
http://www.fordforums.com/showthread.php?t=67400
http://www.fordforums.com/showthread.php?t=45904

Also, I’ve created a little calculator to help you work out roughly how long it’s going to take you to recover the cost of your gas conversion.
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#9 ·
Pilch said:
Engine note will be smoother and less crackly when compared directly to petrol, although the need to modify the timing between the two fuels does effect this somewhat.
And you wont need to warm it up before you drive. No choke but maybe a primer button, nah, V8s don't really need them.
 
#11 ·
Hi have you considered fuel injected gas more power better economy,a guy I know has done a 3.8 V6 with lpg injection and twin turbo's fitted in a Econo ford van goes well.He would like see same set up in my XA V8 coupe.Ford and GMH are about to release injected lpg on their cars as an option.
Cheers Brian.
 
#12 ·
jas24zzk said:
XCGXL,
a primer button...haven't seen one of them for a while.
The true requirement for a primer button actually relates to the distance from the converter to mixer.
the shorter the better....hell i haven't fitted a primer EVER!

Jas
I'm running one on my convertor, was already there when I bought the car. Means less cranking time and easier starting. I will continue to run one even when the distance between convertor and mixer is minimal.

LUV DE COUPE, will be interested to see if Ford or Holden do really bring out factory fitted LPG injected vehicles. 1 order for XR6T LPG injected ute here!!! :hy:
 
#14 ·
Evil XE 351 said:
This is my engine its a 351 cleveland and has twin gas research, i would advise getting this setup as i have found up to 50% gain on power from using my 650 holley the gas research blows it away, as for fuel aconomy i pay more for gas now than i did using petrol. My Engine chews it but gets the performance at 289rwKW
Fill us in on your engine spec's. 289rwkw is a very good figure on LPG!!! Have you run it on the 1/4 mile? For that kind of power it's no suprise it sucks the gas :beerbottl
 
#16 ·
XD408 said:
Someone mentioned before not running higher than 9.5.1 compression, what were the reasons why??? I was told that you can get away with running higher compression levels as it has a higher octane level or something else than fuel?
104 RON is the expectation of LPG, although it is said to vary a bit, plus is is a slow burning fuel. It is a mix of butane and propane. So overall compression can be run higher, just like comparing 91 to 98 RON unleaded.

10-15 years ago it was straight propane which is more like 120 RON, which would be great for high comp.
 
#17 ·
Pilch said:
Fill us in on your engine spec's. 289rwkw is a very good figure on LPG!!! Have you run it on the 1/4 mile? For that kind of power it's no suprise it sucks the gas :beerbottl

Its a cleveland 351 bored 30", Ford motorsport cam Ported and polished heads, elderbrock manifold, cold air induction, regraphed dizzy, honed throttlebodies, dry nitrous injection. ill get my build sheet for more specs i had the whole engine and driveline built by ford performance in melb.I Have ran my car down the quartermile a number of times but just recently after having my cold air i ran 11.9 at 123MpH And for those speaking of gas and whats good and whats not, if someone was going to run straight LPG i would only use Staight Propane! Autogas is too unpredictable and if your car is highly tuned as mine is it will ping like a shitter, and propane 100% is a much smoother gas
 
#18 ·
Evil XE 351 said:
Its a cleveland 351 bored 30", Ford motorsport cam Ported and polished heads, elderbrock manifold, cold air induction, regraphed dizzy, honed throttlebodies, dry nitrous injection. ill get my build sheet for more specs i had the whole engine and driveline built by ford performance in melb.I Have ran my car down the quartermile a number of times but just recently after having my cold air i ran 11.9 at 123MpH And for those speaking of gas and whats good and whats not, if someone was going to run straight LPG i would only use Staight Propane! Autogas is too unpredictable and if your car is highly tuned as mine is it will ping like a shitter, and propane 100% is a much smoother gas
123 mph !!!!

Now that's one tough gas-powered streeter !!!!

It sounds like you are only using 100% propane.

Where can you guarantee a regular supply ?
 
#19 ·
Evil XE 351 said:
Its a cleveland 351 bored 30", Ford motorsport cam Ported and polished heads, elderbrock manifold, cold air induction, regraphed dizzy, honed throttlebodies, dry nitrous injection. ill get my build sheet for more specs i had the whole engine and driveline built by ford performance in melb.I Have ran my car down the quartermile a number of times but just recently after having my cold air i ran 11.9 at 123MpH And for those speaking of gas and whats good and whats not, if someone was going to run straight LPG i would only use Staight Propane! Autogas is too unpredictable and if your car is highly tuned as mine is it will ping like a shitter, and propane 100% is a much smoother gas
Sounds like a nice combo that works well together Very good time too, with more in it possibly. Do you know what 1/4 times / power it has N/A (no nos) ??? What type of heads are they??? Do you have the spec's of the cam??? it would be interesting to see lift, duration, etc.

I hear you about the propane, but it is pretty hard to get, especially in rural areas. I take it your running some high compression???
 
#20 ·
Pilch said:
Sounds like a nice combo that works well together Very good time too, with more in it possibly. Do you know what 1/4 times / power it has N/A (no nos) ??? What type of heads are they??? Do you have the spec's of the cam??? it would be interesting to see lift, duration, etc.

I hear you about the propane, but it is pretty hard to get, especially in rural areas. I take it your running some high compression???

I get a constant 100% propane from a place in melbourne, preston ford performance, ive waked in some photos of my car in more detail for yas just check my pics, as for the cam specs ive got the number and ill check it out for ya, oh and naturally aspirated on the dyno without nitrous just straight propain gave me 234rwKW so a figure i am still very happy with
 
#22 ·
Evil XE 351 said:
naturally aspirated on the dyno without nitrous just straight propain gave me 234rwKW so a figure i am still very happy with
very healthy figure! Looks and sounds like a nice car. Hopefully you'll get some more time out of it down the 1/4 :hy:
 
#24 ·
TruBlu351 said:
Some great times there!

Does your gas controller increase flow when you hit the other gas?

What 60ft times you getting?

My gas system has two gas research throttle bodies, the first for normal driving and the second for givin it the stick. When the second throttle opens due to having no jets in her just blows gas straight in without any restrictions, when you say other gas i gather your talking nitrous, if so i only hit and run nitrous when both throttles are WOT, the gas research twin mixers are tuned to richen as the secondary is opened and keep doing so throughout the secondary motion, obviously my timing advance is quite high so nitrous just speeds up the burning process. Oh and the only thing you should be takin into account the most when changin to straight LPG is your cooling system... If running low timing advance you'll have no problems but with higher timing the engine easily runs very hot and will ping, not what you want, so when converting you must also have a top notch cooling system to go with otherwise you'll be in strife.Also power loss on hot days as gas looses its octane levels rapidly in heat :hy:
 
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