Straight Gas 351 C - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

GS-0351girl · 06-16-2004, 00:14

Hi,
I would be interested to speak to anyone who has rebuilt a 351C on straight gas. I wanna compare power output etc compared with petrol.

If anyone has an idea on pros and cons of gas and whether it will increase the build costs by very much etc etc..

I have heard that there is significant power gain, relatively cheap compared to unleaded/premium and quality of gas is fairly constant (ie. you KNOW when you have just filled up with a baaad tank of fuel)

thanks!!

:fly:

MADXF · 06-16-2004, 00:18

The way I look at gas is if you want an easily registerable/epa compliant build for the street its good. If you are planning on building a weekend warrior, stick with petrol.

Gas is not always consistent, I have have bad batches of gas.

Build costs would go up a little as you would need to get hardened valve seats, bronze guides and better valves (i think).

I'm not talking in spoecific's to a 351c but it should be similar to all LPG builds.

GS-0351girl · 06-16-2004, 00:34

Thanks MADXF,
I am still doing the research, this car will hardly be driven anyway and ordinarily I hate cars that run on the sh*t nut its just after hearing a few things that I wanted to get all the facts before I commit to a rebuild one way or another (petty vs gas).

Ford Grunt · 06-16-2004, 00:35

Add to that the cost of a decent straight gas setup. If you want any decent performance you would want to go dual lines / mixer / converter made by Gas Research or Gas Attack.

http://www.gasresearch.com.au/

Id be taking a half baked guess, but pricing would be around the $2,000 mark fitted.

[ I have an Impco single gas carb setup ill sell for $550 with tank and lines :) ]

GS-0351girl · 06-16-2004, 00:46

Thanks Ford Grunt,

hahah thanks for the offer but I am not ready to buy a system.. I was thinking to spend around 5k on the motor anyway so would that be included or on top of a performance rebuild cost? Ie. do you mean that a total rebuild with that setup is at least two grand or the gas system (like an intake manifold for example) costs two grand.

hope you understand what I tried to write!

Ford Grunt · 06-16-2004, 01:03

Yeah, i was just refering to the cost of the carbs / mixers & convertors.

I don't know the exact cost as I didn't quite go down the path of a full performance setup to need to find out the cost, instead ditched the 351 straight gas XF project and settled for a v8 XD. You will notice the website I posted doesn't show prices.

I have heard though, you can get equal to if not better performance out of these gas carbs as compared to petrol carbs, but you need to sink some serious $$$.

xacoupe · 06-16-2004, 02:12

I know I will draw some flak but unless there is a reason to go gas, ie: EPA or you particularly want to.. I wouldn't bother.

UCNTRY · 06-16-2004, 02:29

have a read of this months street machine magazine its got a section on gas

xdc351 · 06-16-2004, 05:33

I reckon straight LPG is awesome.

Gas can vary in quality from place to place, but generally is very good. My personal favourite is kleenheat but it hard to find servo's stocking it. And yes, if you get a bad tankfull you'll know about it!!!

LPG needs hardened valve seats but so does unleaded, so you going to have to do it either way in the next few years, Stainless valves are also reccomended, but a high performace ULP engine is best to have them too.

Top of the line gas research systems are extremely expensive.... around $4000 tank to throttle body, installed. There are much cheaper options, but if your going for all out power then the GRA kit is the best way to go. Also second hand systems are generally very cheap.

Other than the above there is no other significant costs to an LPG engine over say a hot PULP engine. Both require hardened valve seats, regraphed dizzy, single piece valves, big cam and associated valve gear and both run higher compression than stock.

LPG can handle very high compression ratios with the right cam, but for most applications 10.5:1 is enough. I would not be expecting wild power gains over petrol, but built right they can match petrol engines with the added advantage of costing $20 to fill each time!

Although the anti-LPG crowd will tell you its not worth it, my engine is reliable as it gets, costs bugger all to fill up, makes plenty of power and as soon as I get the cam sorted and upgrade to a dual research setup i'm sure it'll be running side by side with them.... hopefully better

GS-0351girl · 06-16-2004, 21:45

Thanks for the great resopnse guys! I also downloaded this long-ass pdf file from the gas research website so when I feel like a nice light read I will sit down and wade through it! I do prefer fuel to gas and I haven't had a gas car before, will probably stick with what I know but you have to checke these things out anyway!