This is the first dual-fuel Raptor-boosted AU. It's still a work in progress on the LPG side, but is working well on the petrol side, apart from some intake sealing issues. There is slight positive pressure at idle, as evidenced by 2 leaks in the intake system. One is my fault, I thought it would be a good idea to cut off the lugs in the last piece of the factory intake (which the Raptor kit retains) where it engages the Memorex hose. Not such a good idea. The lugs are hollow, not solid as I assumed, and the sealers I have handy are no match for boost. The other leak is around the LPG fitting where it goes into the mixer. I'll work on this when the new piece of intake pipe arrives.

Anyway, with the petrol side sorted, I've been able to give it a bit of a blip, and I'm very pleased with the results. With the combination of 4499's, a 4* advanced cam, a 3.73 diff and whatever contribution the blower makes at low speeds, it feels like a 250 or 245 Hemi in the way the torque is building at 1500 and shoving me back in the seat as the tacho goes past 2000.

But as it reaches 3000 where the 250 has shot its bolt and is ready for a smoke and a sleep, this wicked thing is riffling through the cupboard for stilettoes, fishnets, handcuffs and whip, ready for some serious play. It spins out to high-5's so fast in 1st that the only thing that had time to go through my mind was "FM!". And I'm not being polite and abbreviating the words, I just didn't have time to think the words.

A couple of engine bay shots. The LPG-literate will notice the balance line to the converter in 5/8 and 3/8 hose, which recycled the right-angle fitting from the balance line to the snorkel when it was NA:





Instead of plugging the PCV nipple in the intake piping, I've used it to take off the balance line for the LPG system:



I have air leaks here...



...and here...



...but I have a new piece of intake pipe on order.


Here's the business end, note the plumbed-back BOV:



Here's a shot of the bracket (sort of!). You can just see the top mounting bolt to the lower thermostat housing bolt hole. The bottom of the bracket uses the 4 aircon compressor mount points.



A wider angle:



Damn that 3mm hole in the balance fitting!



Most people wouldn't finish a 3" exhaust like this...





...but then I'm not most people!

I want to get the air leaks sorted before I put it on the dyno. Watch this space...

shouldnt u plum the nov back in after the afm, so it dosnt f**k around with the fuel ratios

keen to see those dyno figures and torque curve!...

Great description of the power. LMAO.

nice setup, atleast you can drive it everyday cause its cheap to fill. nice work

no airflow meter on 6's

What's the go with that 3mm hole in the balanced line fitting? Mine has the same hole which Joe from CMS pointed out recently at the AFD. He actually asked me why the installer put a hole in the fitting??? But now I can see that it is standard on that particular fitting. Should I block mine as well? What is the purpose of the hole?
BTW! Nice work will keep an eye out for dyno figures
Cheers,
Mick

Maybe it's there so your converter can see atmospheric pressure under load?

There was a raging argument on AFF's LPG forum a while ago about whether to put the other end of the balance line on the clean or dirty side of the air filter. Almost all LPG installers put it on the dirty side (ie the snorkel), but apparently this flows too much and makes the mixture too rich. The 3mm hole in the elbow relieves it enough to make the mixture tuneable.

If the balance line is on the clean side of the filter, it's argued, the 3mm hole isn't necessary. But the dirty side camp say this makes the gas mixture go rich when the filter gets dirty, as the suction draws more gas and less air.

I don't know who's right, but I do know that when that type of mixer-ring LPG system is boosted, the hole has to be plugged because the converter needs to get full manifold pressure. I sealed mine at first with silicone, it blew out on the first blip to 3000rpm and the engine ran really rough from 3000 right down to idle, where it just surged... vroom......vroom.....vroomm.... until I put my finger over the hole & it smoothed out again.

Short answer is, if your car's running OK then the hole should be left Mick. But you could slip a self-tapper in temporarily if you want to experiment and see what difference it makes.

Spot on... in fact the engineer told me he could pass my car without a plumbed-back BOV as long as it passed the noise test. The I6 has manifold pressure and temperature sensors which, with engine RPM, allow the ECU to calculate air flow mass. So flow metering takes place in the manifold and isn't affected by the BOV.

Well I had a play and blocked the hole. Since LPG was installed, it has always idled rough on LPG, but nice and smooth on fuel. Now on the V8 the dirty side of the airbox in at the bottom, where mine is getting it's air from, so I blocked it with a 3mm bolt and took it for a run. It now seems to be idling a lot smoother, so much so, that when I switched it between LPG and fuel, and then back again, the idle seemed to stay consistent. Maybe I was running a bit lean for it to be idling rough and by blocking the hole, I have increased the mix enough to smooth it out.
I will leave it blocked for a week or so and see what consumption is like and then remove it and see if there is any change.
Sorry to hyjack your thread mate, but your comment about the hole was timely as I had just been thinking about it
Cheers,
Mick

No worries Mick, glad to help out a fellow Ford fan and Novocastrian!

Hmm this has me thinking about my hole in balance line fitting too. My V8 idles bad on gas with the surging just like you described on yours sly. I'm going to have a looksy and see if I can fix my drama too with that idea. Cheers

Our local cruise mod (castlegreyskull) is organising a Dyno day for us newie folk, so we might get to see the sly mobile on it's virgin run Would you be interested ? If so, i'll let you know when it's on

How come all the Hunter Valley blokes have gas problems?:lol:

Yeah give me a yell when it's organised. I work a roster that has me working every 2nd weekend, so there's a 50% chance I can make it, as long as the gearbox holds out. Any recommendations for a good place in Newie / Maitland areas to get a BTR 4-speed rebuilt and strengthened?