Gas Conversion for a Type 4 Engine

[Brewmaster]

Gas Conversion for a Type 4 Engine

Here is the gas coversion we had done in September on Wilfred the 74 SC Ute. The conversion was done by Geoff Scott and also the Australian Government gives a $Aus 2,500 rebate on gas conversions.

All I can say is ......"Oh my God"........ the old dog is full of gas and suddenly has a spring in his step and speed to burn!.........

To say we are estatic would be an understatement and my 'kruise' along the coast road from Noosa to Caloundra turned into a highway run which I thoroughly enjoyed at errrrr...... 120 km without noticing the speedo getting there. ..... or when I had to pass some plastic modern vehicles (up to 140km)

Here is what it looks like....

Left side of engine showing oil filter, plate and the Converter with the air filter of the Inpco Gas Carby on a 32/36 mm throtle base.



Right hand side of the engine

[Brewmaster]

Cut in the wall between the engine and the gas tank



72/75l gas tank

[Brewmaster]

Here is a diagram Geoff drew to explain what happens with a gas conversion....



As you can see the gas comes in the filler hose and sits in the tank as a liquid.

That liquid gas then goes into the Converter where the liquid gas changes state by being turned into a gaseous state.

Notice the hot oil hose bringing in hot oil and the hose bring ing the cool oil back out.

The gas is then pumped into the Manifold which is a tuned lengthprogressive Plenum style with an Impico 300a gas Carby on a 32/36 throtle base.

Notice that there is twin cone section that has a valve which closes off and allows any gas to bounce back (reversion) and be matched with more incoming gas. Through accoustic tuning Geogg has been able to turn reversion into inlet pressure and the end result is that it produces more torque.

I aplogise if I have not got some things quite as Geoff explained them to me but I am trying to post what he said. I'm a teacher..... not a listener........

[Brewmaster]

What work was done on Wilfred's engine?

Many people have asked me what we were having done to Wilfred's engine for the gas conversion.

Well that is like opening a can of worms as each and every engine will be different and the costs reflect this.

Geoff found some things did not need much work in some areas but others might have to fork out a lot more to fix before the gas conversion commences.

Here is a list of things that Geoff had to do to prepare the old dog for some gas....

• crank grind to suit the case 0.002" clearance (standard)

• new Billett camshaft C-25 234* AT 0.050" lift

• ceramic coated piston skirts

• new rings

• new cylinder heads AMC (made in Brazil)

• modified inlet port 8.75:1.0 compression ratio

• manifold - tuned length progressive Plenum style

• Inpico 300a (mixer) gas carby on 32/36mm throtle bases

Just before I left Geoff showed me pics he took of Wilfred's engine being taken apart ready to add all nis new bits and tits .... ..... can't wait for him to burn me a disc and mail it down to me to post on the forums.

[Brewmaster]

Some more pics to go with Geoff's diagram

First of all there is the filler inlet. Instead of cutting another hole like some dodgy gas fitters do we used the same inlet as the petrol tank. Yes we removed the petrol tank ........ before you ask.

Geoff's Diagram ..... section on the filler and gas tank



Filler inlet in the same place as the old petrol tank



Gas tank 72/75 litres



Here is the safety mechanisms on the gas tank behind the magic box



Some people may ask why the tank is sitting a bit forward of the missing fire wall. Well when Geoff was fitting the tank he found a patch of rust which we are addressing as part of Wilfred's resto ..... hence the slightly forward stance at this moment in time.

[Brewmaster]

Here is the section where the liquid gas in piped to the converter where it meets hot oil and converts the liquid fuel into a gaseous state.

Geoff's diagram section



gas converter with oil filter plate and ingoing (hot) and outgoing (cold) hoses.



Coverter with incoming hot oil hose and outgoing cool oil hose.

[Brewmaster]

Here is the next stage where the transformed liquid has been converted into a gas and heads towards the progressive Plenum style tuned length manifold



Here is the converter feeding into the manifold

[Brewmaster]

[Brewmaster]

Here is the manifold with its tuned length progressive Plenum style manifold. It has a Inpico 300a gas carby on 32/36 throtle base

[Brewmaster]

[Brewmaster]

Here is the converter photographed upsidedown so you can read it.

In Winter Geoff says the button in the middle can be primed to help start the engine on a cold morning...... as this is a common problem with some gas conversions.

[Brewmaster]

When I posted about Wilfred's gas conversion on The Samba I got a real reaction from people in the US

My God what a reaction! ...... within about 30 minutes It had over 50 views

Only one reply and that was from a guy in Pomona, New York.....

......... Well a bit more would have to be done for it to work on a Upright Converted T-4 due to the fact would have to make special intake manifolds. You should post this on the T-4 fourm.

THe nice thing is you can do that to any car. What would be perfect is an old econo box with this unit for a commuter car.

I was looking into the Honda Civic GX. It is a natural gas car and in NY and Calif. they sell a Home Garage Refilling station so you can fill up over night. The one big problem is in NY there are no Natural Gas Stations, therefore you can only go one tank of fuel and home. That would be, I would say roughly 300 miles.
The gov. says the will start putting up stations but with Big Oil running the show and the economy in the sorry state it is in we may not see stations for a while. Nevertheless Great Job!!!! .........

Will be interesting to see if anyone posts any more feedback over the next few weeks but perhaps gas is not as freely available in the States or elsewhere for that matter as in Australia.

Cheers
Brett

[Brewmaster]

Here is a post from an admirer on an other forum in Australia ......

.......... The beauty about CNG conversion and having a home compressing plant is no excise on the fuel.
Also CNG has an octane rating of 120.

Lots of vroom for your buck when done properly! ..........

Hence having to have this done to our engine for the gas conversion .....


Here is a list of things that Geoff had to do to prepare the old dog for some gas....

crank grind to suit the case 0.002" clearance (standard)
new Billett camshaft C-25 234* AT 0.050" lift
ceramic coated piston skirts
new rings
new cylinder heads AMC (made in Brazil)
modified inlet port 8.75:1.0 compression ratio
manifold - tuned length progressive Plenum style
Inpico 300a (mixer) gas carby on 32/36mm throtle bases


Absolutely no regrets having Wilfred converted to gas........ now have to get back to his resto.........

[Dawie]

Hi Brewmaster,

Interesting conversion. What is the gas consumption compared to petrol ? Heard LPG conversions use slightly more,but then in some countries LPG is cheaper than petrol.

What is the cost difference in your country between LPG and petrol ?

[eben]

Dawie in the UK the difference is 49p/L for LPG and about 99p/L for 97Octane unleaded