Oka owners group newsletter

They also had special sheets for under-bonnet sound and heat insulation. probably 30mm thick foam, foil each side and a heavy layer in the middle of the foam. Didn't get a price but one sheet should be enough to do the lid and the critical areas on the sides of the enclosure.

Best way to silence the OKA would be to turn the key off. Even the latest model doesn't seem much quieter than mine. Main reason for renewing it is to avoid the feel of rotten foam sprinkled all over me.

To keep it simple, we had no trouble removing the disintegrating headlining from our Oka, and then just used a wire brush and a turps rag to take most of the adhesive and foam crumbs from the roof area. We then painted Sikoflex ? to both the roof and the back of the new headlining on half at a time and carefully positioned it with the help of broom handles stuck in the roof frame before pressing on and replacing the bar across the roof. It looks great, and it is much more comfortable to travel without the black crumbs falling into your hair and down your neck. Ours disintegrated during a trip away, and we travelled for half the time with green branches stuck in the roof frame to support the sagging lining! Headlining and soundproofing available at Clark Rubber stores. Marj Parsons

Oka Paint Colour:

Query by Tony Lee

OKA Paint Code For XT/LT

Interthane Product: 3/207-00010418

4 Litre kit

(2 Pack 3 Litres Of Paint Plus a 1 Litre Hardener)

NT OKA

Toyota 058

This was posted previously and was supplied from OKA

PAINT TYPE: INTERTHANEIF COLOUR:White CODE: 452202

New Windscreens:

desertrat Terry

If you need to have a new windscreen fitted, find out from your installer if they have the correct rubber for mounting. It is probable that you will need to order the correct rubber mounting from Oka. Ron Quigley

WINDOW WINDER:

Hi, Can any one help me out, I have broken a window winder belt and am having trouble sourcing a replacement. My local belt supplier who has been able to supply all other belts cannot find the code listed in the manual. Also I have been through the service manual from front to back and cannot find any details on how to fit a new belt. The manual is very detailed however any info on front doors winders etc is lacking. Would appreciate any info and assistance. Thanks Wessa

Wessa, I can confirm the Part Number 510L0507250DS is correct. The numbers relate to the length and width.

I got some from Rydell Industrial Belting (17-19 Churchill Road North, Dry Creek, Adelaide), cost $14.30 inc GST in 2006.

See http://www.rydell.com.au/index.htm for contact details of an outlet near you.

The window winder breakdown diagram is in Section 12, Body, of the PARTS manual, not service manual, which should make fitting easier. It was fairly easy but fiddly. Email me if you need any more info.

David

Satellite Phone Query

Information we were given during Fire Brigade training: We were told something like ‘a 000 mobile phone call will access all phone towers within range, not just the tower of the network that you are connected to. This gives more

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coverage to the 000 caller but doesn’t work where there is no mobile coverage at all’. It is a couple of years since I did my training and things may have changed.

• Here is some text regarding satphones

“Buy a satphone and just activate it for the duration of your trip. A mob called Satpac based in Brisbane charges by the month with an access fee of $27.50 per month (last time we did it in 2008) and you pay for calls. We were fortunate to pick up a secondhand phone from a government department, but you’d probably pick one up on EBay for much less than the new price. Apart from anything else, I would prefer to have a satphone so I could talk to someone in an emergency, rather than relying on an EPIRB. We use our satphone for emergencies only, and keep a listening watch for an hour or so at drink time.”

The full text of this letter is in the August ’09 issue of On The Road magazine.

I would add that Satpac uses the Iridium network and we have never had any trouble making calls. You just ring them on [phone] and they send you a SIM card and charge you by the month until you tell them to stop. And, no, I’m not on commission, but I’ve always found them good to deal with! Tony

OKA LIST (from the Website – For Sale))

• SPICER DANA TRANSMISSION T5-250 SERVICE MANUAL XT & LT • SPICER AXLE MAINTENANCE MANUAL XT & LT

• SPICER DANA TRANSMISSION T5-290 SERVICE MANUAL XT & LT • PERKINS MOTORS WORKSHOP MANUAL XT & LT

• SPICER MODEL 70 MAINTENANCE MANUAL FOR AXLES XT & LT • SPICER MODEL 60- 7O LIMITED SLIP SERVICE MANUAL XT & LT • ROCKWELL TRANSFER CASE MAINTENANCE MANUAL FOR LT

• OKA OPERATOR’S MANUAL FOR XT MODEL

• OKA XT SERVICE MANUAL INCLUDING PERKINS MOTOR • OKA LT PARTS MANUAL INCOMPLETED 1997

• OKA TECHINAL SPEC PAMPHLET LT 110 CAB CHASSIS

• OKA TECHINAL SPEC PAMPHLET LT 110 VAN & BUS

• OKA TECHINAL SPEC PAMPHLET LT 110 TOUR BUS

• OKA PAMPHLET LT AND XT MODELS

• OKA PAMPHLET FOR LT 110 ALL MODELS

• OKA SERVICE SCHEDULES XT MODEL/ HANDBOOK 1995 • OKA PAMPHLET FOR RENTING AN OKA

• OKA PAMPHLET MINING LT MODEL • OKA PAMPHLET TOUR BUSES LT

• OKA PAMPHLET CROP SPRAYER LT • OKA PAMPHLET FIRE TRUCK LT

• OKA WORKSHOP SCHEDULE MAINTENANCE XT & LT SERIES WALL CHART • OKA TIE CLIP

• OKA KEY RING

• OKA CLOTH BADGES

• OKA ENAMEL BADGES

• OKA STICKERS

• OKA BELT BUCKLE

• OKA NEWS DEC 94, FEB 95, APR 95, JULY 97, SEPT 97

• OKA OPERATION & TIMES SCHEDULE FOR XT AND LT MODELS (WARRANTY WORK)

• OKA PAMPHLET IN BINDER WITH CAB CHASSIS/VAN&BUS/TOUR BUS/OPTIONS AND SEATS • OKA SERVICE BULLETIN REGISTER

• OKA TRAINING MANUAL LT WITH MAINTENANCE SCHEDULE

Please Contact Isabelle [e-mail]

2010 Subscription Renewals

Please note renewals for the 2010 subscriptions will be due end of January 2010.

Could you please make a $25 cheque payment payable to "The OKA Owners Group" and forward to:

Rowena Paterson

PO Box 230 KALGOORLIE WA 6430

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For direct banking use: BSB No. 063547 Account No. 10131505

Please disregard this notice if you are a new member who has joined during the 2nd half of 2009.

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Hi Everyone,

!

!!!!!!!!!!!!!! !

OKA OWNERS GROUP (PUTTING PEOPLE AND THE ENVIRONMENT FIRST)

NEWSLETTER !Winter 2011

!

We have had a visit from Reg & Dianne Stirling, who have a XT dual cab Oka. Reg is a mechanical

engineer, and the Stirlings have a service station. They have an Oka bus as well, and have led many

outback tours over the years, and are also the backup team for Variety Bashs each year. All this adds up

to a whole lot ofexperience. Reg has recently put a new Perkins motor into his bus (see details next

newsletter), but after doing a swag of research on the Internet, he has found a way to get more power

from the old Perkins in the dual cab, from just playing with the injector pump. Of course, if you modify

your engine to get a better performance, you have to give up something and in this case Reg says it is a

good puff of black smoke when you start up – not enough to be illegal, but not the usual clean exhaust

of a well running Perkins motor. This isn’t the only news on new motors for Okas. Darren Webster now

has his Oka fitted with a Duramax motor and reports that it is going well, not using too much fuel and

plenty of power, and is reasonably quiet as well. Okadoc on the Forum is also working on one of these

and we look forward to more news and information about these motors.

!

It has been a very wet season in the north of Australia this year, and looking in the Westprint newsletter

there are many road closures in outback areas of Central Australia as well, so it would be a good idea to

check carefully if you had planned a trip into these regions. While we had floods in our area before

Christmas, there has been little rain since, so though we have oodles of dry grass, we are looking for

some serious moisture in the near future. We haven’t planned our trip for this year, but may go south

around the coast of southern NSW and Victoria and hope to end up at Kangaroo Island before making

our way home. This all depends on the hoped for break in the weather, of course.

!

Many of you will have received a members’ list for you to look over and check to make sure your

contact details are correct. We were surprised to find so many changes to be made to the list – either

people having moved house or just changed their email address. For our purposes, email is by far the

best way to send out newsletters and information as there is little cost and it is immediate in delivery, but

if you change your email address, PLEASE let us know, as it wastes so much time checking it out if

these come back, and then we have to print and mail as well. Those who receive their newsletter by post

have also been contacted. If we don’t hear from these people we won’t send them a copy in future as we

have no idea if they receive it, or even if they still own an Oka unless they tell us.

!

We have received an email from the Schoenslebens to let us know that they are in South Africa. They

have had a problem with an axle, and are having it fixed in Johannesburg by the Okadealer there – (we

didn’t know there was one). Anyway you can look at their stories and great photos and follow their

adventures on their website, which is:

http://www.schoensleben.ch

Marj Parsons !

2011 Renewal Fees and Royal Flying Doctor donation

I would just like to thank members very much for sending me the 2011 $25 renewal fee.

Each year (once all our expenses have been paid) I donate any left over money to the Royal Flying Doctor Service.

Thanks again, regards

Rowena Paterson

Secretary, OKA Owners Group

! !

Understanding and tuning the Injection Pump of

Land Rover Tdi Engines (NB Same pump as is on an OKA) Copyright © Ian Petersen 2003-2004

The Disclaimer:

This article is presented for the interest of readers from information gathered from various sources including Bosch technical literature and the internet. The author makes no claims to be an expert on diesel engine tuning, nor for the accuracy of this information. The author cannot accept any responsibility for the consequences of actions taken by others using any or all of this information. Make sure you fully understand the information and accept the consequences before making any use of it.

There's no such thing as a free lunch - if you modify your engine to give better performance it will be working harder and components may wear out sooner than otherwise. If you get things wrong it may well ‘wear out’ a lot sooner...

The Basics

The Land Rover 200Tdi & 300Tdi engines of the late ‘80s to late ‘90s utilise the Robert Bosch VE-type diesel injection pump. Like all diesel engines, the purpose of the injection pump is to deliver a precisely- metered charge of diesel fuel to each cylinder injector, in the firing order of the engine. The Bosch VE injection pump uses a single pump plunger to produce these high-pressure fuel charges. The pump mechanism includes a distributor section to direct each successive charge to the appropriate cylinder injector, in the required order.

The actual fuel charge delivered to the injectors is proportional to the pump stroke. The effective stroke is continuously adjusted according to the throttle position and the engine speed (rpm). This function is performed by the mechanical fly-weight governor mechanism within the pump. In a naturally-aspirated diesel (or assuming the boost pressure remains constant in a turbo-charged engine), the governor will adjust the pump stroke to try to maintain a particular engine rpm at any given throttle setting. That is, unlike a carburetted petrol engine where the throttle directly alters the quantity of air/fuel mixture drawn into the cylinders, in a diesel the throttle merely adjusts the 'rpm setpoint' of the engine. At a fixed throttle position, as the load changes (e.g. the road rises or falls slightly) the flyweight governor will increase or decrease the fuel charge to attempt to keep the engine rpm constant, within limits of course, a bit like a very basic ‘cruise control'. In practice, the engine rpm and hence the vehicle speed will vary quite a bit as the load changes, despite the best efforts of the governor. [If you want to get technical, this is because a fly-weight governor is a ‘proportional action’ type of controller and will settle at a different ‘steady state’ point for each different

load on the engine.]

Boost Compensation

Now, the description above stated "assuming the boost pressure remains constant in a turbocharged engine..." Of course, it rarely remains constant for very long. For this reason, the Bosch VE injection pump used on 200Tdi and non-EDC1 300Tdi LR engines has a boost compensator (also called a manifold-pressure compensator or 'aneroid') to enable it to further control fuel delivery in proportion to the boost pressure at the turbo-charger air outlet. This is necessary as the mass of air in the cylinders varies greatly as the boost pressure increases from zero to full boost. At low boost pressures, the cylinder air mass is much smaller and is not sufficient to fully combust the maximum fuel charge. Therefore, the boost compensator’s job is to reduce the maximum fuel charge when the boost

pressure is less than maximum. A tube from the turbo air outlet to the diaphragm chamber on the top of the boost compensator transmits the pressure signal. In order to consistently achieve low smoke

emissions on every vehicle leaving the assembly line, it seems the 'standard' settings of the boost compensator are very conservative. That is, they severely restrict the fuel delivery at less than full boost in order to ensure low smoke emissions. This seems to result in the legendary off-idle sluggishness of the Tdi engines. By carefully adjusting and optimising the boost compensator settings for a particular engine, significant improvements can be had in off-boost and low to mid-range rpm performance, without excessive smoke emissions. [By the way, if you are making black smoke you are just wasting fuel, not making more power. The object is to have the engine just on the brink of making smoke when under full throttle, at any combination of rpm and boost pressure.]

Boost compensation works by automatically adjusting the position of a pump Stroke Limiting Pin within the pump. This pin lies horizontally through the pump body and is visible at the bottom of the compensator well. When in the rearward position (away from the front or drive end of the pump) the pump delivers it's 'high boost' fuel charges to the injectors, as defined by the internal design of the pump. When this pin is pushed forward, the fuel charge, for any given rpm and throttle setting, is reduced to compensate for the reduced air charge to the cylinders when the boost pressure is lower.

Figure 2

The stroke limiting pin is positioned by the up and down movement of an eccentric Control Cone attached to a diaphragm which senses boost pressure. When there is effectively no boost, such as when idling, the diaphragm/control cone is held in the fully up position by its spring and sits against the stop screw in the top cover. In this position, the limiting pin is bearing against the thickest (bottom) part of the control cone. Therefore it is pushed forward to it's most restrictive position.

As boost pressure increases, the pressure above the diaphragm begins to overcome the spring force and the control cone is pushed downwards. The stroke limiting pin now bears against a narrower part of the control cone and is allowed to move backward slightly, allowing increased fuel delivery. Eventually, when maximum boost is achieved, the diaphragm/control cone no longer moves any further downward, the limiting pin ceases to move further rearward and fuel delivery is solely determined by the governor, with no additional restriction from the boost compensator.

Boost Compensator Adjustments

There are three adjustments available in the VE pump boost compensator:

1. The rotational position of the eccentric control cone at the bottom of the diaphragm/cone assembly, adjusted by rotating the assembly. (See Fig. 3)

2. The diaphragm spring pre-load, adjusted by rotating the 'starwheel' on the lower spring seat (See Fig. 2),

3. The diaphragm/cone rest position, adjusted using the Torx stop screw and locknut in the diaphragm cover (See Fig. 4).

The following section shall examine only one of these adjustments in detail and explain its effect on fuel charge delivery, with reference to the appropriate photographs and diagrams.

1. Diaphragm rotational position

1.1 As shown in Figure 3, the control cone

is mounted eccentrically on the diaphragm shaft. Therefore, as the diaphragm/cone assembly is rotated through 180 °, the side of the cone which bears against the stroke limiting pin will change from the ‘most forward’ to the ‘most

rearward’ This is the fundamental adjustment which determines the overall range of stroke limit pin

movement.

1.2 As shown in Figure 4, the position of the diaphragm/cone assembly is determined by the ‘centre

punch’ reference mark near the edge of the central steel plate of the diaphragm. It isessential to note the original position of this reference mark when the diaphragm cover is first removed.

1.3. The eccentric control cone in my 300Tdi is marked “13H”. Presumably there are a range of different pins available to characterise the VE pump for different engine applications.

1.4. For the following description, the position of the diaphragm is described in terms of degrees of rotation from the ‘maximum’ position. This is defined as that which orients the control cone to its ‘most rearward’ position. That is, the position which allows the stroke limit pin to travel most rearward. Therefore the ‘maximum’ position corresponds to the maximum fuel position. In the case of my assembly this coincided with the reference mark being at the ‘twelve o’clock’ position (to the top/high/ tappet cover side, as shown in Figure 4 above). I do not know if this is always the case.

1.5. Also for this description, the travel of the stroke limit pin is defined as starting from the ‘most rearward’ position able to be achieved (maximum fuel position). That is, 0.0mm of travel is achieved when the diaphragm is positioned so that the control cone is ‘most rearward’ and the diaphragm is in the fully depressed position. The pin travel may be thought of as ‘millimetres of restriction’, when 0.0mm means zero restriction of fuel delivery.

1.6. The chart, Figure 5, shows the approximate relationships between the diaphragm rotational position and it’s effect on stroke limit pin position. [The dimensions listed are approximations to the nearest millimetre from measurements taken from my 13H assembly and should not be taken as precise nor completely accurate.]

1.7. The diaphragm/control cone assembly has a total vertical travel of about 10.0mm. At the bottom of the effective travel, it’s diameter where the stroke limit pin bears is about 9.0mm. At the top of effective travel it’s diameter is about 5.0mm. It is mounted about 1.0mm off-centre. Therefore, as shown in Figure 5, the stroke limit pin will move about 4.0mm as the diaphragm/control cone moves downward over its 10.0mm of travel. This 4.0mm of travel may be varied from the ‘0.0 to 4.0mm’ range to the ‘1.0 to 5.0mm’ range by rotating the diaphragm up to 180 degrees from the ‘maximum’ position. As the diaphragm/control cone is symmetrical, it doesn’t matter which way it is rotated from the ‘maximum’ position. Also note that 180 degrees of rotation (! turn) represents the full range of adjustment available.

PLEASE NOTE that the only change Reg Stirling made was to rotate the eccentric control cone 180 degrees.

FITMENT OF AIRBAGS IN AN OKA

Surprisingly, a search of the Oka Owners website revealed only five references to fitment of airbags to an Oka, (and one of those was mine), plus an article by Peter Furlong from several years ago. But I'm aware of at least 6 Oka's with airbags fitted and I'm sure many other people are toying with the idea.

In the May 2011 issue of the CMCA magazine The Wanderer is an article by Collyn Rivers on "Airbag

Characteristics" which makes interesting reading. In an earlier article (Feb 2011) he cautioned that airbags should never be fitted only to either the front or rear of a towing vehicle, citing potential jack- knifing of caravans. (Note you may need to be a CMCA member to access articles from The Wanderer).

Having recently fitted airbags to both the front and rear of our Oka, I was somewhat relieved to read Collyn's conclusion that "there is no reason at all not to use air bags if you wish. They are first rate

engineering products, but specifying them correctly requires considerable skill and expertise". In the

FITMENT OF AIRBAGS IN AN OKA

Surprisingly, a search of the Oka Owners website revealed only five references to fitment of airbags to an Oka, (and one of those was mine), plus an article by Peter Furlong from several years ago. But I'm aware of at least 6 Oka's with airbags fitted and I'm sure many other people are toying with the idea.

In the May 2011 issue of the CMCA magazine The Wanderer is an article by Collyn Rivers on "Airbag

Characteristics" which makes interesting reading. In an earlier article (Feb 2011) he cautioned that airbags should never be fitted only to either the front or rear of a towing vehicle, citing potential jack- knifing of caravans. (Note you may need to be a CMCA member to access articles from The Wanderer).

Having recently fitted airbags to both the front and rear of our Oka, I was somewhat relieved to read Collyn's conclusion that "there is no reason at all not to use air bags if you wish. They are first rate engineering products, but specifying them correctly requires considerable skill and expertise". In the latest article he explains in more detail the implications of adding airbags to a suspension system. He also refers readers to an article on his website (Vehicle Dynamics) which discusses generally how a vehicle behaves on the road. Although much of the emphasis relates to towing and caravan applications these articles are worth reading before embarking on any changes to an Oka (or any) suspension. Fitting of airbags was not a trivial task (for me anyway) so FYI, I have written up some notes on our airbag modification process here.

I wanted to use airbags for three main reasons:

1 to shift some (roughly half) of the load off the springs and suspension pins and thus improve their reliability.

2 to provide some suspension levelling for differing loads, road cambers and to compensate for spring wear (sag).

3 to soften the ride over rough tracks and corrugations, and since we live in the Oka while travelling, being able to level the vehicle at night was an additional side benefit.

Fitting airbags to the rear suspension in 2010 was easier than the front and I’m glad I tackled that first. On a 14,000 lm trip to the Tip of Cape York they performed well, allowing load levelling and raising the rear as necessary. Passengers in the rear reported a very smooth ride even over quite severe corrugations. It was a very different story in the front, however, sitting directly over the wheels, with quite stiff front springs and heavy duty (Ralph) shock absorbers, the ride was shattering over any significant corrugations, and it was that which led us to install airbags on the front this year, in an attempt to provide a smoother ride as well as the other levelling capabilities.