DC-DC Charger

A Victron Energy Orion-TR Smart 24V/24V -17 400W DC-DC Charger has replaced the prior Redarc SBI24 battery isolator setup and mounted inside and above the OEM start battery location.

It allows a controlled high current draw profile suitable for the LiFePO4 house battery bank from the OEM alternator and protects each battery bank from drawing down the state of charge on each other 
A remote on/off switch has been wited for easy access/visibility
Battery terminal hardware was upgraded at the same time and suitable fusing of both battery banks was matched to Victron recommended specifications

Battery Isolator / Charger  - 14/5/2017
A Redarc SBI24D Smart Start Battery Isolator was fitted between the vehicle's 24V battery bank (starter) and the 24V house battery bank.
This isolator acts as a smart gateway between the two battery banks giving the vehicle priority for charging off the vehicle's standard alternator and when it detects the vehicle battery bank is at full capacity will switch charging to the house battery if it is not at full charge.
The isolator prevents either battery bank from discharging the other healthier bank.
It can also act as a means of jumping the vehicle battery bank off the house battery bank in the event of a flat start battery bank by means of a momentary switch.
A 100 Amp fuse on both ends protects the 4 gauge wiring from any shorts/failures.

Onboard Air & Load Assist Airbags

Update with Onboard Air System

To avoid having to regularly have our rear bags pumped up at a service station and to allow some basic side to side levelling when parked overnight at uneven camp sites, we decided to fit an air storage tank and in cabin rear air bag inflation/deflation capability to our existing air bags.

Boss Air Suspension analogue dual gauge, fittings, valves, switches, solenoids and tank were used.

A Thor Air TC100 24V compressor is fitted to top up the tank on the road.

A Nitto style coupling is fitted to attach an air hose if desired to air up tyres

Original Load Assist Airbags install - 29 April 1997

In order to keep the rear of the bus level and balanced once loaded up for the road, we decided to fit a a set of independently adjustable airbags.
We decided on a Boss Air Suspension Toyota Coaster LA-87 load assist kit which is ready to simply bolt on the rear end of a Coaster.

Start Battery Isolation

A common theme amongst Coaster motorhomes owners is maintaining the level of the start batteries when they are not actively driven between trips unless they are kept on a mains charger or a unecesarily complex secondary solar charging system is added to top up the batteries. 

 After numerous failed attempts with smart battery isolators and MPPT solar chargers kept resulting in flat or failed start battery banks after a couple of weeks of not being started, a decision was mnade to just fit a battery cutoff switch. 

 A heavy duty Blueseas 6006 Single Circuit 300A ON-OFF switch was mounted and wired with 0 gauge cabling and Projecta heavy duty satin forged brass saddle clamps in the link between each battery.

As long as we remember to switch the bank off, there should be no more regular flat batteries.
 

House Batteries update

LiFePO4 Upgrade

After 4 years of service and having replaced 2 batteries already, a 3rd Lead Crystal battery failed on us.

Availability of replacements in Australia was now non-existant with a 4-6 month lead time from the factory.

With numerous legal disputes ongoing between importers/suppliers/distributors, we decided to cut our losses and move away from Lead Crystal batteries.

We decided now was the right time to switch from AGM style batteries to more modern technology chemistry in Lithium phosphate (Lifepo4).

After another round of reasearch and various discussions with suppliers, we ended up in discussions with Anthony at Mictronix and agreed on buying a pair of Mictronix 24V 90AH / 2.2kwH Australian made drop in replacement lithium batteries.

Mictronix 24v 90ah Lithium drop in replacement battery

Specifications:

• Weight is only 20KG
• Dimensions: 365 x 220 x 205 - similar size to a standard AGM battery
• 80 amp continuous discharge current
• 250 amp peak discharge current (1 second)
• 80 amp continuous charging current
• 29.2V recommended maximum charging voltage
• low voltage cut off protection
• Charge temperature range: 0°c - 55°c
• Discharge temp range: -20°c to 60°c
• 3 year warranty  
• 10 year design life
• Lithium phosphate chemistry (Lifepo4)
• Drop in replacement for lead acid, SLA or gel batteries
• Very high cycle life. 3000 cycles @ 100%DOD, 4000 cycles @ 80%DOD, 5000 cycles @ 70% DOD
• Safe and inert. Each cell has a built in safety fuse to stop over pressure and thermal run away. Cells are not flammable or explosive like lithium ion batteries
• A+ grade cells are used which are tested before leaving the factory and also after pack assembly
• Impact resistant 3mm seam welded Aluminium case made in Australia. Powder coated in hard wearing texture finish black
• Pressure relief, humidity resistant valve to resist the ingress of water
• Hi quality terminals with M8 bolts for lugged connections. Terminal guards included
• Built in battery management system protecting the battery against over charge, over discharge and a range of other parameters 
• Able to be paralleled for more capacity. Unlimited amount of batteries can be connected together.

In comparison to the previous batteries, these 2 battery modules weight 40kg vs the 186kg of the 4 prior batteries.

We can safely extract 80% (144AH) of this 180AH battery bank as opposed to 50% (133AH) of the 265AH prior battery bank. The 2 new batteries fit easily in the existing battery box with plenty of room to grow if/when required.

Old battery setup - post from 29/4/2017

After consideration of available 24V 300+ AH house battery options namely AGM, Lead Crystal and Lithium/LiFePO4, we settled on Betta Lead Crystal Batteries for their resilience, simplicity and cost effectiveness sourced through Brian at System Logix.
We are using 4 x Betta Battery model 3-EVFJ-265 wired in series to provide us with 24V and ~350 AH at C20/20 Hour rate. Complete Data Sheet Here


A heavy duty box was fabricated and the batteries were aligned for optimal position under the dinette / second bed. The batteries are interlinked with 50mm2 / 0 AWG fine multi-strand battery cable and suitable crimped M8 lugs

Insulating and carpeting cab area

In an effort to improve the noise and temperature in the cab area over long trips, we have removed the old stiff brown factory vinyl flooring over the dry and factured bitumous sound deadener.

Dry ice was used to freeze and crack the factory bitumous sound deadener and a dull metal scraper was used to help lift it cleanly off the bodywork & floor.

Car Builders Stage 1 Sound Deadener was applied to the floor and vertical surfaces in the cab area - it is a ~2mm vibration/sound dampening mat. It consists of a butyl rubber noise absorption layer combined with an aluminium top layer. Joins were sealed with 0.5mm aluminium tape.

Next Car Builders Mass Noise Liner Lite was applied over it over the sound deadener - it is a heavy weight sound barrier, with a total thickness of 8mm and constructed of 2mm Mass Loaded vinyl upper layer, coupled with a 6mm closed cell foam to create an effective means of acoustic blocking. The flexible closed cell foam is water resistant and offers superior thermal insulation. Seams were joined with mass loaded vinyl and cyanoacrylate glue.

Finally charcoal coloured plush pile moulded carpet was sourced through TruFit Auto and trimmed into place for a quieter, cooler cab with a much nicer feel and apperance.

Repowering our tired 1HZ with a fresh 1HZT engine

Our last big trip pushed our Motorhome's original 1HZ 4.2L diesel engine life beyond 500,000 kms and whilst extremely reliable, not consuming any oil or having any mechanical concerns, it wasn't the most powerful engine lugging almost 4.5 tonnes along.
This was particularly obvious when encountering any incline/mountains, attempting to overtake any slower vehicles safely or when the weather was over 30 degrees and we needed AC the most and it became a choice of keeping up with traffic or running the AC.

After researching our options, we agreed that a turbo charged option was preferable based as much as possible on factory parts so we tossed up running the factory mechanical injection turbo Coaster options of either a 94- 1HDT (HDB50-ZRMEX) or the rarer 93-96 1HZT (HZB50R-ZRMRXW1)

After weighing up the cost/benefit of buying an import/used 1HDT and then refreshing it versus a used 1HZ and turboing it, we decided on the later option after speaking with numerous importers and engine builders.

We agreed to work with Reece Diesel on our rebuild. We started with a cheap second hand used 1HZ engine core from a HZJ105R model Landcruiser.
Reece built our 1HZT to the following specifications:

Ground up rebuild of 1HZ long block - inspect, x-ray, hone, machine, complete bearing/gasket/seal kit
New 1HZ head
Rebuilt 1HZ injectors to suit 1HZT
Rebuilt compensated injection pump to suit 1HZT
Reece specification 1HZT ceramic coated pistons & rods
Denco complete turbo kit
OEM Timing kit
OEM Water pump

Freshly Rebuilt 1HZT engine

The Denco Schwitzer S2D based turbocharger kit for low boost torque and reliability

Up it went high enough to clear the engine being lowered down and rolled forward from underneath

After much preparation with a lowering gantry, removing the crossmember and steering linkages as well as engine ancillaries / wiring / hoses etc, down came the old engine

Rebuilt engine fitted with a fresh clutch kit

Up and in went the fresh 1HZT engine

Major differences noted between a Coaster 1HZ and Landcruiser 1HZ engine variants

• 24V vs 12V - alternator, starter, glow plugs, diesel shutoff solenoid
• Oil sump & pickup - front vs rear sump
• Injection pumps
• Heater coolant circuits - 1 one on  Land Cruiser head vs 2 on Coaster head
• Harmonic balancer & secondary pulley - 4 bolt vs 6 bolt and AC offset
• AC mounting bracket different size
• Pilot/Spiggot bearing 12mm vs 15mm ID

Provision for water temperature, oil pressure, boost pressure and exhaust gas temperature sensors were factored into the engine plumbing for fitment of a pair of dual Redarc gauges to be able to monitor the vital engine health parameters whilst driving.

A new OEM heavy duty spec multi-pass alloy radiator is being fitted to help with cooling.

Links:

Reece Diesel

https://www.facebook.com/reecediesel/

Nicer photos & video of our engine by Reece Diesel

https://www.facebook.com/reecediesel/posts/2834929606775919

https://www.instagram.com/p/CLKl_uDg6OS/

Reece Diesel 1HZT rebuild video
https://youtu.be/r2uf80Nj9Z0?t=6

Denco Kit details

https://www.dencodiesel.com/collections/aftermarket-turbo-systems-parts/products/turbocharger-system-toyota-hzj75-landcruiser-with-exhaust