Item

Notes

Relevant Resources/Images

Tyre Pressures

Ensure tyre pressures are good and high. 40psi on the highway is what I use

Tyre size

31” tyres are probably ideal, the larger the tyre - the slower you’ll go. I love 33s personally and happy to trade off a bit of performance for them.

Fit Extractors (also known as “headers”)

Contributes to a free flowing exhaust

Valve Timing

Exhaust and Intake valves should be set to the factory specification.

Inspect the rocker arms for excessive wear as this is very common on 2Hs and makes it nearly impossible to get good valve clearances.

Procedure is described in Factory Service Manual (EM-22)

https://drive.google.com/open?id=0B-KW6mdxQyjDejd5MlNXVXJVd2c

Inlet 0.20 mm HOT
Exhaust 0.36 mm HOT

Below is a link to a video of excessively worn rocker arms on a 2H - note the conical depression in each - they should be smooth (with a profiled surface).

 https://www.youtube.com/watch?v=dBWNGHAh6b0

Minimal exhaust

The 2H loves a free flowing exhaust, use as little in the way of exhaust as you can get away with.

Spill Timing

Ensure injector spill timing is perfect

Procedure is described in Factory Service Manual (EM-23). Manual link below

https://drive.google.com/open?id=0B-KW6mdxQyjDejd5MlNXVXJVd2c

Air Intake free flowing

Ensure filter is clean and if a snorkel is fitted that its not impacting air intake

Vehicle Weight

Keep the weight of the vehicle as low as possible

Fuel Flow

Ensure an unimpeded flow of fuel including:

• Fresh fuel filter
• Factory sedimenter clean
• Brass Gauze screen at inlet on Lift Pump clean - when removing it to clean ensure that new crush washers (14mm internal diameter) are used either side of the banjo when reinstalling        
• Fuel pickup in tank clean (unfortunately to check this the tank would need to be dropped)
  
  

Sedimenter images at this link:

https://photos.app.goo.gl/yTBd1qwecH7oP5L77

Brass Gauze images at this link:
https://photos.app.goo.gl/Qo5LQjASo19fQq9C9

Brass Gauze Screen - marked on this image:

Injector Spray Patterns perfect

Injectors will need attention to ensure spray patterns are good every 200,000klms or so. Any good diesel shop will be able to rebuild them. When refitting the injectors you’ll need new injector seats and gaskets.

Max Fuel Screw not set too conservatively

Wind out screw for more fuel at max throttle, if a turbo is fitted you should ensure an EGT gauge is fitted before doing this. You’re looking for a small amount of smoke under full load, don't get greedy and make sure you can get the screw back to its starting point. Don't rush to do this, consider all other options first, it is sometimes set a bit conservatively from the factory though.

Max Fuel Screw image and adjustment directions here (Full size image at link)

https://photos.app.goo.gl/HYrrksp6DhKEpK9V6

Governor housing drained of oil

Governor housing has a drain screw, ensure all oil is out of it. The oil accumulates from blowby vapours and may impede the operation of the leather diaphragm in the pump.

See it marked on this image (full size image at link)



https://photos.app.goo.gl/a2oYfUFhQnqV9FuQA

Throttle cable not giving maximum travel

Ensure when the throttle is fully depressed that the throttle arm on the inlet manifold is touching the max travel screw and that the butterfly in the inlet is fully open.

EM-26 in the Factory Service Manual

https://drive.google.com/open?id=0B-KW6mdxQyjDejd5MlNXVXJVd2c

Aerodynamics

Roof racks, canopies, roof top tents - all of this stuff adds up to increased air resistance. Its unavoidable when you’re building a vehicle for touring but keep it in mind and think long and hard before adding more items that may make it even worse

Rolling resistance

Keep the vehicle well maintained, wheel bearings in top notch condition, drive shafts greased, uni-joints in great condition etc. It’s very minor, but we’re chasing minor gains in a lot of small areas.

Factory Service Manuals for your chassis.

Driving style

Look for those hills or mild slopes and get a run up.

Get into the right gear earlier as you climb a hill, you don’t want revs to drop too low on a hill as you’ll never recover them.

Transmission notes

Keep in mind that the A440F automatic transmission will definitely result in lower fuel economy - possibly as much as 1-2L per 100klms.. Perhaps more.

Version

Date

Reason

1.0

21st August 2024

Initial version

1.1

22nd August 2024

Aerodynamics and rolling resistance added. Added video of worn rocker arms on a 2H. Added driving style item.

1.2

22nd August 2024

Added image of gauze filter