2H Power Recovery

[Ben Stratford]

ok, so the engine now has 175k Miles on it and runs well but at 28 years old it struggles with hills when fully loaded with occupants and camping gear etc.

Never the most powerful motor to start with, I suspect a few horses have escaped and need rounding up again.

Is there established wisdom of a heirarchy of tasks to do to improve things from minimal cost to most costly?

Its totally standard at the moment and filters get changed every 5k

So far thinking of valve clearances as the first thing to check.

Have read about fuel timing but not sure how easy it is to check.

Other suggestions would be very welcome.

One day an engine swap to a rebuilt 12H-T will happen but I need to find one first!!

 

[moggy1968]

interested on this as mines got a few gee gees absent as well. Doing the tappet clearances did make a big difference, although they were rattling a bit!
I did put it on a dyno a couple of years ago and it had 67 at the wheels if I recall
tyre size makes a big difference to hill climbing ability

 

[Towpack]

I would say, first make sure the valve clearances are in spec then do a compression test which will give you a good indication of the overall condition of the engine. Low compression on one or more pots can be fairly easily diagnosed as pistons/bores or head/valves so you'll have a good idea what to do next. If they're all good then check fuel timing etc.

 

[Rodger]

Like you we have an ageing 2H but ours is pre '85 and of unknown mileage having done service in a 60 that ended up being scrapped while the engine, boxes, etc transferred to our 40. A while back we had similar symptoms - lacking power on climbs etc.
We haven't played with the fuel pump as this appears to be a dark art but we changed the flex pipe that links the chassis fuel line to the engine as they corrode inwards and reduce fuel flow.
We do the valve clearances although they never seem to need major adjustment but we do regularly use injector cleaner. We also found that the viscous fan was creating drag.
The biggest change to the power and general engine performance was removing the exhaust manifold and fitting headers. The change was amazing and climbing hill is no longer a laborious task and it pulls all the way through the rev range now that the engine can breath properly.

Regards,
Rodger

 

[Ben Stratford]

what configuration / bore size are your headers Roger?
Thinking about an exhaust change away frim standard when the current one expires

 

[Ben Stratford]

interested on this as mines got a few gee gees absent as well. Doing the tappet clearances did make a big difference, although they were rattling a bit!
I did put it on a dyno a couple of years ago and it had 67 at the wheels if I recall
tyre size makes a big difference to hill climbing ability

I suspect mine will be a similar figure at the wheels moggy.
It does seem to have more power when its colder weather. Some 2nd gear hills can just be done in 3rd!! Not totally sure why this is but probably why people have intercoolers?

 

[Ben Stratford]

I would say, first make sure the valve clearances are in spec then do a compression test which will give you a good indication of the overall condition of the engine. Low compression on one or more pots can be fairly easily diagnosed as pistons/bores or head/valves so you'll have a good idea what to do next. If they're all good then check fuel timing etc.

A good shout Towpack, but how would you do a compression test - remove the glow plugs??

 

[Rodger]

I'll get relevant measurements and photos done for you over the next few days.
I got this set on sale from www.sor.com but they were actually for an FJ60 and not as advertised for a HJ60, but we got new profiles made and slightly modified the pipes to make it fit. Basically it's 6 into 2 into 1. I also use a ss box and finish the system just behind the driver's door (LHD).

More to follow

Rodger

 

[Rodger]

Well it's raining today so took the opportunity to measure and photo the headers:

Profiles were made from the gasket shape as a template. we had to remove the original profiles as 3 on the FJ60 are wrong. But the head exit is oblong (ish) so we had to do a bit of pipe reshaping.
The 6 are 38mm OD
Then 2 x 3 into 1 and they are 51mm OD
The 2 into 1 is 55mm OD as is the rest of the system.
The vacuum pipe is around 50mm from the pipes and has no signs of heat deterioration.
I have not measured lengths but can do if you so wish.

Sorry it's all a but dirty at the moment after a summer of off-roading. Winter will see it cleaned up.

Regards,
Rodger

 

[Towpack]

A good shout Towpack, but how would you do a compression test - remove the glow plugs??

Yes, removing the glow plugs is the only way you could do it on a diesel.

 

[Ben Stratford]

Thanks Towpack, will need to get the right fitting and remove all glowplugs first to stop anything firing up

 

[Ben Stratford]

Well it's raining today so took the opportunity to measure and photo the headers:

Profiles were made from the gasket shape as a template. we had to remove the original profiles as 3 on the FJ60 are wrong. But the head exit is oblong (ish) so we had to do a bit of pipe reshaping.
The 6 are 38mm OD
Then 2 x 3 into 1 and they are 51mm OD
The 2 into 1 is 55mm OD as is the rest of the system.
The vacuum pipe is around 50mm from the pipes and has no signs of heat deterioration.
I have not measured lengths but can do if you so wish.

Sorry it's all a but dirty at the moment after a summer of off-roading. Winter will see it cleaned up.

View attachment 132407

View attachment 132408

Regards,
Rodger

Great info and pics Roger.
Should be even simpler on RHD with no steering stuff in the way. A 3 inch straight through stainless system exiting to the side behind the rear wheel with tubular manifold would be nice. Its firmly on the list!!

 

[AndycruiserguyLomas]

A good shout Towpack, but how would you di a compression test - remove the glow plug??

Ben, I doubt at the mileage there would be any compression issues if the engine runs smoothly and doesnt use oil, if in doubt knock each injector off in turn and see if the effect is the same. If it is then the comps will be ok.

interested on this as mines got a few gee gees absent as well. Doing the tappet clearances did make a big difference, although they were rattling a bit!
I did put it on a dyno a couple of years ago and it had 67 at the wheels if I recall
tyre size makes a big difference to hill climbing ability

One thing to bear in mind when adjusting the tappets on a 2H engine with quite a few miles on it is that the rocker ends can wear quite badly with quite a significant witness indentation from the top of the valve. This can be accelerated the wider the gap becomes and when the tappets are adjusted with a feeler gauge a false reading even though it "feels" right. The engine will be quieter and more efficient but the tappet clearance will still not be correct.
The way to overcome this is to remove the rocker shaft, turn it over and examine the rockers, refacing as necessary, then the correct tappet clearance will be achieved.



When I drove yours Andy, I didn't think it was short of power bearing the increased weight over standard it was lugging along and its mileage. These engines wear very slowly and only start off with 99 bhp when new so 67 at the wheels is not bad really.

There is only one sure way to increase power on a 2H by 30-50% and that is to add a turbo kit. I've had five 60's with after market kits on, 2 with intercoolers and they absolutely transform the hill climbing abilities and in gear acceleration to modern day standards. Apart from a tweak to the pump an oil cooler is helpful as is top.quality oil.
The 12H-T engine doesn't really have any more power than a turbo'd 2H in my experience as I ran my 61 for a couple of years inbetween the others.

 

[Ben Stratford]

Thanks Andy, more quality info from real experience. So there are quite a few options here.
A rebuilt 12H-T is going to dent the piggy bank, and is a more long term aspiration, so how to get 80% of the benefit at 20% of the cost would be a very good result.
So in what order should upgrades be undertaken then?

 

[moggy1968]

Ben, I doubt at the mileage there would be any compression issues if the engine runs smoothly and doesnt use oil, if in doubt knock each injector off in turn and see if the effect is the same. If it is then the comps will be ok.






One thing to bear in mind when adjusting the tappets on a 2H engine with quite a few miles on it is that the rocker ends can wear quite badly with quite a significant witness indentation from the top of the valve. This can be accelerated the wider the gap becomes and when the tappets are adjusted with a feeler gauge a false reading even though it "feels" right. The engine will be quieter and more efficient but the tappet clearance will still not be correct.
The way to overcome this is to remove the rocker shaft, turn it over and examine the rockers, refacing as necessary, then the correct tappet clearance will be achieved.



When I drove yours Andy, I didn't think it was short of power bearing the increased weight over standard it was lugging along and its mileage. These engines wear very slowly and only start off with 99 bhp when new so 67 at the wheels is not bad really.

There is only one sure way to increase power on a 2H by 30-50% and that is to add a turbo kit. I've had five 60's with after market kits on, 2 with intercoolers and they absolutely transform the hill climbing abilities and in gear acceleration to modern day standards. Apart from a tweak to the pump an oil cooler is helpful as is top.quality oil.
The 12H-T engine doesn't really have any more power than a turbo'd 2H in my experience as I ran my 61 for a couple of years inbetween the others.

It's on the hills and towing it's really noticeable. They reckon you lose about 20% at the wheels compared to doing it at the flywheel so actually 67 at the wheels probably isn't too bad.
I've got my eye on a turbo, just need that engine and 'box off yours now ;o) can you email a price for the complete vehicle, I need to know how many pennies to save!!

 

[chapel gate]

I suspect mine will be a similar figure at the wheels moggy.
It does seem to have more power when its colder weather. Some 2nd gear hills can just be done in 3rd!! Not totally sure why this is but probably why people have intercoolers?

Yes, cold air is denser.

 

[Ben Stratford]

Should an intercooler be one of the first things to do?

 

[AndycruiserguyLomas]

Should an intercooler be one of the first things to do?

Not without a turbo Ben.

 

[Ken Winstanley]

Diesel motors run better on cold days as they receive more oxygen

 

[Ben Stratford]

Been thinking of moving to greenland for better performance!!