Turbo injection timing?

[Otterav]

Hello,
Looking for a consensus, the FSM shows the injection pump timing for the normally aspirated 3B at 14 deg BTDC. The same manual shows the 13BT at 11 deg BTDC. My question is:
For those who have turboed their 3B did you change the injection pump timing, or change the injectors opening pressure? If so did you notice a difference in the running?
Ola
eric

 

[Dougal]

Hello,
Looking for a consensus, the FSM shows the injection pump timing for the normally aspirated 3B at 14 deg BTDC. The same manual shows the 13BT at 11 deg BTDC. My question is:
For those who have turboed their 3B did you change the injection pump timing, or change the injectors opening pressure? If so did you notice a difference in the running?
Ola
eric

Does it mention different regions or countries with the different timing?
Isuzu's sold in california have timing retarded more than those sold elsewhere. The reason being NOx emissions reduce when the fuel injection is delayed.

 

[Otterav]

Hello,
The retarding of the timing on a turbocharged diesel is not an emissions only detail. My 1968 M-109A3 military truck engine was normally aspirated, when I turboed it, I researched the military manuals for details showing the differences between the 2 types of engines. The normally aspirated engine version shows a 25deg BTDC and the turbo version shows 20deg BTDC. It makes sense, the increased volume of air stuffed into the cylinder would create a higher cylinder pressure, which would cause a higher temperature, which would lead to a more vigorous combustion, which would require less advance for optimal power.
Discuss among yourselves!
Ola
eric
P.S. I am trying to figger out if it would be worth the trouble to retard the injection pump timing and having the injectors rebuilt to the 13BT specs.

 

[Tapage]

Interesting .. 2 questions related.

1. Inline pumps can be retaded or advanced ?

2. My 1HD-T rotary pump are advanced up to 4º and it make run ( or up ? ) speed fast from stop .. but less top end speed ..

 

[RHINO]

yup inline pumps are adjustable for timing, typically you loosen a nut or nuts and rotate the whole pump.

 

[Dougal]

Hello,
The retarding of the timing on a turbocharged diesel is not an emissions only detail. My 1968 M-109A3 military truck engine was normally aspirated, when I turboed it, I researched the military manuals for details showing the differences between the 2 types of engines. The normally aspirated engine version shows a 25deg BTDC and the turbo version shows 20deg BTDC. It makes sense, the increased volume of air stuffed into the cylinder would create a higher cylinder pressure, which would cause a higher temperature, which would lead to a more vigorous combustion, which would require less advance for optimal power.
Discuss among yourselves!
Ola
eric
P.S. I am trying to figger out if it would be worth the trouble to retard the injection pump timing and having the injectors rebuilt to the 13BT specs.

In some engines, advancing the timing is enough to break anything from con rods to cranks and heads. I've met one powerstroke owner who was particularly scared of that.

But the Isuzu 4BD1T engines were retarded for emissions reasons. The same turbo engines sold in other states was advanced 8 deg more.
http://library.motoralldata.com/tec...ntrol_System_Application_Chart/Isuzu_isde.htm

 

[Otterav]

In some engines, advancing the timing is enough to break anything from con rods to cranks and heads. I've met one powerstroke owner who was particularly scared of that.

But the Isuzu 4BD1T engines were retarded for emissions reasons. The same turbo engines sold in other states was advanced 8 deg more.
http://library.motoralldata.com/tec...ntrol_System_Application_Chart/Isuzu_isde.htm

Hey,
You will not I was talking about the difference between 14deg BTDC and 11deg BTDC, which involves retarding the timing, and increasing the opening pressure of the injectors from 1700psi(memory) to 2200psi(memory), effectively retarding the timing even more. Anyone actually done this?
Ola
eric

 

[Dougal]

Hey,
You will not I was talking about the difference between 14deg BTDC and 11deg BTDC, which involves retarding the timing, and increasing the opening pressure of the injectors from 1700psi(memory) to 2200psi(memory), effectively retarding the timing even more. Anyone actually done this?
Ola
eric

I'm wondering why you're heading down this route?
Are you worried about the strength of the engine so much that retarding the timing is necessary?

It will hurt your power and fuel economy.

 

[Tapage]

yup inline pumps are adjustable for timing, typically you loosen a nut or nuts and rotate the whole pump.

how I can do that . ? this it's mine ..

 

[Dougal]

how I can do that . ? this it's mine ..

Look further forward, where the pump bolts onto the timing cover.
They usually have four bolts and slotted holes. Loosen the bolts and you can twist the whole pump.

 

[Tapage]

Look further forward, where the pump bolts onto the timing cover.
They usually have four bolts and slotted holes. Loosen the bolts and you can twist the whole pump.

Twist to the right it's advance ? ( front view of the Cruiser and clocking )

 

[lynchmob]

Twist to the right it's advance ? ( front view of the Cruiser and clocking )

Looking from the front - turning the pump to the right would be retarding the timing.

Anyone considering moving the pump may want to check where the timing is now before doing so. The engine manual has a fairly simple process where you use a stand pipe on #1 outlet on the injector.

All you need is a short length of injector pipe with the nut to attach to the pump. Would be useful to see how far you have moved it as well.

 

[Tapage]

Looking from the front - turning the pump to the right would be retarding the timing.

got it .. !

I never touch the timing of my 2H IP only the fuel ( 2.5 turn over factory setting ) so I would take a test this weekend ( If i can get time .. fiancee order home improvement time )