Horsepower differences in 4FB, 4HB, 4DB etc.

[EastTexasRed]

Is anyone able to explain to me what differences in the standard 2.5d engine cause differences in horsepower? Is it pistons, head, injector pump, air delivery? A combination of these? The reason I ask is because I have a 1994 4FB 70PS which burns oil but which has a good injector pump and I have a 2000 4HB 76PS with a bad injector pump. I'd like to put the pump from the first onto the second. They are both Bosch V series pumps and I was told they are interchangeable. But then someone else told me they are calibrated differently to give a different injection pressure and that is where the difference in horsepower comes from. Anyone able to give a definitive answer?

[wojciech]

Anyone able to give a definitive answer?

Problem is... convexo-convex.
Under link http://www.dieselpartsworld.com/33704.html
you can find Stanadyne pencil injectors parameters according to their numbers.

In data tables you can find injectors numbers according to engine power, year etc.




Try to find more threads about injectors with more data - in every one is some errors, this two tables are also little bit inconsistent. Problem is very difficult to make sense for 100% certainty...

[Chug]

Fit the pump it will be ok, it may just need the fuelling playing with.

It looks like the 4fb will have 0 460 414 113 Bosch pump
and the 4hd will have 0 460 414 119 Bosch pump
both are VE4/11F2000R rated pumps

VE = VE type pump (VP is also a VE pump)
4 = number of cylinders
11 = 11mm plunger
F = mechanical governor (E = electronic governor)
2000 number = governor controlled RPM (this is pump rpm not engine rpm)
R = clockwise rotation

you can look at the different pump info and part numbers here
http://dieselcatalog.online/en/bosch/li ... bosch.html

[EastTexasRed]

Problem is... convexo-convex.
...

Wow! That may take some time to digest, but many many thanks.

Does that reply mean the injectors determine the horsepower?

And ... ummmm ... what does "convexo-convex" mean?

[EastTexasRed]

Fit the pump it will be ok, it may just need the fuelling playing with.

Thanks, that's what I wanted to hear. If my addled brain can remember to do it, I'll let you know how it goes.

[Chug]

Mainly injectors yes, but the pump also needs to be fuelled up more for higher rated injectors, your pump will probably need fuelling increasing as it comes from the 70ps engine then put on the 76ps, unless someones fitted 70ps injectors!

[Keef]

and to be honest, I've had many 70ps and 76ps vans and have never noticed a difference in power anyway!