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Hello

I have heard stories about people gaining an extra 5O horse power from an OM352 by changing Diesel pumps?
If this is true,what diesel pump do you change it to?
Thanks in advance.
 

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BenzWorld UNIMOG statesman
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Diesel Talk
is a good start, DONT forget the pyrometer. Depending on hours, you might want to have your injectors rebuilt. I did and it made an immediate difference in power. More fuel wont matter if it can't get there.
Great information.

BTW this information is already in the DIY / FAQ's. You can find that thread via the ULTIMATE MOG STICKY at the top of this forum. It's a good practice to reveiw them before posting questions.

oh..... and if you ever see anything worthy of being put in Ultimate sticky please do not hesitate to let me know.
 

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oh..... and if you ever see anything worthy of being put in Ultimate sticky please do not hesitate to let me know.
How bout Trucktors photo cache
 

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How bout Trucktors photo cache
Just one question on that photo cache, what kind of super computer must he have to save all that on? Truely awesome!!!!!!!!!!!!!!
MUD
 

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Moggers:

I have an archive of old e-mail and some discuss this subject. I note the referenced article discusses rodding up a 110HP engine.

Here's an example from JACK RUSSELL, discussing this more in depth:

*****************************

Message: 9
Date: Tue, 1 Jun 2004 07:08:10 -0700
From: Jack Russell <[email protected]>
Subject: Re: [MOG] 406 timing
To: Mog Mailing List <[email protected]>
Message-ID: <[email protected]>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed


On May 31, 2004, at 8:53 PM, PATRICK KENNEDY wrote:

> I recently turned up the Injection Pump on my 1978 406 from 80 hp
> to approx 130 hp and installed a exhaust pyrometer. I also advanced
> the timing by marking the pump with a scribe and rotating it an
amount
> I determined. According to my calculation I was unable to advance the
> timing enough due to limited travel of the pump.
> When other people have done this (Kai?) were you able to do it
by
> just rotating the pump, or did you have to remove it from the engine
> and advance it one tooth?

Kai is the one to answer timing specific questions, but be aware that
the pump used for the higher output naturally aspirated 352's in
Unimogs ([email protected] HP, [email protected] HP, and [email protected] HP) is not
identical to yours. Your pump has 8.0mm plungers and barrels. The
higher HP units use 9.0 mm plungers and barrels. In other words to get
more liquid (fuel) flow, you need a larger diameter "straw".

Do not take the pump off to advance it a tooth.

Jack Russell

*************************

I have more info from the old masters about higher HP OM352's, including differences in compression, piston cooling, turbocharging, ect. As questions arise, I'll see if I can find pertinent messages.
 

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Thanks for posting that Keith, that is definitely interesting info about difference in OM352 fuel pump piston diameter.

SG
 

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Don't forget that the UNIMOG pump is basically a tractor pump.

For better throttle response, more like that of an auto, use an 8mm or 9mm plunger pump from one of the many OM352 MB truck engines.

Back under my rock,

-Sean P.
 

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Humph,
And what indeed is wrong with a "tractor pump"
My old MB Trac 1000, 6 cyl, 352 engine?? started last night,literally first kick, having sat since September without being started.
This in for us a britterly cold night -5 degrees Celcius,
an that with jump leads offen the already undersized battery in my wee "G".
The 1.9 TDI Galaxy was harder to start and she had only been sitting 6 weeks!!
 

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Humph,
And what indeed is wrong with a "tractor pump"
Absolutely nothing. It's the perfect pump for what the Mog was originally designed to do. But, if you change the trucks primary use, it could be wise to change the IP.

It's all in how the pump governor handles changes in engine speed vs load. The tractor-type pump will try to keep a static RPM, whatever the cost, which is great for off-road and low RPM action.

A on-road pump is much smoother 'on-road', but would struggle and cause the engine RPM to fluctuate too much while plowing or crawling (for fun or work).

There is a GREAT Bosch diesel IP manual available that details the torque curves of the various types of pumps - very interesting reading !

*EDIT* BTW, the reason a Mog with a tractor pump starts so well is because that type of pump AUTOMATICALLY sets the fuel delivery to 100% at -0- RPM. So, you're basically full fuel on start. That's why you feel that weird surge of power and RPM for a fraction of a second when a Mog OM352 first fires up - before the governor has a chance to get things under control.
 

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There is an old L1100 (or something like that?) truck not far from me with the 352A, and I have been trying to talk the owner down to a reasonable price. The thing is a complete basket case, though the engine does start and run well. I took the IP# to Hoffmans fuel service, they did confirm that it was a 9mm pump, and that there were a good number of different governer parts to tune it differently. I sometimes wonder if I could secretly lowjack the thing, so if it ever disappears I'll know what yard it got towed to. There are two more of those trucks that drive by my shop every day, and they have way more acceleration than any regular 352 mog, turbo sounds sweet all spooled up too!
 

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As luck has it, my motor code is 353.940. It's nice to know my pump has the larger plungers - thanks in kind, Mogasaurus!
 

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My OM353.902 has the smaller HP at 84, and therefor the smaller plungers. What are my options in swapping plungers?

ACUF
 

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I think your best bet will be to find an injection pump with the larger plungers. Switching them out may be an option, but by the time everything is said and done it would probably be more costly than a good used pump.

Cheers,
Ben
 
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