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Discussion Starter #1
Well, I think I will rebuild my OM352 this winter. I think it has started to knock a little on a couple of the rods.

I am planning to keep the OM352 block at this time...

So...What to do....

Ideas (some not mine, some mine)

-P7100 pump
-10mm plungers in the factory pump
-U1700 pump curve
-OM366a/la head
-Ported and polished OM352 head (is it really any worse breathing? I have thought so in the past, but the CSA seems to disagree...)
-0.060 oversize
-Bigger oil pump
-oil cooled pistons (like internal oil cooling, not just spraying it on them)
-lower CR (like all the factory MB OM352/366 engines running over 150 hp)
-Aftercooler
-Propane (I mean, shit, why not...)

Or:

-Just give up and put an OM906la in....

Interested and open to thoughts and knowledge of the collective before I start...

Will update this thread as progress is made.

C.
 

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Good timing, I have similar questions. I have a 170hp 352 motor (80,000km on it) on the way to replace my 125hp. I was thinking about "refreshing" it at least whist it is out.

My list was:

Gasflow head ( done this to all my vehicles I have ever overhauled), maybe ceramic coating the inlets and outlets as well.
Valve guides with seals
new rings and honed cylinders,
new bearings (mains and big ends)
valve seats
new air pump
water pump and seals
getting the crank/pistons/flywheel all balance to make it as smooth as possible.

I was also thinking of ceramic coating the piston crowns and the skirts, and the back of the valves whilst it was all apart. I have heard good reports on the benefits, not sure how long it lasts but the theory seem pretty good and it is not expensive over here.

The new motor comes with the 170hp fuel pump with the boost compensation aneroid, big oil pump and oil squirters etc. With my little turbo and inter-cooler, I was thinking of trying to get around 200-220hp out of it by turning up the fuel pump and the boost and I understand I can get the injectors modified as well to match.
 

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Good timing, I have similar questions. I have a 170hp 352 motor (80,000km on it) on the way to replace my 125hp. I was thinking about "refreshing" it at least whist it is out.

My list was:

Gasflow head ( done this to all my vehicles I have ever overhauled), maybe ceramic coating the inlets and outlets as well.
Valve guides with seals
new rings and honed cylinders,
new bearings (mains and big ends)
valve seats
new air pump
water pump and seals
getting the crank/pistons/flywheel all balance to make it as smooth as possible.

I was also thinking of ceramic coating the piston crowns and the skirts, and the back of the valves whilst it was all apart. I have heard good reports on the benefits, not sure how long it lasts but the theory seem pretty good and it is not expensive over here.

The new motor comes with the 170hp fuel pump with the boost compensation aneroid, big oil pump and oil squirters etc. With my little turbo and inter-cooler, I was thinking of trying to get around 200-220hp out of it by turning up the fuel pump and the boost and I understand I can get the injectors modified as well to match.
Just buy new Kolbenshmidt pistons. You cannot get your Pistons coated and install new rings for the price of Kolbenshmidt pistons that are already coated with new modern rings installed. I believe I paid $65 a piston new.
 

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What 2 Do

Well T Modler
I know a guy who has a really strong OM-366 LA engine (45 k miles)
As well as al the SBU mog engine furniture off a 1994 U1200 to convert it to a mog engine--366 is so smoothe-- it's a no brainier 4 me. Can get lots of safe power out of it too.
TLane
 

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Seriously consider TLane option, if it was not for the wife list (sometimes very different than mine), that 366 or what it is in would in my mog, or my yard, respectively...

I looked at the cummins option, can be done, but boatloads of custom fab - and I can fab just about anything, but the time...wow...
 

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What is the maximum rpm on a 366LA vs a OM352A. I thought there was quite a difference, hence you need the high speed axles which were standard on a OM366 Unimogs. No point having more power but losing 20kph in speed.

Apart from the 366 cyclinder head, what else do you need for the swap, intake manifold, cam cover, exhaust manifold, injectors? waterpump?

What would the actual power gains be, anyone done some proper dyno tests or at least a 0-60kph series of tests, fuel consumption before and after, etc.

"Seat of the pants" tests after someone has spent a lot of money tend to be very biased, especially if the old engine was stuffed :)
 

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What is the maximum rpm on a 366LA vs a OM352A. I thought there was quite a difference, hence you need the high speed axles which were standard on a OM366 Unimogs. No point having more power but losing 20kph in speed.

Apart from the 366 cyclinder head, what else do you need for the swap, intake manifold, cam cover, exhaust manifold, injectors? waterpump?

What would the actual power gains be, anyone done some proper dyno tests or at least a 0-60kph series of tests, fuel consumption before and after, etc.

"Seat of the pants" tests after someone has spent a lot of money tend to be very biased, especially if the old engine was stuffed :)
A well speced om352 can be smooth as silk and quiet. Mine is!! I can't justify a 366 unless it just happened to be in the truck already. A fresh build of a 352 with the right selection of parts will match a 366 in my opinion for both smoothness, noise and power. On thenotherhand I am more than confident the 366 will turn 3000rpms or more just like my 352.

Basically I don't favor either engine as I think they can both achieve similar results.
 

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I'd have to check, and I'm on the road, but my
OM366A has a redline at 2800-2900 RPM.
From what I remember ( what I was told ....that I remember),
The Rev limits for the OM 366A vary based On the 'Euro
Numbers'.
So, the Farmers with OM 366 A's in their AG Unimogs
Favored the " Euro 1" spec, which allowed for a higher
Rev limit , which allowed them to run implements at higher revs .
The Euro 2 rating limited the RPM for better emissions-
Less RPM = less combustion cycles = less emissions.
I don't know the specifics of the situation, nor the politics,
But my truck has an OM 366 A , which revs to 2900
Easily.
 

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Both are fine engines, suspect the 366 is a tick more evolved.

I have upgraded to a holset, very nice change on my 352a.

A rebuild is likely in my future.. Tweaked a bit if possible.
 

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I can attest to DokaTD's excellent OM352. It runs much better than my 366 in the power and smoothness department, but it does have work done.

Talking to Neil at Merex, he says the only reason the OM366 was rated at a lower RPM in the Unimog was because of emissions. I'm sure they can take 2800-3000 RPM easily.
 

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Here's a Hellgeth beast:

wheelbase 3250mm, with high performance engine based on OM366LA, 303hp at 2600rpm and 951Nm at 1800rpm , special turbo for higher boost pressure at a wide range, central high performance intercooler with separate fan, injection pump and injectors modified for higher fuel rates, split gearbox, fast axle ratio, Michelin 365/80R20 XZL tires, Inox steel exhaust, additional fuel tank 300 l lhs,
I'm sure back in the day they tuned OM352's accordingly as well.

Then Jurgen's (of Hellgeth) 320hp (no torque figure listed) OM366LA, not bad for a camper ;) wonder what the German equivalent is for the Dukes Of Hazzard horn sound is:

U1300L Marokko.JPG
 

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Discussion Starter #15
Wow, OK, let me try to get this back on track.

First, if anyone wants to swap in a Cummins, I applaud you. Have at it. If you think it will be easy, then stop Armchair Unimogging and go out and look at what is really required and the trade offs. It is not simple or particularly viable on some UNIMOGs, mine among them.

Second, I have plenty of power currently. The OM352/366/356 is a fine engine that makes plenty of power if managed right. I am only thinking of playing with it because it needs to be refreshed.

Third, the OM366 series also has siamesed port issues. The only reason I am looking at a 366 head is because:

1. I know where a couple are that are fairly well priced.
2. I dislike the intake through the valve cover design of the 352 (personal preference, and I don't really want to start a he said she said battle regarding others' opinions on it.)
3. I think it will make for a quieter engine. (Again, my opinion...)

Fourth, I want to keep the 352 block for one reason: I already have it. If I already had a 366 block I would similarly want to keep it. Sometimes the simplest reason is the correct one. Also, the later 352 and early 366 blocks are the same.

Fifth, why are we talking about 500hp engines in UNIMOGs again? I am not always in the mainstream, but what is the attraction of converting your truck/tractor into a dyno queen. Other than breaking everything in the drivetrain...

Sixth and last, this is a thread about an OM352 engine rebuild and options. Excuse my frankness, but please take all of the Cummins drivel over to a Mopar forum, or at least stop junking up my thread with it and reply to the existing Cummins engine thread(s). I would like this to be a useful and clean technical thread on OM rebuild options. I may ask the mods to remove the offtopic posts.

Let's get back on topic...

C.
 

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As many of you know my 366A as a new crate motor was warmed up by Hellgeths. It also has the Stainless 4" exhaust with a Flowmaster Muffler, with low restriction. I chose the 236 HP upgrade and hav not been sorry. That upgrade included, oversized piston spritzers, Big injectors,larger plungers in the IP, advanced Bosch timing. The 4" exhaust allows extra HP to be utilized. I have felt my engine has gotten stronger as it has gained some miles. They governed my engine at 3300 rpm-74 MPH topped out. I have had it there once---it ran smooth as silk. Was scary though. I generally run it down the freeway at 61mph with the big trucks and it is turning at about 2600-2700 rpm--no problem.
My engine temp never exceeds normal. Even on mtn grades it runs normal. I am planning an MERZ intercooler in the future so we will see how that goes. Bottom line is--the 366A and LA engines are robust---will give long service with normal running and good care.
I have a neighbor with 5-MERZ 1219 5ton, 20 foot, flatbed trucks. All have MERZ 366LA engines and all have over 400,000 miles on each of them, average. He hauls bins of fruit from the field to local packing sheds. These trucks work every day during the fruit season and never let him down. Running and running and running. His only failures have been Garrett turbos wearing out--but easy fix.
Mercedes builds a good diesel.--- The 352A, or the 366A will give you good service.
My 2 cents worth.
TLane
1987 435T
 

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As many of you know my 366A as a new crate motor was warmed up by Hellgeths. It also has the Stainless 4" exhaust with a Flowmaster Muffler, with low restriction. I chose the 236 HP upgrade and hav not been sorry. That upgrade included, oversized piston spritzers, Big injectors,larger plungers in the IP, advanced Bosch timing. The 4" exhaust allows extra HP to be utilized. I have felt my engine has gotten stronger as it has gained some miles. They governed my engine at 3300 rpm-74 MPH topped out. I have had it there once---it ran smooth as silk. Was scary though. I generally run it down the freeway at 61mph with the big trucks and it is turning at about 2600-2700 rpm--no problem.
My engine temp never exceeds normal. Even on mtn grades it runs normal. I am planning an MERZ intercooler in the future so we will see how that goes. Bottom line is--the 366A and LA engines are robust---will give long service with normal running and good care.
I have a neighbor with 5-MERZ 1219 5ton, 20 foot, flatbed trucks. All have MERZ 366LA engines and all have over 400,000 miles on each of them, average. He hauls bins of fruit from the field to local packing sheds. These trucks work every day during the fruit season and never let him down. Running and running and running. His only failures have been Garrett turbos wearing out--but easy fix.
Mercedes builds a good diesel.--- The 352A, or the 366A will give you good service.
My 2 cents worth.
TLane
1987 435T

My 352 experiance is almost identical to your 366 experiance. My engine is also worked over a bit but im only about 200hp due to my IP. This could be easily overcome though. I also am maxed out at 3300RPM and regulalry run up there as the engine is smooth as silk.

Both engines are great. Both can achieve excellent results.
 

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Discussion Starter #18
OK, so I figure I will probably start this build in December, just gathering bits until then.

Terry's build sounds like a pretty nice place to be and I know first hand how DtD's runs (like a scalded puppy, almost as fast as my scalded dog :1poke:).

The 4" exhaust is a very good point, anything that increases pressure drop across the turbo is good. I am currently pushing about 26 psi with a little smoke, so assuming that I am aftercooling in the new build, I will need more turbine speed to make enough boost at the engine. Obviously fuel can play a part in that, but pressure drop is the free way....

That will mate up well to my 4" cowl in any case...

I have a 60 lb propane tank that has no home at the moment, so I may fog the engine also.

C.
 

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Discussion Starter #19
Seriously consider TLane option, if it was not for the wife list (sometimes very different than mine), that 366 or what it is in would in my mog, or my yard, respectively...

I looked at the cummins option, can be done, but boatloads of custom fab - and I can fab just about anything, but the time...wow...
If Terry did not live almost as far as possible away from me in these United States, I would have already bought it. 2500+miles is a complicating factor (both cost and time).

C.
 
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