Coming through where?
There are 180k on the engine
There are 180k on the engine
Mercedes OM617 Powered 110 Build Up
The starting vehicle:
1986 110 with 2.5 liter Petrol engine, leaking fuel tank, and interior and under hood area covered in carpet and other sound deadening material.
Purchased from a UK dealer. It was used by DRA for flight testing of countermeasures equipment. Unique in that it had 44,500 miles and was without front vents presumably to cut down on noise and interference.
1986 110 with 2.5 liter Petrol engine, leaking fuel tank, and interior and under hood area covered in carpet and other sound deadening material.
Purchased from a UK dealer. It was used by DRA for flight testing of countermeasures equipment. Unique in that it had 44,500 miles and was without front vents presumably to cut down on noise and interference.
Attachments
261 - 280 of 401 Posts
I decided since I'm still awaiting my oil pan I might as well change out the head gasket .
First impressions of Om617 compared to 2.5NA... For reference, it is intercooler mated to 1.4 XC.
Night and day difference in power and driveability! The turbo lag is pronounced - for the first few meters as it builds RPMs it seems almost more anemic than the 2.5na. This is likely exacerbated by the intercooler. However, boost builds quickly and predictably and pulls the truck along nicely through the gears. Speedo isn't hooked up yet, but I had no problem keeping up with traffic on flats in 55mph zone. This seems unimpressive unless you have driven a heavily laden 2.5. More to follow on this after speedo is hooked up.
I live around constant hills. The truck can pull up long grades at 45mph with EGT hovering around 1000f. I didn't expect it to cruise up these hills at 60... But it would have been nice. Local steep grades with lower speed limits require me to rev high in lower gears to keep the 25-35 speed.
Low speed running in high range isn't ideal. This is likely due in most part to the switch to a 1.4. Also, the need to rev high for useful torque is limiting. I expect to spend more time in low range than before. While anemic, the 2.5 had a predictable power band in the lowest of rpms and could idle over a lot without stalling. The om617 with this gearing seems to want to stall.
Even at WOT the smoke is minimal. The engine is about the same noise level as the 2.5.
Overall so far pleased and glad to have taken the truck through this metamorphosis. One nagging problem left is a significant oil leak from the oil temp sender. It interferes with the bell housing adapter, and must be turned (unthreaded) slightly to fit past. This turn causes it to leak a good bit - more than is safe. I'm either going to have to shave material from the bell housing adapter or plug the temp sender hole with a 12x1.5 bolt. Even then, I'm not sure how I will remove the sender since it can't be turned a full rotation.
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Night and day difference in power and driveability! The turbo lag is pronounced - for the first few meters as it builds RPMs it seems almost more anemic than the 2.5na. This is likely exacerbated by the intercooler. However, boost builds quickly and predictably and pulls the truck along nicely through the gears. Speedo isn't hooked up yet, but I had no problem keeping up with traffic on flats in 55mph zone. This seems unimpressive unless you have driven a heavily laden 2.5. More to follow on this after speedo is hooked up.
I live around constant hills. The truck can pull up long grades at 45mph with EGT hovering around 1000f. I didn't expect it to cruise up these hills at 60... But it would have been nice. Local steep grades with lower speed limits require me to rev high in lower gears to keep the 25-35 speed.
Low speed running in high range isn't ideal. This is likely due in most part to the switch to a 1.4. Also, the need to rev high for useful torque is limiting. I expect to spend more time in low range than before. While anemic, the 2.5 had a predictable power band in the lowest of rpms and could idle over a lot without stalling. The om617 with this gearing seems to want to stall.
Even at WOT the smoke is minimal. The engine is about the same noise level as the 2.5.
Overall so far pleased and glad to have taken the truck through this metamorphosis. One nagging problem left is a significant oil leak from the oil temp sender. It interferes with the bell housing adapter, and must be turned (unthreaded) slightly to fit past. This turn causes it to leak a good bit - more than is safe. I'm either going to have to shave material from the bell housing adapter or plug the temp sender hole with a 12x1.5 bolt. Even then, I'm not sure how I will remove the sender since it can't be turned a full rotation.
Given enough fuel and air, virtually anything is possible...at least for a short period of time 
New and improved oil pan design
New and improved oil pan design...
There are a few improvements.
Structure is stronger, oil volume larger, with turbo drain and crankcase ventilation easier, and turbulence has less overall effect.
Note the "more relaxed" oil pickup baffle.
New and improved oil pan design...
There are a few improvements.
Structure is stronger, oil volume larger, with turbo drain and crankcase ventilation easier, and turbulence has less overall effect.
Note the "more relaxed" oil pickup baffle.
Attachments
New Oil Pans
Here are some pictures after the final welding, then machining.
Note the slant that compensates for the engine tilt to allow the oil filter housing to clear the Defender-Style Bulkhead.
Here are some pictures after the final welding, then machining.
Note the slant that compensates for the engine tilt to allow the oil filter housing to clear the Defender-Style Bulkhead.
Attachments
I have been revisiting the OM617 on my build. First part is trying to fix leaks.
I noticed some leaking at the lift pump. While searching online I found that user Greazer on Peachparts and STD sells lift pump kits. Got one plus a IP spring kit he sells.
Lift pump new vs old
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I noticed some leaking at the lift pump. While searching online I found that user Greazer on Peachparts and STD sells lift pump kits. Got one plus a IP spring kit he sells.
Lift pump new vs old
Old lift pump removed
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IP spring - new on top - old on bottom. Greazers uses a stiffer spring.
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Spring Valve installed
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Lift pump installed
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Rebuilt injectors from Greazer - 315# with German made internals.
New vs Old
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New vs Old
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