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+--- Thread: What should I look for? (/showthread.php?tid=2217)
What should I look for? - DieselSchlepper - 02-02-2011
I like the idea of the OM617. I guess that means 1981 to 1985 W123's. Any exceptions, anything more desirable?
RE: What should I look for? - larsalan - 02-02-2011
Earlier too. People are liking the older manifolds.
http://en.wikipedia.org/wiki/Mercedes-Benz_OM617_engine
RE: What should I look for? - garage - 02-02-2011
Well to start with, get one that does not have the trap oxidizer, and it would also be nice to not have to deal with the egr.
RE: What should I look for? - Walkenvol - 02-03-2011
IMHO, if your capable of an engine repower then EGR removal is of no concern as there are $30 kits available to block off the holes in the intake and exhaust manifolds. I made my own in about 30 minutes. If one eliminated all options with an EGR it would reduce the majority of the available OM617 turbo'ed models from which to choose.
RE: What should I look for? - garage - 02-03-2011
Why block off the holes if you can just get a non egr manifold IMHO
RE: What should I look for? - Walkenvol - 02-03-2011
I claim no expertise but from my readings the OM617.950 with 110 hp used from 1978 to 1980 didn't come with an EGR. The OM617.951 and 952 used from 1981-1985 was 125 hp and came equipped with an EGR. So the OM617 turbo we are referencing was sold in the US for 8 years of which the 1st 3 years it had no EGR and 15 less HP. One eliminates 63.5% of the potential donors by choosing only engines produced without an EGR (assuming an equal number of OM617's from each year are still available) along with the loss of 15 HP. $30 or 30 minutes eliminates the EGR. While I also would prefer to have the non-EGR intake and exhaust manifolds to transplant on to a 125 HP OM617, finding them for $30 is not likely in my part of the woods.
That's the logic to my position. If the information is inaccurate please correct it. Thanks!
RE: What should I look for? - casioqv - 02-03-2011
So whom makes the EGR blocking plates?
I'm looking for a set for my OM602... I'm guessing when the EGR valves get old, simply disconnecting the vacuum line from them isn't sufficient to stop all exhaust recirculation?
RE: What should I look for? - Walkenvol - 02-03-2011
http://www.peachparts.com/shopforum/showthread.php?t=92534
Here's a thread on blocking off the EGR on an OM617. I don't have any knowledge of the OM602, but on my OM617 the port in the intake manifold to the EGR was completly stopped up with gunky carbon type of deposits. I don't think any gasses could have reached the EGR so disconnecting the vacuum lines would have probably been fine. Since I had the intake manifold off, I wanted to clean it out to improve the air flow and wanted the eliminate the EGR for both weight and appearance. Hope this helps.
RE: What should I look for? - DieselSchlepper - 02-04-2011
Some advance the idea that if an engine is designed to run with ERG removing actually hurst performance.
RE: What should I look for? - casioqv - 02-04-2011
My understanding is that the EGR systems are designed to deactivate at high throttle so really no engine is "designed to run with EGR" under heavy load. In this case, removing the EGR can't affect engine output at high throttle openings one way or the other. But at part throttle, I can't imagine replacing a significant volume of your intake air with low-oxygen exhaust could possibly do anything to improve performance. With the EGR removed, you can always re-adjust or remove the ALDA to burn more fuel with the extra oxygen now available.
I don't think maintaining EGR on an old diesel is a realistic option in any case, since they rarely still work after a few decades and getting them working again would require expensive dealer-only parts. Every old diesel I've owned had a worn out EGR valve that sprays oil around the engine bay until it's blocked off. I'm guessing these valves eventually get permanently stuck either open or closed (not sure which).
RE: What should I look for? - larsalan - 02-04-2011
(02-03-2011, 02:10 PM)casioqv So whom makes the EGR blocking plates?
I'm looking for a set for my OM602... I'm guessing when the EGR valves get old, simply disconnecting the vacuum line from them isn't sufficient to stop all exhaust recirculation?
this has turn into an egr delete thread
Maybe this guy sells kits
http://www.youtube.com/watch?v=SCOAlREmDrI
The plate on the intake is easy to make but the plate for the exhaust has to be some sorta cup shape to fit. Mine tool forever to grind and it's smashed on there junkyard style. Sealed well and all just janky looking.
I guess you can just put a plate on the intake and put the egr' flex hose back on.
RE: What should I look for? - ForcedInduction - 02-04-2011
(02-04-2011, 03:04 PM)DieselSchlepper Some advance the idea that if an engine is designed to run with ERG removing actually hurts performance.
The OM61x and OM60x engines were not designed for an EGR.
An EGR is a bad option for any engine. The only potential advantage it ever has is with gas engines since it can reduce pumping losses past the throttle.
RE: What should I look for? - DieselSchlepper - 02-06-2011
I remember what was said: If the engine is designed to run with the cylinder volume partially filled with exhaust gas, then fuel/air must be supplied to make up the difference.
RE: What should I look for? - yankneck696 - 02-06-2011
<<The OM61x and OM60x engines were not designed for an EGR.>>
Then why did the designers design them with them?
Ed
RE: What should I look for? - larsalan - 02-06-2011
prolly cause they designed the engines then the law changed and they had to slap on that junk.
RE: What should I look for? - casioqv - 02-06-2011
(02-06-2011, 09:47 AM)DieselSchlepper If the engine is designed to run with the cylinder volume partially filled with exhaust gas, then fuel/air must be supplied to make up the difference.
Air will automatically replace the exhaust gas with the EGR removed. Without adding fuel performance would be exactly the same with the EGR removed and adding even more fuel is just a matter of adjusting the pump.
RE: What should I look for? - winmutt - 02-06-2011
(02-06-2011, 05:23 PM)yankneck696 <<The OM61x and OM60x engines were not designed for an EGR.>>
Then why did the designers design them with them?
Ed
They didnt.
RE: What should I look for? - ForcedInduction - 02-07-2011
(02-06-2011, 05:23 PM)yankneck696 Then why did the designers design them with them?
They didn't. It was added 2 years into production for the 617.95x and 6 years in for the USA 617.91x (8 years for the OM616). The OM61x series never saw an EGR outside of the USA (excl. Japan)