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+--- Thread: safe rev zone? 617.952 (/showthread.php?tid=3620)
safe rev zone? 617.952 - lgreeley83 - 05-09-2012
Hey all just got my tachometer wired up and working. I was suprised that when i thought i was over revving i am actually only at about 3k rpm. What do you guys feel is a safe rev zone?
RE: safe rev zone? 617.952 - Simpler=Better - 05-09-2012
Unless you've messed with the governors, the pump should limit you to 5,000-something to keep the engine "safe"
RE: safe rev zone? 617.952 - willbhere4u - 05-09-2012
^^^ ditto around 5k It wont rev high enough to blow up! It limits it around 5k-5.5k
RE: safe rev zone? 617.952 - lgreeley83 - 05-09-2012
5k seems very high. Maybe it wouldnt if i had a w/m set up.
What is your normal range though? I feel like 3k is generally my max with my manual trans. I dont think i get much more out of the motor beyond that.
RE: safe rev zone? 617.952 - willbhere4u - 05-09-2012
I take my 240d up to 4500 pretty often
RE: safe rev zone? 617.952 - larsalan - 05-09-2012
I thought the word was that 2800-3100 was like best torque from the motor.
RE: safe rev zone? 617.952 - sassparilla_kid - 05-09-2012
I'm pretty sure I've had mine to 5.5k+ on some WOT straightaways runnin' down the highway before
RE: safe rev zone? 617.952 - lgreeley83 - 05-09-2012
i fear exploding motor but you guys make it seem like nothing.
RE: safe rev zone? 617.952 - Torkey - 05-09-2012
I had my OM617 on the dyne last week. They hooked up a tach to the crank pulley and I got it up to 8K. It did sound like it was going to explode. I haven't messed with my IP so I'm really curious now.
RE: safe rev zone? 617.952 - DeliveryValve - 05-09-2012
(05-09-2012, 09:02 PM)Torkey I had my OM617 on the dyne last week. They hooked up a tach to the crank pulley and I got it up to 8K. It did sound like it was going to explode. I haven't messed with my IP so I'm really curious now.
That's impossible. The IP will cut off at around 5,500 rpms. I think there no way a 617 would ever go way past 6,000 rpms and live.
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RE: safe rev zone? 617.952 - winmutt - 05-09-2012
I concur, the tach reading was incorrect. I hit the cut off pretty frequently, once a week or so....
One member at schumans had his reving up to 6k but not for long on stock...
RE: safe rev zone? 617.952 - DiseaselWeasel - 05-10-2012
Whatever the engineeers though is the limit - 5.5k. I regulerily rev my cars to the redline.
In fact, the previous owner of my ex 250TD was always easy on the throttle. When I gave the engine some revs & hard load, a huge amount of sparks blew out the exhaust
Anf after that, there was a notable increase in power & pick-up! Engines need to 'burn free' from time to time. Without hydraulic valve adjusters you better check the valve clearance after a 'burn free' blast, as a lot of deposits might be burned off the valve seats, altering the clearance.Give 'em hell!
RE: safe rev zone? 617.952 - lgreeley83 - 05-10-2012
my pops was revving the hell out of my car one day while driving it and i was freaking out. He said that motors have a memory and sometimes they need to be reflashed...i guess i will drive like a mad man tommorow.
Wish my motor luck.....
When we say burn free.....what kinda egt temps we talking about? Maybe i.am just getting too technical but i am putting my pyrometer in next week. How long sustained high rpm?
RE: safe rev zone? 617.952 - Kozuka - 05-10-2012
Max Recommended EGT Temp is 1250F or the FSM says 1440F in less that 3-5 second bursts with later-style cylinder heads. Everyone who drives with a lead foot like me should need a pyrometer as an idiot gauge and benz should of included one stock.
RE: safe rev zone? 617.952 - Simpler=Better - 05-10-2012
(05-10-2012, 11:09 AM)Kozuka Max Recommended EGT Temp is 1250F or the FSM says 1440F in less that 3-5 second bursts with later-style cylinder heads. Everyone who drives with a lead foot like me should need a pyrometer as an idiot gauge and benz should of included one stock.
No one would watch it though :p. How many people have killed engines by not watching their dummy lights?
RE: safe rev zone? 617.952 - Hotrodbenz - 05-10-2012
With the stock turbo and 20psi I never worried and I'm on stock fuel I know I'm just making heat but it's faster with the boost than it was when I got it
RE: safe rev zone? 617.952 - lgreeley83 - 05-10-2012
Well i got up to about 4k rpm today. A lot of smoke even with 20+ psi boost at that rpm. I guess turbo being a blowdrier at that point doesnt burn the fuel as well. Oh just remembered i think i am leaking oil through the back bearing on turbo. Time for intercooler or wm injection? Turbo rebuild.
RE: safe rev zone? 617.952 - larsalan - 05-10-2012
20 psi? I thought you had a stock turbo?
The point is to get the valves hot, right? Melt off all that carbon build up. The old italian tune up. 4k sounds like normal aggressive driving, provided there is no other cars in the way.
If you really want it hot you are needing a long steep hill. Then, climb it through all the gears getting high rpm from each one
Again, no other cars in your way, might be past the speed limit at that point. Oh and do it twice or thrice.
Did you ever adjust those valves since you bought that car? First 617, right? It's a good thing to learn to do and really only takes like 1hr. Need 14mm or 9/16 wrenches and 13mm to remove the valve cover.
Whatever is 'near Chicago' doesn't have any great hills to my recolection. But there are plenty of cops and traffic.
RE: safe rev zone? 617.952 - lgreeley83 - 05-10-2012
my boost gauge only goes to 25 and i can bottom it out pretty easily. My wastegate on the kkk was disconnected when i got it, upon reconnection boost level didnt really change so maybe it is stuck shut?
Did the valves on my 616. Have the gasket for this one and will probably adjust here soon. Pyro in next week with the non egr exhaust mani and w115 install. All gaskets on hand :-) got some work to do. School finals next week so soon after that. ;-)
RE: safe rev zone? 617.952 - larsalan - 05-10-2012
so you claim your kkk can push 20+ psi? or 25+?
RE: safe rev zone? 617.952 - lgreeley83 - 05-10-2012
Well i have never been 100% sure what turbo i have. There are pics in another thread of my turbo. I know it is not a garret. Either my turbo pushes that high or my boost gauge is wrong. I havr a cheap sunpro gauge putting a new isspro in with my egt gauge.
I wouldnt embelish :-) i will take a vid later.
RE: safe rev zone? 617.952 - w123love - 05-10-2012
With the mani tranny in my wagon I’ve pushed 5k a couple times when I was merging and not watching. Damn stereo is too loud to hear anything. Probably hit 5.3K at one point. No problems to report.
RE: safe rev zone? 617.952 - larsalan - 05-10-2012
everyone always told me stock turbos cant do more than like 14psi. But, I've never bypassed the wastegate. I just tuned them up to like 12 psi. And I am still hard pressed to get all the way to that. Usually see like 10-12psi max. And like you said, what's the point without fuel to burn.
RE: safe rev zone? 617.952 - lgreeley83 - 05-10-2012
I dont know what has been done to my pump. I know i have a non turbo pump that will poor out black smoke when i want it to. I imagine the prior owner did something to it but i have no clue ehat. I know i cruise a little below 5 psi and as soon as i step on the pedal i am over 10 psi. 15-20 psi no problem. 20+ a few seconds wot.
Vid tomorrow no lights inside my car to film with at night.
RE: safe rev zone? 617.952 - erling66 - 05-11-2012
(05-10-2012, 06:53 PM)larsalan Did you ever adjust those valves since you bought that car? First 617, right? It's a good thing to learn to do and really only takes like 1hr. Need 14mm or 9/16 wrenches and 13mm to remove the valve cover.
Hi I just bought a 300SD and it should need a valve adjustment after 300K+ miles. To which clearance do you adjust them? hot or cold?
RE: safe rev zone? 617.952 - aaa - 05-11-2012
The cold clearances are on a sticker above the headlamps. .1/.35 mm I think.
RE: safe rev zone? 617.952 - lgreeley83 - 05-11-2012
My bad my gauge only goes up to 20. You will see my boost get there pretty quickly and go beyond to maybe 25.
This is around 3k-4k rpm in third gear flat road. To many police and other cars to do it in 4th.
https://www.youtube.com/watch?v=9U1qKV3vWQM&feature=youtube_gdata_player
RE: safe rev zone? 617.952 - aaa - 05-11-2012
The most likely cause is a disconnected wastegate hose/line. Easy way to identify a Garrett is by the rubber wastegate hose that fails all the time. The kkk has a metal line.
RE: safe rev zone? 617.952 - lgreeley83 - 05-11-2012
Its funny how we went from engine rpm to turbo. I like it. Ive read forced say kkk turbo handles 20 psi fine. Maybe it is true maybe not? Should i put much effort into reconnecting wastegate properly i.e. cleaning it so it actually works? I know that high it becomes a blow drier. I should probably get better at reading compressor maps too. I know my pump is modified but the extent i dont know.
I assume i should get it working.
RE: safe rev zone? 617.952 - ronnie - 05-12-2012
You can find a compressor map for the k26. I found one and if I remember right around 15 psi is the limit for efficient use, but it will go more for sure, just not as efficient.
I thought factory red line was 5200? I have not taken my 616 past about 4200.
RE: safe rev zone? 617.952 - Theturbodave - 05-17-2012
I know they will go to 5800 without a problem above that you may run in to valve train issues. I run my wagon for i would say 2 mins in a run group at 4800 to 5800 constant with no issues. I think the valve springs and valve adjusters are more of the problem in higher rpms than the bottom end coming apart. I dont think there is a reason to go any higher than that because the stock cam profile wont let the engine make any power or tq past 5600. All dyno runs i have seen show this.
Just my 2cents worth.
RE: safe rev zone? 617.952 - sassparilla_kid - 05-17-2012
So I'm thinking somebody at some point has done some tweaking of my IP, because on the highway a little bit ago I decided to check and see where my car would cut off. It pulled like a freight train all the way to 6k rpm and with speedo and tach needles pegged it was still pulling, it didn't feel like the fuel was cutting off at all, it may have just started to at about 5800 or 5900 or so, but it still kept on pulling, and felt like there was more potential to go even further. I only ran it 6k for less than 10 seconds though because I started having visions of what might happen if the timing chain snapped or if valves made contact with pistons lol
RE: safe rev zone? 617.952 - Captain America - 05-19-2012
There should be an overboost protection @ about 14.6 psi.
The stock turbo can make much more than 14 psi, but anything over 14 is over running (revving) the compressor
These diesel engines are IDI (in direct injection) and are very different than the now common, common rail diesels. These can rev to 6k no prob while the new ones are stuck at 3k
RE: safe rev zone? 617.952 - sassparilla_kid - 05-19-2012
(05-19-2012, 12:55 AM)Captain America These diesel engines are IDI (in direct injection) and are very different than the now common, common rail diesels. These can rev to 6k no prob while the new ones are stuck at 3k
Does it have to do with the mechanical IP vs. electronically controlled injection?
RE: safe rev zone? 617.952 - Captain America - 05-19-2012
(05-19-2012, 12:59 AM)sassparilla_kid(05-19-2012, 12:55 AM)Captain America These diesel engines are IDI (in direct injection) and are very different than the now common, common rail diesels. These can rev to 6k no prob while the new ones are stuck at 3k
Does it have to do with the mechanical IP vs. electronically controlled injection?
No sir. It has to do with how the fuel is injected into the engine (location location location)
Exampl would be that the Benz engines have a pre chamber that the fuel is injected into where the ignition begins, then exits out the pre chamber holes into the cylinder vs. fuel being injected directly into the cylinder.
RE: safe rev zone? 617.952 - sassparilla_kid - 05-19-2012
Oh alright, I'm not sure I fully understand but maybe if I let it sink in for a while it will come to me