Author Topic: Over revved engine - well maybe  (Read 1783 times)

Bonnyboy

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Over revved engine - well maybe
« on: August 17, 2022, 20:36:34 »
I was merging onto the freeway the other morning and I thought I was going fast enough and in the correct gear to easily slip into traffic but this twit in a pickup decided it was time to speed up -  so not to be forced into the weeds, I nailed my accelerator and got infront of him but in the process my car revved up to the red line and made a funny sound what I think is a sputtering sound of "valve float". 

It was only for a couple seconds Until I was able to shift into a higher gear but hearing that sputtering sound and loss of power made me feel sick.   The car drove fine for the rest of the day but I am wondering if there is any way to check to see if I damaged anything.

I have been going into the garage and hugging my car and saying "I'm sorry" but I wonder if there is more than that I can do.



Ian
69 280SL
65 F-100
73 CB750K
75 MGB
78 FLH
82 CB750SC
94 FLHTCU
08 NPS50

Todd

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Re: Over revved engine - well maybe
« Reply #1 on: August 18, 2022, 00:33:05 »
Sounds very racey to me.  Nicely played!

If you'd done damage, you would have known instantly.  It's an extremely stout engine.
Todd

ja17

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Re: Over revved engine - well maybe
« Reply #2 on: August 18, 2022, 06:00:51 »
Many years ago, I campaigned a Mercedes sedan rally car with a M130 engine. It was hammered, flogged and frequently over-reved. I never did hurt it. I remember well, the "valve float" you experienced. The engine outlasted the rest of the car. As long as the engine is healthy and well maintained, you should be fine. I would not make a habit of doing that for sure.
They say Mercedes engines are designed to run at red line all day long.
Joe Alexander
Blacklick, Ohio
1969 Dark Olive 280SL
2002 ML55 AMG (tow vehicle)
2002 SLK32 AMG (350 hp)
1982 300TD Wagon turbo 4spd.
1963 404 Mercedes Unimog (Swedish Army)
1989 flu419 Mercedes Unimog (US Army)
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Bonnyboy

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Re: Over revved engine - well maybe
« Reply #3 on: August 18, 2022, 13:22:31 »
Thanks for the reassuring comments.
Ian
69 280SL
65 F-100
73 CB750K
75 MGB
78 FLH
82 CB750SC
94 FLHTCU
08 NPS50

thelews

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Re: Over revved engine - well maybe
« Reply #4 on: August 18, 2022, 18:20:53 »
I wouldn't disagree with you, but they sure aren't free revving like a Porsche or Alfa.  4000 rpm it says "what do you say we give it a shift?"  Same with the 190, just don't feel like they encourage you to wind them up.  That said, I have wound them up and have no doubt they can take it.

PO of my car drove it 375 miles in 4 hours once.
Enjoy some pictures at this link:
http://www.flickr.com/photos/8292359@N06/sets/72157603240571101/show/

John - Wisconsin
1967 Early 250 SL Red/Caviar, Manual #1543
1961 190 SL 23K miles
1964 Porsche 356
1970 Porsche 911E
1991 BMW 318is
1966 Jaguar XKE
1971 Alfa Romeo GTV 1750

vbrad

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Re: Over revved engine - well maybe
« Reply #5 on: October 06, 2022, 03:16:57 »
I experienced the same situation when my mechanic took the car out for a spin to test his work.
Seems there is a rev-limiter to prevent over-revving (fairly standard in European cars of that era), and what you encountered may have simply been the limiter doing its job.

ejboyd5

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Re: Over revved engine - well maybe
« Reply #6 on: October 06, 2022, 10:56:06 »
Forget about it.

MikeSimon

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Re: Over revved engine - well maybe
« Reply #7 on: October 06, 2022, 12:14:29 »
I experienced the same situation when my mechanic took the car out for a spin to test his work.
Seems there is a rev-limiter to prevent over-revving (fairly standard in European cars of that era), and what you encountered may have simply been the limiter doing its job.

I don't think the W113 had a rev limiter. That was facilitated through electronic ignition or FI. Cannot see how they would have done that on a 280SL
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Jordan

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Re: Over revved engine - well maybe
« Reply #8 on: October 06, 2022, 20:48:48 »
I don't think the W113 had a rev limiter. That was facilitated through electronic ignition or FI. Cannot see how they would have done that on a 280SL

The early 911's had rev limiters.  And those were carburetor engines.
Marcus
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ja17

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Re: Over revved engine - well maybe
« Reply #9 on: October 07, 2022, 05:03:49 »
There is no factory rpm limiter on these engines. However Bosch did make a distributor rotor which was a rev limiter. These were used on some other models of the era. I believe that some of these will fit in the W113 distributors.
Joe Alexander
Blacklick, Ohio
1969 Dark Olive 280SL
2002 ML55 AMG (tow vehicle)
2002 SLK32 AMG (350 hp)
1982 300TD Wagon turbo 4spd.
1963 404 Mercedes Unimog (Swedish Army)
1989 flu419 Mercedes Unimog (US Army)
1998 E430
1974 450SLC Rally
1965 220SE Finback

JamesL

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Re: Over revved engine - well maybe
« Reply #10 on: October 07, 2022, 06:04:43 »
Prompting the thought… could that be programmed into a programmable 1-2-3 distributor, should it be a need?
James L
Oct69 RHD 280 in DB906 with cognac leather

Berggreen

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Re: Over revved engine - well maybe
« Reply #11 on: October 10, 2022, 08:46:37 »
Prompting the thought… could that be programmed into a programmable 1-2-3 distributor, should it be a need?

Good question, and I would also be interested to hear more about that option. :)
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thelews

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Re: Over revved engine - well maybe
« Reply #12 on: October 10, 2022, 15:42:18 »
Yes, the bluetooth 123 tune lets you set a rev limit in the phone app.  It also has a lockout option, can select and car will not start.
Enjoy some pictures at this link:
http://www.flickr.com/photos/8292359@N06/sets/72157603240571101/show/

John - Wisconsin
1967 Early 250 SL Red/Caviar, Manual #1543
1961 190 SL 23K miles
1964 Porsche 356
1970 Porsche 911E
1991 BMW 318is
1966 Jaguar XKE
1971 Alfa Romeo GTV 1750

Rahul

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Re: Over revved engine - well maybe
« Reply #13 on: October 10, 2022, 18:55:47 »
Is that the "TUNE+-6-R-V-M-IE" model, John?

Thanks
1971 280SL auto #571 over parchment

Iconic

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Re: Over revved engine - well maybe
« Reply #14 on: October 10, 2022, 18:58:54 »
Ian (Bonnyboy),
If your car is running fine now, that is the key.
I don't know if these are "interference" engines or not.
I'm guessing that they are "non-interference engines" because if you float the valves on an interference engine, you bend or break the valves, it happens almost instantly. You cannot back off in time..... AND you know it.
I did this (over-rev) on a NON-Mercedes car, and I knew instantly after the event that things were different. It just ran a little rough, in my case. Didn't break any valves, but "kissed" most or all of them and some had a slight leak when done.
If your car is running well, I'd just enjoy and forget it.
But, in the future, if you want to prove you are OK, a leak down test will not only tell you the cylinders that are affected, but you can listen at the exhaust or intake and tell which valve is not seating properly anymore. Or of course, the leak down test will show you have no issues. A leak down test gives much more information than a compression test.
Take care,
Mark
1970 280 SL Automatic, USA version, Grey-Blue (906G/906G), Blue leather (245)
1968 SS396 Camaro Convertible (owned since 1977 -- my first car :D)
1984 Porsche Euro Carrera coupe, LSD, SlateBlueMet/Blue
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