Author Topic: Can I fit an 09 cam in a 250 head ?  (Read 6577 times)

Dave H

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Can I fit an 09 cam in a 250 head ?
« on: January 12, 2015, 19:40:59 »
I am rebuilding my 250 m129 motor.
I have a perfect condition 09 cam c/w towers which I acquired from Germany.
Can I use it...? Will it cause any valve piston / piston clash ?
The 86 cam i have has a 130 duration but the 142 of an 09 sounds better .
Has anybody done this ?
Will I run into any unforeseen problems ?

Mercedes 250SL    1967
Mercedes 250SLK  2014
Alfa Romeo 166 3.2 Ti
Fiat 500

Benz Dr.

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Re: Can I fit an 09 cam in a 250 head ?
« Reply #1 on: January 13, 2015, 07:00:23 »
I'm using a 230SL cam in my 129 engine and it works quite well. I changed the cam timing slightly by using an offset woodruff key to advance the intake valve to about 12 degrees BTDC which is similar to a euro 280SL cam. You can use any combination cam and towers in a 129 engine as long as it's not a late 280SL cam.
1966 230SL 5 speed, LSD, header pipes, 300SE distributor, ported, polished and balanced, AKA  ''The Red Rocket ''
Dan Caron's SL Barn

1970  3.5 Coupe
1961  190SL
1985   300CD  Turbo Coupe
1981  300SD
2013  GMC  Sierra
1965  230SL
1967 250SL
1970 280SL
1988 560SEC

ja17

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Re: Can I fit an 09 cam in a 250 head ?
« Reply #2 on: January 13, 2015, 07:06:39 »
The cam towers are different diameters with the later camshafts. You will need to check these. I am not sure when they changed.
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

GGR

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Re: Can I fit an 09 cam in a 250 head ?
« Reply #3 on: January 13, 2015, 12:30:02 »
I have been playing with camshafts quite a bit, on M116/M117 engines though. In my experience, displacement does influence quite a bit the way a camshaft profile will work on an engine. For a given profile, the smaller the displacement, the more aggressive the engine behavior. Fitting a 09 camshaft on a 250 will have your engine be more aggressive than a 280 fitted with the same camshaft. Your torque and power curves may be pushed up in the rpm range by quite a bit, and you will loose some torque at lower rpm, with some consequences on driveability in town for example. One way to deal with it is to advance the timing of your camshaft by a few degrees to get your curves back a bit lower in the rpm range. Another way, especially if you like the aggressive nature of the engine, is to adapt the rear end ratio so as to get back into sufficient torque when you upshift. Nothing wrong with any of it, but you will be entering uncharted territory as you will have to adapt the timing of your camshaft to your liking, and then the injection and ignition adjustments to it. The difficulty is that standard/stock adjustments won't really apply anymore. But if you like tinkering, it's a lot of fun!

Dave H

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Re: Can I fit an 09 cam in a 250 head ?
« Reply #4 on: January 13, 2015, 18:04:55 »
Thank you Dan , Joe and GGR.
This is just the information i was after.
I will have to dig a bit deeper when i get round to doing it but it will give me something to tinker with after the restoration is complete.
(probably in the next ten years at this rate )
Thanks guys
Mercedes 250SL    1967
Mercedes 250SLK  2014
Alfa Romeo 166 3.2 Ti
Fiat 500

Dave H

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Re: Can I fit an 09 cam in a 250 head ?
« Reply #5 on: April 24, 2015, 11:50:58 »
Dan
Just to confirm.
You advanced your timing to 12 or 12.5 ?
Cant find the post but seem to remember a 12.5 setting from somewhere.
Is 12.5 too much ?
I will advance and accurately set the v/v timing with a DTI and an off set woodruff key.
Gonna call her the Biege rocket !!!
230 exhaust header set up also sounds the way to go.

 :D
« Last Edit: April 24, 2015, 12:26:02 by Dave H »
Mercedes 250SL    1967
Mercedes 250SLK  2014
Alfa Romeo 166 3.2 Ti
Fiat 500

Benz Dr.

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Re: Can I fit an 09 cam in a 250 head ?
« Reply #6 on: April 24, 2015, 14:27:47 »
Dan
Just to confirm.
You advanced your timing to 12 or 12.5 ?
Cant find the post but seem to remember a 12.5 setting from somewhere.
Is 12.5 too much ?
I will advance and accurately set the v/v timing with a DTI and an off set woodruff key.
Gonna call her the Biege rocket !!!
230 exhaust header set up also sounds the way to go.

 :D

Biege Rocket? It doesn't grab me like '' Red Rocket. ''

I think I used 12 degrees or whatever the euro 280 cam is set at. I figured it wasn't a good idea to go any further than that and that a consideration for a proper safety margine had been accounted for by the factory.
 I would agree that all of the normal timing specs and other info normally used to set up one of these engines goes out the indow the more you change things. My car is highly modified from stock yet it retains a stock apearance with period correct 113 parts. As an example, I'm running 40 degrees ignition advance and yet it never pings. You would see a big difference using header pipes.
1966 230SL 5 speed, LSD, header pipes, 300SE distributor, ported, polished and balanced, AKA  ''The Red Rocket ''
Dan Caron's SL Barn

1970  3.5 Coupe
1961  190SL
1985   300CD  Turbo Coupe
1981  300SD
2013  GMC  Sierra
1965  230SL
1967 250SL
1970 280SL
1988 560SEC

Dave H

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Re: Can I fit an 09 cam in a 250 head ?
« Reply #7 on: April 24, 2015, 14:55:32 »
Got these standard 250sl specs off the site.

breaker point gap:  0.3-0.4 mm
dwell angle: 38 degrees +3, -1 degrees
Bosch distributor part #: IFUR 6 0 231 116 051 (MB part no. 001 158 02 01)
timing: 8 degrees BTDC at idle, and 30 degrees BTDC at 3,000 RPM, both without vacuum advance connected
CO value at idle: 3.5-4.5

The 40 degree advance your running, is that 40 degrees BTDC at 3,000 RPM, without vacuum advance connected ?
I will be using a 123distributor so hopefully one of pre set curves will suit it.
Mercedes 250SL    1967
Mercedes 250SLK  2014
Alfa Romeo 166 3.2 Ti
Fiat 500

Benz Dr.

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Re: Can I fit an 09 cam in a 250 head ?
« Reply #8 on: April 24, 2015, 16:23:55 »
Those numbers are correct depending on how you do things. I set my timing to about 40 degrees at 3,000 RPM. I leave everything connected because that's the way it will work when you're driving your car. If you unhook the vacuum line you should see an automatic 10 degrees of advance if your distributor is working properly. Sine you are using the 123 unit, just make sure you are getting full advance before 3,000 RPM. In most cases it's probably fully advanced by 2,700 RPM but 3K is more of a max amount rather than the actual setting.

We are now using NGK BP5ES spark plugs and these are the only plug I recomend. The standard gap is .032'' but you should be able to open them up to .035'' with the 123 distributor. Watch out for carbon core coil wires or spark plug terminals of more than 1K ohms. Ideally, you shouldbe looking for 6 - 7K of total resistance in your entire ignition wire ( secondary ) system; 5K for the rotor and 1K at the plug terminals. You don't need any resistors on the coil wire or distributor cap terminals.
1966 230SL 5 speed, LSD, header pipes, 300SE distributor, ported, polished and balanced, AKA  ''The Red Rocket ''
Dan Caron's SL Barn

1970  3.5 Coupe
1961  190SL
1985   300CD  Turbo Coupe
1981  300SD
2013  GMC  Sierra
1965  230SL
1967 250SL
1970 280SL
1988 560SEC

Dave H

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Re: Can I fit an 09 cam in a 250 head ?
« Reply #9 on: April 24, 2015, 17:05:16 »
Thank you Dan.
I will keep you posted.
Block is in for Rebore at the moment so it will be some months.
Got a getrag 5 speed and Mark Turnbulls kit to mate up to it.
Coincidently he lives 15 miles up the road from me, he has sold his kit all over the world but never expected to sell one on his doorstep.
His car is beautifull in china blue and drives like a new car.
The 5 speed makes all the difference .
Mercedes 250SL    1967
Mercedes 250SLK  2014
Alfa Romeo 166 3.2 Ti
Fiat 500

Benz Dr.

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Re: Can I fit an 09 cam in a 250 head ?
« Reply #10 on: April 24, 2015, 21:43:54 »
All of the 113's should have been 5 speeds.
1966 230SL 5 speed, LSD, header pipes, 300SE distributor, ported, polished and balanced, AKA  ''The Red Rocket ''
Dan Caron's SL Barn

1970  3.5 Coupe
1961  190SL
1985   300CD  Turbo Coupe
1981  300SD
2013  GMC  Sierra
1965  230SL
1967 250SL
1970 280SL
1988 560SEC

66andBlue

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Re: Can I fit an 09 cam in a 250 head ?
« Reply #11 on: April 25, 2015, 01:12:49 »
Dan, I agree .... as long as they are automatic, but could even be a 6-speed automatic!  :)
Alfred
1964 230SL manual 4-speed 568H signal red
1966 230SL automatic 334G light blue (sold)
1968 280SL automatic (now 904G midnight blue)

Benz Dr.

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Re: Can I fit an 09 cam in a 250 head ?
« Reply #12 on: April 25, 2015, 12:17:14 »
If you live in a big city the auto probably makes more sense. I don't think anyone was making 5 speed autos at that time, were they?
1966 230SL 5 speed, LSD, header pipes, 300SE distributor, ported, polished and balanced, AKA  ''The Red Rocket ''
Dan Caron's SL Barn

1970  3.5 Coupe
1961  190SL
1985   300CD  Turbo Coupe
1981  300SD
2013  GMC  Sierra
1965  230SL
1967 250SL
1970 280SL
1988 560SEC