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1984 380 sl (currently wkg on 5.0 euro motor swap). 2002 Ford Expedition
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Discussion Starter #1
First time posting but have been enjoying reading for months.

I purchased a 1984 380sl two years ago from family who had purchased the car new. I have always enjoyed the car, love the style, but feel it is under powered. Is there any way to enhance the performance of the 3.8. I was reading that the euro model of the same year had 9.0 to one compression vs 8.3 and 215 hp vs 155hp. Are these pistons available? Are there any after market induction systems that will I could upgrade to. I have kept the car original but am not a purest and it no longer has to pass emission testing. I would like to get 75 to 100 more hp if possible without swapping for a 500 series. It will need a valve job in the near future and just hate to spend the money and end up with the same performance. I dont mind spending more if there is a good return in terms of increased horsepower. Thanks and I appreciate any sugestions.
 

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Depends on the day!
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your BEST and MOST cost effective mod would be to drop a 500SL Euro engine in.

Any FI would be custom, ie megasquirt or something more costly, ie motec etc...

new pistons etc, etc and you're looking @ 7-9K easy by the time you're done with the just the engine.

a 5L swap makes sense on Every level..building up a US 380 is just expensive and un-rewarding.

Jonathan
 

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450SLC
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I agree with what Jonathan has said, these cars arnt like the standard US muscle car that has tons of options on what pistons to use and what can be changed so internal engine mods are very hard and expensive.

If you want to keep the 380 motor then you best bet is a Megasquirt controlling a supercharged intake(turbos wont fit) but again it will all be a custom job like OZBENZ - Australian Mercedes-Benz Forums • View topic - supercharged 450SLC 5.0 and with the Megasquirt look for any post from a guy on these forums called Oughtsix, he has a website that details his install of MS II.

But easiest option is dump a bigger motor in the car.
 

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Also, as an aside, I have a Euro 500SL engine w/ 40K on the clock and one of the Cleanest engines internally I have seen sitting mothballed in my shop.. My asking price is Less then it would cost to do the heads on your 380.

Jonathan
 

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1984 380 sl (currently wkg on 5.0 euro motor swap). 2002 Ford Expedition
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Discussion Starter #5
Also, as an aside, I have a Euro 500SL engine w/ 40K on the clock and one of the Cleanest engines internally I have seen sitting mothballed in my shop.. My asking price is Less then it would cost to do the heads on your 380.

Jonathan
can you email me at [email protected] What do you want for the motor?
 

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1984 380SL
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More power for what? My 380 has plenty left at 60 mph. These are luxury roadsters not really sports cars; they're too heavy, like 4000 pounds. And that 5.6 engine will get 10-12 mpg whereas I get 20-22 in the 3.8 which makes it very practical.

You have a beautiful specimen there, I like the color combo.
 

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1984 380 sl (currently wkg on 5.0 euro motor swap). 2002 Ford Expedition
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821 Posts
Discussion Starter #7
More power for what? My 380 has plenty left at 60 mph. These are luxury roadsters not really sports cars; they're too heavy, like 4000 pounds. And that 5.6 engine will get 10-12 mpg whereas I get 20-22 in the 3.8 which makes it very practical.

You have a beautiful specimen there, I like the color combo.
I appreciate the compliment on color combo. I know it is fine on the high end side 80 feels like 55 in most cars but I live in houston and and driving fast on the highways just gets ridiculous between the cops and idiot drivers. I just want it to perform better stop light to stop light. Thanks for your comments.
 

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1986 560SL with M120 V12 Engine, 1988 560SL Stock
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I think Jon's got the best idea. A 5.6 engine will also give you plenty of power and be more redily available but will require the computers and wire harness as well.

Otherwize go all the way for a 6.0L M120 V12.:D
 

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1978 280slc
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The 3.8l is a low compression engine isn't it? Figure out a way to put a turbo on it, if you blow it up then go and get the eurospec engine.
 

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450SLC 5.6 Twin-turbo
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supercharge it is a lot of work but its the optimum about the engines low compression is just ideal to blow in with some extra air and you gain easily 100-170hp depending on some other factors ,otherwise go for a euro 560 engine 300hp. and aftermarket EFI.
 

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1984 380SL
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What you want is low-end torque for pickup, I guess. How about a different rear end? That might not hurt you much at freeway speed.
 

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1989 560SL 2014 A6 2012 Tahoe
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I appreciate the compliment on color combo. I know it is fine on the high end side 80 feels like 55 in most cars but I live in houston and and driving fast on the highways just gets ridiculous between the cops and idiot drivers. I just want it to perform better stop light to stop light. Thanks for your comments.
Bring that thing to the Toad Club at the Richmond Arms. It'd be nice to see a couple of 107's out there. Third Weds of every month 7pm.
 

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1981 380SL - Lorinser bodykit w/16x7 LOs - AKA "Frau Blau"(Lady Blue)
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I appreciate the compliment on color combo. I know it is fine on the high end side 80 feels like 55 in most cars but I live in houston and and driving fast on the highways just gets ridiculous between the cops and idiot drivers. I just want it to perform better stop light to stop light. Thanks for your comments.
Don't take this the wrong way, but sell it to someone like one of us here that appreciates it for what it is and buy yourself something else. Did I mention I have a brother with a Maserati biturbo that he's looking to get rid of??:D
 

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1984 380 sl (currently wkg on 5.0 euro motor swap). 2002 Ford Expedition
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Discussion Starter #14
Don't take this the wrong way, but sell it to someone like one of us here that appreciates it for what it is and buy yourself something else. Did I mention I have a brother with a Maserati biturbo that he's looking to get rid of??:D
I am keeping the car, it has alot of sentimental value to me. I am just checking to see if there is any room for improvment. I appreciate your coment though.
 

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450SLC
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I suggest you get talking to Jonathan that just posted about the Euro engine he has. Jonathan and his shop have been around for a long time and is known for doing good work so if your serious about this then get the engine from him. A) its euro B) its from a guy who isnt going to sell you a piece of shit B) omg its going to be so much more powerful then the 380 C) Swapping difs for a higher ratio is a bad idea if you ever at all do cruising on a highway.
 

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1984 380 sl (currently wkg on 5.0 euro motor swap). 2002 Ford Expedition
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821 Posts
Discussion Starter #16
I suggest you get talking to Jonathan that just posted about the Euro engine he has. Jonathan and his shop have been around for a long time and is known for doing good work so if your serious about this then get the engine from him. A) its euro B) its from a guy who isnt going to sell you a piece of shit B) omg its going to be so much more powerful then the 380 C) Swapping difs for a higher ratio is a bad idea if you ever at all do cruising on a highway.
Thanks for the advice, I agree 100% with you. I did not see his web link in the thread until an hour ago. Im going to call tomorrow. Thanks again.
 

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Outstanding Contributor , Bob's Your Uncle!
-----'83 280 SL----- 5 speed....The PIG
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MBZ '87 300SDL, MBZ '85 380SL, RR '77 Silver Shadow II, MBZ '98 E300TD
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I second the notion that if you aren't happy for whatever reason with the 3.8l's torque (off the line pull), the 5.0 liter is almost a drop in. Same fuel pump assembly, same wiring harness across the engine and uses the same fuel distributor. The fact that you don't have to mix and match an engine built for the KE system and it's higher pressures with a K system with lambda is a big plus and simplifies the retrofit. I did a conversion years ago before I sold the car and still miss it.

Some domiciles care if you exchange engines, check local laws for emissions and registration or titling that may be affected first. Due diligence....

In the swap I did some years ago now, I believe I just had to remove the 380SL's 3.8L fuel distrib/air metering housing off the top of the engine and unplugged all the sensors and vacuum piping, pulled the coolant, fuel and electrical cables, etc. and dropped out the engine on the subframe. When I lifted the engine off the subframe and plunked the 5.0 liter onto it, everything was a direct bolt up and nearly painless. The particular used but low-mileage 5.0 liter I got came from the abundant pre '86 500 SEL/SEC's, which required some relatively minor modification. I think the issues there between sedan/coupe and the SL roadster was the oil pan and the oil filter pedestal. If I recall, the oil filter pedestal points up for SEL/SEC and for the SL, has to point down for space reasons. The oil pan is shaped differently. I think the SEL/SEC have a two piece job and the SL uses the large single piece aluminum job, of course, it's been awhile too. It was relatively minor and worth the fun the 5.0 liter tended to add on empty roads or accelerating off the line. The 5.6 liter has very little above what the 5.0 liter has, especially if you can afford to employ a different exhaust without all the emissions restrictions.

Cheers
 
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