Author Topic: Diesel to gas engine swap  (Read 418 times)


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  • Posts: 69
  • Location: Los Angeles, CA
Diesel to gas engine swap
« on: 26 August 2019, 11:18 AM »
Been a looong time since I posted here since I sold off my '73 450SEL but considering getting back in the game. A couple problems around my neck of the woods: 1) smog inspections for all gas-engined post '75 vehicles, 2) decent pre-'76 W116s are really scarce. There are plenty of later cars available relatively cheaply mostly because nobody wants to deal with the hassle of smog checks on such an old car. Diesel cars are even cheaper because nobody seems to want a 300SD. So I had a crazy thought, most diesel-powered vehs are "smog-exempt" in California, not sure of the full legality of this but one could technically swap a M117 into a later 300SD and never be bothered with smog checks since the motor vehicle dept has no idea what engine is in this car. Legal issues aside, has anyone actually attempted to swap a M117 into a 300SD?


  • W116 Addict
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  • MB Enthusiast
  • Location: Fort Collins, Colorado
Re: Diesel to gas engine swap
« Reply #1 on: 26 August 2019, 03:26 PM »
I dont know about that but just yesterday we were talking about rebadging a car with electric vehicle emblems so one could use the express lane for free.....

Still thinking about custom euro front plate for my 6.9, how about "10 MPG" ?
'68 250S, '77 6.9 euro, '91 300SE, '98 SL500 '14 CLS550

Diesel 617

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  • Posts: 233
  • Location: Illinois
Re: Diesel to gas engine swap
« Reply #2 on: 27 August 2019, 03:20 AM »
using two w116 chassis, 100% possible. However, buy one of each vehicle. Otherwise, you will need a garage and lots of time trying to reinvent the wheel.
X3 1980 300SD Blown Heads, trans -Retired
1980 450SEL Parted out/Scrap
1980 450SEL to Diesel Parted Out/Scrap
1979 280SE Euro Spec Cloth Seats Sold
1979 300CD Daily Driver - Sold

Inventory of w116 Parts


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  • Posts: 76
  • 6.9 in a 450SE
Re: Diesel to gas engine swap
« Reply #3 on: 17 September 2019, 08:56 AM »
Have you seen this car? It's pre-75, gas, and in LA for $6k. Currently the best-priced W116 in your area.
1976 450SE 6.9 FrankenBenz (#2288?)
1977 450SEL 6.9 #2333