Date registered: May 2013
Vehicle: 1961 190SL
Location: Northern California, USA
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
"my guess is that the oil broke down under extreme heat and I've blown the engine"
Guesswork is not diagnosis. Why don't you take a deep breath and disassemble the engine you have and find out what is wrong with it. Only after you know what the problem is can you evaluate potential solutions.
Being a street rodder at heart the sbc solution that brett suggests appeals to me. From what I've seen of the one Mercedes in my garage, a 1961 190SL, the Mercedes engines are overly complex, difficult to work on, underpowered, butt ugly and parts probably cost a fortune. A fire breathing sbc can be built from a $100 dealer 4-bolt 350 core and really high quality parts like cylinder heads are so inexpensive in the aftermarket that reusing old parts is not necessary. The Edelbrock heads I used on my street rod engine have beautifully finished ports and combustion chambers, bronze valve guides, swirl polished stainless steel valves, guide plates and helicoil inserts in the exhaust header bolt holes all for less than the cost of a top quality valve job.
The LS family of engines is lighter and more powerful but it is a distributorless, computer controlled piece that requires grafting in of a lot of the OEM electronics or use of a pricey aftermarket electronic system. My son has one of those on my engine stand right now and it is totally unlike the sbc Gen 1 engine. It's interesting to look at but I have no idea how the ignition system works. Fortunately my other son is an electrical engineer.