2 cycle out of a 4cycle? - Page 3 - PeachParts Mercedes-Benz Forum

t walgamuth · #31 02-13-2008, 10:42 PM

Cervan, man go take a valium.....or find a large wooden mallet and give yourself a quick whack in the noggin or two.

This is much crazier than the accura engine thing.

The old 671 jimmies were cool sounding motors, they screamed like a v12. Of course back when they were in vogue I did not know what a v12 sounded like but I knew I loved to hear them wind out.

A 371 is out too, the weight of it would totally mash the front end of your benz.

'

Just getting a benz running nicely in stock form is quite a task for most of us.

Tom W

GREASY_BEAST · #32 02-13-2008, 10:55 PM

Quote:

Originally Posted by ZackaryMac

2 stroke diesels all do, to the best of my knowledge.

There are piston-ported 2 stroke diesels. Detroit made one model that didn't have valves... it was a 4cyl, forgot which model. A company called deltahawk is making a piston-ported (no valves) 2 stroke V4 diesel for aircraft. 2 stroke diesels have to be scavenged somehow, some older ones were crankcase scavenged, as well as piston-ported, I believe, but the common method is via supercharger, or in the case of the deltahawk, a turbocharger blowing through a supercharger which gives supercharger performance at low rpm and turbo at high rpm.. I wonder if you couldn't get a high-power 616 up and running for less than you could get into a 603 for.... 603 turbo motors are quite rare...

MB-Owner-in-ind · #33 02-14-2008, 11:12 AM

Quote:

Originally Posted by ZackaryMac

2 stroke gas engines don't have valves like you are probably thinking (reed, rotary, or the piston itself are the valves), however 2 stroke diesels all do, to the best of my knowledge. As mentioned before, the valves are all exhaust, as the air is brought into the cylinder through "holes", or ports, part way up the cylinder wall. If you've ever seen a chainsaw engine apart, you'd have a good idea what this is similar to.

2 stroke gas use oil in the gas or injected oil for crank/cylinder lube, 2 stroke diesels use engine oil like any other diesel.

2 stroke gas typically are naturally asperated (I have heard of race turbo'ed engines), 2 stroke diesel have to be force inducted (supercharged) to run.

Same name, similar concept, much different excecution.

I believe that the Detroit diesels have exhaust valves but ports for intake and I haven't ever heard a two stroke diesel with intake valves that had any popularity. The early Detroits were NA.

#34 02-14-2008, 03:12 PM

You would need alot of excess airflow to clear the cylinder of exhaust since the valves are right next to each other.

The 2-stroke Detroit's, in the right conditions, could run completely without the lower rod caps. In theory anyways, I don't know if they actually tried it.