tjkj2002 wrote:
naturist wrote:
The reason engines started routing crankcase fumes into the intake in the '60s was because that was the easiest, cheapest, quickest way to cut vehicle emissions of unburned hydrocarbons by something like 80%. The reason it is still used today is that it still represents the largest single source of pollution from even a modern vehicle. The reason(s) gassers don't have the problem with crud buildup in the intake is as noted, the lower compression and lack of a turbo decreases blow-by quite a lot AND gassers do not create as much soot, which is the heart of the problem for us diesel jocks. A little oil down the intake with no soot to gum it up just flows freely a few thousandths of an inch thick. Add the soot, and now it can start to build up.
Modern multi-port FI gas engines have the same carbon buildup inside the intake and throttle body.The difference is it is a hard and dry buildup unlike a turbo diesel which is more of a oily glob.
Also there are spray cleaners that can clean up the dry build up gassers get in their intakes and throttle bodies. Also the gasser will start having symptoms sooner when the crud builds up so it gets fixed, a turbo diesel will just keep running and loose power at highway speeds. Speaking from experience, it takes a lot more cleaner to clean a diesel intake thanks to the oil.
Another factor I suspect but have not been able to confirm, the diesel gets more EGR jacked into the intake to compensate for the higher compression ratio. More EGR results in more heat and fried oil gunk along with the soot from the exhaust.
If the EPA wack jobs had a working brain, diesel engines would have a Smart DEF system instead of EGR, that only comes on in areas that are prone to smog like LA and forget about it in the rural areas where it is not an issue.
Another argument for disbanding the EPA and replacing it with a private organization made up of Environmental Engineers like ASME who put their profession and ethics above any Political Agenda.