Bill I have to say your opening statement made me laugh. I have experience with both of the versions. Don't expect Norvel performance . If you would like a Norvel though I currently have one listed in the classifieds. Here is my experience which I wrote about on Stuka Stunt a few years ago .
I will offer my experiences. I used both the MK1 and the MKII. The MKI was a Chinese engine produced by CS. This engine is no longer offered by Brodak and parts availability is thinning. This engine was down on power for my style of flying but reliability was good in terms of consistency. This engine was offered with a regular glow plug which in my opinion is a very poor option for 1/2A engines. Henry Nelson made a head to accept Nelson plugs for the CS version. This head though at the time was $35 I modified the stock head to accept Merlin style head buttons and this GREATLY improved performance and starting.
The MKII, made in Moldavia by the same makers as the larger .40 and .25's. AAC construction which to me is a very nice offering for an engine that typically doesn't receive this until you get into the $200. The MKII shares no parts with the MK1, it also comes with no muffler. In addition, it utilizes that same regular glow plug head. Again, this robs several hundred rpm's. I have no idea why the designer would utilize this. Nelson plugs are currently the least expensive plugs with the best reliability and they yield the highest rpm. Why wouldn't you use them? I've seen the MKII running with a Nelson plug. Power was up but this requires a machinist to make a entire head for this to work. A Nelson plug typically yields 800-1000 rpm's over most plugs.
The MKII is also very very mild. I believe there is a lot of hidden power within this engine. The crankshaft is designed like the Cox Medallion. A hotter crank should've been offered for this engine to allow for high performance. I found it to be extremely tight initially requiring my standard go through and loosening up. Fuel recommendations for both engines were 10% nitro and 20% oil. A BIG THUMBS DOWN. I quickly threw out that idea and went with my standard 1/2A Sig 35% nitro fuel. Automatically easier starts and the engine responded with a traditional 1/2A attitude. I also found the APC 5x3 made the best rpm's. My bench testing received 21700 rpm's using the APC. This engine runs very reliably and smooth. One thing I didn't do was weigh the engine and draw comparisons.
Both Brodak engines will fly all of Brodak's offerings. His 1/2A kit line is fabulous. I never had a Brodak 1/2A that didn't fly well. In addition, these engines will fly all the traditional 1/2A's. However both engines are beam mounted engines. John has redesigned many of his kits to accept beam mounts and therefore this shouldn't be an issue. I just redesign the firewall to accept a Dave Brown mount for beam mounted Cox TD's, Norvel's etc. The MK 1 has the same bolt pattern as the Norvel and others. I never bothered to check but I hope the MK II does.
Line length on these can range from 35'-40'. You could use Spiderwire and probably and I mean that conservatively try 42'. TO keep the speeds up, keeping the line length in the 40' range would be my recommendation. 35' is the standard Cox length, but both the NK1 and MkII make a bit more power. All of this is relative to the plane your flying so keeping different line lengths is in order. I also fly 1/2A's like the larger models so my style of flying demands pretty much all the power I can get. These engines were geared towards the sport flyer and the beginner. I enjoyed using both of them. I do feel the MK II for the money is a good buy. Ken
Topic: Brodak 049's (Read 1952 times)
