David Levy:
I’m trying to decide what overhaul shop to use for my 68 Sport, MB-381, O-320-E2C. I’m looking at Mattituck, Penn Yann, Zephyr, and Lycon.
Lycon seems very interesting. No charge for the engine horsepower upgrade STC, however I understand I also need an STC for the airframe. Also, they will port and polish for an additional $900, bringing HP close to 180. I understand from Lycon that a wide deck engine is required for the 160 HP upgrade. Is the O-320-E2C a wide deck? How can you tell?
I’m going with new cylinders. Lycon suggest Lycoming. Is that the best bang for the buck? Would cylinder choice be affected by the port and polish process (would a particular cylinder be more reliable with the HP increase)? Has anyone gone through this process with Lycon? What are the gotcha’s? Man….., I can just taste 180 hp!
I would guess the prop repitch issue should be addressed after flying it with more horsepower? Any suggestions appreciated.
Bob Steward, A&P-IA:
Mattituck (now a captive of TCM), PennYann, and Zephyr all have established national reputations as field OH facilities that are able to do nearly all that Lycoming does for a factory reman, EXCEPT zero time the paperwork.
LyCon in Visalia CA has a national reputation as a performance shop. They can do a “stock” OH, but their real forte is precision and performance work. They balance the rotating assembly, they massage the ports and valve systems for better (and more even) flow, and they run the engine on a Dyno to give you a read-out of the HP (which needs to be adjusted for the “California dyno” effect) as part of the package. Regarding the port-and-polish effect, the number grows with each telling. It used to be 172 HP. All the O-320-E series are “wide deck”. And exactly HOW will your prop feel about 180 HP? Compare the Type Certificate limits for prop pitch with your current prop. There may be no adjustment allowed. Then you must seek field approval for the pitch change, probably as part of the approval to mount the modified engine on the airframe. Of course, you won’t want to mention the 180 HP number when the FSDO inspector is within miles of your plane. The prop is rated at 165 HP, so any claims in excess of that might get you a LOT of hassle.
No 160 HP airframe STC exists for these planes. You’ll need a field approval for the installation in the airframe.
LyCon has published data that says the Superior investment cast “Millennium” cylinders flow 12% LESS than Lycoming and ECI cylinders. So those looking for performance would rule out Superior Millennium right from the start. I’ve had excellent results with the ECI product and rate their warranty better than Lycoming, and MUCH BETTER than the totally non-existent warranty from Superior. If you want to know the gory details of a set of Superior cylinders, that were machined wrong and NEVER replaced under warranty (and cost me $5,000), just email for the whole story. Needless to say, I won’t use Superior today, even if they were FREE.
This is a common mod for the Grumman Cheetah and Traveler, and there is a follow-on STC to install a Sensenich 74DM7-61 prop with 2 more inches of pitch. I’m sure it could be found applicable to the Musketeer. The prop has been SHORTENED to 72.5″ and the tips re-contoured to a “Hoerner” profile. No reason this could not be done on a Musketeer. However, I’d advise caution, and keep in mind the rule of thumb on prop pitch. Each inch of change equals about 50 rpm change in full throttle cruise RPM. So several test flights would be good before changes in pitch are done.
As I have previously mentioned, anyone that wants examples of the paperwork, that was used to put the high compression engine on the A23-19 airframe, should look up N300JL in the FAA records and order the data package for it on CD. This plane used to be local to me, and years ago was converted to high compression.
As a side note, there are 2 ways this conversion can be done:
Method #1 is to just swap out the pistons for the higher compression #75089, and this then leaves you with out the larger bearings, etc. of the true 160 HP. The STC to do this on Grummans limits the RPM to 2650 so that the total HP is not above the Lycoming limits of +5%/-0% of rated HP. The official net result is 157.5 HP. This did not require any testing for noise, because it didn’t officially change the power output. It DID move the torque curve down, making the engine much stronger in the lower RPM for T/O and climb.
[Editor’s note: Once again we have an example of how power changes, like application changes/acro engines, can involve much more than apparent superficial changes, if we are to preserve reliability and engine integrity]
Method #2, and I think this is what LyCon is doing, is to bore the case main bearing saddles for the larger front bearing assembly, and essentially change the engine configuration from an “E” to a “D” series, which are factory-rated at 160 HP.