My original build had a "stock" O-200. Off eBay as a core and flew as a engine out of a Cessna 150.  Worked OK but climb and speeds were basically poor.  After a bad landing I had to open it to inspect so made a few changes.

▪Changed pistons to 9.5-1 compression.  

▪Vetterman tuned exhaust.  Did this before my bad landing and was an immediate increase in performance.  

▪plane power alternator as old one shorted out.

▪Skytec starter, old one failed and sent a bearing through the oil pump thus needed a new accessory case.

▪P-MAG powering top plugs to fit the new Zenith supplied cowl..

▪Added oil filter mounted on oil cooler pad

▪Added engine driven fuel pump.  This was a 3 grand upgrade with cost of new cam, pump and getting case tested, weld repair of #2 bearing support and cutting in the pump pad .  This was not cheap but I lived through a failed electric pump luckly while doing a run up.  It gets real quite real quick.

▪Added oil air separator which made a big difference in oil on the plane as well as reduced oil usage. 

I also changed from a warp drive 3 blade prop to a Ed Sterba wood prop.  My cruise speeds went from 85 knots to 95 to 100.  I used to run at 2600 and now run 2450 to 2500 and get better speeds.  Only down side is now I am stuck with 100'LL.  I was getting 6 gallons per hour and just tested this past weekend with 4.8 per hour at 7,500 feet.

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I've heard of the Vetterman, but am not familiar with it.  Were cowl modifications needed?  Did you have heat muffs on the old pipes / still have them with the Vetterman?

What pitch / diameter prop did you obtain from Sterba?


  1. For the exhaust, no cowl mods needed.  It is s cross over system.   He made the heat muff for carb heat and cabin heat.  The prop is 72 diameter by 50 pitch.  I climb out at 75 knots and 2500 RPM.  It looks like a piece of furniture.   ED said he pitches a prop a bit high and will repitch for free if is too much.  

Glenn thanks for the report.  I'm not flying yet (Cruzer).  I have heard from various sources that the single best thing for better performance is having the right exhaust so it's interesting to hear of your experience with Vetterman and I will definitely look into that.  I also have the 9.5:1 pistons and have been wondering if I'm going to need an oil cooler but it sounds like you're doing fine w/o one?  I also have the Plane Power alternator, lightweight Skytec starter and Tempest oil filter pad.  Also had the cylinders flow balanced and ported by Lycon.

Since the Cruzer is high wing, gravity should work for the fuel but I'll probably add an electric pump.

Couple of other questions:

1.  What did the Vetterman exhaust cost you?

2.  Any performance advantage with the P-Mag...sounds like you didn't have to add the blister on the cowl to accommodate a large spark plug?

3.  Do you have the "aerobat" 2 3/4" inner attachment tube to your oil breather line (see pic)

4.  Ditto on Carl's questions.

Thanks for the great info.

I think the exhaust was 1700.00 with mufflers.  He asked for photos and 4 dimension based on firewall it certain bolts on the engine.  My pipes extend about 5 inches below the bottom of firewall and it fits perfect.  I did need a prop extension for the front crossover pipe to clear the cowl.  At the time I had made my own cowl which was not very streamline.   Was kind of like a bonanza cowl.  I had a ACS "Cessna 150 style" exhaust before.   First flight after the change I was WOW I have more power.  

The P-mag makes for a smoother running engine, adds 

Glenn, what do you have your timing set at?

Looks like part of your answer above got cut off...


It did get cut off.  I have the P-Mag defaulted to 29 degrees.   Being kind of conservative. 


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