Fence baffles for the 3300?

[Sonex32]

Anybody know of somebody that's done fence baffles for the 3300? Would like to give it a go on my Panther, but not enough to start from scratch.

Tony

[Chatterton]

Not directly related, but the Sonex aluminium cylinder head baffles on my 3300 are badly cracked and need replacing. On one of these sites I have seen a picture of a Sonex without its cowls on showing the Jabiru fibreglass baffles fitted which looks neat. Has anyone experience of these, please? Would appreciate any information, particularly comparisons from anyone who may have tried both.
Bob Chatterton.

[tonyr]

Fence baffles on an Australian 3300 Sonex by Peter Anson here, (bottom of page): http://sonexaus.wikispaces.com/Peter+Anson+-+Sonex+894
The Bristell production aircraft also uses fence baffles on their Jabiru installation. There were some better pics floating around but I cant find them now!

Anyway here is the link to the Aussie distributor [urlhttp://andersonaviation.com.au/][/url]

Fibreglass ducts have been used by Lynn Jarvis on his 2200 powered Sonex since late 2003/2004. His head temps run quite cool, around 120C (from memory) after some experimentation.
A couple of pics here: http://flysafe.raa.asn.au/constructors/jarvis_cowling.html
The early Jabiru fibreglass baffles did require some radical trimming to fit within the cowl, particularly the RH side.

Cheers
Tony

[Sonex32]

Not directly related, but the Sonex aluminium cylinder head baffles on my 3300 are badly cracked and need replacing. On one of these sites I have seen a picture of a Sonex without its cowls on showing the Jabiru fibreglass baffles fitted which looks neat. Has anyone experience of these, please? Would appreciate any information, particularly comparisons from anyone who may have tried both.
Bob Chatterton.

Bob,

Early on, if you bought a 3300 from Sonex it came with the glass baffles. Then they switched to aluminum. I tried both, and went back to fiberglass, as they cooled better for me. My aluminum baffles were the first iteration, and it's very likely there have been changes since then. Pete Krotje can fix you up with glass baffles should you want to try those. Some assembly required.

Tony

[Sonex32]

Fence baffles on an Australian 3300 Sonex by Peter Anson here, (bottom of page): http://sonexaus.wikispaces.com/Peter+Anson+-+Sonex+894
The Bristell production aircraft also uses fence baffles on their Jabiru installation. There were some better pics floating around but I cant find them now!

Anyway here is the link to the Aussie distributor [urlhttp://andersonaviation.com.au/][/url]

Fibreglass ducts have been used by Lynn Jarvis on his 2200 powered Sonex since late 2003/2004. His head temps run quite cool, around 120C (from memory) after some experimentation.
A couple of pics here: http://flysafe.raa.asn.au/constructors/jarvis_cowling.html
The early Jabiru fibreglass baffles did require some radical trimming to fit within the cowl, particularly the RH side.

Cheers
Tony

Tony,

Thanks for the links! Made contact with the Bristell folks and it looks like they're moving back to the fiberglass ducts. Had a look at Peter's website and it appears he's still fiddling with changes to his fence baffles to get them to cool efficiently. Since the Jab wasn't designed for fence baffles, it lacks good attach points as found on Lycomings (and Corvairs).

Tony

[peter anson]

Hi Tony, Just noticed this post for the first time so hope the info is not too late to be useful. I have long since stopped fiddling with the fence baffles on my 3300. They work really well. The engine runs cool and temperatures are fairly even. I was running a ground-adjustable prop which had almost no fan over the intakes so it heated up pretty quickly on the ground. Once in the air , the story is different. The CHTs will actually fall on full throttle climb. Even a fast taxi gets enough air through to stabilize temps. Fitting the fences on the sides of the engine is no problem because they just attach with the valve cover bolts like the usual ducts. Fitting at the front is to a couple of 5/16 bolts either side of the oil pump - I think the bolts plug oil galleries. Fitting at the back is fiddly on the Sonex because the fence has to duck around the fuel filler. That might not be a problem on the Panther. Basically, the fence at the back is just anchored by the two sides and the starter motor. I originally intended to put a clamp on the starter motor to make a proper mounting point but have never bothered. I keep on hearing that the Jab 3300 has overheating problems and the only way to solve the problem is to fit water-cooled heads, but even on hot days the highest temp I have seen is about 145 C.

Peter Anson
Sonex 894
180 hours