Jabiru 3300 Installation tricks/tips/gotchas

[mikebeavers]

I have a second generation 3300 and am about to start my Phase 1 with it. I am very excited to hear you are happy with your Jab. Does your engine have hydraulic lifters? What sort of climb temps to you get from 5 & 6 CHTs and EGTs?

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[wlarson861]

The generation 4 engines have hydraulic lifters and the new cast case and cylinders. Several outside dimensions have changed but it still fits the old mount. As for cylinder temps the hottest I have seen are around 335. But the cht on the efis are all very equal. I would say 5&6 are probably the warmest which would be the value above. On a high altitude test flight (9000 + feet) OAT was 65 F. and the heads were all in the 280 range at about 4 hours on the engine. Testing continues when the weather allows.

[DCASonex]

In addition to all the other good tips, would add routing the vent line as high up as possible to underside of cowl before turning down into your catch bottle. If an A model Sonex, route it along side the fuel filler box.

The original Jabiru engines in Sonex tended to run high CHT on # 2 cylinder and cool on #6, this was due to the prop directing air in a spiral aimed upward at intake on left to #2 and downward at right intake to #1. New cylinder configuration may alter that, but air flow direction will still be needed to be taken into account for good CHT spread. Do not be afraid to trim the top leading corner of #2 cylinder much the same as directions for trimming on #1 cylinder. Not sure if that is still needed with new B cowl. Air running into vertical surfaces, even fins tends to produce turbulence that greatly reduces the ram air effect that can aid cooling. Turbulence can help even out uneven CHTs but often at cost of raising the average.

If an A model Sonex, consider using a 1/2" to 3/4" spacer behind prop for better clearance inside cowl. May not be needed with the new B cowl. If you find that is needed, PM me for more info, not something to be done casually. May be able to purchase from Prince.

If using Bing Carb, direct an air cooling vent to top of fuel pump same as you will be doing to magnetos. Also extend rear wall of right plenum down to shield the pump for cylinder #5. Would also direct a vent towards your Kabota voltage regulator, and mount that with fins vertical.

Pay attention to how you seal rear of left intake plenum around the motor mount above #6 cylinder. Any air that enters intakes and does not pass through fins to pick up heat just adds to the air that must exit, and that increases back pressure in cowl and reduces cooling.

Do NOT use K&N oil filter with the nice hex on end. Have had two fatigue and crack at spot welds for that hex, one resulting in total oil loss.

Unless you will be flying in warm weather year round, consider obtaining one of Steve Rance's TOCAs (Thermal Oil Cooler Adapters.)

If new heads still have the small hole between cylinders, consider cutting off the large ring terminals for the under-the-plug thermocouples and crimping on new small ones and fasten with screw tapped into the to small hole. Slip insulation over the ring terminal shank and last several inches of wire to the ring terminals. Your readings will be 15 - 20 deg. F higher than under-the-plug, but the insulation will result in them more accurately reflect CHTs at each cylinder, and no need to mess with them when checking plugs.

David A. Sonex TD, originally Jab 3300 now CAMit 3300.

[wlarson861]

The gen 4 engine fins were not cut on either side and cowling fit. The small holes between and bellow the spark plugs now come tapped and fitted with brass screws. I ordered the AeroVee CHT probes that have small ring terminals that fit perfectly. I am using an Aeroinjector so the pump drive was removed and block off plate fitted. I used the Sonex baffles, though highly modified they do not have any vanes in the top of the baffle nor fences on the front. The CHT"S so far have been very equal with no cylinders showing much deviation, much more even than the normally aspirated AeroVee. This may change after the engine breaks in. Thanks for the suggestions and I may need further information as I test the engine further. I need one more hour in phase one but the next 100 hours are still test flights, at least in my experience.

[DCASonex]

Bill,

Thanks for the update on your gen 4 engine. Very interested in seeing how that holds up. if cylinder plating works and is durable, may be better than any of the steel cylinder Jabirus or CAMits since it eliminates cylinder distortion due to differential expansion of the two materials.

David A.

[mikebeavers]

The generation 4 engines have hydraulic lifters and the new cast case and cylinders. Several outside dimensions have changed but it still fits the old mount. As for cylinder temps the hottest I have seen are around 335. But the cht on the efis are all very equal. I would say 5&6 are probably the warmest which would be the value above. On a high altitude test flight (9000 + feet) OAT was 65 F. and the heads were all in the 280 range at about 4 hours on the engine. Testing continues when the weather allows.

Thanks for the info on the CHTs. How do you like your performance?

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[wlarson861]

First take off was scary! I was still rolling in throttle and about to raise the tail when it left the ground. Lowered the nose till I hit 65 mph and started up while feeding throttle. at 85 mph I saw 1200 fpm climb and was nearing pattern altitude. Made the turns and reduced power to keep out of KPIA airspace. I will say that it climbs like a homesick angel and scoots when level compared to what I have had. Starting to see a cht difference among cyliders as the engine breaks in. Added the air dam baffles in the front of the cylinders but didn't get to fly before Oshkosh. Keep you posted.

[scoop]

Love the Jabiru i have 8 hrs on mine now Waiex # 094

[builderflyer]

Welcome to the world of the Jab 3300. After flying mine for 13 years I will say that when lightly loaded, the takeoff performance is a real hoot. It's like having a tiger by the tail and requires remaining very alert to avoid running off the left side of the runway which 3300 drivers have been known to do now and then.

Have fun,

Art,,,,,,,,,,,,,,,,,Sonex taildragger #95,,,,,,,,,,,,,,,,,Jabiru 3300 #261

[Arnieb]

I have a Jabiru 3300A in my Sonex tail dragger, I was having trouble with vapor lock got that figured out. Now I am getting high CHT's not sure on how to fix this one. I talked to Jabiru at Oshkosh but they were no help. I am not the builder I am the second owner when I bought the Sonex it had only 1 hour on it.

Arnie
N338SR