JohnC

Hi Nev, yes every crankshaft, whether it be a 2 cylinder horizontally opposed or a straight 12 cylinder engine, will be subject to an element of torque reaction or "crankshaft wind-up" as it was called in the old days, however when the engine is designed this is, or should be, compensated for. Regardless of application (aero, auto, generator, marine, etc) all engines will have an element of load on both ends of the crankshaft and there will never be equilibrium due to "drive end" heavy load and "auxiliary end" light load, therefore unwanted harmonics (especially from a propeller) and opposed forces trying to shake or pull things apart will always be apparent - it is the designers job to engineer and compensate for this. Camit appear to have addressed this via a rubber drive belt and larger alternator in effect increasing the load and drag on the "auxiliary end" of the crankshaft and providing a damping effect due to frictional losses with in the drive belt and pulleys, however they (and Jabiru) still offer the internal wound coil alternator so they must be pretty confident they have "engineered out" this problem by increasing the bolt size from originally 1/4" to 5/16" to 3/8", adding two additional dowel pins, a starfish to increase the grip surface area, increased the torque (gripping force) of the bolts and different lock washers. If they had done all of this in the first place I have no doubt we, and others, would not be having this conversation. This is certainly not intended as a criticism of Jabiru because had they "over-engineered" everything from the start with huge bolts, brackets, fixings, castings, thicker materials etc, the conversations people having now would be "don't bother with a Jabiru engine they weigh half a ton!" - sometimes a manufacturer just cant win or do right for doing wrong, however they will always be judged by the their customers / potential customers on how they "react and rectify" when a problem is encountered.

Dear all, my experience of the 3300 engine flywheel bolts is disappointing. My engine sheared the bolts (luckily on start up) despite the 100 hour torque checks as detailed in the engine manual, however I was always of the opinion this was a waste of time as simply checking how tight the loctite is holding the thread is futile and a torque setting of 24ft/lb was far too low for this type/size/application of bolt (my own calculations concluded these bolts will take over 60ft/lb (dry thread) before over-stress / distortion). This all happened before the revised engine manual (June 2016) recommended “do not use loctite, use Nordlock washers and torque to 39ft/lb”, this can only be perceived as an “admission of guilt” by Jabiru as they knew fine well they had a problem and needed a quick fix. Luckily I had a spare low hour (380 hours with new valves / seats) 3300 engine in storage and decided to fit this engine rather than having the hassle of removing 6 snapped bolts buried in the end of a crankshaft – this is a job for another day. Needless to say prior to installation I replaced the flywheel bolts in the spare engine as the latest engine manual and bulletin. Where things get interesting was the tightness of the existing bolts in the spare engine, I used a torque wrench (old fashioned dial indicator not a modern click-stick) to remove the old bolts and was concerned to discover all the bolts came out easily with a torque pressure of anything between 5ft/lb and 20ft/lb, one can only conclude that none of the bolts were providing adequate compression tension between the flywheel and crankshaft so things could have started to move, the bolts shear-stress and snap. Many people also overlook the fact that the starting torque and forces these bolts sustain during start up is similar to whacking the flywheel with a hammer every time the starter motor engages. My advice for anyone with the early 6 x 5/16” bolts is:- 1 – If you haven’t replaced them (regardless of engine hours) replace them now using latest method. 2 – Make sure you don’t have starting problems if you do “sort it”, every clunk of the starter strains the bolts. 3 – Check the bolts every 50 hours run maximum and any movement, doubts or concerns replace all of them with new including new Nordlocks, and check the flywheel and crank at the same time for any unusual marks or signs of movement. 4 – Replace the bolts every 250 hours and inspect the old ones with UV/dye for any traces of stress, wear or unusual marks. Anything untoward investigate for crank or flywheel problems, and ware or elongation of the flywheel and crankshaft holes and threads.. Stick rigidly to the above and you shouldn’t encounter a failure, high maintenance it may be but better than looking for a field in a “glider” at 3000ft. My opinion of the theories concerning propellor types, harmonics, etc carry little weight, if the prop is balanced and the engine isnt "shaking out of the airframe" it's highly unlikely it will cause the flywheel to "vibrate off" and snap 6 bolts. I use Sensenich and always have - they certainly know more about propellers than most. I have personally lost all confidence in the Jabiru engine and in the process of ordering a Camit engine as, it certainly appears, Camit have addressed all of the flywheel, head, piston, rocker gear, valve and lubrication problems Jabiru engines all appear to encounter around the 400 + hour run time.

Unfortunately they are aprox 20,000km from my airfield - some guys get all the luck.

Dear all, thanks for the replies and responses. Detailed below is an email trail from a Camit user with over 100 engines sold/used and one engine with nearly 2000 hours - the contents are factual and self explanatory, 10 out of 10 for Camit. This, and a discussion today with a delighted UK Camit engine owner (over 100 trouble free hours), has given me the confidence to proceed with the purchase of the Camit engine. I like to use fact based information to draw conclusions and speaking to two independent individuals in different corners of the world with "real world" experience couldn't be better - the www is a good thing. In Jabirus defense designing, building, certifying and marketing an aero engine is a mammoth task and no small achievement that they deserve credit for, and my opinion of the Jabiru range of aircraft and J400 aircraft hast changed - it is the best light sport 4 seat on the market. However Jabiru need to accept they have made / are making mistakes with this engine (they are only human like everyone else) and start the modification process quickly, maybe with Camit's help? Thanks again to everyone who commented and replied. From: John Cherry [mailto:[email protected]] Sent: 29 September 2016 06:09 PM To: [email protected] Subject: Camit Aero Engines Dear Sir/madam, I was given your name that you may be able to provide feedback as a user of Camit engines, I am considering purchasing a Camit 3300 and would like your general opinion of the Camit engine and any issues you may have encountered. I believe you are in the minority of organizations that have experience of several Camit engines now clocking up many hours. I brief reply will suffice and I thank you in advance for your assistance. Best Regards John Cherry From: Bat Hawk [mailto:[email protected]] Sent: 29 September 2016 03:05 To: 'John Cherry' <[email protected]> Subject: RE: Camit Aero Engines Good day John, We have installed over a hundred Camit 3300 SLRE engines into our Bat Hawk aircraft and have only praise for them. We had problems with one engine early on , due to overheating. That problem was resoved and since then, they are all running like a dream. We used to use Jabiru engines, but had to stop using them because of all the “ engine-outs” we were experiencing. Our Bat Hawk aircraft was starting to get a bad name because of the “s - - -“ Jabiru engine. Since we moved to Camit all our engine problems ceased. Our Camit powered Bat Hawk with the highest engine hours is now just under 2000 hours, and is still going like a bomb. The Camit engine is so much cheaper to purchase and operate than the Rotax option. We are very happy with the Camit engines we’ve installed , and can highly recommend them. Check out our website : www.bathawk.co.za You will also find a lot of happy customers on Facebook. Look for Bat Hawk. Kind Regards, Andrew Andrew Pappas Micro Aviation SA Cell 082 338 9848 Fax 086 659 4672 From: John Cherry [mailto:[email protected]] Sent: 29 September 2016 09:33 PM To: 'Bat Hawk' Subject: RE: Camit Aero Engines Dear Andrew, Thank you for your prompt reply and your “real world” experience of the Camit engine, I must also add this is exactly what I wanted hear. May I ask if you would have any objections to me posting this email on a forum and forwarding this email to friends and associates considering replacing their Jab engines with Camit engines? Thanks again and happy flying. Regards John From: Bat Hawk [mailto:[email protected]] Sent: 29 September 2016 04:51 To: 'John Cherry' <[email protected]> Subject: RE: Camit Aero Engines Hi John, I wouldn’t mind at all if you want to advise to your friends and associates about the very successful new Camit SLRE engines. There are many, many changes that have been done to make this new Camit engine so reliable. They run very much cooler than the old Jabiru used to. There is no more pistons breaking off at the oil ring groove, no more head crushing, no more hydraulic lifter problems, no more dropping of valves, no more fly-wheels coming loose, Camit engines have new barrels with a much larger “footprint” flange and much larger cooling fins, for improved cooling. There are a lot of very successful internal mods as well. Camit have also developed a “ high heat” engine for us that we use in very high ambient temp areas. You cant go wrong with a Camit SLRE engine. We really trust and believe in them. Kind Regards, Andrew Andrew Pappas Micro Aviation SA Cell 082 338 9848 Fax 086 659 4672

Thanks for the link i will email them for their opinion and experiences to date.

I emailed Ian at Camit with a several questions a couple of days ago and awaiting his reply, however I am 90% sure at this stage I will be ordering a Camit 3300 within the next few weeks if I get positive feedback, however I would like to hear from someone who had one of the first Camit engines and get their independent opinion of the engine in real world operation simply for piece of mind. Everything I have heard so far from Camit and others appears to be positive and they certainly appear to have addressed the many problems with the Jabiru engine. I would personally disregard any rumors from the Jabiru camp for obvious "conflict of interest / commercial competition" reasons, and if Camit get the reliability issues sorted with this engine design they, in my opinion, will have a world class / leader of an engine. Please keep the comments and information coming.

Dear All, I would like to reopen this thread as Camit appear to be moving quickly with new products etc, and they certainly appear to know whet they are doing. I am considering replacing my Jab3300 with a new Camit engine as I have been unlucky with the Jab engine including snapped flywheel bolts, misfires / coil problems, a forced landing, low compressions and, needless to say, my confidence in the Jab engine has completly gone. When operational all the t&p's were perfect with a "by the book" maintenance regime and good in-flight engine management with full EMS and all cylinder temperature monitors - the engine started giving problems around the 500-600 hour mark. My question is has anybody got a Camit engine with a few hundred hours and has the experience been positive and problem free? I can not and will not throw any more time or money at the Jab engine as this engine, in my opinion, has major design, assembly and material application issues.