Hi, just an update on my 3W85 thats in my TA152 in the video section here. Since flying in that video i have made a few changes to the aircraft and engine. I replaced my home made prototype retracts with a set of Sierra,s that i had found second hand but not used, after spending 3 months on my retracts they worked ok as you can see in the video and they even took quite a bounce on landing but i did not have the necessary knowledge and machinery to convert my prototype into a decent looking finished set, so in went the Sierra,s. I also found out that the 3W engine had incorrect timing, apparently 3W set the timing at there factory it was pulling 5200 with a PT 27X10 prop. but in my ignorance of gas engines i did not know any better it should have been at least over 6000 so as you can see in the video the power was marginal It took me some time to find the timing problem i sent it back to 3W and also the engine guru at Airborne but both did not find that the timing was out and they both sent it back with mumbled excuses and wrecked shoulders from trying to start it.
I found the problem by elimination i bought a new CDI ignition to replace the 3W set it was not 3W as they wanted stupid money for there's,after fitting the new ignition it was still a pigs ear to start and the revs. were no better and on some of the attempts at starting i noticed that it was sometimes back firing out the exhaust and i figured that sounds like a timing problem, in the package with the new ignition there was a timing wheel with instructions on how to set the timing so i thought i might as well check it and bingo the problem was solved the timing had been set at 4 degrees before TDC. when it should have been 27-30 BTDC. How i managed to get it to go at all was a miracle, after i reset the timing it started up first or second flick, the trouble was i had set the engine up in the living room late at night as my workshop did not have enough room (yes i do live alone thanks) I don,t know if you have ever heard a 3W85 in an enclosed space at midnight well my neighbors have lol. it was deafening but i was whooping round the living room like a nut case and started it 6 more times just to make sure.
As the timing magnets set in the hub were so far out i had to fix the new sender further round the hub and could not use the original drilled and tapped holes i used a radiator hose circlip, the engine with with the new set up and a 26X10 PT prop was now pulling 6300rpm.and i have now test run with different props for about an hour.
It was now time to test the aircraft again with this new set up.
In the pits on start up and testing before the flight it all looked good with 6300 rpm, but suddenly i lost 1000 rpm.i thought bugger here we go again.
I tried for a couple of hours with the needles and different settings but no luck and then it dawned that i had been here before with 5200rpm on the engine,i eventually got round to checking the timing and found it was out again.
What i had then found on pulling everything off the front of the aircraft to get at the sender was that the sender had moved slightly, because originally the timing magnets had been drilled and incorrectly placed on the hub i had to move the sender 1 inch round the hub to get the timing correct and then to fix the sender in that position as it was way past the original holes you should bolt the sender to in the hub. I had used a fastener that you normally use for fixing top hoses to radiators in cars but it was made of ally and it had worked loose.so the solution was found and on re-timing it it again pulled 6300.
I then flew the aircraft for the first time yesterday with that extra 1000 revs it has transformed the aircraft, the flying and take off were great it pulled like a 14 year old boy (Qt. from Col.Simpson lol.) it is such an easy good aircraft to fly you would never believe it was weighs over 20KG and on the first attempt at landing i touched the top of the Banana tree by the windsock (OOPS) and had to go around it powered up with flaps and gear down no problem for the go around, this time i lined it up well but a bit slow great control all the way down but with an heavy aircraft you must get at least a 9 out of 10 on your landings or you will break something i bounced a bit and damaged a retract mount no real problem to fix.
The landings are the key to getting this aircraft worked out i just hope i can learn to land it correctly so i can get it finished.
CU in the pits
Blackfingernail

"You never finish a scale aircraft you just stop working on it" quote Dave Platt.
Looking forward to seeing some decoration.
Cheers
Stan

hi all seeing as God has been doing a we we on the field over the last 4 weeks and its to soft for heavy aircraft i have been fiddling in the workshop so some update shots. (8-(