Bucker Jungmeister repair

Following a dead stick landing in Pea field my Bucker Fuselage split. After stripping out the hardware and peeling back the covering it quickly became apparent that most of the failure was in the joint glue but i think calling it glue is too generous - maybe the chinese make it from snot or babies teardrops !

There is a "good side" Kevin, at least you've a clean break to repair, not the usual torn mess of fibres that won't quite go together. Perhaps the wily Chinese designed the joint as a breakaway feature, but I don't think they'd be so kind.

Clamped the parts with rope ties

Looking further at the FG30 it appears the inlet valve mechanism has failed. The cam seems to have full lift but the push rod has dropped.

The excessive valve clearance is due to inlet pushrod wear with swarfe in the tappet (cam follower) socket. Note the exhaust side benefits from valve stem blow past. This engine has at best had 1 1/2 hrs running !

Google reveals that inlet cam wear is common on Saito engines due to lack of lube in the design. So the sum up, my experience with expensive Saito engines is a disappointment compared to my cheap and nasty Chinese NGH which has run for nearly 3 years in my GP Stearman which has stopped once due to requiring a de-coke.

I wonder if fitting nipples to the rocker covers and linking them together with silicone tube might allow some of the exhaust blow-by oil/vapour to reach the inlet rocker and pushrod Kevin?

John Ireland wrote: I wonder if fitting nipples to the rocker covers and linking them together with silicone tube might allow some of the exhaust blow-by oil/vapour to reach the inlet rocker and pushrod Kevin?

Were on the same wavelength John, but that would be difficult with my installation, so my thoughts are

1. Silver solder a nipple on the pushrod tube for direct oil injection prior to flight
2. ditto both pushrod tubes and link those with silicone tube.

Kevin Ross wrote: Silver solder a nipple on the pushrod tube for direct oil injection prior to flight

That seemed to work quite well in the early days of flight. Why should it not work today?

having concluded that the only source of lube at the front end of the motor is via the exhaust valve, ALL the cylinder blow past lube is passing straight thru the rear vent so no oil is getting fwd of the main crank bearing onto the cams or the inlet tappet/ pushrod, ive carried out this mods. Pic 1 shows the groove in the exhaust tappet guide which is getting lube from the exhaust rocker cover and pushrod tube. Pic 2 shows the new groove ive made in the inlet tappet guide.Also ive installed a new vent nipple at the front, so the plan is to restrict the blow past lube from the crankcase rear vent and divert some to the front of the motor.

the pics are displayed in reverse order

Finally ordered some matching Oracover for the repaired fuselage. A closer look reveals my compound curve covering skills have regressed.