Your engine core is not only of value to you in the form of a deposit, it’s of value to us to be able to overhaul to new specifications for another customer. Often, we are asked about core deposit refund time frames.

Here are some insights into the process of your returned engine core. Once we receive it off the truck, it is visually inspected for missing components and to ensure that the engine is in as removed condition. Commonly missed items to name a few are logbooks, flywheel/ring gear supports, breather fittings, dipsticks, inter-cylinder cooling baffles, accessories and carburetor throttle and mixture arms. It is also looked for damages. Often dipstick tubes are not removed and broken. These need to be removed to prevent this.

The engine is then moved inline to disassemble and inspect. The same department that processes customer engines for overhaul, also disassembles core engines.

Once disassembled, our primary focus for core deposit refund is the inspection of the crankshaft and crankcase and if they meet spec to be safely and legally reused in future engine builds. We hold to specifications outlined by the manufacturers and the FAA which can include checking for cracks, pitting in the crankshaft, bearing journals under serviceable size, bent crankshafts, or bent prop flanges. Crankcases are checked for cracks and wear in common places and if they can be repaired for future engines without risk.

If the crankshaft needs repair after inspection, it requires the crankshaft to be sent to an FAA certified machine shop that specializes in aircraft crankshafts. This is an effort to retain a viable crankshaft from your engine for future builds and to get you full deposit refund. Risks of the machining process can be material removal required is beyond limits, a poor reaction in the plating or hardening processes, warpage in the repair process. These things are rare but are risks to the value. If a crankshaft needs to be sent out, the current turnaround time can be 9 to 13 weeks after our inspection.

If the crankcase needs work after inspection, we do this work in our own facility. Cases go through a 30-point check list. At times crankcases need welding for stress fractures. We also correct any flaws in bore alignment to name a few. Any repair to a case risks warpage or a loss in strength. Again, this is an effort to retain a viable crankcase from your engine for future builds and to get you full deposit refund.

If both crankcase and crankshaft are verified good for future builds, core deposit refund is then issued. The process is not a quick pass-through process. We want to assure customers like you receive not only your deposit refund, we want to assure customers get the best Pinnacle engine possible.