Little Runaway Posted May 24, 2017 Report Posted May 24, 2017 Hello all, Long time lurker, infrequent poster. Question for you RayJay experts out there: Is the fuel servo used with the RayJay STC motor installed on an E/F the same as a non-STC'd standard A1A motor? I'm in the middle of an overhaul and the engine shop has asked for a copy of the STC to see if there is something different about the fuel servo. thanks, Aaron
RLCarter Posted May 24, 2017 Report Posted May 24, 2017 Wouldn't it be in the paper work for the STC?
carusoam Posted May 24, 2017 Report Posted May 24, 2017 See if I understand this correctly... 1) your E has a rayjay TN... 2) you don't have the STC paperwork for it... 3) The mechanic is trying to tell if a different part of the fuel system is required.... 4) I haven't heard of the fuel system being modified when other people talk about this hardware... 5) I'm under the impression that the Turbo normalizer isn't changing much about how the engine operated originally. 6) See if you can get the proper STC from Ray Jay. That might be a big challenge... PP thoughts only, not a mechanic... We have a few M20F operators that use a ray jay TN on their IO360 around here... we recently had a user with an O360 using one as well... Best regards, -a-
Little Runaway Posted May 24, 2017 Author Report Posted May 24, 2017 Thanks for your replies. Apologies--I should have been more clear. Yes, my E has a RayJay TN and it was installed in 1977 according to the logs. Unfortunately, I don't have the original STC paperwork. I haven't heard anything about a different fuel servo or seen one in the pictures of RayJay kits. Hopefully, one of the RayJay owners can confirm. thanks, Aaron
KSMooniac Posted May 24, 2017 Report Posted May 24, 2017 I'm pretty sure the servo is the same, but you need to track down a copy of the paperwork. The fuel injectors might be different, but the servo is likely unchanged from the stock engine.Sent from my LG-US996 using Tapatalk
Brian Scranton Posted May 25, 2017 Report Posted May 25, 2017 Looking through my RayJay documents, the servo is not listed as a change. The mechanical fuel pump is--it reads, "The new diaphragm fuel pump installed on each engine is required for satisfactory turbo operation...the pressure regulating section of the pump is referenced to turbo compressor discharge pressure to insure proper fuel pressure programming..." So it is my understanding, based on this, that turbo-specific fuel control happens at the pump, prior to the servo. Boost pump remains un changed as well. There a quite a bit of mods in the STC (about 25 pages worth). So you should for sure get/own that. The oil system (scavenge, cooler, etc), the induction system, the fuel system as it relates to reference pressure and fuel injectors, the cowl, the cabin heat...all have been modified. 1
Little Runaway Posted May 25, 2017 Author Report Posted May 25, 2017 Thank you, Brian. Much appreciated! Aaron
M20F Posted May 25, 2017 Report Posted May 25, 2017 Hi - I will try to remember to look this weekend I have all the ppwk/drawings.
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