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Engine-driven Fuel Pumps: Tempest vs Lycoming

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After 6 years and 1200 tach hours, my engine-driven fuel pump is starting to occasionally miss a beat. Might be time to replace.

I see two clear options on the Spruce lineup: The Tempest pump (which came stock with my then-factory-new IO-360-M1B), and the Lycoming pump.

Clearly the Tempest has served me well, but do any of y'all have recommendations for going with the Lycoming pump? Is there another brand to consider? And why?
 
Sid, there was another thread recently where a poster had a drop of oil sitting on the heads of each bottom bolt/screw in their Tempest fuel pump. The brand new pump that shipped with my (carbureted) Titan engine several years ago did the same. Nothing major, the pump worked fine, just annoying. And obviously not something that everyone experiences.

I sent it back to Tempest for a warranty replacement, but because a few others had experienced similar, I opted to purchase a new Lycoming pump instead and sold the replacement Tempest.

The Lyc pump has been dry as a bone for a few years and a few hundred hours.
 
The Lyc pump has been dry as a bone for a few years and a few hundred hours.

My original Lycoming pump did the oil leak on the screw heads thing. Diaphragms are a rubber/fabric/rubber sandwich, and it appears the core material wicks oil to the perimeter and screw holes when the rubber layer is cracked.

Sid, I doubt there is much difference, but it takes a long time to tell! I've got a Tempest going right now, and should have an opinion in about 8 more years ;)

https://vansairforce.net/community/showthread.php?t=160388
 
Sid, there was another thread recently where a poster had a drop of oil sitting on the heads of each bottom bolt/screw in their Tempest fuel pump.

https://vansairforce.net/community/showthread.php?t=198776

Here’s the post Kurt referring too… mine. Changing oil yesterday, this is how things looked. Every screw would tighten 1/2 to 1 full turn. There are lock washer installed, but seem too small to really do much. I’m replacing two with Nordlock to see if they hold better. I decided to remove one screw entirely, surprisingly they are about 3” long and show that blue locktite was used. I reapplied some permatex blue on the screw and reinserted, with split lock washer.

So I’ll see if a change and where, nordlock or new blue locktite with existing split lock washer, or no change.
 

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I just had my fuel pressure suddenly drop to the point of engine roughness (10 PSI) - last flight OK, next flight this happens. Had to fly back with the electric boost pump. A bit frightening, as the most I ever use the electric pump is for start priming - will it run continuously for the return to the airport? Mechanical pump is a Tempest high pressure pump, only 450 hours old. Finding no loose or leaking fuel line fittings, replaced the pump and now all is well. Somewhat disconcerting, as Tempest claims these pumps to be good for TBO. I then decided to also have the electric boost pump overhauled to provide a bit more confidence in case this kind of thing happens again.

For what it's worth, the shop that overhauled my boost pump told me that now all the mechanical pumps are made by Tempest, so if that is true, if you buy a Lycoming, you will get a Tempest anyway...
 
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