Hyperbolic vs. Straight Tappet Body

[avrojockey]

Researching more replacement parts...

Lycoming parts catalog shows 15B26262 which is the new hyperbolic design, there's been low oil pressure reports so Lycoming went back to the straight body with 15B26588. You can use either or, but the whole case must have the same.

Superior equivalent has only the straight version SL72877, and from what I can gather, the Cam kit comes with the straight version also 15B26588.

Anyone have any guidance on upgrading the hyperbolic design which is intended to improve wear characteristics? Lycoming recommends straight design for multiple "field" overhauls.

Also, does the Superior SL72877 have the DLC coating like Lycoming has now?

 

[lr172]

Also, does the Superior SL72877 have the DLC coating like Lycoming has now?

It was my understanding that these are only available from Lyc. Good news is someone forgot to mark them up a few thousand percent, so not ridiculous expensive. I think I only paid around $75 each back in '19 and they were definitely not 5 digit part numbers. These are uniquely numbered parts. They DID NOT go back and add DLC to all of their traditional parts.