moly vs zddp

[Dave R.]

Am considering one of two oils, one is Amsoil (high zddp) and Redline (high moly) This is going into a 2003 Moto Guzzi that specs 5w40. It is engine only, dry clutch, no starter clutches. It has the new hydraulic valvetrain that is hard on cam lobes and follorers (non roller). I was wondering in respect of the cam which would give best barrier film protection, zddp or moly? thanks.

 

[AV8R]

Current engineering thought is that high Zn and P give predictable, effective anti-scuffing and anti-wear, but wear levels may increase from higher polishing if the formulation contains really high levels of aw additives. This depends somewhat on the types of zinc compounds, and there are quite a few, diaryls and dithios mostly, having a wide range of activation temperatures. Moly dithios and lower zinc levels may give lower wear on cam noses, etc. but are not necessarily more reliable aw performers, especially in the presence of water. I think I might try Amsoil first, with a UOA, then do the same with RL.

 

[satterfi]

The last data I saw, showed Redline 10w40 had more Zn and P than Amsoil 10w40.

However, with different lots, reformulation, lab error etc., it's impossible to say for sure.

One thing for sure, both have high levels.