Alfa Romeo Forums banner

1 - 3 of 3 Posts

·
Registered
Joined
·
139 Posts
Discussion Starter #1
Do you know what dialkyldthiophosphate (or ZDDP) is? Since the 90's this zinc component has been gradually reduced in our engine oil since it has been found to clog cat converters in modern cars and as a result effect driveability and emissions The reduction of this component in our oil for use in older cars like ours, especially in engines with ohc flat tappet valve actuation can, over time, result in an extreme increase in wear patterns especially between the cam lobe and tappet surface. ZDDP together with phosphorous create a sacrificial film or barrier that reduces friction, heat and eliminates metal transfer. Probably the most damage will occur in a newly built motor during break in. For those of you in the automotive field, have you noticed an increase in reports of cams going flat? Me too.You might want to read this report at Zddp In Motor Oil - Marina Alta Classic Car Club. Cheers
 

·
Registered
Joined
·
5,984 Posts
14ppm of ZDDP seems to be the lowest safe level in motor oil for flat tappet engines, and this issue has been covered before on the BB. I believe that 'one-shot' oil additives are now available in case of doubt.
 
1 - 3 of 3 Posts
Top