tony starr
Senior Member
I've heard many using diesel oils in their flatheads - is there a specific reason why?
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oil
- Thread starter Graeme / New Zealand
- Start date
miller91
Member
Flatheads run pretty dirty...like diesels! Plus HDMO's (Heavy Duty Motor Oils) have some additives that have been regulated out of standard duty oils (zinc, phosphorus, etc). There is a lot of misinformation out there, but basically old technology, i.e. flathead anything (pre-PCV, especially) creates lots of acidic load, fuel and moisture contamination of the oil, premature breakdown of viscosity, etc. Frequent changes, HDMO's, at least some filtration, (i.e stock cartridge filters...which actually work pretty well) and maintenance of oil breathers, oil filters, a good air filter (grit and particulate matter is basically sandpaper in an engine) really help. Adapting a PCV, something I am a fan of, performs even more wonders.
petehoovie
Well-known member
"To quote one 2005 research study: “The most common antiwear additives used in engines are zinc dialkyldithiophosphates (ZDDPs), which have the chemical formula Zn[S2P(OR)2]2, where R is an alkyl group. ZDDPs have successfully been used for over 60 years, and to date no superior antiwear additive has been developed for use on steel.”
ZDDP has an excellent track record at protecting the sliding metal-to-metal cam lifter interface. Historically, ZDDP has been added to oils in amounts resulting in approximately 0.15% phosphorus and 0.18% zinc. ZDDP protects by creating a film on cams and flat lifter contact points in response to the extreme pressure and heat at the contact point. The film of zinc and phosphorus so formed provides a sacrificial wear surface protecting the base metal of the cam and lifter and bearings from wear."
Gimme more Zinc....
ZDDP has an excellent track record at protecting the sliding metal-to-metal cam lifter interface. Historically, ZDDP has been added to oils in amounts resulting in approximately 0.15% phosphorus and 0.18% zinc. ZDDP protects by creating a film on cams and flat lifter contact points in response to the extreme pressure and heat at the contact point. The film of zinc and phosphorus so formed provides a sacrificial wear surface protecting the base metal of the cam and lifter and bearings from wear."
Gimme more Zinc....
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