Sorry to expand the issue, but oil choices for flat tappet cams (solid and hydraulic) are a lot more complicated these days due to the changes in oil formulations, mandated by the EPA, designed to reduce the amount of emission by-products that foul modern catalytic converters. The main culprit appears to be a zinc additive (ZDDP) which is especially good at protecting metal-to-metal contact like cam lobe-to-lifter surfaces. Problems can occur especially in the cam break-in period but can also crop up later in a broken in engine. Heavy duty oils originally designed for deisel applications, like Shell Rotella T or Chevron Delo 400, had been exempt from the EPA standards and had plenty of ZDDP until recently when they too have been required to reduce their zinc although that amount is still currently higher that traditional passenger car oils. Another thing to consider is the ZDDP additive is sacrificial so if you don't drive your car much, or that hard, maybe conventional oils are still fine. The Bob Is The Oil Guy website has a ton of info on this subject that is well worth reading. FWIW, I'm currently using Chevron Delo 400 15W-40 in my 66 GT350 and so far so good.
ck. out this page from Mobil 1 http://www.mobiloil.com/USA-English/MotorOil/Oils/Mobil_1_15W-50_.aspx It appears they have "reformulated" the Mobil 1 15W-50. And this would seem to benefit the "flat tappet" crowd. http://www.mobiloil.com/USA-English/MotorOil/Oils/Oils_FAQs.aspx#Mobil_1_FAQs3 ".... Why are you reintroducing Mobil 1 15W-50? Have there been any changes to the formulation, or is it identical to the previous product? Mobil 1 15W-50 is being reintroduced based on popular demand. Mobil 1 15W-50 provides higher viscosity, designed to provide extra protection for performance vehicles and vehicles that operate in severe service, such as towing, hauling and racing. Additionally, Mobil 1 15W-50 contains higher levels of anti-wear (ZDDP or Zinc DialkylDithioPhosphate) that may be required for certain racing applications and camshaft designs. This is a new Mobil 1 15W-50 formulation and is not the same as the product that was marketed a few years ago....." I've been using it ( the 15W-50 Mobil 1 synthetic ) for about 15,000 miles in my original 289 Hi-Po engine. Can't tell any different in oil pressure. No new oil leaks, etc. Took a look at the lifters & cam recently. They look as new. Z. Ray '66 GT-350
Hi Keith! just to stir it up a little,Castrol makes a full synthetic 5-50 that is very highly rated by the sae and it is available in any costco store for about $36.00 for 6 liters.the most important thing is changing it on a regular basis and useing a good quality filter every time you change oil.We were taught to prefill the filter and pull the coil wire,then spin the engine over untill the oil pressure reads on the gauge,prior to running the engine.this simple procedure prevents any chance of a dry cold start.We sell Ford,royal purple,and mobil 1 or we can order pennzoil,if you want.Call if you need help.Good luck! A D @ Campbell Ford.
From my experience with 427 and 428 Ford engines, instead of 10w30 or 10w40, I would use 20w50 Castrol with the addition of 1/2 bottle of GM EOS supplement. There may be other oils that would work fine, but we used to spin FE Ford engines 8200RPM and never had a problem with 20w50 Castrol. Has anything been done to your oiling system?
