Zinc/Break-in oil/Flat tappet
 

Muscle car enthusiasts can learn new tricks. The talk has been not enough zinc in the oil and use a break-in oil after rebuilding. Nothing is further from the truth.
Flat tappet engines require at least 100000 PSI rated oil. High zinc or low zinc isn't the cause or cure it's the oils wear capability that counts. Many break-in oils are very low in PSI thinking
your engine needs to wear (how ridiculous). A great blog or site is 540RAT an engineer who has tested hundreds of oils and debunked the zinc theory which often damages engines.

Ok... Ill bite.... So whats in this 100000PSI rated engine oil that is not in all the others?

What's in the 100000 PSI oils, I guess is the million-dollar answer. I know I wiped my cam out after using Lucas Classic car 5-30 with high zinc. On the oil test chart, it ranked 258 with 63000 PSI wear. 540RAT blog is very interesting and he makes sense. I'm a believer!!

Before I knew about the lack of zink in modern oils I used Castrol synthetic 10/40 and never had a problem. I only use for flat tappet cams and I’ve never had a problem with them going flat. I haven’t decided what to use in my 440s but I have five 5 gallon pail’s of old Valvoline 50 w race oil. ??

I now use Quaker State 5w30 Full Synthetic because it has the highest wear rating of upwards of 153000. Crazy protection for stock flat tappet or draggers.

All I will say about the subject is..... The inhibitors and the modifyers of whats in the oil is just and important as the building of the camshaft. If they are not on the same page. Chit happens.

I guess I will have to sit down and read 540RAT'S Blog one day!!!!!
Thanks for bring it to the site. I like good research. I have never had to add snake oils to any of our builds. Maybe i have always just been lucky on how we do things around here.....

Cheers

I just put a new hyd cam and lifters in my 318 and added a bottle of zinc so should I be good to start it then?

Bad move with the zinc. Read 540RAT blog on zinc and oil.