Rotella question

Jay - I had a rebuilt flathead put in my 40 in late 2010. so far I have changed the oil three times. I ran straight 30wt when the motor went in, freshened it up with WalmMart Straight 30, and at the most recent oil change time, used Shell straight 30. Oil is in good shape, dark gold in color after a couple of hundred miles.

I thought about using a multi weight oil, but if it aint broke dont fix it.
In the old motor, I used Castrol 20-50. it didnt leak much after that...

If it works, stick with the straight 30wt you have been using, Just change it every 1000-1500 miles or i do it seasonally if I havent used the car that much.

Chris
 
I agree, stock valve springs don't need the zinc. Anything stronger and you do. They took the zinc out of the oil because it wipes out the catalytic converters and almost all modern cars have roller lifters that don't need it. I have seen wiped out solid lifters from a hi perf flathead due to lack of zinc. Isky cam and lifters and valve springs, about 200lbs pressure over the nose of the cam. I tried to insert a picture but don't have it on a website to refrence.
 
I'm with Deuce Roadster on this one. A stock flathead might not need additives but once you get into increased spring pressure, watch out. While some of you may accuse me of being bi-******, I do own both high peformance flatheads and overheads. Any current engine builder will tell you the most critical time in an engine's life is the first few minutes of break-in. It is not uncommon to see a solid or hydraulic cam lose one or more lobes during break-in. There have been many explanations; bad lifters from China (likely) and lack of zinc in modern oils being the most prevalent.

Many high performance engine builders and race teams have gone to running Rotela or Delo, not just during break-in but during races. Synthetics are great, but at the frequency of oil changes I do in my hobby car engines, the costs are hard to justify. After watching the lobes disappear on both my Ford and Brand X overheads, I have vowed to only build roller cam engines in the future. The initial cost may be high, but it's cheap insurance with today's oil. I'd love to try one in a flathead. Anybody have any experience with this? Are the lifters still available?
 
Read the attached info and make your own decission. Even the guy useing Walmart isn't to far off. Almost any oil seems to work in these engines. The Valvoline Blue looks good to me with all the right kind of additives but Castrol 20/50 has worked for over 30 years and over 110,000 miles in my 39. G.M.
 

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My last trip to Wally World I saw some Quaker State oil called Defy. On the outside of the container it said "added zinc". For those that feel they need the zinc this may be the answer.
 
When we used the 20W/20 Texaco Havoline back when I was a kid, the engines ran just fine until the were worn out. Regular oil & filter changes made more difference on longevity than the type of oil. No motor oil is going to make an old flat motor last any longer than they were designed to. You can use the re-refined stuff if you want and it won't matter unless you decide you can run the 5000 miles between oil changes. The way the filtering system is, a person should be pretty religious about oil changes. I wouldn't go more than 3000 miles. If you want to baby it, change it every 2000 miles. The four ring piston motors just flat wear faster and there isn't a thing that can be changed about that except changing to three ring after it gets bored out to applicable specifications for 3-ring pistons.
 
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