Time to start up my rebuilt 351W in my 1966 F100. This is a new rebuild and it has never had oil in it. What oil is recommended? I want to start with the right one and keep using it. I will put some zinc in since I don't have a roller cam. Curious if I should use synthetic oil in it or stay away from it.
I live in Portland, Or.

 

You'll get a whole lot of differing opinions and suggestions on this... when I rebuilt my 351M I used VR1 10-30, recommended by a friend who has done a few rebuilds, so far so good, did cam break in, changed oil, ran it another 500 and changed it, think I have about 1500 or so now on the oil in it and everything seems to be good.

 

My choice is Driven GP-1 30w break in oil. GP-1 30 Grade Break-In Specialty Motor Oil (drivenracingoil.com) Then switch to a good oil with a little zinc. Never add ZDDP to oil that has that in it already it can actually increase the wear.
Opinions vary, your call.

 

Definitely need to use a non-synthetic oil...otherwise the initial piston ring break-in will literally not happen and will take up to 1k miles to occur.... and you don't want that!

 

This is exactly what I was always taught. Break in with a quality dino oil, and if you want to switch to syn later, fine, but put a couple thousand miles on it first.

 

BTW- DO NOT USE ADD ZDDP on your initial startup..... this can have real devastating effects and literally cause damage especially to the piston rings during initial break-in!!!!!!! Yes you can add it later, but IMHO, wait 1000 miles.Just a little fyi/IMHO...

You will hear some people say to "Drive it like you stole it"..... Well, anyone who just stomps on any new drivetrain component has absolutely no knowledge or caring for mechanicals......the damage that is done is beyond simple explanation and I will sum my thoughts up this way...

Want it to go fast- break it in fast...

Want it to live long, break it in slow........

Here's what I do and have recommend to anyone who has asked me regarding new engine break-in...

While much of the engine components are seated, there are some (such as piston rings) that can take up to 1,000 miles to fully seat. Here's what I do with every new engine I have ever built (my dad as well)...for the 1st 1,000 miles

After the initial run (20 minutes @ 2000-2500 rpm+), I shut the engine off and let the engine cool down. I look for and fix any and all leaks... and you're very likely to have some and it's normal!
After all the initial tuning, etc. is done, I will go for a slow drive, 1-5 miles, 15 to 25 mph- lightly varying the speed. Come back, oil change and cooling system flush.
During 50 miles, again, under 35 mph, varying speed, change oil at 50 miles again and retorque all bolts (cylinder head, etc.)... An important FYI- let the engine sit for 24 hours+ prior to retorquing the heads/manifolds (especially) because residual heat sink can occur and cause variances due to material expansion/contraction.

I avoid/lock out overdrive and drive normally (city & hwy)- this keeps the rpm's constantly varied...do not beat on the engine, at 500 miles, I change the oil & filter to remove any mfg contaminants that may exist.

At between 800-1,000 miles.....we go for a long trip....something in the 2-4 hour driving range, running 70-80 mph without the use of overdrive- this keeps the RPMs higher and again, varies the rpm's by the natural flow of traffic and the drivers foot.. Upon my return, I change oil & filter.

At this point you can add ZDDP and run synthetic oil and do your regular oil change intervals.