AFTER new engine break in

[Bart]

I just got my rebuilt 351 Windsor back from the rebuild. The guy told me that AFTER the 15 minute/2000 rpm run in there was no need to run a zink oil or additive. The cam is hardened by the run in and doesn't need anything further. Has any one ever heard that before. I've always been under the impression that a flat tappet motor always needs the zink to cushion them.

 

[sanndmann3]

I would keep running the zinc. Never heard of the additive as break in only. My impression is you use it for the life of the engine. Is he confusing it with the moly grease that you coat the cam with for break in? Makes me wonder about the builder...

 

[sykanr0ng]

/\/\ +1 on all that.

Zinc is softer than steel or cast iron, it acts as a cushion.

 

[SteveL]

I don't remember needing it for the life of the motor. I think it was needed for break-in and the first few oil changes.

 

[Broncobowsher]

My understanding is that you don't need to keep running it. But I still do. Just not full strength. A little swig of the zink elixir on an oil change. An ounce or two? I let valve spring pressure dictate how much to run. The two old school engines I still have ('61 and '77) are bone stock valvetrain. If I were running a hotter cam and stiffer springs, probably would go up to a half bottle.

So far everything has been fine. Right, wrong, don't know. Figured a little wouldn't hurt. I've heard too much is worse than not enough as well.

I know part of the break in is the surfaces mating, and the zink being driven into the pores of the iron.

 

[DirtDonk]

There's a reason that zinc-rich oils marketed for older vehicles are now a main component of the shelves at auto parts stores.
It's different than the break-in lubricants, as was said. I say use the right oil, or use the additives for flat-tappet cams other than the break-in type.

Plenty of people get away with modern oils for awhile, but I believe the reason that the availability of high-zinc content oils is so much broader now is that there were a whole slew of high-mileage cam failures in older vehicles for awhile.
I don't have any empirical data to support that, but it's what I think went on and why I will use the oils for older engines as long as I have flat-tappet cams to protect.

Paul

 

[5001craig]

My engine builder said to always run zinc additive. He recommended Brad Penn oil as it took care of the cam problems he had after zinc was removed. And it's easy as the zinc is in the oil.

 

[Tiko433]

Flat Tappet cam I always use a zinc additive. Not a break-in additive. I usually grab Hyper Zinc. From what I read over the years the oil companies have been putting less zinc in modern oil.

 

[Bart]

I would keep running the zinc. Never heard of the additive as break in only. My impression is you use it for the life of the engine. Is he confusing it with the moly grease that you coat the cam with for break in? Makes me wonder about the builder...

I've had quite a few engine built by this company over the years (for my 12 vehicles) and never had a problem. The current engine (to be replaced) was built by them some 10-12 years ago. It's just starting to show some blue smoke, but considering the extremely dirty environment it worked in (hard off roading) I think it did fine. I'm not sure who this guy is as I never dealt with him before. Always with Matt the owner. I'm betting that this guy didn't know I was speaking of a flat tappet engine or he's too young and think all engines are now rollers. I agree that continued use of zink rich oil is a must. Thanks.

 

[Bart]

Thanks all, I agree that zink is a must for flatties. Amsoil has an oil they call Z-rod. It's a zink rick oil for the older engines.
I seem to remember that one should break an engine in (first 500 miles) or organic (dino) oil and synthetic oil after that. Anyone want to comment on that?

 

[blubuckaroo]

Yes, I use Comp Cams break-in additive even after break-in.
But...I've always felt that adding a container of anything to four to six quarts of oil was a pretty crude way of going about things.
My next motor will either be a roller or be fed an appropriately blended oil.
This stuff may not be available in your area, but there's always Amazon.
https://www.summitracing.com/parts/...MIyZTwkILf1wIV15d-Ch3lggbcEAQYBCABEgLrN_D_BwE

Also, there's a lot of documentation on the subject of ZDDP and detergents and how they get along in motor oil.
They actually don't get along well, and so oil with added zinc needs to be changed more frequently.
That's really not such a big deal though, since most cars with flat tappet cams also have carburetors, and need frequent oil changes anyway.

It may seem expensive, but you've got to pay if you want to play.

 

[Bart]

Yes, I use Comp Cams break-in additive even after break-in.
But...I've always felt that adding a container of anything to four to six quarts of oil was a pretty crude way of going about things.
My next motor will either be a roller or be fed an appropriately blended oil.
This stuff may not be available in your area, but there's always Amazon.
https://www.summitracing.com/parts/...MIyZTwkILf1wIV15d-Ch3lggbcEAQYBCABEgLrN_D_BwE

Also, there's a lot of documentation on the subject of ZDDP and detergents and how they get along in motor oil.
They actually don't get along well, and so oil with added zinc needs to be changed more frequently.
That's really not such a big deal though, since most cars with flat tappet cams also have carburetors, and need frequent oil changes anyway.

It may seem expensive, but you've got to pay if you want to play.

My new flat T is fed by throttle body injection but it still gets an oil change once a year. We wheel a lot with lots of dirt so the annual isn't a bad idea.

 

[sykanr0ng]

I seem to remember that one should break an engine in (first 500 miles) or organic (dino) oil and synthetic oil after that. Anyone want to comment on that?

One of the big disadvantages of synthetic oil over organic is cost.

Changing oil which costs 4 or 5 times as much after only using it 500 miles was seen as too expensive.

 

[Bart]

One of the big disadvantages of synthetic oil over organic is cost.

Changing oil which costs 4 or 5 times as much after only using it 500 miles was seen as too expensive.

In reality, the cost of organic here in commifornia isn't much less than dealer priced Amsoil.

 

[blubuckaroo]

One of the big disadvantages of synthetic oil over organic is cost.

Changing oil which costs 4 or 5 times as much after only using it 500 miles was seen as too expensive.

Also, the big advantage of synthetic in these engines isn't the lubrication qualities, but it's more about the stability at high and low temperatures.

 

[sykanr0ng]

In reality, the cost of organic here in commifornia isn't much less than dealer priced Amsoil.

In the late 1970's and early 1980's when synthetic oil came into consumer use that was the price difference through most of the country.
That is what caused engine builders and people who had engines built to say use organic oil for the break in oil changes.