Got an S&S crate motor for the Harley and the Indy put in some Amsoil 20W50 V-twin.

went down the rabbit hole looking at this and other Amsoil products and saw they make a High ZDDP oil called Amzoil Z-Rod, synthetic and specified for flat tappet engines.

Anyone here have any experience running it in our engines??

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Kind of expensive, But for what the crate motor cost, its a small price.

I see it mentioned in PCA Club Racing circles, and some seem to swear by it. Haven't tried it myself.

I saw a thread on the Bird board where someone contacted Amsoil about the ZDDP levels and it was stated to be

Zinc 1440

Phosphorus 1320

Sounds like good numbers to me ...??

Thanks for posting that!

That is the lowest recommended drain interval I've seen on an Amsoil product.

A good friend is a dealer and he had 24 Blackstone oil analysis done to compare Amsoil products to Castrol GTX oil.
Amsoil was extremely impressive!

At 20k all three cars (Fiero V6, Pontiac GXP V8, Prius) came back "oil fine, continue to use" from Blackstone. Castrol OK at 7.5K and gone by 10K.

He wanted to test their claim of 15K and Amsoil kicked ass!

They are too expensive, and they are semi "multi-level", but actual testing proved their claims 5k over...

Going to have to gets some from my friend.

Been using Mobil 1 20w50 in all my older flat tappet motors. Has 1560 and 1770 phos and zinc.

Designed for air cooled flat tappet motors. Otherwise known as V Twin oil. Highest numbers I know of.

I've also heard of the long drain intervals for Amsoil. No reason to doubt the oil's ability to handle it, but there's no way I'd do that in a vintage aircooled engine. Even if driven regularly. Half of the reason to drain oil regularly is to get rid of combustion by-products that build up in engine oil. There's no way to get around that, and the best oil doesn't eliminate that requirement.

I completely agree!
Blake and I expected the old school Fiero (86) to wipe out its oil sooner.
The Blackstone reports are extremely detailed and show debris levels.
The 200K 30-year Fiero was a tiny bit dirtier but not what we were expecting.
His testing regime took 3 years to complete. He's got a "book" of reports.

I advise early car, non-boosted at 5k synthetic, 2.5k dino

Late 10k with synthetic (100%- not a "blend" 1% synthetic is a bend!). I use Mobil1 as it has 95% of the qualities of the Amsoil at 40% of the price.
Boosted or high RPM 5K with synthetic. 2-3K with dino.

For the most part I use Mobil1 exclusively.
The only straight up Dino oil I have right now is some special GTX20/50 for "cLassics" with high ZDDP. This oil I bought specifically for my 75 for initial ressurection mileage.

Good chance I'll change to the Amsoil stuff mentioned in this thread...

absolutely agree with this...
changing oil not only removes combustion by products...
but also removes particulates that the filter missed.

I've lost a crank before in a matter of hours when a particulate was in the oil re-circulating around and around....

we change oil every race weekend for just this reason
an oil change is much cheaper than a rebuild, or scored part...
that even with multiple oil filters on the motor...

just safer to change oil often.
I stick with the 3k recommendations on street motors...(sometimes 1k on low driven motors)
just because oil is cheap.

air cooled motors especially
as the tolerances on modern motors are so much better...
but its still a safe way to operate.. harms nothing to change oil early... and cheap compared to a rebuild.

and I'd hate to miss a particulate that went through the cycle for 10K

brant

I use Driven 15w/50 and change oil/filter .every 3k or 1 year which ever comes first. Family car is a 2015 Ford Fusion 2.0 that uses Castrol GTX 5w/30 that I change every 5k

I have used Driven since my 3.2 was rebuilt and I change it every 3K or 1 time per year, which ever comes first. I have had 2 Blackstone Labs oil analysis reports done and the reports come back showing everything is perfect.

It is expensive but you get what you pay for. I run it in my 914 and I am very happy with it. If you’re not sold on the brand Amsoil, Check out the you tube videos done by Farm Project where he compares it to all the others. It will make a believer of most people.

its a great oil. I ran it in my 3.2 SS turbo motor for years. It was put to the test I can assure you of that.