Pick my oil

[CheezWhiz]

Got an old GTO with a rebuilt street/strip engine and flat tappet solid cam. Builder is recommending a 10w40 oil and says I don't need to worry about zinc since cam is broken in already. I definitely trust him but I'd rather be uber-careful and use something with more zinc in it. Several questions:

1) Anything wrong with putting GM EOS, Comp Cams break-in additive, etc. into synthetic oil?

2) Anybody aware of an off-the-shelf product in a 10-40 or 15-40 with substantial zinc content? Seems as if the closest grade avail in most racing oils is a 20w50. My engine is more of a street setup and I am not sure 20w50 isn't a bit on the heavy side.

Thanks!

 

[aquariuscsm]

There`s always Valvoline VR1 and it`s available at any auto parts store. Really easy to find.

 

[CheezWhiz]

Thought about that, but I think VR1 only comes in 20w50 or 10w30. Since the builder says 10w40, think I'd be better off with plain old Valvoline 10w40 and EOS/another zinc supplement?

 

[addyguy]

Use any HDEO 15W-40.

 

[FrankN4]

If You want a synthetic, and that is what I would want, you could run a synthetic XW-40 diesel oil and get in the 1300 or so ZDDP range. You could run a 10W-40 Synthetic motorcycle oil, such as Mobil !, and get 1600 plus ZDDP.

With the diesel oils and the motorcycle oils, you will have little or no FM if that is important to you.

 

[cven]

Brad Penn is a favorite with the muscle car crowd. What motor is in your goat?

 

[REDDOG]

1 I would use Amsoil AMO 10W-40 or AME 15W-40, especially if used in the winter.

2 If stored during the winter use your fav HDEO.
My opinion.

Not a fan of "beefing up" oil with OTC additives. Buy an oil that is up to the task out of the bottle.

 

[FrankN4]

Quote:
I would use Amsoil AMO 10W-40 or AME 15W-40, especially if used in the winter

I completely forgot about Amsoil 10W-40 AMO. Years ago it was sold as their motorcycle oil as I used it in my old Honda Nighthawk. It has phosphorus at around 1265 and zinc at around 1378, and it is a PAO.

 

[Kruse]

Originally Posted By: CheezWhiz
Since the builder says 10w40, think I'd be better off with



I have a question I'd like answered. Now this isn't a knock against your builder, but how does he know for SURE that your engine absolutely needs a 10w40 and why are you following his advice so strictly? Just because it's how he's always done it, or why? Does he have a lot of oil data at his disposal?
Just curious.

P.S. I've got an vintage muscle car myself, so I know putting just any old oil it it is not an option.

 

[NHHEMI]

I have always run Royal Purple 20W-50 or 10W-40 in my street/strip vehicles. That includes an Old's 442 with a seriously built 455 capable of mid 11 second runs a friend owned. For me I ran it in 440/383 MOPAR BB's and it did great there too. They offer a racing oil as well. I/we used the 20W-50 99% of the time. I would not consider it too thick for your application but if you trust your builder follow his advice. Afterall, he built the engine so he knows it.