pjg

Amsoil 20W-50 Z-Rod looks good. http://www.amsoil.com/techservicesbu...t%20tappet.pdf

blown 87

We always use the BG MOA in flat tappet cars when we do a oil change.

928mac

The Amsoil 20W-50 Z-Rod is expensive but I don't see a choice if you want the best.
$130 for a case of 12

Unless the vavoline or mobile 1 can equal it for less money.

I tried to order that discounted valvoline when it came on a few months ago but their web site did not except a canadian address.

Bilal928S4

How does 20W-50W Castrol GTX rate?
Bilal

Jadz928

Here's a chart from 2009. Untitled, sorry. FWIW.

Bill Ball

Those are some very nasty looking lifters as well as cams. I can't find the pics I took of my cams at 200K miles when I refreshed the cover seals, but the cam lobes looked very good. I found one tiny pit on the backside of one lobe. I have used M1 15W/50 exclusively and the car has not been babied.

I assume you are doing springs as well as lifters with the new cams.

z driver 88t

That table is defintley outdated at least with repsect to M1 15W-50. They don't even offer the 15W-50 EP anymore and the values listed for the regular 15W50 are not current. Oil formulations seem to change fairly often - I would really recommend sticking to recent VOAs if possible.

Tons of recent VOAs over on

http://www.bobistheoilguy.com/forums...oard=11&page=1

And is probably the most active forum on the web for VOAs and UOAs.

jeff spahn

My car probably doesn't sit non running for more than a couple weeks at a time.

GregBBRD

Surprised to see so much variance in Royal Purple.

Unless I'm missing something, looks like you really don't know what is in their oil, from batch to batch.

Little bit scary.

Bill Ball

The table was updated in October and shows the SN/SM rating for 15W/50, so it should reflect the most recent formulation.

hacker-pschorr

At 10-12 dollars a quart (or more) that's why I stopped using it. Way to much iffy data being posted from oil analysis.

For that kind of money use Redline or Torco, or Brad Penn and VR1 for a lot less $$$ with known "ingredients".

z driver 88t

I think we may be referring to different "tables".

There is a table on the Mobil 1 site which shows October 2011. This table lists Zn and P levels for the SN oil which DO NOT agree with the most recent SN rated VOA that was anlayzed by Blackstone in September.

The VOA (virgin oil analysis - I assume everyone here knows this acronym?) shows for SN rated Mobil 1 15W-50 from September 2011 analyzed by Blackstone:

Zn 1117 ppm
P: 950 ppm.

Maybe somehow they changed the formula in October but the values in that table look the same as the one they've had for quite a while, at least on the 15-50.

When I wrote the table was outdated I meant the one Jadz928 posted since it was dated 2009.

There is no arguement from me that Mobil 1 is claiming Zn ad P levels are adequate in their most recent PDF for SM/SN rated oils dated October 2011.

There IS argument from me that limited lab testing done in September 2011 does not support this statement. I think you would have to agree with that.

As I said - there could have been a lab error or it could have been a bad batch of oil but actual data posted so far does not agree with the specs provided by Mobil. I would just like to see a few more VOAs on the new US spec SN 15W-50 to be comfortable.

brealytrent

I don't mean to jump in mid-conversation but, wow, that's too bad about the cams. I know it's unrelated but when I got my 924 it was barely running, and taking off the cam cover showed the problem: the #4 cam lobe was wore so much it was almost round. The others were all worn and some of the flat tappets now had big, deep gouges with cracks. Luckily, finding a spare head for it was cheap and easy.
The problem in my case was that the oil fed to the cam comes from this little spray tube that runs the length of the head and the little plastic elbow it connects to was broken, keeping it from getting full pressure and thus the #4 piston's cam didn't get enough oil.

Speedtoys

For those in the SF Bay interested..

I'll arrange a visit to Redline in the new year..im good friends with the Sr Chemist there.

Great guy..good with hard questions.

outbackgeorgia

So, is there a conclusion that the cam wear was the result of oil without adequate ZDDP? Did the owner use a specific oil for an extended time period?
Was the cam wear due to some other issue such as inadequate oil to the upper end?
Dave