Do i need zinc additive?

Status
Not open for further replies.

Ribbedroof

Comic Book Super Hero
Supporting Member
Jan 4, 2009
4,862
6,889
113
Wellston, OK
I knew what you meant. One never really knows what is what, think of how many people put late heads on early stuff, and since there's no history, it could be anything.

I know of 2 different '88 half-ton truck 350s that were cast as roller blocks, that were factory-delivered with flat tappet camshafts....I'm sure there was some GM internal flowchart as to what got which valvetrain, as I imagine was the case with the aluminum core supports in BOP G bodies.
 
  • Like
Reactions: 1 user

ck80

Moderator
Moderator
Supporting Member
Feb 18, 2014
5,742
9,114
113
I recommend a good diesel oil with the high zinc until you know better.

It's cheaper to get a quality diesel one and change it every 3k miles, than it is to buy modern car oil then buy and add a zddp-type additive and wait every 5-10k miles.
 
  • Agree
  • Like
Reactions: 1 users

Trottiert

Not-quite-so-new-guy
Apr 10, 2020
29
32
13
Uxbridge MA
I recommend a good diesel oil with the high zinc until you know better.

It's cheaper to get a quality diesel one and change it every 3k miles, than it is to buy modern car oil then buy and add a zddp-type additive and wait every 5-10k miles.
I appreciate the recommendation!
Should I look into an additive now as I've just changed it, or drain it and replace with.... what is a quality diesel oil?
 

melloelky

Comic Book Super Hero
Oct 22, 2017
4,135
9,484
113
mass
I recommend a good diesel oil with the high zinc until you know better.
It's cheaper to get a quality diesel one and change it every 3k miles, than it is to buy modern car oil then buy and add a zddp-type additive and wait every 5-10k miles.
the diesel oil's aren't what they use to be as they're emission bound now.seeing you've already changed the oil,drain out the amount of addtive that you'll be adding,add the addtive and go from there.if your THAT concerned and have the $$ swap the oil for something designed for a flat tappet with the higher than normal level of zinc/zddp.
 
  • Agree
Reactions: 1 user

ck80

Moderator
Moderator
Supporting Member
Feb 18, 2014
5,742
9,114
113
the diesel oil's aren't what they use to be as they're emission bound now.seeing you've already changed the oil,drain out the amount of addtive that you'll be adding,add the addtive and go from there.if your THAT concerned and have the $$ swap the oil for something designed for a flat tappet with the higher than normal level of zinc/zddp.
As of December 2019:

15W40 CHEVRON DELO 400LE Diesel Oil, conventional, API CJ-4, CI-4 Plus, CH-4, CF-4,CF/SM, = 73,520 psi
zinc = 1519 ppm
phos = 1139 ppm
ZDDP = 1300 ppm

15W40 “NEW” SHELL ROTELLA T Diesel Oil conventional, API CJ-4, CI-4 Plus, CH-4, CF-4,CF/SM = 72,022 psi
zinc = 1454 ppm
phos = 1062 ppm
ZDDP = 1200 ppm

CASTROL GTX DIESEL, 15W40 conventional, API CJ-4, CI-4 Plus, CI-4, CH-4, CG-4, CF-4/SN
“Load Carrying Capacity/Film Strength” = 66,323 psi
zinc = TBD
phos = TBD
moly = TBD
total detergent/dispersant/anti-deposit build-up/anti-sludge TBD
TBN = TBD

Not my personal testing, but came through an old inline 6 engine modifying forum
 
  • Like
Reactions: 1 users

Trottiert

Not-quite-so-new-guy
Apr 10, 2020
29
32
13
Uxbridge MA
As of December 2019:

15W40 CHEVRON DELO 400LE Diesel Oil, conventional, API CJ-4, CI-4 Plus, CH-4, CF-4,CF/SM, = 73,520 psi
zinc = 1519 ppm
phos = 1139 ppm
ZDDP = 1300 ppm

15W40 “NEW” SHELL ROTELLA T Diesel Oil conventional, API CJ-4, CI-4 Plus, CH-4, CF-4,CF/SM = 72,022 psi
zinc = 1454 ppm
phos = 1062 ppm
ZDDP = 1200 ppm

CASTROL GTX DIESEL, 15W40 conventional, API CJ-4, CI-4 Plus, CI-4, CH-4, CG-4, CF-4/SN
“Load Carrying Capacity/Film Strength” = 66,323 psi
zinc = TBD
phos = TBD
moly = TBD
total detergent/dispersant/anti-deposit build-up/anti-sludge TBD
TBN = TBD

Not my personal testing, but came through an old inline 6 engine modifying forum
Wow, thank you
 

ck80

Moderator
Moderator
Supporting Member
Feb 18, 2014
5,742
9,114
113
Wow, thank you

You're welcome.

Manufacturers change their formulations from time to time.

I've been a delo guy, BUT, that was also helped by being able to buy it in bulk through the big box club.

However, for additional piece of mind, there are companies out there that will send you sample tube and will analyze the oil you send in. When draining your pan hold the tube in, mail it off, 4-6 weeks later you get a report of everything that was count in the oil. So if some bearing somewhere was wearing and putting fine metal in, you can maybe see a spike before you spin something and eat a crank.

Also gives an idea of what the oil condition was based on your driving area/style to decide how far to go between changes.

One thing to beware of, to earn the "grade" rating in the given content categories, the "acceptable" levels in PPM can vary 1000-1400. So oil A and B can be same grade and equal ratings. Oil A could have 950PPM, Oil B could be 1275PPM. Both carry the same labels if the criteria was to fall between 900-1300ppm for certification.

Then again, same thing can happen within the same company, product, and grade as well.
 
Last edited:

Yav8

Master Mechanic
Aug 19, 2014
275
114
43
Manitowoc wis.
There is a easy to check if it hyd or flat tappet. Just pull a push rod and check the length. Hyd rollers are 7.195 and the F/T are 7.800.
 
  • Like
  • Informative
Reactions: 1 users
Status
Not open for further replies.

GBodyForum is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com. Amazon, the Amazon logo, AmazonSupply, and the AmazonSupply logo are trademarks of Amazon.com, Inc. or its affiliates.

Please support GBodyForum Sponsors

Classic Truck Consoles Dixie Restoration Depot UMI Performance

Contact [email protected] for info on becoming a sponsor