Zinc phosphate (ZDDP/ZDTP) in engine oil
05-25-2008, 11:17 AM
#1
Safety Car
Thread Starter
Zinc phosphate (ZDDP/ZDTP) in engine oil
August 08 Corvette Enthusiast has an article on engine oil talking about the need for zinc phosphate (ZDDP/ZDTP) to reduce engine wear in older engines. Modern oil has eliminated this. Article recommends using a supplement like Kirban Performance Products ZDDPlus.
I recently bought a 73 454 with original engine and 55K miles. I went with Mobil 1 synthetic. Do I really need the supplement?
I recently bought a 73 454 with original engine and 55K miles. I went with Mobil 1 synthetic. Do I really need the supplement?
05-25-2008, 01:32 PM
#3
Team Owner
Member Since: Sep 2006
Location: Westminster Maryland
Posts: 30,173
Likes: 0
Received 2,878 Likes
on
2,515 Posts
You should post your question in the C2 area. Perhaps John Z will see it and reply. He knows stuff!!!
Regards,
Alan
Regards,
Alan
05-25-2008, 03:43 PM
#5
Melting Slicks
I just wanted to chime in...I read somewhere that Royal Purple is high in ZDDP/ZDTP. That's what I'm using in my new GM Performance crate (350/300hp) with 4,000 miles. As soon as I find the info, I'll post it.
Later
Later
05-26-2008, 11:41 AM
#8
Racer
According to the article, oils rated SL or SM do not have zinc phospate, which is supposed to reduce wear on flat tappet camshaft lobes and lifters. Google ZDDplus for more info. Better safe than sorry. Some of these mid 70's camshafts are not that great to begin with!
05-26-2008, 07:54 PM
#9
Drifting
thegazman
Better to be safe than sorry. If you have flat tappets and want to be safe from scuffing and the possibility of losing a cam lobe, use an additive. I noticed where Corvette Central is now selling an oil additive called ZDD Plus, part number 301157 which is designed to provide the needed lubrication for flat tappet cams. Most synthetics do not provide the lubrication needed for flat tappet cams as most oils are now produced for roller camshafts.
Ken
Ken
07-22-2008, 03:56 PM
#10
Cruising
Member Since: Oct 2006
Location: Chicago IL
Posts: 14
Likes: 0
Received 0 Likes
on
0 Posts
good article in Summer 2008 Corvette Retorer (NCRS)
Latest Corvette Restorer has an interesting article on this subject.
Latest SM oils for modern cars have about 1/3 less ZDDP (800 ppm vs 1200 ppm) than older oils that were designed for use with older valve trains.
Diesel spec oil, CJ-4, like Rotella mentioned above, is best cost effective alternative today @ 1200 ppm.
On Mobil website, you can find the ZDDP specs for various producst, Mobil 1 10/30 @ 800ppm, 20/50 @1000 ppm.
I have Mobil 1 5/30 in my LS4, with Lucas Stabilizer because I do not drive it often and I am concerned about dry start-ups, but will likely go to the Rotella on the next oil change.
Any feedback on the above comments is appreciated. Hope this helps,
Rob
Latest SM oils for modern cars have about 1/3 less ZDDP (800 ppm vs 1200 ppm) than older oils that were designed for use with older valve trains.
Diesel spec oil, CJ-4, like Rotella mentioned above, is best cost effective alternative today @ 1200 ppm.
On Mobil website, you can find the ZDDP specs for various producst, Mobil 1 10/30 @ 800ppm, 20/50 @1000 ppm.
I have Mobil 1 5/30 in my LS4, with Lucas Stabilizer because I do not drive it often and I am concerned about dry start-ups, but will likely go to the Rotella on the next oil change.
Any feedback on the above comments is appreciated. Hope this helps,
Rob
07-22-2008, 04:10 PM
#11
Le Mans Master
Member Since: Sep 2001
Location: Wellington, FL
Posts: 9,992
Received 417 Likes
on
288 Posts
St. Jude Donor '11-'12-'13-'14-'15-'16-'17-‘18-'19-'20-'21-'22-'23-'24
Mobil advises using their Mobil 1 High Mileage synthetic, among several other choices, vs. their regular synthetic in older (flat tappet) engines. I just made this change for my '76 after using their regular synthetic for over 10 years w/o any issues. However, Mobil does state that with normal driving, the reg. syn. is fine. 
http://www.mobiloil.com/USA-English/...t_Engines.aspx
http://www.mobiloil.com/USA-English/...t_Engines.aspx
Last edited by Jud Chapin; 07-22-2008 at 04:13 PM.
07-22-2008, 04:53 PM
#12
Drifting
Just do a "ZDDP" search in "this forum" and you'll find tons to read on the subject. Bottom line is, use whatever oil and weight is your favorite and add a bottle of ZDDPlus ($9.95) at each oil change. Eastwood, Zip Products and a couple of other places sell it. Kirban Performance is a distributor for ZDDPlus and sells to Zip as well as the public. Navone Engineering actually created the product and has a website with lot's of information. Just go to www.zddplus.com.
07-22-2008, 05:01 PM
#13
Melting Slicks
August 08 Corvette Enthusiast has an article on engine oil talking about the need for zinc phosphate (ZDDP/ZDTP) to reduce engine wear in older engines. Modern oil has eliminated this. Article recommends using a supplement like Kirban Performance Products ZDDPlus.
I recently bought a 73 454 with original engine and 55K miles. I went with Mobil 1 synthetic. Do I really need the supplement?
I recently bought a 73 454 with original engine and 55K miles. I went with Mobil 1 synthetic. Do I really need the supplement?
But it's your $$$ so do what make you feel good!
07-22-2008, 06:57 PM
#14
I just finished reading the article in The Corvette Restorer. This article cleared up a lot of questions I had about ZDDP in oil and old cars. I recently switched to Rotella in my car. It sounds like when I install a new flat tappet cam I can use Rotella and GM EOS during break-in.
07-23-2008, 07:04 AM
#15
Le Mans Master
I use Mobil 1 15W-50 Racing which has 1,200 PPM ZDDP and is specifically recommeded by Mobil for flat tappet engines. Check their website. There are numerous oils with the correct amount of ZDDP for flat tappet engines. Most oil companies do not recommend additives be added to their oils. You probably better off just buying an oil with the right amount of ZDDP rather than adding additives. IMHO. 1,200 PPM seems to be the magic number. See the chart below:
http://www.mobiloil.com/USA-English/...duct_Guide.pdf
http://www.mobiloil.com/USA-English/...duct_Guide.pdf
Last edited by jb78L-82; 07-23-2008 at 07:13 AM.
07-23-2008, 08:26 AM
#16
Pro
I used the GM EOS during break-in of new cam. Now I'm using the ZDDP additive with oil changes. Looking at this chart I'm tempted to go with Mobile 1 15W-50. How pricey is it?
07-24-2008, 09:37 AM
#18
Le Mans Master
Member Since: Sep 2001
Location: Unreconstructed, South Carolina
Posts: 7,739
Received 628 Likes
on
556 Posts
I just finished reading the article in The Corvette Restorer. This article cleared up a lot of questions I had about ZDDP in oil and old cars. I recently switched to Rotella in my car. It sounds like when I install a new flat tappet cam I can use Rotella and GM EOS during break-in.
That's the protocol many racers round here are using ... straight regular Non-syn Rotella T 15W-40 ... but if it's a break-in add EOS. And it's what I do too.
07-24-2008, 05:36 PM
#20
Melting Slicks
the real problem is that the big cams and high spring pressures a lot of you guys are running on the street were never intended to go 100k+ miles like a factory engine with reasonable ramp rates and spring pressures. Even the roller lifters are failing after 10k miles because they just can't go that long under such high loading no matter what oil you are using
Last edited by turtlevette; 07-25-2008 at 08:54 PM.