Oil Weight Question/Differences
Thread Starter
Instructor
Joined: Jun 2009
Posts: 164
Likes: 5
From: Kernersville NC
Oil Weight Question/Differences
I've read through the majority of the oil postings and understand the need for the parts per million for ZZDP for flat tappet engines. I went so far as to contact Mobil1 for updated information for their current oil listings.
Mobil1 Weight ZZDP PPM
15W - 50 1,000 - 1,100 (Racing)
10W - 40 900 - 1,000
5W - 40 1,100 - 1,200 (Diesel but can be used for gas engines)
All 30 weights and lower had much less than the above the technician informed me for flat tappet motors.
My question is what is the difference in running the 50 compared to the 40 engine oil? Why would I run weight over the other?
I have a new to me 82 with a rebuilt 350 running the CFI TBI system. I'm unsure of the miles on the engine but to be on the safe side less than 50k. Car will never be dragged, street raced, or driven hard and put up wet. I would let her breath and clean out her throat on occasion but nothing to write home to mom about.
Not trying to dis other oils I've just always used the Mobil1 Synthetic but am looking at Amsoil as well. As long as it does its job well and keeps my engine safe I'm happy.
Sorry to add another oil question to the pile.
Mobil1 Weight ZZDP PPM
15W - 50 1,000 - 1,100 (Racing)
10W - 40 900 - 1,000
5W - 40 1,100 - 1,200 (Diesel but can be used for gas engines)
All 30 weights and lower had much less than the above the technician informed me for flat tappet motors.
My question is what is the difference in running the 50 compared to the 40 engine oil? Why would I run weight over the other?
I have a new to me 82 with a rebuilt 350 running the CFI TBI system. I'm unsure of the miles on the engine but to be on the safe side less than 50k. Car will never be dragged, street raced, or driven hard and put up wet. I would let her breath and clean out her throat on occasion but nothing to write home to mom about.
Not trying to dis other oils I've just always used the Mobil1 Synthetic but am looking at Amsoil as well. As long as it does its job well and keeps my engine safe I'm happy.
Sorry to add another oil question to the pile.
Racer
Joined: Mar 2007
Posts: 306
Likes: 0
From: New Hampshire
I've been using nothing but Mobil1 in my 77 Vette for years and never worried about the level of ZZDP. I have read other posts that say when you change a cam, you need lots of ZZDP or the cam will go bad. Hasn't happened to me in over 10 years of a cam change. I don't run my engine at 6K either though.
Thread Starter
Instructor
Joined: Jun 2009
Posts: 164
Likes: 5
From: Kernersville NC
Have a few more calls to Mobil1 and more research I found that the "ranges" given were actually the phosphorous and zinc content. So the first group is phosphorous and the second is the zinc ppm content.
The diesel oil would seem to be what I'm leaning toward but have found several papers recommending prolonged use of the diesel oil in gas engines for fear of the detergents damaging the rings and seals. Yet, recommend the oil for 500 miles for allowing the stronger detergents to help clean a gas engine.
I found that Mobil1 makes a "European" oil 0W-40 that I'm leaning towards and has a phosphorous and zinc content of 1000 and 1100 respectively.
Here is the break down from the mobil1 website that I finally found with the comparisons between, what I think to be, all their consumer product offerings here in the US.
http://www.mobil.com/USA-English/Mot...duct_Guide.pdf
The diesel oil would seem to be what I'm leaning toward but have found several papers recommending prolonged use of the diesel oil in gas engines for fear of the detergents damaging the rings and seals. Yet, recommend the oil for 500 miles for allowing the stronger detergents to help clean a gas engine.
I found that Mobil1 makes a "European" oil 0W-40 that I'm leaning towards and has a phosphorous and zinc content of 1000 and 1100 respectively.
Here is the break down from the mobil1 website that I finally found with the comparisons between, what I think to be, all their consumer product offerings here in the US.
http://www.mobil.com/USA-English/Mot...duct_Guide.pdf
Pro
Joined: Dec 2008
Posts: 531
Likes: 0
From: Frisco TX
I've read through the majority of the oil postings and understand the need for the parts per million for ZZDP for flat tappet engines. I went so far as to contact Mobil1 for updated information for their current oil listings.
Mobil1 Weight ZZDP PPM
15W - 50 1,000 - 1,100 (Racing)
10W - 40 900 - 1,000
5W - 40 1,100 - 1,200 (Diesel but can be used for gas engines)
All 30 weights and lower had much less than the above the technician informed me for flat tappet motors.
My question is what is the difference in running the 50 compared to the 40 engine oil? Why would I run weight over the other?
I have a new to me 82 with a rebuilt 350 running the CFI TBI system. I'm unsure of the miles on the engine but to be on the safe side less than 50k. Car will never be dragged, street raced, or driven hard and put up wet. I would let her breath and clean out her throat on occasion but nothing to write home to mom about.
Not trying to dis other oils I've just always used the Mobil1 Synthetic but am looking at Amsoil as well. As long as it does its job well and keeps my engine safe I'm happy.
Sorry to add another oil question to the pile.
Mobil1 Weight ZZDP PPM
15W - 50 1,000 - 1,100 (Racing)
10W - 40 900 - 1,000
5W - 40 1,100 - 1,200 (Diesel but can be used for gas engines)
All 30 weights and lower had much less than the above the technician informed me for flat tappet motors.
My question is what is the difference in running the 50 compared to the 40 engine oil? Why would I run weight over the other?
I have a new to me 82 with a rebuilt 350 running the CFI TBI system. I'm unsure of the miles on the engine but to be on the safe side less than 50k. Car will never be dragged, street raced, or driven hard and put up wet. I would let her breath and clean out her throat on occasion but nothing to write home to mom about.
Not trying to dis other oils I've just always used the Mobil1 Synthetic but am looking at Amsoil as well. As long as it does its job well and keeps my engine safe I'm happy.
Sorry to add another oil question to the pile.
Oil topics have been beaten to death on every forum board I have belonged to - both auto and cycle
I see two options if you run a flat tappet cam today
1 - either use a special oil for your application like Joe Gibbs' Hot Rod cocktail
http://www.joegibbsracingoil.com/hotrod/index.html
2 - run regular Valvoline and use the proper additives (ZDDP or GM EOS)
If you are not running your car hard I'd probably go with option #2.
I don't think Mobil 1 in any grade today is sufficient for flat tappet applications. Sure people have gotten away "with runnin 30 wt Castrol for 25 yrs" but you don't want to be the one to wipe a cam
Personally, I would not run diesel oil in anything but a diesel
Good Luck, Ed
Le Mans Master
Joined: Jan 2000
Posts: 8,918
Likes: 27
From: New Hill NC
As far as weights are concerned, it makes little difference. You should be more concerned with the low number, which indicates the cold start viscosity. Under what conditions will you be cold starting the engine would be the question. If you look at viscosity charts for oils in the 200 degree operation ranges, there is very little difference in the viscosity numbers.
Le Mans Master
Joined: Oct 2007
Posts: 7,453
Likes: 976
From: RI, Now Franklin/Nashville TN
Have used Mobil 1 15W-50 Racing since 1986 in my L-82 with the OEM flat tappet cam as others stated above. Besides having 1,200/1,300 PPM of ZDDP (not 1,000 and 1,100 PPM as stated above, see chart from Mobil 1 attached), it is a full synthetic with uniform size molecules, unlike organics that have molecules of all different sizes, for maximum wear protection in addition the correct amount of ZDDP. Note that Mobil's recommendation specifically states " that 15W-50 is for performance vehicles and racing and FLAT TAPPET applications". I would use any full synthetic that has the correct amount of ZDDP over an organic oil.
http://www.mobiloil.com/USA-English/...duct_Guide.pdf
http://www.mobiloil.com/USA-English/...duct_Guide.pdf
Last edited by jb78L-82; Jun 30, 2009 at 07:42 AM.
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Le Mans Master
Joined: Oct 2007
Posts: 7,453
Likes: 976
From: RI, Now Franklin/Nashville TN
Premium Supporting Vendor
Joined: Aug 2001
Posts: 5,364
Likes: 38
From: King George VA
Kipring,
In answer to your original question, the engine was designed to operate with an oil having a viscosity of about 10-11 cSt at a normal operating temp of about 212F. That is a 30 grade oil. By definition, a 40 grade oil has a viscosity of 12.50-16.29 cSt at 212F and a 50 grade 16.30-21.89. While I feel that a 40 grade is close enough to that of the optimum 30 grade, I feel a 50 grade has too high a viscosity.
As an FYI, AMSOIL makes these 30 and 40 grade Group IV PAO basestock synthetic oils which have phosphorus on the order of 1275 ppm, and zinc on the order of 1365 ppm.
AMSOIL SAE Synthetic High Performance 10w40
AMSOIL Series 3000 Synthetic 5w30 Heavy Duty Diesel Oil
(Note that this is a CI-4+ diesel oil)
In answer to your original question, the engine was designed to operate with an oil having a viscosity of about 10-11 cSt at a normal operating temp of about 212F. That is a 30 grade oil. By definition, a 40 grade oil has a viscosity of 12.50-16.29 cSt at 212F and a 50 grade 16.30-21.89. While I feel that a 40 grade is close enough to that of the optimum 30 grade, I feel a 50 grade has too high a viscosity.
As an FYI, AMSOIL makes these 30 and 40 grade Group IV PAO basestock synthetic oils which have phosphorus on the order of 1275 ppm, and zinc on the order of 1365 ppm.
AMSOIL SAE Synthetic High Performance 10w40
AMSOIL Series 3000 Synthetic 5w30 Heavy Duty Diesel Oil
(Note that this is a CI-4+ diesel oil)
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