[GT182]

Originally Posted by Chief of the 60's

There is no way running diesel oil would ruin engine bearings. Fact is, most high end engine builders use a diesel oil, like Rotella, for break-in oil.

The engine builders around here won't touch it. You tell them that and they laugh you right out the door. I'll tell one of the best [now retired] engine builders here and he'd throw me out the door or die laughing.

[Chief of the 60's]

Originally Posted by GT182

The engine builders around here won't touch it. You tell them that and they laugh you right out the door. I'll tell one of the best [now retired] engine builders here and he'd throw me out the door or die laughing.

Hmmm.... Oddy, Musi, Shafiroff, Herbert all no names.

[TedRamAirII]

I have a hard time with Rotella 15w40. Nowhere in their literature is Diesel Motor OIL rated for Gasoline Engines. They do list T6 5w30 Multi Use for gas engines. Oil companies stand behind their product. If you have a gas engine and have a lubrication failure, that turns out to be CJ or CK rated oil that you used, they are not going to help you. If Shell tells you not to use it, do you believe them, or the guy that says they don't know what they are talking about.

[Sirrotica]

You can go too far with adding ZDDP, and it's been proven that more, isn't better. When there is too much ZDDP in oil it will have an adverse effect and actually cause scuffing components (flat tappet cams and lifters) to fail prematurely than the same base stock oil with less ZDDP in it.

I doubt that running diesel oil is going to cause flat tappet cam or lifter failure by itself, but I won't say it couldn't happen, cause I really don't know myself. Now ramp up the levels of ZDDP more than what the oil company puts in it when it's formulated (additives) and you can be running into problems that too much ZDDP causes.

Diesel oil has to deal with many times the amount of soot caused by a higher volume of blowby due to compression ratios near 18-22.5 to 1. and a fuel that doesn't burn as clean. Gas engines have soot too, but not anywhere near the volume in diesels. Stands to reason that the soot element alone is going to cause a different formulation of oil. Can the oil be interchanged on a gas engine? better to ask the experts from the oil manufacturer, than the experts on the internet

Most brand name oils made today have started using other friction modifiers because the feds wanted ZDDP cut back. If you do some due diligence you'll find that there are other chemicals that oil manufacturers can use to supplement the oil in a flat tappet application.

FWIW, if you really want to know what works for your application, don't ask on forums. When I have a lubrication question I simply call the oil companies tech lines. They know much more than anyone on the internet knows about their own products.

I had a problem in an air cooled application that kept seizing the pistons on a parking lot blower, causing it to break the connecting rod at high RPM. I called Pennzoil, gave them the rundown of the problem and the application. They recommended their 10W30 synthetic and the engine never tossed a rod after switching. BTW this was when synthetics weren't common place, and they were very pricey.

I know that no one wants to hear this, but one of the biggest enemies of engine oil and engine longevity is the junk filter system Detroit engineered. Just installing a better filter system is going to at the very least double the longevity of your oil and engine, likely 3-4 times over a standard filter system.

When you start removing solids from the oil 20-40 times smaller than the regular oil filter is designed to catch, it makes a huge difference. I didn't believe it until I switched on my own stuff, it flat out works exactly as advertised. The under 10 micron stuff is invisible to the human eye, but your engine knows it's there, silently wearing the internally oiled parts prematurely.

[68 461 Bird]

Originally Posted by Sirrotica

Can the oil be interchanged on a gas engine? better to ask the experts from the oil manufacturer, than the experts on the internet

FWIW, if you really want to know what works for your application, don't ask on forums. When I have a lubrication question I simply call the oil companies tech lines. They know much more than anyone on the internet knows about their own products.:

So then why should we listen to you?

There's a lot of inteligent people on this Pontiac forum with a lot of experience on what has worked for them and what has not. I would trust that information before I trust a large corporation that is only interested in making a buck.

[Sirrotica]

Originally Posted by 68 461 Bird

So then why should we listen to you?

There's a lot of inteligent people on this Pontiac forum with a lot of experience on what has worked for them and what has not. I would trust that information before I trust a large corporation that is only interested in making a buck.

You don't need to listen to anything I say, you need to read the study that GM funded about how much wear is reduced by filtering down to 1-2 microns. I didn't do the study, GM did, and the results speak for themselves.

I did the reading and research before I decided to change filtering on my own vehicles. The experiment is now ongoing over the last 8 years on my own private vehicles, gas and diesel. I change oil every 3-4 years and run between 30-40,000 miles. No adverse oil related problems, try that with a conventional filter and see where you are.

[Fullsize455]

Originally Posted by Sirrotica

You can go too far with adding ZDDP, and it's been proven that more, isn't better. When there is too much ZDDP in oil it will have an adverse effect and actually cause scuffing components (flat tappet cams and lifters) to fail prematurely than the same base stock oil with less ZDDP in it.

I doubt that running diesel oil is going to cause flat tappet cam or lifter failure by itself, but I won't say it couldn't happen, cause I really don't know myself. Now ramp up the levels of ZDDP more than what the oil company puts in it when it's formulated (additives) and you can be running into problems that too much ZDDP causes.

Diesel oil has to deal with many times the amount of soot caused by a higher volume of blowby due to compression ratios near 18-22.5 to 1. and a fuel that doesn't burn as clean. Gas engines have soot too, but not anywhere near the volume in diesels. Stands to reason that the soot element alone is going to cause a different formulation of oil. Can the oil be interchanged on a gas engine? better to ask the experts from the oil manufacturer, than the experts on the internet

Most brand name oils made today have started using other friction modifiers because the feds wanted ZDDP cut back. If you do some due diligence you'll find that there are other chemicals that oil manufacturers can use to supplement the oil in a flat tappet application.

FWIW, if you really want to know what works for your application, don't ask on forums. When I have a lubrication question I simply call the oil companies tech lines. They know much more than anyone on the internet knows about their own products.

I had a problem in an air cooled application that kept seizing the pistons on a parking lot blower, causing it to break the connecting rod at high RPM. I called Pennzoil, gave them the rundown of the problem and the application. They recommended their 10W30 synthetic and the engine never tossed a rod after switching. BTW this was when synthetics weren't common place, and they were very pricey.

I know that no one wants to hear this, but one of the biggest enemies of engine oil and engine longevity is the junk filter system Detroit engineered. Just installing a better filter system is going to at the very least double the longevity of your oil and engine, likely 3-4 times over a standard filter system.

When you start removing solids from the oil 20-40 times smaller than the regular oil filter is designed to catch, it makes a huge difference. I didn't believe it until I switched on my own stuff, it flat out works exactly as advertised. The under 10 micron stuff is invisible to the human eye, but your engine knows it's there, silently wearing the internally oiled parts prematurely.

I'm curious about this far more advanced filtration system you seem to have found.. more details?

Also, do you have anything to back up your claims on other friction modifiers that effectively replace zddp in flat tappet cam engines? I've never heard of that.

Also, it's not so much the feds that demanded the reduction of zddp usage, it's the fact that it destroys catalytic converters. Yes, the feds mandated it as a result, but the damage to catalytic converters is the reason.

[Sirrotica]

Originally Posted by Fullsize455

I'm curious about this far more advanced filtration system you seem to have found.. more details?

Also, do you have anything to back up your claims on other friction modifiers that effectively replace zddp in flat tappet cam engines? I've never heard of that.

Also, it's not so much the feds that demanded the reduction of zddp usage, it's the fact that it destroys catalytic converters. Yes, the feds mandated it as a result, but the damage to catalytic converters is the reason.

Just research "bypass oil filtration" and read up on it. I researched it for roughly 6 months before I decided to try it out. Contrary to the detractors I did spend my own money and spent time doing considerable research on the subject.

I was a dealer for Frantz bypass oil filters until the company was sold off to another entity and they eliminated the dealers that owned franchises. I'm no longer a dealer, and am not trying to sell anything to members here on PY. I'm just trying to get enthusiasts to recognize the Detroit designed system has many compromises, and of course it's better than no oil filter at all. There are much better alternatives that make more sense, and are much more efficient.

I'm not going to get into all the nuances about why one is better than the other on someone else's thread.

If anyone is truly interested, all they need to do is read this article:

https://www.machinerylubrication.com...-filtrationand

If it peaks your interest then do some more research.

[Fullsize455]

Originally Posted by TedRamAirII

I have a hard time with Rotella 15w40. Nowhere in their literature is Diesel Motor OIL rated for Gasoline Engines. They do list T6 5w30 Multi Use for gas engines. Oil companies stand behind their product. If you have a gas engine and have a lubrication failure, that turns out to be CJ or CK rated oil that you used, they are not going to help you. If Shell tells you not to use it, do you believe them, or the guy that says they don't know what they are talking about.

Delo 400 meets the current SN standard for gasoline engines, so it is absolutely usable. I believe Rotella used to meet the old SF standard, which is absolutely acceptable for any old flat tappet engine. It doesn't meet the current SN standard, most likely due to zinc content, but they couldn't care less about testing it to meet an obsolete standard. Do you think Rotella is really that different from Delo oil? Do you think they've gone backwards with the new variants of it?

You have to understand, oils have not gone backwards in terms of their engine protection capabilities. They have advanced significantly over the years. However, they have also had to comply with ever more stringent emissions requirements, and in the case of diesel rated oils specifically, if you look at the different classifications, most of the changes are related to emissions. Consequently, the same has happened with gasoline engine oils. The oils with higher zinc content are not going to meet the current SN standard, and there is no point in testing or classifying new oils by old obsolete standards, and I suspect that is why Rotella is not gasoline engine rated any more. But if you look into all of this and what the ratings mean, you see pretty clearly that, just because an oil is not rated by the API for certain engine use to emissions requirements, that does not necessarily mean it is not perfectly acceptable for use in an old flat tappet engine.

And to address 68 461, I agree in some part about not blindly trusting what anyone has to say while they stand to gain from selling you a product. At the same time, they obviously have a wealth of knowledge, so getting info from them is certainly valuable, but you have to consider the source and seek out info elsewhere as well if you want to figure out what is definitively the truth.

Keep in mind that the oil companies will NOT ever tell you to use something that violates emissions requirements, nor will they ever tell you to use an oil that is not rated for gasoline engine use in a gasoline engine. However, as many of us here know firsthand from extensive personal experience, many diesel engine oils are perfectly acceptable to use in many gasoline engines. The oil company may not necessarily lie to you, but they also will never tell you to use something that is not appropriate based on the API certs, and thus you are not at all being told the whole story. Hence, research. Simply calling Pennzoil for a recommendation is foolish, just as simply asking in this one forum would also be foolish. If you really want to know, you have to expand your research to every source you can reasonably find.