20W 50 CF4 on 1970 Royal Enfield iron barrel

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I'm a fan of HDDEO as they have superior anti wear additives, particularly ZDDP. I'm particularly looking at HDDEO 15W-50 or 20W-50 as they can be used with old motorcycle engines that does not have integrated clutch, though wet clutch assembly reside in a seperate compartment. I'm hoping heavy duty diesel oils flow equally well through the crank case and timing setup.

I have come across Gulf 20W50 oil sold for Compressed Natural Gas engines. I have gone through the MSDS sheet (Yes. Gulf makes the sheets available online with all the necessary details). Does CNG oil work fine on old petrol engines? How does CNG oils differ from other S/C oils?

Here's the link to msds.

I'm open for other recommendations as long as they are cheap and available online/offline in India.

Looking at cost efficient oils because I belive in more frequent oil change. Thanks in advance!
 
And what's with the title of this post? And no, I did not follow the link.
I will venture a guess that the OP is located in Eastern Asia and the Royal Enfield is a m/c with iron barrel being the cylinder.... Man I spend too much time around niche vehicles :)

At first glance I thought Enfield rifle, but they were long out of production by '70.
 
Your 1970 RE will likely run on just about any oil. I'd use a 15W-50 if available and change it often.
 
CNG oil typically has a much lower TBN because CNG engines don't deal with nearly as much acidic blowby as gasoline or diesel engines.
The only reason for considering Gulf 20w 50 CNG is because of its MSDS showing ZDDP content between 0.61 - 1.13 %

I don't find msds data readily available online for lubricant manufacturers in India. And have to rely on the very few that publish data like Gulf, Total and equally available in local market.

I will venture a guess that the OP is located in Eastern Asia and the Royal Enfield is a m/c with iron barrel being the cylinder.... Man I spend too much time around niche vehicles :)

At first glance I thought Enfield rifle, but they were long out of production by '70.
That's correct! It's a Royal Enfield motorcycle from 1970 with the Iron bore.

Your 1970 RE will likely run on just about any oil. I'd use a 15W-50 if available and change it often.
I think I am left with this option. There are plenty of oils out there, Motul, Shell, Castrol, HP, Servo, Total, and a few more. However these are all rated 15w50 or 20w50 and made for petrol engines. Its only me, leaning towards HDDEO due to its superior anti wear additives and they are economical too.
 
If you can easily get motorcycle specific 20W50, I believe that would serve you well. The older Castrol 20W50 used to be fine for high temp use in air cooled engines, iron or alloy cylinder. I doubt that a 20W50 would even have to be have motorcycle specific. I don't know if the '70 RE had a separate gearbox with its own gear oil like old BMW's or not. A full syn may not be wise in that engine. My favorite used to be Spectro, especially Golden Spectro syn blend. It's pretty costly today. I got very good protection from it for many years in an old '72 BMW, including traffic grid heating. That had steel sleeves and was pre Nikasil coatings. At one time they supplied the BMW branded motorcycle oils in the US. It appears that Spectro does not have an India distributor. They do in AUS., NZ and Taiwan.
 
CNG oil typically has a much lower TBN because CNG engines don't deal with nearly as much acidic blowby as gasoline or diesel engines.
The opposite...or that was the case in NZ. When we had half the country running on CNG, the oil appeared to run forever - pull the dipstick out at 20,000km, and it's as clear as the day it was poured in. So people left the oil in forever...like it never got dirty, so why change it ? There was so much acid build up the lead would leach out of copper/lead bearings...so part of a CNG conversion was often to convert to heavy duty bearings as part of the job. So we had special CNG oils, extra high in TBN.

For the Enfield any 15W-40 HDEO would do a good job, or any 20W-50 would be up to the task too.
 
The CNG oils I know of have a lower ash level and are a lower TBN compared to their HDEO counterpart, they're lower TBN because they have less ash producing additives and the reason for that if I recall right is that higher ash oils in CNG oils are more likely to lead to deposits on the exhaust valve and cause seating issues and excessive seat wear.
 
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The oil the OP is referencing is a low TBN, low ash, NG oil.
 
If you can easily get motorcycle specific 20W50, I believe that would serve you well. The older Castrol 20W50 used to be fine for high temp use in air cooled engines, iron or alloy cylinder. I doubt that a 20W50 would even have to be have motorcycle specific. I don't know if the '70 RE had a separate gearbox with its own gear oil like old BMW's or not. A full syn may not be wise in that engine. My favorite used to be Spectro, especially Golden Spectro syn blend. It's pretty costly today. I got very good protection from it for many years in an old '72 BMW, including traffic grid heating. That had steel sleeves and was pre Nikasil coatings. At one time they supplied the BMW branded motorcycle oils in the US. It appears that Spectro does not have an India distributor. They do in AUS., NZ and Taiwan.
Thanks for checking availability of those oils in India. RE motorcycles until 2008, had seperate gear box, and seperate clutch case. So there are some options open to try. My interest is to first look out for 15W-50 or 20W-50 rated HDEO. 50 being a better oil for hot conditions, I prefer to stay safe choosing either 15w or 20w50. But its become hard to find HDEO oils with these ratings. And even if they are, the manufacturers fail to publish msds to know if ZDDP was ever added.

The opposite...or that was the case in NZ. When we had half the country running on CNG, the oil appeared to run forever - pull the dipstick out at 20,000km, and it's as clear as the day it was poured in. So people left the oil in forever...like it never got dirty, so why change it ? There was so much acid build up the lead would leach out of copper/lead bearings...so part of a CNG conversion was often to convert to heavy duty bearings as part of the job. So we had special CNG oils, extra high in TBN.

For the Enfield any 15W-40 HDEO would do a good job, or any 20W-50 would be up to the task too.
So, its a general advice not to use CNG oils on petrol engines due to their extra high TBN to protect the bearings.

Also, on the topic of SAE, does 15W40 HDEO suit well? The manual recommends 20W50, and I'm okay with 15W50. But 15W40 for a tropical climate, like in India?? 🤔
15W40 would be an easy buy, I'd grab a Shell Rimula or Mobil Delvac.

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The oil the OP is referencing is a low TBN, low ash, NG oil.
So, low TBN isn't a nice thing for petrol engines. I think I got the answer for starting this thread.

Now, do you have any advice on appropriate TBN figures one must check and using HDEO 15W40 ? The manual recommends 20W50. 20W50 is rare in HDEO category.
 
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The lower TBN means the oil change interval is potentially shorter than if the TBN was higher to begin with. If all the other additives, add up (no pun intended), don't see why you couldn't use it. Shorten the OCI and see what analysis looks like. However, using an oil for gas engines versus CNG engines would solve the problem out right.
 
The lower TBN means the oil change interval is potentially shorter than if the TBN was higher to begin with. If all the other additives, add up (no pun intended), don't see why you couldn't use it. Shorten the OCI and see what analysis looks like. However, using an oil for gas engines versus CNG engines would solve the problem out right.
Ha ha. I also believe that frequent OCI is better than running long, just because it's recommended by the oil manufacturer. I'll give this particular CNG oil a try, will drain it in 1000kms or less than that and see how it behaves. Thank you !
How about a pic of the cycle??? I always liked them.
I purchased the motorcycle last month and it needed a lot of work. Currently undergoing complete overhaul and repainting. Managed to click one or two pics. UCE (Left) and Cast Iron (Right)

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Ha ha. I also believe that frequent OCI is better than running long, just because it's recommended by the oil manufacturer. I'll give this particular CNG oil a try, will drain it in 1000kms or less than that and see how it behaves. Thank you !

I purchased the motorcycle last month and it needed a lot of work. Currently undergoing complete overhaul and repainting. Managed to click one or two pics. UCE (Left) and Cast Iron (Right)

View attachment 79775
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Love the lines of those. Enjoy!
 
When I had a bullet I ran 20W-50 Castrol. Any HTHS oil thick enough to help resist burning will be fine. The old design is a crude, 1938 designed frame with a motor last updated with bigger bearings circa 1953 or so. Very loose piston tolerances. Not the newer ones they make now with fuel injection and new engine design.
If you're not in the mountains where it actually gets cold, you don't even need a multiweight oil. I'd stick to regular gasoline or diesel engine oils though. Not sure what is different about LNG oils, and with gazillions of other inexpensive and appropriate oils, why bother with the LNG specific oil? Is it free?
Is it a 350 or 500?
 

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When I had a bullet I ran 20W-50 Castrol. Any HTHS oil thick enough to help resist burning will be fine. The old design is a crude, 1938 designed frame with a motor last updated with bigger bearings circa 1953 or so. Very loose piston tolerances. Not the newer ones they make now with fuel injection and new engine design.
If you're not in the mountains where it actually gets cold, you don't even need a multiweight oil. I'd stick to regular gasoline or diesel engine oils though. Not sure what is different about LNG oils, and with gazillions of other inexpensive and appropriate oils, why bother with the LNG specific oil? Is it free?
Is it a 350 or 500?
Ah, that 5speed olive green looks so classy!

Okay, though there are plenty of them locally available with appropriate viscosity (15w50 or 20w50) ratings, the inexpensive ones don't have ZDDP additives. And most of them don't publish their datasheet and safety sheets online to get much idea about the oil. So inclined towards Heavy Duty Diesel Engine Oils, but they don't come with 50 weight.
 
Ah, that 5speed olive green looks so classy!

Okay, though there are plenty of them locally available with appropriate viscosity (15w50 or 20w50) ratings, the inexpensive ones don't have ZDDP additives. And most of them don't publish their datasheet and safety sheets online to get much idea about the oil. So inclined towards Heavy Duty Diesel Engine Oils, but they don't come with 50 weight.
Well, here in the States people have been running 40 weight HDEO like Rotella and Delo in Harley's and other air cooled engines for decades without any negatives. I run a 10W-40 in my air cooled Yamaha V-twin. It gets in the mid 90s F here.
Sport bike boys just don't know the pleasure of a kick-start thumper!
 
Well, here in the States people have been running 40 weight HDEO like Rotella and Delo in Harley's and other air cooled engines for decades without any negatives. I run a 10W-40 in my air cooled Yamaha V-twin. It gets in the mid 90s F here.
That's giving some confidence to try out Shell Rimula (Indian equivalent of Rotella) or Mobil Delvac. Both come in 15w40 ratings. In addition to that, the workshop manual published by Pete Snidal, suggests getting 40 weight if the conditions doesn't get extremely hot.

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Sport bike boys just don't know the pleasure of a kick-start thumper!
Rightly said!
There are so many annoying YT videos where this thumper is taken high rpm racing against modern bikes. 😔
 
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