• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

Motorcycle Oil Castrol 4T 20W50 Any Information

Share this page

RAC68

RAC68

Darth Vader
Offline
Just recently a friend recommended I use Castro 4T 20W50 Motorcycle oil in place of the Racing Oil I presently use and acquired at a much lower price at the end of the Racing season. My choice of Racing oil was primarily to acquire the additives eliminated from standard oils with catalysts as it is considered a specialty lubricant. Well, according to my friend, the Castrol 4T is formulated for high temperatures, high RPMs, and lots of stress protection. It also seems to be designed for flat tappet lifters and cam. However, with none of the specifics, I am wondering if anyone else had heard of these benefits and any negatives. Best of all, I have seen this oil for around $14US for a 4L container.

Any info would be appreciated,
Ray (64BJ8P1)
 
Update:
I just read a submission on oils for Healeys on healeys-request@autox.team.net by Bill Lawrence and found information addressing Motorcycle oil. Being an infrequent topic of interest for me, I was never cognizant of the meaning of the oil package codes and their meaning. In Bill's submission, he clearly presented the basics and indicated the "S" to mean Spark (ignition) and the following letters to provide the additive package included. For those looking for Zinc was included in SD - SL and eliminated in anything past SM. Since Motorcycle engines do not have Catalytic converters, the 4T designation would be most likely to have the use of earlier packages (prior to the Catalyst) and contain those additives addressing the requirements of a flat tappet engine.

Again, I am not up on this topic and would appreciate knowing why, if at all, Motorcycle oils (4T) would not be in good use in a Healey engine?

Ray(64BJ8P1)
 
Here are some comments by LN Engineering (Porsche people - gasp!) about motorcycle oils:
Motorcycle oils have higher levels of phosphorus/zinc for enhanced wear protection and the same high-temperature detergent technology for superior wear protection and engine cleanliness, even at elevated oil temperatures. Specifically motorcycle oils for aircooled engines are designed for very high localized oil temperatures and high overall oil temperatures, and typically have high flash points coupled with higher HTHS viscosities and lower noack% losses. As a whole, it would appear that all most motorcycle oils we tested have excellent anti-wear additive levels and most are not SM or SN rated oils, but rather earlier SG, SH, or SJ rated. In a pinch, it should be fairly easy to find a motorcycle oil with any of these SG, SH, or SJ ratings at your local auto parts store when it may be more difficult to get Brad Penn or Swepco, without having it shipped to you. Please do remember that motorcycle oils typically have levels of Zn and P that will kill catalytic converters, so if you have one, either remove it first or use another oil, like Brad Penn or Swepco. Also, motorcycle oils are not as detergent as the aforementioned Brad Penn or Swepco, so you must change the oil much more often, even though the perception of being able to go longer because the oil costs more is a false one.
Click to expand...

You can read more about ZDDP/ZDTP/ZDP at the FAQ section of their website: https://lnengineering.com/resources/2014/02/28/frequently-asked-questions-about-motor-oils/
 
Cost wise and ZDDP wise stay with racing oil. They were never downgraded to meet current engine demands, and are well suited for our flat tappet engines.

P.S. I like VR1
 
GregW said:
I haven't used it, but I found this at a local "old school" auto parts store. https://www.classiccaroil.com/
Click to expand...

At $27 for 5 liters, that's $5.13/qt - compares well to $6.39/qt VR1 current price at O'reilly Auto Parts. Adding shipping if bought online would close the gap.
 
Hi All and thanks for responding. None of us wants to open the Oil discussions again but it seems that whenever I get comfortable with a brand and grade of oil, the specs change to address another environmental condition. I have now read quite a bit on what Motorcycle oils are and the conditions formulated for. Since 4T oils seem to be more reflective of the conditions presented in our Healey engines, I am still wondering why there is resistance to its use. The price is much better then racing oils and easier to acquire. Is it the fact that it has motorcycle rather than classic car on the container? Although I have found oils with the Racing Oil designation, if no indication for "Off Street Only" all the benefits have been stripped and only the marketing designation remains.

So, wouldn't 4T 20W50 be a more stable and better matching oil for our cars?

All the best,
Ray (64BJ8P1)
 
Hi All and thanks for responding. None of us wants to open the Oil discussions again but it seems that whenever I get comfortable with a brand and grade of oil, the specs change to address another environmental condition. I have now read quite a bit on what Motorcycle oils are and the conditions formulated for. Since 4T oils seem to be more reflective of the conditions presented in our Healey engines, I am still wondering why there is resistance to its use. The price is much better then racing oils and easier to acquire. Is it the fact that it has motorcycle rather than classic car on the container? Although I have found oils with the Racing Oil designation, if no indication for "Off Street Only" all the benefits have been stripped and only the marketing designation remains.

So, wouldn't 4T 20W50 be a more stable and better matching oil for our cars?

All the best,
Ray (64BJ8P1)
 
RAC68 said:
....

So, wouldn't 4T 20W50 be a more stable and better matching oil for our cars?

QUOTE]
Maybe. In your reading you may have seen that ZDDP is not a single compound, but a broad range of compounds that can be tuned to achieve the best results in a particular type of engine. Same with the other additives. I'm not sure how the conditions in an air-cooled motorcycle combined engine/clutch/gearcase compare with those in a '50s Austin engine. Those differences are why diesel oils are not recommended for gasoline engines, even old ones.
Click to expand...
 
A consensus--at least as much of a consensus as you can expect given the topic--is that Valvoline Racing (VR1) 20W-50 has sufficient ZDDP and is suitable for our Healeys. I've been using it for a couple years with no issues (not that I'd expect any with any modern oil with sufficient ZDDP either in the oil or added, but I don't think additives are a great idea). It's readily available at parts stores and until recently was about $4-5/qt. Now, it's around $6-7/qt.; if I were a cynic I'd say the price got bumped when more and more older car owners started buying it (an oil company would never take advantage of its customers, would it?).
 
(an oil company would never take advantage of its customers, would it?).

BOB:
Ain't you bought no gasoline here lately??--:greedy_dollars:
 
John/Derek, I looked for Castrol Classic and have found only references priced in Pounds. I guess it is not sold in the US. Also, I appreciate that the ZDDP package in oils can be, and is, modified to address specific conditions, however, I would expect the stress, RPMs, and heat conditions of an MC is not far from the conditions we see in our Healey engines ... if not much worse. I happened to access the Ferrari forum and they too are looking at MC oils as a way of getting sufficient ZDDP and additive packages for their engines. It seems to me that the US has enough classic cars to make a good market and I have no clue why Castrol doesn't provide these oils prominently in the USA.

Bob, I use VR1 Racing Oil (not Road Legal) and then picked up another quart of Racing Oil but found it was Street Legal. Researching, it was catalyst approved so I the level of ZDDP was not close to the levels purchased last year. The reason I started looking into 4T MC oil was because I was far from sure if I had what I wanted even when it said Racing Oil. If I could get an oil, at a reasonable price, designed for Classic Car engines, I would definitely opt for it. But I don't seem to be able and 4T Motorcycle oil seemed a very good alternative.

I am not pushing for 4T oils but looking to find a reasonably priced oil that has the correct packages and I don't have to think twice about. If that oil was available we would not have this discussion.

Ray (64BJ8P1)
 
Pulled a qt of VR1 off the shelf and it reads:

'High-Zinc formula also protects push-rod and flat tappet engines.'

- and -

'Not recommended for extended use in vehicles equipped with catalytic converters.'

Nothing about 'street legal' or not; IIRC I heard/read elsewhere the ZDDP content is 1,200ppm. I didn't know any oil was not 'street legal;' just that if you use an oil with ZDDP you'll hose your converter.
 
Back
Top