TR6 Switching to 5 - 30 wgt oil for a TR-6????

[bunzil]

If I understand the topic correctly, the recently released SJ Classification of oil is the most stringent, and highest quality conventional motor oil available. While I know engine technology has improved, so also has oil - dramatically!! In fact, most new cars seem to be calling for 5-30 weight (SJ classification).

As we all know, lighter oil improves cold weather starting, as well as more gently deal with long periods of idle cars like Triumphs.

Since these oils didn't exist when oil specs where written by Triumph for these cars, shouldn't they now be considered.

In short, for cars like ours that sit idle for long periods, would switching to 5-30, or 10-30 SJ oils be beneficial???

 

[Mickey Richaud]

My understanding is that the newer oils are formulated for the closer tolerances that today's engines have. Our old British iron just never were built to those tolerances. For my money, I'm sticking with Castrol 20W50.

Mickey

 

[bunzil]

Thanks. I considered that and I've used Castrol 20/50 for years. But is it really a tolerance issue? I don't know, and certainly lighter oils will be more prone to leak.

My question is, and some dialouge might help the entire community; because we've been so brainwashed to use only 10/40 or 20/50, have we failed to recognize the technological advancements of the past 25 years?

I live in NJ and try and start my car at least once a month (and drive it) in the winter. But I cringe ever time I start it worrying about the lack of oil for the first few seconds. Wouldn't this, over time, be a leading cause of wear to a low mileage engine and, if so, wouldn't a modern lighter oil be beneficial?

I don't want to talk synthetics either as I understand they don't embrace stored cars very well.

 

[Mickey Richaud]

Good food for thought. I'll be curious to hear some other opinions...

Mickey

 

[bunzil]

Me too. It would be nice if there was an oil expert in our ranks to give us the straight answer. After all, if we ask Castrol, they'll tell us to follow the manufacturer's recommendations - who have been out of business for 20 years, well before the current oils were produced.

I worry we are all being too conservative, and superstitious....

 

[trboost]

The TR owners manual suggests 10-40w or 30w oils in winter temps & 20-50w for summer driving. Detergent formulations & additives have been modified over the years but I think the the same rule of thumb applies. Thinner oil in the winter flows easier & quicker through the engine and lower ambient temps allow for a lower maximun oil viscosity.

Thick or thin oil will leak equaly when hot , so that's not a factor. If you have a leak, oil does not plug it , thin or thick. I have been using 15-50w mobil 1 which seems to work very well & if it lives up to it's advertising should lubricate better & not break down. There was a very detailed article in Corvette mag that examined the chemistry & properties of synthetic oils & it was inconclusive as to long term results as oposed to conventional oils that are changed frequently. The consensus was that technicaly it should yield better results over the life of your engine. Cheap insurance. Mobil 1 & other FULL synthetic oil is supposed to hold dirt in suspension better & not break down under tuff conditions, true or false , who knows. I drive my car through the year & change the oil about three times so the cost is not a killer but it's worth the peace of mind considoring the investment & my lack of enthousiasm to pull the motor again /ubbthreads/images/graemlins/nonod.gif

 

[bobh]

Has anyone considered installing an Accusump? I'm trying to learn more about them. Although they appear to be intended for racing applications. They sound like the ideal add-on to prevent wear at startup.

 

[bunzil]

[ QUOTE ]
The TR owners manual suggests 10-40w or 30w oils in winter temps & 20-50w for summer driving. Detergent formulations & additives have been modified over the years but I think the the same rule of thumb applies. Thinner oil in the winter flows easier & quicker through the engine and lower ambient temps allow for a lower maximun oil viscosity.

Thick or thin oil will leak equaly when hot



Interesting observation on the thick or thin oil leaking. As for what the owners manual suggests, I think we can throw that out completely. They didn't have super high quality 5-30's when they wrote the book.

So the question remains: can we run today's lighter oils in these cars for the clear benefit of less internal wear when starting from cold? If indeed the oils remain the same thickness as you suggest, then oil pressure wouldn't be an issue. And since I think we can assume heat isn't an issue (TR's don't run as hot as a modern car) can we use the same 5-30 year round?

As for synthetics, I've read, but can't recall where, that synthetics do not offer the same long term corrosion protection for internal engine surfaces. It's fine for daily or frequent drivers, but not cars that sit a lot. But don't quote me on this.

 

[bunzil]

I have not considered an Accusump, but view it sort of like adding an oil cooler. That is; a bit of overkill. That's my opinion of course...I've just never felt that TR's really run that hot to require an oil cooler.

 

[bunzil]

I did some reading on 6-Pack's site. They say use 5/30W in the winter but switch to something heavier in the summer as 5/30W becomes too thin. This is contrary to what was said earlier. If indeed it becomes too thin, what about all the modern cars who call for 5/30 year round?

 

[sparkydave]

I was curious about using thinner oil too, so I just put 10W-30 in my Midget. I've noticed that compared to the 20W-50 I had before, the oil pressure comes up faster and the valves are quieter. The oil pressure hasn't changed that I can tell. As long as you have sufficient oil pressure, you should be fine in summer, even if you decide to go with 5W-30. The other reason I did is because the 20W-50 was so thick in winter it could barely turn over.

 

[bunzil]

Also you've got those poor unlubricated cylinder walls.

I'll be anxious to see what we get this evening when folks come home and open up this thread. The more I think about it, the more I think we are hanging onto the old 20/50W rule because "that's the way it's always been."

You may be right: if oil pressure remains the same, why not switch to a lighter grade? It's all about oil pressure isn't it?

 

[sparkydave]

If you really want to learn more about oil (and read more conflicting opinions on oil), try https://www.bobistheoilguy.com.

I too was thinking we were sticking to 20W-50 because "that's the way it was", but bear in mind that oils today have better additives and fewer impurities than they did 30-40 years ago when our LBCs were built.

 

[LastDeadLast]

I too have been thinking of swtiching to 10w30. Here in another article that seems to support that (and it's a vintage car site to boot!)

https://www.boss302.com/oil.htm

 

[bobh]

5W-30 requires less energy to pump. By decreasing pumping losses less energy is required to run the engine. Manufactures use lighter oil to help increase fuel mileage.
The only thing that cools the bottom end of your engine is the oil. You would probably need to monitor the oil temp to determine if an oil cooler is required. I plan to install one.
The Accusump suggestion is offered as a way to prime your engine. Thinner oil may flow more easily but does not eliminate the time it takes to build oil pressure. The Accusump will build pressure before anything in the engine moves. It may be an old wives tale, but "most wear happens at startup" makes sense. Our cars sit for days or even months between startups. Priming the engine is something to consider. For all but a very few of us maintaining pressure in hard turns or under severe braking is not a benefit or a concern. I haven't decided whether or not to install one.
Look at it this way. LBC ownership is esoteric. Likewise oil coolers, Accusumps, glyptol, Armorall, polly bushings, stainless exhaust......
Over the years several magazines have tested thinner synthetic oil in heavily modified engines and drive trains. All reported more power at the wheels. Some mentioned the concerns of owners about lower oil pressure and thinner oil. The bottom line is it's a personal decision. Certainly no oil manufacturer is going to make any recommendations. Our litagation crazed society sealed their lips years ago.
One possible source of comments is hard core racers. If they use thinner oil and their engines stand up. Then 5W-30 may be fine.

 

[trboost]

From what I've read it's conventional mineral based oils that don't offer long term corrosion resistance due to acid that is created when reactice carbon atoms react with oxygen. Synthetics like Mobil 1 & Castrol formulas RS are more stable & tend not to contain these reactice carbon atoms. Something I just learned is that Mobile 1 is not a true synthetic, it is mostly made from Polyalphaolifins comes from the purest part of the mineral oil refraction process, the gas. That's why you can mix it with reg motor oil with out damaging parts.

There is a ton of info on this. If I can find the article from Corvette mag I'll post it some where.

This article is pretty thorough. https://www.repairfaq.org/filipg/AUTO/F_oil_facts.html

Engine cold start up has always been a topic of converstation & opinion. The basic steps that help would be an oil filter conversion, installed so the filter remains filled. A motor in decent shape should show oil pressure with in a few second after start-up. The best maintanence is to drive the car. Long periods between running & driving cause many problems due to lack of lubrication,bearing rotation & other parts meant to be submersed in oil/grease and in motion (drive train,chassis & engine). If possible try and drive the car often. Believe me ,I know this is not a reality for every one but it is a solution.

 

[bunzil]

The article at Boss302.com seems to cover the subject well and certainly supports a switch to 10/30W.

Agree that running the car frequently is the answer but it's impractical here for a number of reasons, not the least of which is time during the day. I put around 1,000 miles a year on my car, and it's come down to annual oil changes. It's so clean at this point I can't see the level on the dipstick. And I use a spin-on PH-3600 which holds the oil nicely, vs. draining back down into the sump.

I suppose the answer is to watch the oil pressure - if it remains the same, that ought to be fine. No? 10/30W would seem to do a better job in this area than 10/40 and certainly 20/50. BTW - boss.com dealt with 20/50 at length.

 

[Alan_Myers]

Hi,

Hey, I'm no expert on oils, but I am opinionated! /ubbthreads/images/graemlins/cool.gif

No way! 5w30 is far too light. The real issue isn't if the engine is hard to start because of the oil. There are ways around that (see below).

In my mind, the much, much more important consideration is whether or not the engine will be adequately lubricated once it's warmed up and working.

With 5w30, it simply won't be.

You will see oil pressure drop dramatically when the engine is warmed up, right on the dash gauge. Perhaps dangerously low! Engine wear will accelerate, big end and main bearings will start to knock, small end bushings will soon rattle, and you'll be ready for a rebuild.

In fact, I've done just the opposite with a friend's late model Pontiac - that called for 5w30 originally. I now regularly use 10w40 in the hottest Summer months and a 50/50 blend of 5w30 & 10w40 in the Winter. That engine has nearly 150K miles on it (still going strong!), is a design that's known to be prone to overheating, gets run on the highway a lot, plus she tends to go a 4000-5000 miles between oil changes. Taking all these factors into consideration, a slightly heavier oil is needed.

Being in N. Calif. where temps seldom get below 40F, 20w50 is what I'd use all the time in any old TR motor. 10w40 is the lightest that can be used - in sub-freezing weather, but I used 20w50 year round in Colorado when the car was a daily driver with some miles and wear in the engine. If you must use a synthetic oil (I won't), it's viscosity is more stable at various temds, so the same 20w50 would probably easier to start in really cold weather.

If an engine has some miles on it (because wear increases clearance in all the bearings and the oil pump, reducing pressure), maybe mix half 20w50 and half 10w40 for colder weather.

There are a variety of ways to help the car start in cold weather, but still provide the best possible lubrication once the engine is warmed up.

One is to install an electric block heater to be used in cold weather, before starting. There are various types of these, some simply install into a radiator hose and are then plugged into a household outlet or extension cord. The heater will warm up the coolant mixture enough to take the edge off and help the engine start more easily in really cold weather.

These electric heaters might be a somewhat better arrangement than some other techniques I've used or seen used. I have put a 100-150 watt light bulb under the hood of the car while it's parked. The little bit of heat this puts off keeps the edge off the cold.

That's nowhere near as extreme as they often used when I was a kid in Northern Montana. My Dad was a radar officer and one of the pilots on a radar site out in the middle of nowhere. The base's airplane sat outside next to a dirt/grass landing strip. In mid-Winter its engine oil was probably about the consistency of road tar, when temps got as low as -56F! So, they'd build a small fire in a 30 gal. oil drum situated right under the engine's sump to warm it up! My civilian brother-in-law used the same trick on his "bush plane", but I certainly am not recommending this for any LBC!

At any rate, I'd strongly suggest finding other means of helping the engine start in cold weather, to make it possible to use the highest recommended viscosity of oil at the more critical times when the engine is warmed up and needs good pressure and proper lubrication.

Personally I think an Accusump (or similar from other manufacturers) is a great idea, although it won't address cold start issues. For anyone unfamiliar with it, this is an additional oil supply that's plumbed into the pressure side of the the engine's oiling system. It gathers up some oil from the system while the car is running and stores it under pressure, including when the car is shut off.

There are manually and electrically operated models. With the manual version, a lever is used to open and close a valve, at startup and shutdown respectively. The electrically operated type can be wired to the ignition so that the pressurized oil is released the moment the ignition key is turned and the stored, pressurized oil is released even before the engine begins to turn over. This pushes a quantity of oil into the engine and pre-lubricates it. Makes sense to me!

After all, cold startup is the toughest few moments of running for any automotive engine. That short time when the oil is working its way up from the crankcase to the mains, big end bearings, cam bearings and on to the valve gear, then back down onto the cam lobes and cam followers is when probably 75% of wear and tear occurs. Ever notice the "clatter" of most Triumph motors (and others), right at startup? Some, but not all of that is bearings and other moving parts waiting for oil to reach them.

The noise is made worse in that many engine tolerances are greater when the engine is cold, before metals warm and expand to their normal operating clearances. Some modifications can also compound the noise: A "hotter" cam means bigger valve lash clearance. Modern "no-lead" valve guides need more clearance than the originals. An Accusump won't fully prevent the cold-start, clearance-related noise, but that's really not harmful anyway. However, the noise that's caused by lack of lubrication is the sound of damage being done, hopefully only a little at a time.

It never hurts to increase an engine's total oil volume, either. And an Accusump (oir similar) will add 1 to 3 extra quarts of oil, depending upon the size used.

Depending upon how it's plumbed, an Accusump will also generally feed directly to the main oil gallery, insuring a good supply of oil the crankshaft mains first, which are biggest and probably the most important bearings to insure receive oil. (For example, I know the GT6 motor has a real issure with low main pressure at high rpms, I think mostly at the front of the engine. An external "balance" pipe can be plumbed in pretty easily to insure that all the mains get a good, equal supply of oil pressure at all rev ranges and the engine doesn't tear itself up.)

Another benefit from an Accusump comes during "spirited" driving. In hard cornering, if there is enough surge the oil pump's pickup down in the sump pan might get uncovered and momentarily suck air, starving the engine for oil. In this circumstance, the Acccusump will also pick up the slack and help insure a constant pressure and steady flow of oil.

It's probably minor, but an Accusump likely also helps keep the oil a bit cooler by increasing oil volume, provbiding some more surface area for heat transfer, plus its aluminum container transfers heat well. TR engines "prefer" to run down around 185F (it's not uncommon for modern engines run at 200-225F, for example), but overcooling needs to be avoided.

The only "negatives" to an Accusump that I can think of are the additonal complexity and extra plumbing. These mean more opportunity for leaks. Also, I have to assume that there's normally no way easy way to drain all the oil when it's time for a change. Some of the old will remain in the Accusump and mix with the new. (The same is true of an oil cooler.)

For a variety of reasons, I won't use synthetic oils in these older-design engines, although I know the stuff has many fans. I've had some bad experiences with it and the "high mileage" type (i.e., most synth. oils) has too much detergent for an old TRactor, which needs some coking in certain areas to help keep engine compression up and prevent leaks. Mainly, I see no reason to pay extra $$ for oil that I'll be changing every 3-6 months and will seldom see more than 1000-3000 miles use. The engine made 125K miles, all on plain old mineral-based oils, during the first 25+ years I owned the car. If that can be used as any guide, once the current rebuild is done that engine will probably outlive me!

/ubbthreads/images/graemlins/cheers.gif

 

[bunzil]

Now THAT'S an answer.

I seem to agree a 5W30 is too light, but what about a 10W30?
The site mentioned earlier boss302.com/oil.htm seems to hit the nail right on the head. Check it out, and comment. Here are two very interesting comments from the site:

"Also, thicker is not better, no matter what your mechanic or engineer told you. 20W-50 has 40% more viscosity (resistance to flow) at operating temperature than 10W-30. This means that your engine has to work 40% harder just to move the oil around inside your engine. An engine with thick 'oil' produces significantly less power, uses more fuel, produces more emissions and runs hotter, all contributing to shorter engine life.....Unfortunately, the rule that 'you can't teach an old dog new tricks' prevents many 'experts' from accepting the facts. Indeed, when I was a kid, it was Castrol GTX 20W-50 in every car I had! In the years since, I have been working in the automotive lubrication industry,....."

But perhaps most importantly he goes on: "In a properly running engine with a properly functioning cooling system, it doesn't matter if you are driving in sub-zero temperature or 100 degree heat. The design of the cooling system will cause the engine & coolant, and therefore the oil to operate at whatever temperature it was designed to operate at. So what I'm saying is that the first number is critical in terms of climate. That is why the 'W'(winter) designation is put after the first number, not at the end. The second number has almost no correlation to ambient temperature, only the regulated temperature of the engine."

This last part I find most intriguing. In some respects, aside from tolerances, he almost renders the second number - which LBC owners hold so dear, as meaningless.

As for Accusumps and the like, I have to believe you can operate a TR for years without such devices. As I said a while back, my big concern, living in not-all-that-cold NJ, is the dreaded mid-winter start, when the car has been idle four weeks. And here I would think 10W30 would be beneficial.

 

[Alan_Myers]

[ QUOTE ]
The article at Boss302.com seems to cover the subject well and certainly supports a switch to 10/30W....


[/ QUOTE ]

... in a Ford 302 V-8 engine.

What oil was originally called for in that particular engine? 30W? 10w40?

This question would have to be answered before the info could be considered for or applied to any other engine design.

Even then, there are lot's of other key factors that need comparison: The type of oil pump used, the design and materials used in bearings, size and design of oil passages in the engine, normal engine operating temperatures, etc., etc.

I think I'll just stick to 20w50... as recommended by Triumph for use in the engines they designed, built, and then tested extensively on street, dyno and race track. Their recommendations seems to have worked out pretty well for most TR owners who read and followed their manuals over the past 40-50 years.