Engine design VS Lubrication

[ZGRider]

Why is it that almost no one wants to consider the design of a motorcycle engine before recommending an oil? It seems that all everyone here wants to do is say: "I like this oil so you should use it."

Here is my list of engine factors that should be considered before making an oil recommendation:

1. Is the engine air-cooled or liquid-cooled? (heat breaks down oil.)
2. Does the engine share oil with the transmission? (trans. gears shear oil quickly.)
3. Is it a high RPM engine? (consistently over 10,000 RPM)
4. Does the engine have high-pressure plain bearings or low-pressure roller bearing? (Roller bearings require little lubrication)
5. Does the engine have a history of lubrication issues? (Shovelheads, Ducati Bevel-drives, Honda VFs, Norton Commandos, old Triumph Twins?, etc)
6. Placement of the camshafts (BMW airheads have the cam in the bottom of the sump, submerged in oil vs OHCs far from the sump)
7. Dry-sump VS Wet sump? (Dry-sumps generally have greater oil capacity than wet-sumps because they have external oil tanks with no limiting volumes.)
8. Oil capacity of the engine? (Yamaha YZ & WR 450 engines hold just 1 qt of oil -- won't take long for that to break down)

If you don't know the answer to these questions -- Ask !

Or better yet, do some research on your own....

There is no sense in spending $10 per qt. for oil that your engine doesn't need and won't benefit from, while neglecting an engine that would benefit from a higher quality oil.

So, since this is a site for logical, inquisitive thinking and not just someplace to brag about how much we spend on "boutique" oils -- could we all be more thorough in this regard before we pony up our recommendations?

 

[Boomer]

This is one of the more thoughtful postings about oil I have read in quite a while. Good job for making all of us think a bit more!

 

[synormin]

Originally Posted By: Boomer
This is one of the more thoughtful postings about oil I have read in quite a while. Good job for making all of us think a bit more!

+1

 

[EagleFTE]

Good summary. I thought we were already considering these things (at least on this forum) but I could be wrong. Certainly there are many not into oil that are not considering much at all and just put in what dad used, what cost least, what cost most, or what Joe down the street uses.

Some here are certainly trying to answer these questions and learn what is over kill and what is not. I think we need to use a little consideration for the guy that posts on what to use in his liquid cooled, shared sump bike and not go off on I use xyz because it has a 500+ degree flash point.

Usually you will see responses that couter each other. As you said "I use this and that makes it the best" vs. "why use that when that application will never see those temps or shearing due to gear/clutch operation". They will have to find the truth in the end. We are here to help right? Well some of us.

And there is much to be learned. For example a guy said years ago that the Brits really did not consider that someone would actually ride a Norton in 100+ ambient temps every day and did not consider that in their oil recommendations or design.

 

[bonnie john]

what are the issues with old triumphs and commandos ?

 

[EagleFTE]

Just that if you ride them in the Mohave Desert vs. the UK you will see temps not necesarrily taken into consideration by the OEM and you might want to use a high temp shear stable oil and/or an oil cooler. Never owned one but some over here say that using such oils will make them much happier in these conditions (110 to 115 degrees F). I'd have to search for the web site where commented on if it still exists. Pretty much same applies to other air cooled engines.

 

[ZGRider]

Originally Posted By: bonnie john
what are the issues with old triumphs and commandos ?


Are you kidding me? Old Triumphs had "pusher type" oil pumps instead of gear pumps that were notorious for letting oil drain back into the dry-sump. Also those engines (both Norton and Triumph) had issues with crankshaft end bearings because of flexing of the crankshaft. This is not to mention piston-to-cylinder tolerance issues and overheating problems. You name it -- and they had it.

 

[EagleFTE]

"PolyEster (RedLine) oils have by far the best performance in extreme high temperatures, and are the preferred oil in old "air- cooled" Nortons. I put "air-cooled" in parenthesis as one could also call these engines "prayer- cooled." The Norton 750 commando will destroy a Group I oil fill in 75 miles on a 100 degree day. No kidding. The Brits really did not understand until about 1990 that some of us live in places where the temperatures get over 80 degrees and cities are more than 10 miles apart. If you love those old British twins, you need to find a good supply for RedLine oil."

From

http://motorcycleinfo.calsci.com/Oils1.html

 

[XCELERATIONRULES]

I've never used motor cycle specific engine oil in any of my bikes,and the motors always outlast the electronics or other related components.
Changing the oil at least twice a year in my climate,with correct weight oil works great.
I do spend a few bucks more on synthetic,but would never pay $10 a quart for any oil.

 

[Nessism]

I don't understand what you would change oil wise due to these factors: High RPM, plain bearing crank, placement of camshafts, dry/wet sump.

Please explain.

 

[bigbird_1]

Originally Posted By: EagleFTE

If you love those old British twins, you need to find a good supply for RedLine oil."


Or just add an oil cooler.

 

[bigbird_1]

Originally Posted By: Nessism
I don't understand what you would change oil wise due to these factors: High RPM, plain bearing crank, placement of camshafts, dry/wet sump.
Please explain.


Are you kidding?
If you aren't, unless someone wants to take 30 minutes typing it out for you, do some Googling on principles of 4 stroke internal combustion gasoline engines.

 

[ZGRider]

Originally Posted By: bigbird_1
Originally Posted By: EagleFTE

If you love those old British twins, you need to find a good supply for RedLine oil."


Or just add an oil cooler.


And a Nicasil cylinder, upgraded crank bearings and upgraded oil pump.

 

[ZGRider]

Originally Posted By: Nessism
I don't understand what you would change oil wise due to these factors: High RPM, plain bearing crank, placement of camshafts, dry/wet sump.

Please explain.



Nessism:

I have to be brief, but here goes:

Wet/Dry Sump:
Dry-sump engines have no oil in the engine, it is in a separate tank somewhere else on the bike -- advantage because the oil resides away from the heat of the engine and the separate tank usually holds more oil than the wet-sump engine. Tank can even be in the frame of the motorcycle.

OHC VS push-rod:
The farther from the supply of oil the cams are the more likely there could be oil starvation - i.e. Honda VF V-4 engines in the early 80's BMW air-heads are push-rod with the cam located under the crankshaft submerged in the oil -- almost no chance of oil starvation. Advantage -- push-rod engines.

Roller-bearings VS Plain bearings:
Plain bearing require high-pressure, clean and substantial amount of oil. The oil film between the plain bearings prevents metal-to-metal contact. Any problems with oil supply, oil quality, or oil pressure spell doom for plain bearings and crankshaft and rods. Advantage roller bearings -- almost no bikes use roller bearings anymore, except Harleys

Liquid cooled VS air-cooled:
This is pretty obvious as air-cooled engines can get very hot when air is not flowing over heads and cylinders. Many air-cooled use oil coolers to offset this problem. Heat kills oil very quickly.

Shared transmission engines VS separate transmissions:
Straight-cut transmission gears shear oil down very quickly, so if the trans uses the same oil as the engine then twice (or more) as much wear takes place. Separate trans can use much heavier oil that resists shearing much longer. Advantage separate transmission.

Summary:
Oil is damaged by heat, shearing, and contaminants. Any engine design that introduces more of these conditions shortens oil life.

Therefore: Engines that are multi-cylinder, high-RPM, OHC flat-tappet, shared-trans/wet-sump, air-cooled, plain-bearing would have the shortest oil life and would be good candidates for very good synthetic oil (Grp IV and V synthetic) Not many engines have all these attributes. Most Asian engines are all of these except not air-cooled, but liquid-cooled.

Alternately, An engine that is roller-bearing, pushrod, separate trans/dry-sump, liquid-cooled, low RPM, would put the LEAST stress on it's oil and nearly any oil (Grp II) would be a good candidate for these engines. Harleys as an example are all of these but not liquid-cooled.

Got it?

 

[bonnie john]

i think you're getting a little mixed up there

commandos had SOME mains probs when they "combated" the 750's. the cranks flexed and the "fix" was a bearing with barrel shaped rollers which didn't gouge the race surfaces when the crank flexed. NEVER heard of triumph doing the same thing though

i've heard of nortons and bsa's wet sumping, because of the oil leaking through their gear oil pumps. design fault, gears don't seal proper against gravity fed oil

triumph OTOH use a positive displacement twin plunger pump. because of its design, it does not leak unless there is dirt in the system or has covered a huge mileage and the check balls in the pump MAY need reseating

triumph suffered extreme piston, ring and wall wear probs on SOME 67-68 650's. it was a combination of heat and hard running which caused probs with the original 9:1 flat top pistons, and was overcome in 1969 by using a domed piston ( and i think chrome top ring )

and overheating prolly came from u.s. desert "racers" who ran straight pipes and no aircleaners without regard to jet changes

Originally Posted By: ZGRider
Originally Posted By: bonnie john
what are the issues with old triumphs and commandos ?


Are you kidding me? Old Triumphs had "pusher type" oil pumps instead of gear pumps that were notorious for letting oil drain back into the dry-sump. Also those engines (both Norton and Triumph) had issues with crankshaft end bearings because of flexing of the crankshaft. This is not to mention piston-to-cylinder tolerance issues and overheating problems. You name it -- and they had it.

 

[ZGRider]

Bonnie:

I'm not disputing what you said, but even though the specifics are different, the overall picture is the same. Triumph/Norton oiling systems were archaic and troublesome, compounded by poor quality control and inadequate cooling spelled short engine life. It was very common to have to rebuild the top-ends every 30,000 miles and bottom-ends every 50,000 miles. Of course, better quality oil and oil cooling might help that stat, but the you know the rest of the story. Those engines were good engines, just not great. Many Triumph owners upgraded the plunger oil pumps to modern designs. The oiling systems just could not cope with the power that tuners tried to get out of those engines. Hence, they need(ed) the best oil available.

 

[Silk]

Back in the day('70's for me) I don't remember any problems with my British bikes that I could blame on lubrication.99% of British bike problems were caused by butchered owner repairs (mine included)They wore out because they didn't use air filters,and jetting was just a rough guess.

Roller bearings not used anymore??? Inside every transmission,and every single cyl dirt bike.

Worse bikes ever for lubrication caused wear were the early aircooled Japanese trail bikes...RFVC XR Hondas in particular.

I don't think the BMW airhead camshaft runs in the sump oil....but being in the bottom of the engine certainly helps,although it didn't help aircooled VW's.

Otherwise good post.

 

[ZGRider]

Originally Posted By: Silk
Back in the day('70's for me) I don't remember any problems with my British bikes that I could blame on lubrication.99% of British bike problems were caused by butchered owner repairs (mine included)They wore out because they didn't use air filters,and jetting was just a rough guess.

Roller bearings not used anymore??? Inside every transmission,and every single cyl dirt bike.

Worse bikes ever for lubrication caused wear were the early aircooled Japanese trail bikes...RFVC XR Hondas in particular.

I don't think the BMW airhead camshaft runs in the sump oil....but being in the bottom of the engine certainly helps,although it didn't help aircooled VW's.

Otherwise good post.


Roller bearings on the crankshaft of multi-cylinder engines (Yes, single-cylinder dirt-bikes still use roller cranks) Transmissions are splash lubricated. All the oil running back in the engine goes right on the cam in the BMW airheads, so technically not in the oil but certainly adequately lubricated.

BTW, I have seen more than my share of Triumphs and Nortons seized tighter than a drum and if that is not a lubrication issue, I don't know what is. We like to think of those bikes fondly, but remember those were some of the most hated bikes in the world when the first Japanese bikes came ashore. They leaked oil, they siezed regularly, they had poor electrics, horrible carburation, flexing crankshafts, valve guide problems, and wet-sumped often. Those engines still had Whitworth bolts on them? Only the last year of Norton Commandos (1975) had left-hand shifting and psuedo-electric start. They didn't even use oil filters for cryin' out loud (except later and it was bolt-on.) Crankshaft oil passages always had to be cleaned out every time you pulled the bottom-end apart.

I personally saw a warehouse full of old Triumphs and Nortons that were traded in on new Hondas and Kawasakis and the dealers couldn't even give them away and had to scrap those bikes. This was in the early 70's when you could buy a Honda 750-4 that didn't leak, had great electrics, made 70HP, electric start (that worked), disk brakes, handled at least as good as a Triumph, and didn't need to be rebuilt at 25K miles.

I personally like old Brit bikes, but I haven't forgot why the British motorcycle industry is basically no more (except the new Triumph.) I'm not trying to get into a technical discussion of old engines, just trying to use examples.

Yep, Honda has definitely had their share of "bad oilers."

But, my point is that every engine has unique lubrication issues by design and that should always be considered when choosing an oil.

 

[Jimbo]

Originally Posted By: ZGRider

...
1. Is the engine air-cooled or liquid-cooled? (heat breaks down oil.)
2. Does the engine share oil with the transmission? (trans. gears shear oil quickly.)
3. Is it a high RPM engine? (consistently over 10,000 RPM)
4. Does the engine have high-pressure plain bearings or low-pressure roller bearing? (Roller bearings require little lubrication)
5. Does the engine have a history of lubrication issues? (Shovelheads, Ducati Bevel-drives, Honda VFs, Norton Commandos, old Triumph Twins?, etc)
6. Placement of the camshafts (BMW airheads have the cam in the bottom of the sump, submerged in oil vs OHCs far from the sump)
7. Dry-sump VS Wet sump? (Dry-sumps generally have greater oil capacity than wet-sumps because they have external oil tanks with no limiting volumes.)
8. Oil capacity of the engine? (Yamaha YZ & WR 450 engines hold just 1 qt of oil -- won't take long for that to break down)
...


I'm surprised no one added,

9. Wet or dry clutch? (Friction modified oils or moly additives may cause slippage of wet clutches.)

Lets review my 1990 Yamaha 200cc single.

1. Air Cooled - hard on oil
2. Shared engine and trans oil - hard on oil
3. Not high rpm - easy on oil
4. Roller crank - easier to lubricate
5. No history of problems - easy on oil
6. OHC - harder to lubricate
7. Wet sump - hard on oil
8. 1 liter total capacity - hard on oil
9. Wet clutch - specific friction requirement

Yamaha recommends API SF mineral 20W/40 above 40F and 10w30 below 60F, changed every 3000 miles.

All of these should work fine.

15W/40 HDEO, such as Rotella T, $3 q (ChinaMart)
5W/40 Rotella T synthetic, $6 q (ChinaMart)
10W/40 four stroke motorcycle oil, such as Castrol Actevo Xtra 4t semi syn, $5 l (on sale)

I just aquired the bike, old and possibly neglected. So, I am giving it an initial "flush" with 15W/40 HDEO, which will be followed by the Castrol.

 

[boraticus]

Just curious, but when was the last time anyone here ever had a problem with any relatively late model (post 1970's) motorcycle engine due to a lubrication issue?

Engine design (lubrication systems in particular), production quality and modern oil has virtually eliminated engine failure in a well maintained engine. That's why we all have so much time to talk about it because the problem isn't there using up our time.

I've got several (8) motorcycles and tons of small OPE engines. I'm maintenance conscious but certainly not obsessed with it. Everything gets oil changes as required by my assessment of necessity. An engine with fresh oil, stored for a couple years will not be getting oil changes as per manual's instructions. Engines being flogged mercilessly in dirty, dust, hot conditions will get oil changes more frequently than recommended.

I generally use HDEO (Rotella 15W40) in just about everything. Been doing it for years and have not had an oil related problem....ever.

It seems that some tend to obsess over Hollywood oils because they think they are gaining some magical advantage by paying big bucks for it. I truly sympathize with them.

In all of my years of engine ownership I can only recall one case of engine failure that was oil related. I had bought a new 1976 Ford F100 with a 302 V8. When it had around 5000 miles on it, the serviceman at the shop I used recommended that I switch to Amsoil synthetic (they were the local Amsoil dealer). Seemed like a good idea at the time. A few months and a couple thousand miles later, the engine started to rattle. I took it to the same shop for inspection. The serviceman told me that the push rods were mushrooming due to inadequate lubrication. When I asked him how that could happen considering that I was using Amsoil synthetic oil? He replied that cold weather operation was creating too much condensation in the oil and that the oil wasn't very good a dissipating the moisture. Needless to say, that was the end of my association with that shop and that oil. The only thing I use synthetic oil in now is my snow thrower and that's Mobil 1.

So, the bottom line is that very much has changed over the years. Engines are built better, oils are much improved and engines seldom have lubrication issues if properly maintained, regardless of what type of decent quality oil is used.