Author Topic: Another oil question (Read 3928 times)

Tetge · « **on:** June 08, 2005, 06:22:17 PM »

I went all over town today and I could not find 10-40 Mobil 1 gold cap anywhere. Pep Boys did not stock it. Wal*Mart did not stock it. And the same for Auto Zone. Pep Boys had some 15-50 gold cap (at $5.99 a qt) and I picked that up since I can always use it in my Guzzi. Wal*Mart had 10-30 gold cap in the 5 qt bottle for $24.95 but, I live in the desert and I am already running the bike hard, so I was afraid to go down on the oil weight. I am assuming that 15-50 will be perfectly safe in the bike? Any thoughts about 10-30? Anyone know if any of the major auto parts houses in California stock the 10-40 gold cap?
I have 430 hard miles on the Bandit already and it needs an oil change soon.

Red01 · « **Reply #1 on:** June 08, 2005, 09:03:10 PM »

I know some desert/hot weather folks have used 15 & 20W50 oils with no ill effects.

Some drag racers (IIRC, Fast Larry) use 5 & 10W30 - but they're doing that to help the engine spin up as quickly as possible with long term reliability less of a concern.

Tetge · « **Reply #2 on:** June 09, 2005, 04:15:06 AM »

Thanks. I'll go with the 15-50 gold cap since it is readily available. I am a drag racer and I raced tonight at LACR. The track altitude is 2710' and the DA was 4370'. I ran 11.696 @ 116.470 off a 1.944 60' tonight, which was my best ET ever at LACR with any vehicle. My result converted to 11.05 @ 122.89 at sea level according to the conversions for DA. But I am still struggling with the launch which is very tricky for a person not accustomed to the power of the Bandit. Overall, the Bandit with only a Holeshot slip on added and only 450 miles on the ODO is impressive. I like it a lot, but, I have been riding my 1987 MotoGuzzi Lemans SE since I got it new in 1987 (I still have it) so the Bandit is a super fine modern super bike by my standards.

Quote from: "Red01"

I know some desert/hot weather folks have used 15 & 20W50 oils with no ill effects.

Some drag racers (IIRC, Fast Larry) use 5 & 10W30 - but they're doing that to help the engine spin up as quickly as possible with long term reliability less of a concern.

RUSS M8 · « **Reply #3 on:** June 11, 2005, 05:24:11 AM »

I'm running Motul 5100 semi-synthetic in my B12, it's 10W40 but I'm about to try some 5100 15W50 (because I can get some cheap oil) I think it will go well, will let you know!

Bazza · « **Reply #4 on:** July 18, 2005, 04:29:13 AM »

Tips from my Petroleum Engineer friend regarding B-12's

50 weight oil should not be used. He says that most manufacturers make recomendations per oil weight based on pump volume and oil line size.

50 weight is suitable for big lugging V-twins which have massive oil supply lines and high volume pumps. They do not require as much volume of oil to be distributed due to the lower rpm's and larger top end supply lines.

B-12's require high volume flow of oil due to the higher RPM's compared to lets say a lugging Harley. (Thus 40w & not 50w) You may not get a satisfactory supply of oil to the top end in really extreem conditions with 50w.

Now to the 30 weight question.

Manufacturers also base oil recomendations on bearing tolerances. The larger the space between surfaces, the thicker the oil is usually the case. The air cooled B-12 has rather large bearing tolerances than a water cooled bike. This is necessary as an air cooled engine works in much more extream tempreture ranges than a water cooled bike. (The moving parts expand & contract a lot more than a water cooled bike, that is kept at more constant running temps.)

Running 30w oil in a B-12 may cause long term wear as it may not provide a good enough lubricating barrier between surfaces at high tempratures. It will provide good flow through the engine though.

Racers will go with the lighter oil as it will not rob as much energy as 40w when sloshing around in the crankcase. Thinner oil does save energy.

Keep in mind that most racers do not expect an engine to last a long time either.

ray nielsen · « **Reply #5 on:** July 19, 2005, 12:03:40 AM »

You might consider Mobil 1 Truck & SUV oil in a 5W-40 weight. It carries the highest diesel (CI-4) and gasoline (SL) ratings and has a high Total Base Number (TBN) that indicates it will protect against acidity for a long time betwen oil changes.

Many others on this list have had good luck with Shell Rotella T synthetic in the same 5W-40 weight, but it might not be as available as the Mobil 1 Stuff. Our local auto parts stores and Wal-Mart carry it for about $5.50 or so a quart.

Red01 · « **Reply #6 on:** July 19, 2005, 11:00:03 PM »

Quote from: "Bazza"

Tips from my Petroleum Engineer friend regarding B-12's

50 weight oil should not be used. He says that most manufacturers make recomendations per oil weight based on pump volume and oil line size.

50 weight is suitable for big lugging V-twins which have massive oil supply lines and high volume pumps. They do not require as much volume of oil to be distributed due to the lower rpm's and larger top end supply lines.

B-12's require high volume flow of oil due to the higher RPM's compared to lets say a lugging Harley. (Thus 40w & not 50w) You may not get a satisfactory supply of oil to the top end in really extreem conditions with 50w.

Now to the 30 weight question.

Manufacturers also base oil recomendations on bearing tolerances. The larger the space between surfaces, the thicker the oil is usually the case. The air cooled B-12 has rather large bearing tolerances than a water cooled bike. This is necessary as an air cooled engine works in much more extream tempreture ranges than a water cooled bike. (The moving parts expand & contract a lot more than a water cooled bike, that is kept at more constant running temps.)

Running 30w oil in a B-12 may cause long term wear as it may not provide a good enough lubricating barrier between surfaces at high tempratures. It will provide good flow through the engine though.

Racers will go with the lighter oil as it will not rob as much energy as 40w when sloshing around in the crankcase. Thinner oil does save energy.

Keep in mind that most racers do not expect an engine to last a long time either.

Some valid points - but according to the owners manual, 50w can be used in higher temp service... likewise, 30w can be used in cooler temp service. The bigger problem with running 30w oils is finding one without the friction modifiers (ie; non EC rated) that can make the wet clutch slip.