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Today's Motor Oil And Flat Tappet Cams
- Thread starter racecar builder
- Start date
- Joined
- Jan 2, 2019
- Messages
- 6,526
If I designed, engineered, re-engineered or modified the engine I will specify the oil to use. If not then the manufacturer normally recommends what spec oil to use based on what their engineers think is best. In either case these recommendations normally come from both design requirements and testing.
There is a great deal of discussion about oil on the racing go-kart forums I used to participate in and often my customers would tell me what they thought about the subject. To that I would reply that my recommendations came from experience but they were welcome to do whatever they wanted since our race engines carried no warranty.
The simple answer is that your engine needs oil and it needs the proper amount to keep it happy, if you feel you know better than the manufacturer or builder go right ahead and use what you like.
Cheers,
John
There is a great deal of discussion about oil on the racing go-kart forums I used to participate in and often my customers would tell me what they thought about the subject. To that I would reply that my recommendations came from experience but they were welcome to do whatever they wanted since our race engines carried no warranty.
The simple answer is that your engine needs oil and it needs the proper amount to keep it happy, if you feel you know better than the manufacturer or builder go right ahead and use what you like.
Cheers,
John
,with todays cars there are so many factors that take precedence to engine longevity......manufacturers have to meet fuel economy and emission targets,which is far more important to them than how long you car lasts,and then the oil has to be suitable for a number of add-ons,that may cost more to replace than a motor rebuild.
- Joined
- Jan 2, 2019
- Messages
- 6,526
When I was a kid people who had 100,000 miles on a car were few and far between. Today with normal maintenance two or three hundred thousand is pretty common. I’d say that’s a testament to both the manufacturers and oil suppliers.
Say what you will but longevity wasn’t one of the virtues of cars in “the good old days”
Cheers,
John
Say what you will but longevity wasn’t one of the virtues of cars in “the good old days”
Cheers,
John
Yes a very interesting thread.
My thoughts were on the same as ^^^^
When I was a kid to a young man if your vehicle had 70-80k you better get ready to work on it.
My folks had a 69 Pontiac Tempest. It got regular service at the Standard station with Mobile oil. It made it to around 150k before the sold it.
Today’s motors are just getting broken in at 150.
So the way I see it, either motors are better or lube is better, maybe both.
My thoughts were on the same as ^^^^
When I was a kid to a young man if your vehicle had 70-80k you better get ready to work on it.
My folks had a 69 Pontiac Tempest. It got regular service at the Standard station with Mobile oil. It made it to around 150k before the sold it.
Today’s motors are just getting broken in at 150.
So the way I see it, either motors are better or lube is better, maybe both.
- Joined
- Feb 9, 2017
- Messages
- 5,249
Very interesting thread. Being originally a air cooled VW driver and mech the first 5yrs I was working garages I did nothing but rebuild one engine after another. Usually 2-3 a week. My drivers I never had to rebuild and was always turning cars as I found better and better ones for super cheap.
My last was a '66 bug that my dad bought from a ranger in Yosemite. She was original owner and it had 110,000mi with original engine and was very tired. I had gone back to college and was in the auto dept and was able to for the first time blueprint an engine. I was transferring to another college for a two yr program and was going to be commuting constantly.
4yrs later I had put 125,000mi on the engine and even though it ran perfect and used no oil I couldn't believe it was ok. So I tore it down. It was standard practice that you would have to toss the cam and lifters, the exhaust valves and the exhaust guides would be shot. I was anxious to see how one of my engines would fare firsthand as they had always just driven off never to be seen or heard of again. For the first time ever the cam and lifters looked new except with a polished look where the cam rode on the lifter. They still had the original dome to them and there was no wear on the cam either. Both had the original grind marks showing. Luckily I marked where they came out of and put them back in the same place along with the cam. Tossed the exhaust valves but the exhaust guides had no wear. I had never seen this. Same for cylinders. So for the first time I basically did a ring and bearing along with seals and exhaust valves. Early on an old German who worked at the dealership who my dad was friends with told him to run nothing but Castrol so I always ran 20-50GTX and during our brutal summers that are often over 100deg from May to Oct straight Castrol 50w.
This thread has me rethinking going to Mobil1 in everything.
My last was a '66 bug that my dad bought from a ranger in Yosemite. She was original owner and it had 110,000mi with original engine and was very tired. I had gone back to college and was in the auto dept and was able to for the first time blueprint an engine. I was transferring to another college for a two yr program and was going to be commuting constantly.
4yrs later I had put 125,000mi on the engine and even though it ran perfect and used no oil I couldn't believe it was ok. So I tore it down. It was standard practice that you would have to toss the cam and lifters, the exhaust valves and the exhaust guides would be shot. I was anxious to see how one of my engines would fare firsthand as they had always just driven off never to be seen or heard of again. For the first time ever the cam and lifters looked new except with a polished look where the cam rode on the lifter. They still had the original dome to them and there was no wear on the cam either. Both had the original grind marks showing. Luckily I marked where they came out of and put them back in the same place along with the cam. Tossed the exhaust valves but the exhaust guides had no wear. I had never seen this. Same for cylinders. So for the first time I basically did a ring and bearing along with seals and exhaust valves. Early on an old German who worked at the dealership who my dad was friends with told him to run nothing but Castrol so I always ran 20-50GTX and during our brutal summers that are often over 100deg from May to Oct straight Castrol 50w.
This thread has me rethinking going to Mobil1 in everything.
- Joined
- Sep 2, 2013
- Messages
- 5,100
I would have to disagree with you on the need for thinner oil in newer engines. The Ford Coyote 5.0, among most other modern engines I can think of run considerably tighter tolerances than anything from 70's or 80's. Using the Coyote as an example. main bearing clearance is .001-.002. Running high viscocity (10-40 or heavier) oil in an engine like that just robs power, and could do serious damage. The manufacturer recommendations are there for good reasons. Mike
Someone mentioned the misuse of the term "clearance" and "tolerance" above.
Take note: they are VERY different animals.
Clearances are the gaps for the oil molecules to move in to prevent metal to metal contact.
Tolerance is the precision with which that clearance is produced and maintained.
In the 70s, those tolerances were such that most of the bearing width, for example, had the design clearances. The rest of the bearing width was either too tight (and would wear in) and too loose and servers no function in terms of bearing action.
Today, the clearances are maintained within millionth of inches across the entire bearing widths. No wearing in and full function of ALL of the bearing surfaces. In addition, the accuracy of surface roughness has improved out of sight.
That goes for pistons, bushes, mating surfaces etc. As a result, there is as good as no running in (wearing in) any more and engines last for 3 or 4 times as long as earlier ones with identical design clearances.
Oil development has kept pace with much less variation of molecule size and shape, reducing accidental metal metal contact for longer and longer periods.
Sent from my GOME 2017M27A using Tapatalk
Take note: they are VERY different animals.
Clearances are the gaps for the oil molecules to move in to prevent metal to metal contact.
Tolerance is the precision with which that clearance is produced and maintained.
In the 70s, those tolerances were such that most of the bearing width, for example, had the design clearances. The rest of the bearing width was either too tight (and would wear in) and too loose and servers no function in terms of bearing action.
Today, the clearances are maintained within millionth of inches across the entire bearing widths. No wearing in and full function of ALL of the bearing surfaces. In addition, the accuracy of surface roughness has improved out of sight.
That goes for pistons, bushes, mating surfaces etc. As a result, there is as good as no running in (wearing in) any more and engines last for 3 or 4 times as long as earlier ones with identical design clearances.
Oil development has kept pace with much less variation of molecule size and shape, reducing accidental metal metal contact for longer and longer periods.
Sent from my GOME 2017M27A using Tapatalk
I believe that engine and oil technology has progressed to beyond what most consumers are aware of. To me it is amazing that the engine in my motorcycle is redlined at 15000 rpm and that the same oil lubes the gearbox. I follow manufacturer's oil recommendations that provide specs. I ignore the brand hype.
Outside temperatures around here can get very cold. For a daily driver thinner oils are a must or a cold engine will not start. I have gone as low as 0w20 with plenty of oil pressure at operating temperature. With extended oil change intervals I would stick with the thinnest oil specified.
Oil for competition engines that run to the limits of everything is a different requirement than oil for a daily driver.
Outside temperatures around here can get very cold. For a daily driver thinner oils are a must or a cold engine will not start. I have gone as low as 0w20 with plenty of oil pressure at operating temperature. With extended oil change intervals I would stick with the thinnest oil specified.
Oil for competition engines that run to the limits of everything is a different requirement than oil for a daily driver.