Detergent vs. non Detergent oil?

[oldcarlover]

Is there any adverse effects of using a non-detergent motor oil in my 50

ply. The only way I can find a weight lower than 30 is in a detergent based blend. I do not run an oil filter on my flattie, so I do change the oil more

frequently than the service requirements.

[Young Ed]

The danger is supposedly that you will loosen up all the crud thats in the engine. Now if you've been doing frequent oil changes you shouldn't have as much crud. If it was my engine I'd switch to detergent and ramp up the oil change interval for the first few times. And if you do go to detergent don't go back to non detergent.

[Plymouthy Adams]

try your local air compressor sales and service for non detergent oil of various weights..

[michael.warshaw]

my machinist told me to use non detergent oil for the reason that it will nott keep the dirt in suspension, and since a falthead will only filter about 10 percent you want less dirt floating around.

[Young Ed]

Your machinist will be seeing you again for another rebuild if you follow that advice.

[michael.warshaw]

why is he wrong?

[Robert Horne]

why is he wrong?

Would you rather have dirt floating around in your newly rebuilt engine, where you can flush it out very often, or, would you rather have the dirt in your engine stay there in the form of "sludge"?

[55 Fargo]

Your machinist will be seeing you again for another rebuild if you follow that advice.

I agree Ed, freshly rebuilt engine, what hell do you need non-detergent oil for, heck you should be able to use synthetic oil.

Just change the oil and filter often, and this engine will go a long time.

Not sure why that machinict would give that draconian advice, especially on a rebuilt engine....

[Young Ed]

why is he wrong?

First of all he's off on his oil filter theory. Its true that not 100% of the oil is filtered 100% of the time. But just saying only 10% is filtered is wrong. It all gets filtered eventually. And as Robert said you want the dirt to stay in suspension so when you drain the oil the dirt comes with it. My machinist has us using non detergent straight 30 for the first 250 miles. Then changing to detergent.

[Robert Horne]

The danger is supposedly that you will loosen up all the crud thats in the engine. Now if you've been doing frequent oil changes you shouldn't have as much crud. If it was my engine I'd switch to detergent and ramp up the oil change interval for the first few times. And if you do go to detergent don't go back to non detergent.

I bought an old $500 beater Chevy for the winter, with alot of miles on it. Just before winter I changed the oil with a name brand 10 W 30. Soon after I started the engine, alot of smoke came out the tailpipe like I had broke many of the rings. I had to drain the new oil, and replace it with 30W. Car was ok all winter. The 10 W had broke loose the sludge.

[Don Coatney]

why is he wrong?

He is not wrong if he is the one covering the warranty. If you do not do exactly what he says any warranty will be voided.

[Plymouthy Adams]

there are those out there that still like to break an engine in with non detergent oil especially if the top ring is chrome..allows for a quicker seating..some parts even call for non detergent if used in an overhaul and specified on the assembly/warrant of the part (pistons)...it is an arguement that will be argued/defended by many....IF the builder of your engine recommend it and stands behind his work and should you go with HD and wipe a component..could be he may refuse to honor the work...best fight this battle with your builder..

[moose]

I'm going to have to go partially on the side of the machinist. A freshly rebuilt engine does not have all the dirt, carbon or sludge in it, but there are plenty of places in a new engine for that stuff to come from. When the cylinders and the rings wear in, they produce a fair amount of "dust" that goes right in the oil. and the initial blow-by before the rings seat adds carbon. Every thing else that has to take time to wear-in, like the cam and tappets, timing chain... Even the bearing journals will add to the oil sediment. All this sediment (in a non-detergent oil and a partial filtration system) sinks to the bottom of the oil and is drained out when the oil is changed hot. A detergent oil keeps the "dirt" in suspension so that it can be pulled out when it goes through a full filtration system. This is what I've been told by aviation maintenance instructors. In aviation, fresh rebuilds are always instructed to run ND oil for a certain set of hours.

That being said, in my broken-in partial filtered engine, I run 15W40 year round, and will continue to do so. As long as the engine is tuned and the electrical is good, you should have no problems starting.

[Young Ed]

I didn't read it as just for breakin. I read it as forever. I do agree on using non detergent for break in. I did that in both my flatheads too.

[moose]

I agree. Break-in only, now. When did they come out with multi-viscosity detergent oils? From new these cars were run with ND, right?

[old stovebolt]

when it is all said and done.....the most important thing is changing the oil

(and filter) on a regular basis. That is the key to an engine's long life.

[suntennis]

At one time you could buy oil base product that was made just for cleaning the inside of engines.Using this may cause some exhaust smoke while in use along with removing some of the sludge within the engine. I have used such a cleaner with no known damaging results. You would think if there was a high risk of damage to engines such a product would not be sold. The point being that the cleaning effect of a detergent oil is going to be far less than an engine cleaner. Engine cleaners are used for a very short time as compared to regular oil which is used for hours.

[greg g]

Just wondering if he didn't do a good job of cleaning out your engine. Where do you suppose the dirt would come from in what is basically a new engine. Will you be running down a lot of dirt roads withthe air filter and oil fill breather off? Or are you going to put it in a cup at a time from the side of the road??

Most of the dirt is Carbon created as a left over of incomplete ignition, and cooking it out of oil due to high temps. Sludge in older engines was a result of the non detergent oil picking it up and then releasing it into the bottom of the oil pan where it was supposed to remain when the engine was shut off, ad where it should have come out witht he old oil durig an oil change.

The job of detergent oil is to suspend these particles and carry them to the filter where the filter can remove them rather than having them build up in the oil pan or other creveses inside the engine.

We have already had a discussion two regading the effectivness of the bypass filter system. It has been established that 30 % of the oil flow is directed to and through the filter as the engine runs, so if 30 % of the 5 quarts passes through the filter every minute the engine runs, how many minutes would it take to pass all of the volume of the oil through???

On the other hand maybe new metal absorbs non detergent oil more readily than detergent type.....

My machinest recommended detergent 30w for the first 300 to 500 miles, changing oil and filter then and using 10W40 from then on. 15000 to 20000 miles have suggested he might have been correct. He also told me to drive it like I stole it as a break in.

By the way what kid of warrenty is he going to issue??? Perhaps the phrase "Did you get it in writing?" might have some meaning here.

[norrism1]

At one time you could buy oil base product that was made just for cleaning the inside of engines.Using this may cause some exhaust smoke while in use along with removing some of the sludge within the engine. I have used such a cleaner with no known damaging results. You would think if there was a high risk of damage to engines such a product would not be sold. The point being that the cleaning effect of a detergent oil is going to be far less than an engine cleaner. Engine cleaners are used for a very short time as compared to regular oil which is used for hours.

Suntennis, Back the 60's, dad would use 4 quarts kerosene with one quart oil and new filter. Run for 5 minutes then drain and change filter. Always cleaned insides with no problems. Ran smoother and no knocking afterwards. Really helped a congested engine that was running bad.

[james49ply]

My 2 cents:) I have had many cars in my 60+years and I have found that running a new / rebuilt engine with 30wt for breakin, then switch to 10/40 has always worked for me. I now have been using Amsoil Synthetic for over 20 years, and have had wonderful results. My 48 stock motor runs 10/40 and runs very good. I had to run regular hd to clean the insides, changed after it showed color change, did this several times, then switched to synthetic. My habits with vehicles has been 150.000 miles minimum before getting new ones due to rustbelt corrosion, never lost an engine, and when I got rid of car next owner had a very good motor. I had a 1978 cj5 jeep that with 240,000:D on the engine still did not loose any oil between changes, did not smoke, and still retained the OEM specs for engine compression, same with my Harley that has 165,000:cool: on it, these were run on synthetic oils, changed regularly every 3,000 miles.

[JBNeal]

One of the tips I was told from several older machinists was to do the speed variation break-in for the first 500 miles; if done in a hilly area, it yields the best results. The theory was that the combustion chamber temperature would vary more significantly than it would if the first 500 miles are driven slow & steady. This would have the effect of tempering the piston rings, effectively extending their service life and producing a stronger motor because of reduced blow-by. After the 1st 500, that's the ideal time to switch to synthetic blends if desired.

[austinsailor]

Actually, it has to do with seating the rings. Ideally, you should go from about as slow as you can in high, then accelerate up to speed, slow down again, then do it over, and continue for about 500 miles. Of course, that isn't practical, so the varying speed is what's called for. What they don't mention is the speeding up should be pretty hard on the throttle. The idea is to push the rings against the wall and seat them well.

Every new vehicle I've had I've always tried as often as I can to accelerate as often as I can, trying hard to put a load on the motor. I've never had one be an oil burner or have problems.

I don't think it's such a big deal on new cars the way they build them now, but when we do our overhauls it is.

Also, I've heard from several sources that using synthetic during breakin is not good, it won't let rings seat, it's too slippery. This obviously doesn't apply to all new cars, as some now come from the factory with synthetic.

[michael.warshaw]

im goig to listen to the builder that way if i have a problem, i was doing what i was told to do.