Detergent oil?

This is why you are never recommended to "clean" an engine that has been run on non-detergent oil by running detergent oil in it. If you want to change to a detergent oil I'd recommend that you do so after you have just rebuilt the engine. If you are already planning to do the rebuild, running detergent oil is a good way to cut down on your cleanup time.

Good luck.

Mike

A non-detergent oil doesn't carry the contaminate in suspension the same way.

There is some discussion about that if an old ( read: dirty )engine has never seen detergent oil, that sudden introduction may cause alot of the 'dirt' to 'fall out' at once, doing who knows what to the engine.

Every few months there is a big discussion on this.

I wonder if anyone has ever thought about gradually introducing detergent oil into a non-detergent system, say one quart det, with the ballance non det.. and then each oil change upping that ratio untill you have switched over to completely det oil.

I wonder if anyone has had any experiencewith this specifically?

Soundguy

My 1969 BMW 2002 has 385K miles and you can almost use the valve cover as a dinner plate. Valvoline 10-40wt detergent oil. I also use same oil in my '52 8N and I don't know how many hours it had on it when I got it.

I highly recommend modern detergent oil in your old N-Engine. If your concerned about washing something off, guess what, its doing its job. Change it in 10 hrs for 3 changes and you're going to get all the loose stuff. Then use a thermostat to get and keep the oil hot enuff to suspend all the particials and soot and change it hot every fall..... ..... ...Dell