first thanks to all veterans.has anyone flushed an old engine out and changed to regular oil.
I assume you mean started using detergent as opposed to non-detergent oil. I have done that several times in various cars. I usually drain the oil in the pan then fill it with a mixture of 1/2 oil and 1/2 kerosene and run the motor for about ten minutes at idle so it reaches normal operating temperature but being sure to keep it from overheating. I then drain the mixture out and repeat the process 2 more times. Finally, I go with straight oil and after about an hour of running time I change the oil again and am good to go. A lot depends on how much crud has built up over the years but I have never had any trouble doing this. One thing that I would suggest is to run an outside oiler. I always run an outside oiler on all of my cars so I can make sure oil is getting to the front of the engine. When you stir up all that crud there is always a chance of clogging the oil tube. I am sure others have different method they use but this one works for me!
You can also add a gallon or so of diesel fuel after running the 50/50 kero and just hand crank it through a few times over a couple of hours time. Diesel fuel really cuts the sludge but it is not safe to run the engine faster than an idle more than a minute and with no more than a quart of diesel to 3 of oil.
ATF also is a sludge cutter. It works good on carbon too. A qt. of mineral spirits or MEK and a qt. of ATF with 2 qts. of oil works good but it is slow. You can run the engine at a slow speed for a while, let it sit and then run it some more.
I have also used Marvel Mystery oil with the same results.
Scott,
Remove the crankcase and transmission inspection covers. If what's inside doesn't look generally caked in sludge then put the covers back on and simply switch to detergent oil. If it's a mess I suppose you could try the kerosene thing. Personally however, if I were going to do that, I would only use 1 qt. of kero and 3 qts. of oil. Kerosene is a terrible lubricant.
my engine looks pretty clean inside it may have had detergent already in it.i drove it around the block twice then added a can of engine flush,up n down street once and drained immediately.bought one of those filter kits for tranny cover.