Non-detergent oil in old engines???

[Boondox]

First time I've ever heard this, but one of my buddies who works on old cars for a living swears that one should not use detergent motor oil in an engine that did not use it when new...like in the 315 Poly V8 in my '57 Dodge truck. He said it attacks the seals and gaskets in those old timers. [img]/forums/images/icons/confused.gif[/img] [img]/forums/images/icons/confused.gif[/img]

Is there any truth to this..? I was counting on modern detergent motor oils and frequent changes to get out the sludge I could not reach without tearing the engine down.

Pete

[chrisjbell]

I have heard that, too, but I'm not sure if I believe it.

<font color="blue"> He said it attacks the seals and gaskets in those old timers </font color>

That might be true for an engine that has never been rebuilt. But any motor that is 40+ years old has to have had a rebuild (or else it is a Miracle Motor and should be preserved in some kind of museum [img]/forums/images/icons/wink.gif[/img]). Presumably, the seals and gaskets would be made of up to date materials instead of the stick and bark that was used back in the day [img]/forums/images/icons/smirk.gif[/img]. And I think I read in one of your posts that you've recently rebuilt it.

So if it does have modern gaskets, etc. then I can't see why a detergent oil will hurt it. And let's face it - if the gunk and sludge is what is holding your engine together you probably need to think "rebuild" anyway. If cleaning the thing up kills it then you had a bigger problem on your hands already.

[Inspector507]

All I know is.......don't switch back and forth. You'll be rebuilding it just like I did. Used some non-detergent when I was young and dumb. Then went back to detergent with an oil change. It went ka-boom the next day when all the sludge got loosened up and went all over the place.

[s1120]

IMHO there is realy not a need anymore for non-detergent oil. If your motor is SO sludged up from using non-detergent, or not changing the oil, it should be cleaned out. No mater what oil you have in it, and sludged up motor does not have the oil control that it should. If the motor is an overhead valve moter, oil can pool up in the head, and leak past the valve guides, and in a worst case leave the crankcase low of oil.[mustly a high RPM auto problem] My feelings, and what I would do with a tractor I had, is if I did not know what was in it, change it, and in a short run time[a few hours or so] then dump it, and replace the oil, and filter. If it gets real dirty fast, change it agean. Just keep a good eye on it for the first 25-50 hours or so. Once you get good oil in there, just keep it changed, and your motor will thank you. Plus, if it is almost time for a rebuild, it will be a lot cleaner inside there. [img]/forums/images/icons/smile.gif[/img] [img]/forums/images/icons/grin.gif[/img]

[egon]

Pete:

Sure wish I could alliviate your dilema but about all I can think of is contacting the marketing department of the major oil companies. Someone on the staff should have an answere.

Another source would be an antique car club.

Just for thought how about all the old tractors like the Ford 8N. They are the right age. Wonder what type of oil the owners use.

Egon

[RichZ]

Pete, I use non-detergent oil in my vintage tractors (built in 1951 and 1967), but the reason I was told to use it is that if the rings are worn, and the sludge is filling up the spaces, detergent oil will clean them out, and I might need a ring job.

I never heard anything about detergent oil attacking old seals and gaskets.

[Boondox]

Well, I removed all the sludge from the oil pan and under the valve covers while I had them off. What's left I figured could be handled by three oil and filter changes at 250 mile increments before reverting to the recommended 1500 mile intervals. For the first fill I might do the old quart of ATF in the oil trick to loosen things up.

The engine really looks odd at this point. As I remove parts they are cleaned, bead blasted, and repainted. So I have several very good looking parts on an old hulk of an engine! Sure am looking forward to starting the beast! [img]/forums/images/icons/grin.gif[/img]

Pete

[s1120]

<font color="red"> For the first fill I might do the old quart of ATF in the oil trick to loosen things up.
</font color>

Just be carful Pete, You don't want things to clean out TOO fast. Good thinking with the 250 mile changes though. Now after a few of them, and the oils stying kinda clean, then try a little atf. Just don't leave it in for too long.

[rbhollabaugh]

In engines that have never seen detergent oil - you will see a "varnish" build up in certain areas of the engine. This can be beneficial in that these deposits may be in places where metal has worn away. If you now put detergent oil in the engine these "varnish" spots will disapear leaving a wider clearance. If the engine has alot of wear this could be the straw that breaks the camel's back.
I've seen it happen more than once.
Can't comment on the comaptibility of detergent oil and rubber seals as I've never seen a problem.

[Bayrat]

I have heard of this happening in car engines. I had it happen to an old lawn tractor and mower. My dad left them with me when he got new ones, they were very old and had used only non-detergent. I changed them both over to detergent because that was all I had at home at the time, wrong thing to do. They turned into mosquito foggers [img]/forums/images/icons/grin.gif[/img]. I discovered at the time that you can buy non-detergent oil from Agway, they call it utility oil and it is sold by the pail.