Alright guys, I have a engine that I finally got running. (1960 cad 390) Here`s the deal, Prior to this ,the eng was sitting in a garage on a stand for 10 years or so. I got it , pulled the heads to see how it looked. Pretty much everything was decent. Motor spun tight but,I figured its fine. I did a quick lap job on the valves (leak tested & no leak)& put new seals on them. re***embled & repainted the eng, dropped it in my car with the idea it would fire up. Well it didn`t! I realized I had very little to no compression. I figured the rings are stuck. I put mystery oil in the cylinders for a while & tried that. The motor almost fired. I figured it needed to spin faster so I put 2 batteries together & ran the car & ignition wires to 12v. It lit up & runs ,smoked like hell! Pretty funny. As it ran -barely, the motor came to life a little. Now I think its running on 5 maybe 6 cylinders ,it runs & a couple cylinders pop out the exhaust here & there. Also doesn`t even really smoke now, no noises in the eng or anything. I got it to idle,ran it 20 mins figuring it will heat up ,cool down & some rings will loosen up. some did but, not all. My question is ,what can I put in the cylinders to try to help these rings free up ? I`ve herd of some things but, not sure what to do . Or, should I keep running it doing heat cycles to hope they eventually free up? thanks in advance.
I would pull the Motor Down. Not worth the Alternative of Destroying the Cylinder Walls. If the Oil rings are stuck also it won't be Running for Long.
You're on the right track. Drain the old oil and add fresh with MMO or a similar detergent additive. Keep running it at operating temperature, or drive it if possible, to get it well circulated through the engine. In addition to the rings it may may also have some sticky lifters. Adding MMO to the cylinders only doesn't really do much for the lifters and other areas of the engine. You might also consider at least dropping the pan for cleaning and to make sure the oil pick up screen isn't plugged.
Thanks! I did have the motor apart (except removing the crank,piston/rings & cam) All is clean & was spotless. For the most part the lifter noise has just about gone away as well. I will try to run it more but , carefully. Like another member had said , I dont want to damage the cylinders. It would be easy to remove & pull apart but then what if?
Try seafoam, mix it in your oil and dump some in the cylinders let it soak in and then run it. You may have to oil the cylinders again to get compression.
Just something else to double check. Are the valves set correctly? Set too tight? I did that with a Chevy once. Valves too tight don't give good compression. Neal
Get the engine started and warmed up fully. Hold the throttle open to about 2000 to 2500 rpms, and slowly dribble water down the venturis from a water bottle until the engine starts to stumble, let it recover. And repeat. This is an old school trick from way back and it does work. It steam cleans the combustion chamber and ring lands.
Are you sure the valve guides aren't rusted and holding the valves open? I'd check valve function before digging into the short block.
If the Caddy has been sitting for 10 years, you are lucky that it turns over. What I have found with these motors is the aluminum pistons corrode & bond to the rings. If that is the case, nothing short of a teardown will save it.
Sorry if I do take this thread a bit off topic, but just a general question; To clean and help the hydraulic lifters, how much (per a gallon) you're advised to add MMO? (I think the lifters of my '60 Chevy 235 tends to stick a bit, like to try MMO...)
I've added a pint of MMO to existing oil in old engines and ran them around town for a few days. It usually worked pretty well. I've seen transmission fluid used too, recently on a friend's 429 Mercury with noisy lifters.
CD2 works better than anything I have ever used. Just bought a 1953 Ford Golden Jubilee tractor, smoked so bad the neighbors thought it was on fire. Sat for over ten years just did the second oil change NO SMOKE!
Looks like typically you add 1 qt. of MMO in place of a qt. of oil for a 5 qt. oil change. As a fuel additive use 4 oz. per 10 gallon of fuel. http://www.marvelmysteryoil.com/index.php/site/mmo/ For a lifter noise I'm ***uming you want to add it to the crankcase. When you specified "per gallon" it sounded like you were planning on adding it to the fuel.
put some Seafoam in the oil and in the gas, hit those rings from both sides, stuff works great, have had good luck with it.
A few long drives might straighten it out. Like a couple of hundred miles at a time. Thin oil, MMM Rislone Bardhal or your favorite mix in the oil. And just drive. The heat and oil will start the rings to free up if anything will.
Marvel's is just the stuff for stuck rings and lifters &c, it's designed for it. Replace both 20% of the crankcase oil with MMO and dose 4oz per 10 gallons in the fuel. It's not guaranteed this is your problem but if you're gonna try it, this is the way to do it. A few heat cycles and some highway driving, if it's going to work it shouldn't take all that long.
Thanks, I was asking for oil, but being European and used to metric system, I'm not fluent with imperial units way of talk. I recall the 235 oil displacement is 5 quarts, thus next time I put in 4 quarts of 10W30 oil and 1 qrt. MMo.
Be aware an American quart is different to an English (Imperial) quart. (US is smaller) A US gallon is less than an English (Imperial) gallon. This can cause confusion with talk of gas tank capacity and m.p.g.!
Yes you are correct. My other 60 eng was stuck & wouldn`t free up. I pulled it apart & the piston corroded over the rings. I`ve never seen it like that before. I couldn`t even remove them from the piston!
I would love to put it on the road but the car is not worthy yet. I have the parts to make it so but, I wanted to be sure the eng is good before I do the brakes & install a complete new exhaust . If the eng won`t free up I `ll rebuild it & that takes time & $$$. Who knows how long it would sit. I have other projects as well.
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