I have my 1939 Engine about back together, all new pistons, valves, brgs, ground crank .010, cylinders standard, T-chain and gears, etc. My questions is... Now days, does a person "break in" the engine with non-detergent oil? as was recommended years back when I was but a youngster. Thanks for the help,
SD Glenn
This is a good question and will be watching for the responses on this. My understanding of detergent oil is that its properties keep the, well, lets just say "unwanted" stuff suspended in the oil so the filter is much more efficient. The sludge that was in the oil pan, valve covers and various "pockets" inside an engine is much less prevalent with detergent oil, which essentially alows the oil to better do its job lubricating cleanly.
Not sure what the "break-in" oil marketers are focusing on but I would think vescosity recomendations (from origonal mfr. of the engine) would be most important to insure maximum oil pressure and circulation right from the first time you crank it up.
Good point about the zinc and the other post.
Zinc additive may still be available from ZDDplus in Colorado.
I would imagine that there are probably minimal if any environmental impacts by adding a couple of teaspoons to the oil
though ZDD recommends one few ounce bottle to 4 to 5 qts. of oil.
Thanks for the response guys, all good info. I used Moly myself (a lot of years ago), good stuff. Nowdays (this is the first engine I have built in at least 20 years) I use STP for assembly. I did have my engine assembled, then stripped it down again. lol The crank was ground .010 under, only they did not get it the complete .010, it was so tight I didn't dare start it, so I took the crank back to the machine shop today and got it back in the engine a few minutes ago, now I can turn it over. lol I sure am getting used to going thru these engines. I only problem I seem to have is getting the flywheel on, sure had a time of it the first time. I never had one that you had to leave the bell housing loose to get the flywheel in. OR am I doing something wrong? Let me know if there is an easier way, I will put that back on tommorrow. I wasn't aware of the Zinc requirement. Is that in Non-detergent oil? OR does it make a diffence?
Thanks,
SD Glenn
Quote from: SD Glenn on July 23, 2012, 11:10:14 PM
Thanks for the response guys, all good info. I used Moly myself (a lot of years ago), good stuff. Nowdays (this is the first engine I have built in at least 20 years) I use STP for assembly. I did have my engine assembled, then stripped it down again. lol The crank was ground .010 under, only they did not get it the complete .010, it was so tight I didn't dare start it, so I took the crank back to the machine shop today and got it back in the engine a few minutes ago, now I can turn it over. lol I sure am getting used to going thru these engines. I only problem I seem to have is getting the flywheel on, sure had a time of it the first time. I never had one that you had to leave the bell housing loose to get the flywheel in. OR am I doing something wrong? Let me know if there is an easier way, I will put that back on tommorrow. I wasn't aware of the Zinc requirement. Is that in Non-detergent oil? OR does it make a diffence?
Thanks,
SD Glenn
For what its worth, I've had the flywheel off the engine of my '33 without removing the bell housing or engine from the car. Other than being a PITA to remove and re-install while laying on your back in the remains of the oil leak you're trying to fix, I don't recall any particular issues. But they could well have changed flywheels and/or bell housings over the years.
Modern oil has more zinc in it than there was in oil for the first 20 years of the life of my Plymouth so I don't see the need to add more to it now. The relatively low pressures on the cam on our L-6 engines compared to a 50s or later push rod OHV V8 engine (what the ZDDP was increased for) mean it is not necessary. Plus there are other anti-scuff and wear additives being used now.
You're better off using detergent oil especially after the engine's been rebuilt. These old engines operate at a lower average temperature and the detergent and additive packages found in today's oil really helps keep the oil useful for a longer period of time.
Issues from cam wear are apparent in engines with flat tappets using high valve spring pressure and aggressive valve opening and closing rates but our engines have much milder valve acceleration rates. If you are worried about possible cam wear due to reduced ZDDP you can supplement your engine oil with products such as Lucas break in lube or use an older or diesel oil which does not have the API sunburst logo.
Diesel oils also typically have a very high detergent level and additives designed to work well with lower average engine temperature. They are generally available in single weight versions. I use 30 wt high detergent diesel oil in both the Plymouth and my '57 Chevy truck. The '57 has used detergent oil since I built the engine in '92. The Plymouth engine has to come apart but after it's reassembled it will also be refilled with detergent oil for break in.
hth
My engine is running beautifully. I love it. Drove it the first time today, about a mile or so. I plan on taking a trip to Rapid City and Sturgis for the Motorcycle Rally the end of the week, spend maybe a week or so. Should be a nice trip to break this engine in with. I will remove the breakin oil at Rapid City and go with 10W30 from then on. I look forward to checking out the "Swamp Cooler", from Pierre on to Rapid it is like a desert. Should have about 1000 miles on before I get home. I also have "AAA" for emergencys. lol Thanks for all the help guys. One more Question: Should the 1939 model have a pressurized cooling system???? The cap that is on it now is not pressurized.
Thanks,
SD Glenn
Quote from: SD Glenn on August 07, 2012, 01:19:54 AMOne more Question: Should the 1939 model have a pressurized cooling system???? The cap that is on it now is not pressurized.
Thanks,
SD Glenn
No. It was '49 or maybe even the early 50's before pressurized cooling systems came in on Plymouth.
Thanks Tod, I appreciate the help. I may not take the Plymouth to Rapid City, That is kinda a long slow ride going accross SD, west river. There isn't much for towns OR farms out there. lol I did put on about 40 miles today and enjoyed the ride, but I don't think 12 hours getting to Rapid would be much fun. lol I will wait till it is broken in, then look out.
Thanks everyone.
SD Glenn
I have been using detergent oil in my Plymouth for years. Since living in Florida I only use 30W oil because of the heat. I also add a bottle of STP. There are times the car sits for awhile and STP is supposed to give it that extra protection. I also make it a point to change the oil every year. Even if it has less than a thousand miles on it.