5w30?

ffernald

ffernald

Member
Being part Scot, I'd like to use some 5W30 oil that has been on the shelf for a while in a '36 engine (not a rebuild) that I've never run. Will that be acceptable or should I not be so frugal (notice I didn't say cheap) and spend the big bucks for some fresh 10W30 or 20W50?

Thanks, Fred
 
Define "a while". Motor oil typically has a 5 year shelf. After that, the additive package can start dropping out, and there will be a sticky goo at the bottom of the bottle...which was all of the good stuff.

My personal opinion is that 5w-30 is a little light, but there are as many opinions about that as there are people.

Neal
 
5-20 and 5-30 oils were designed for new very close tolerance engines with roller tapit lifters and cams, they don't have any zink, in the oil, not good for older model engines with flat tappit cams and lifters, that oil will have the red seal on the front of the container saying for gasoline engines, that means it for engines with roller tappits
 
ffernald said:
Being part Scot, I'd like to use some 5W30 oil that has been on the shelf for a while in a '36 engine (not a rebuild) that I've never run. Will that be acceptable or should I not be so frugal (notice I didn't say cheap) and spend the big bucks for some fresh 10W30 or 20W50?

Thanks, Fred
Click to expand...
The 5w/30w will most likely be too "thin" for a 1936 engine. The bearings have much larger clearances than "modern" engines that specify that weight.
I think you may be "penny wise and dollar foolish" in this particular scenario. The damage that may very well occur upon the bearings and adjacent surfaces will be far more costly to repair than simply purchasing heavier weight oil now.
 
The 36 engine has a unique set of bearings and only 37 lb spring pressure on the valves, so I give 5/20 a go. If and I mean a BIG IF it was a fresh engine. Those floating bearings would be the coolest in town. Cam ware is another Myth. How many have ever seen this in a stock engine???
 
Ron, its not so much the cam because its only in contact with the lifters very little as the lobe turns, its the lifters that take a beating and all the wear, the lifter is in constant contact with the cam in the same place as the lobe turns lifting them, a have seen very few cams with lobe wear, but I have a bucket full of lifters that have been worn with cupped bottoms, I don't have then resurfaced any more I just buy new ones
 
I personally feel the quality of the 5/20, 5/30 etc. synthetic oils are far superior to any of the old oils that ruined the old lifters. Unless someone or oil supplier does dome extensive tests on an old/new flathead we'll never know. How ever I will be running 5/20 synthetic oil in my engine
 
537 people have read this post, I wonder if any one of them are using synthetic oil in their Flatherds????
 
If they are, they probably have plenty of cardboard on the floor under the car to collect the leaks. The quality that makes synthetics so great in modern cars lets it leak thru the rope seals. At our shop, we install break in oil on rebuilds to be replaced after at least a couple of hundred miles. It contains lots of ZDDP (zinc) that allows the cam and lifters to settle in. Then, any quality brand name oil is OK. We also use a good assembly lube for the initial start up.
 
The oil back in 1936 had no zinc either. all that came to be post war.
Also people used straight 10W oil in the winter. sometimes cut with some kerosene in very cold weather. After driving for a few miles, the oil still got hot and very thin. The motors lived for years like that.
Don't sweat it. use that oil.
 
they may have lived for yrs because they weren't driven that much, they were done at about 50,000 miles, ask around and see how many guys have had to replace the cam because they ran oil with out zink in it, after the war when the rpm's and horse power were increased in the engines zink became very important, I would never run a 5-20 oil in any of my flat tappet engines, that is for roller tappet cams
 
I run Mobil-1 15/50 in my stock '51 with no problems or leaks. I had a case left over from my hemi-powered dirt modified, so I tried it. I have no complaints.
 
Well I know of several running Synthetic oil with no problems and with 50/55 lbs of spring pressure I think the lifters will live longer than with your zink filled regular oil. I discussed this with an oil distributor, and what your talking about is another Myth put out by people with no practical knowledge. 5-20 synthetic is the new 10-30. Just curious, have you ever got synthetic oil on your hands? You can't get it off.
Thanks Pete, I know there are others.
 
Although I have a V8 & 1/2 (Lincoln V12) I am VERY Happy with Rotella 15W40.
1200 mile trip with NO oil consumption. Hydraulic lifters still sound like a sewing machine
 
yes ive had synthetic on my hands, stp also, but we were talking about using 5-20 oil in the flathead, I said no because that oil was for modern engines with roller tappets, theres nothing wrong with synthetic , but diesel engines run for 500,000 miles on oil designed for them, and they all have zddp in there formulations, and they run a lot more compression, up around 22 to 1, and a lot more valve spring pressures, way more than any gas engine sold by the car makers, zink was designed to do a job and it does it very well, discussing oil is like discussing religion and politics, no one wins, feeling just get hurt
 
You must log in or register to reply here.
Back
Top