let's have a discussion on the best oil for a flathead oil to use. The brand, weight, and type.Spring is here and need to change mine. I have used pennzoil 20-50 for many years,what do you think?
There's an oil thread every week. I use dead dinosaurs, but if you must find a special oil for a flatty the recommended is a non detergent oil. Not as hard to find as one may think that is what they sell for lawn mowers.
I used Wolf's Head 30W non-detergent. The one time I tried synthetic it blew it out through the exhaust. But on my old Ford 9N tractor...15W40 diesel oil.
if you have a clean, rebuilt motor, why would you want to dirty it up with non detergent? if a tired old motor with crud from 1960 still in the pan, run non detergent
So I'm not flathead specialist, have never owned one, but let's just put basic lubrication practice into use here. The prescribed oil for these engines when new was a pretty much non-additized straight viscosity grade oil; depending on temperature Ford recommended 10W, 20W , and 30. Depending on where they lived people probably used 10W or 20W in the winter (the W stands for winter) and 30 in the summer. These engines originally had no filtration, or just by-pass filtration, and no pcv. The oil had to be changed frequently, at least twice a year if driven modestly, but far more often if driven a lot of miles, or extreme duty (heavy loads, stop & go, dirt roads, etc). And they'd get what, about 50K miles engine life, maybe? So fast forward several decades to today, modern oils are light years advanced compared to what was available from 1932 to 1953. The clearances still dictate similar viscosity rates, but multi-viscosity oils make that easier on us, we can use 1 grade all year, we don't need winter & summer grades. And modern oils are loaded with additives that were't available back in the day. You could purchase just about any brand of 10W30 motor oil today and it will far surpass any oil available back when that flathead was new, and that viscosity grade will work in any climate. Although if I lived in the southwest area of the US, and I had a flathead engine, I'd probably go with a 10W40 (or 15W40) viscosity grade, just to have a little extra film strength during hot summer days. The additive package in just about any brand of passenger car motor oil will be far better than any oil available in 1953, so any brand should be fine for your flathead. The lower levels of zinc in today's oils are still better than they were back then, and the quality of modern ZDDP formulas offer far better performance than the old technology, so I don't think you have to worry about zinc levels, unless you've got some exotic high lift, high spring pressure valvetrain. The old 3/4 race cam should be fine with modern oil. If you're really worried about the zinc, use a heavy duty diesel engine oil (one that does not carry the API SN license) and it will have more zinc than is needed. Don't use the aftermarket zinc additives, they are not needed and will likely do more harm than good. All modern oils, both passenger car and heavy duty diesel, are loaded with much better detergents/dispersents and will keep the engine clean. Forget about adding any Marvel Mystery Oil, that was something developed when motor oils had no detergents and the MMO would help solubolize varnish and deposits, should not be needed with modern detergent oils. The bottom line is, individuals may have their brand preference (I do), but at this point it doesn't really matter too much, they all provide minimum performance levels far superior to what is needed in that old engine. I'd stick with a multi-viscosity oil and not spend too much time worrying about it all. Add a bypass filter if it doesn't have one, and get out there and drive it as often as you can. Change it frequently, and the engine will live far longer than it would've back when it was new. If you get let's say 4k miles per year, every year, that engine should outlive you.
So if you have used Pennzol 20-50 for years, you must have been satisfied with it. What do you want to gain by the change?
What do you want to gain by the change? Probably the sound... Pennzoil 20/50 doesn't have that 'Calif. Hot Rod Zazz' to it... Sounds like old geezer lube.
You run non detergent for the same reason that they always have run non detergent. No oil filter to trap the crap. The advice I gave is good sound mechanical advice. Maybe that is what confused you.
That's what I was told. No filter- non detergent, Filter- detergent. Non detergent 30 weight for me. Oriellys even carries it in the back.
Dollar General made national news because the oil they were selling was not formulated for modern vehicles. It said right on the bottle (in small print) for vehicles manufactured before 1980. Part of the problem was that it was non detergent the other part of the problem was that it had too high a zinc content and supposedly would gum up a modern engine. It was import oil. LOL
The Jalopy Journal
