Best oil for an 8ba

M

mfirth

Well-known member
I'm a first timer with an 8ba of unknown mileage. Some folks say to use 20w50
in it & others say no way. Any advice will be appreciated, thanks.
 
20W50 is fine. Just don't use any synthetic on a high mileagenengine if it has not been used before. Leaks can develop.
 
Valvoline VR-1 20W50 racing oil has the higher zinc content which is better for flat tappet cams like our flatheads. A little more expensive, but good insurance. Most auto parts places carry it.
 
You here a lot of openions on which oil to use in a flathead. From all the information I have read I decided to use Ford Motorcraft SAE 15 W 40 diesel oil. Haven't used it long enough to form an openion its just another option.
 
In my opinion, the worst oil you can use in a flathead is 20/50 or 15/40. Unless you have some loos bearings. 10/30 is the best oil to uuse, keeps the bearings much cooler. Now with that said, nobody really knows, they all seem to work the same. Proves the flathead is a great engine.
 
I was just reading the 1932-36 service bulletins today for fun. SAE 40 for summer SAE 20 for winter, was what it said. Just passing it along. Interval in those days, 2000 miles.

It may shame me, but I put in what I can get my hands on easily. Usually, because it's the way the world is these days, it's a multi-grade, frequently SAE10w-30. I try to change it about every thousand miles. Most recently it was a Valvoline SAE10w-30 semi-synthetic for high mileage engines. Four changes in the fourteen months since I became custodial of a very tired '35. I can't imagine it leaking from any new places, so the semi-synth doesn't bother me.
 
drolston said:
Valvoline VR-1 20W50 racing oil has the higher zinc content which is better for flat tappet cams like our flatheads. A little more expensive, but good insurance. Most auto parts places carry it.
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Extra zinc is NOT needed in a flathead! There is still sufficient zinc in modern oil for the low spring pressures of flatheads and other old engines. In the '50's, when these were just old oil burning/leaking clunkers, it was common to use re-refined oil or the cheapest non-detergent oil available. No zinc there! I have never seen a flathead with a wiped-out cam lobe in spite of this!
 
GM use 20W50 only drove over 100,000 miles with no problem. The best thing one can do is change oil every year and no more then 3000 miles. Keeping the oil clean is most important I have found. I use 15W40 for manny years with no problem. I guess each his own. I know some use the cheapest oil they can buy? That scare me.
 
I have to 2nd Ol' Ron's opinion on the 10W/30 for engines that have been brought back to proper OEM clearances. On all flathead V8 engines post war and many pre-war, the recommendation was 20W/20 for most weather conditions and 30 for for hot weather. You can use the heavy polymer stuff if you want but it just creates more oil friction & windage drag in the crankcase and therefore more oil temperature. The engines with loose clearances or worn bearings & rings might benefit from more viscosity but tight ones won't.

The more modern engines use the thin stuff for the same reason so they will get better fuel mileage.
 
nebrfox said:
You here a lot of openions on which oil to use in a flathead. From all the information I have read I decided to use Ford Motorcraft SAE 15 W 40 diesel oil. Haven't used it long enough to form an openion its just another option.
Click to expand...
O'Reilly has it on sale for $21.95 till the end of the month, got a pair of the 5qrt jugs when I was in the Granite state monday.
 
40 Deluxe said:
Extra zinc is NOT needed in a flathead! There is still sufficient zinc in modern oil for the low spring pressures of flatheads and other old engines. In the '50's, when these were just old oil burning/leaking clunkers, it was common to use re-refined oil or the cheapest non-detergent oil available. No zinc there! I have never seen a flathead with a wiped-out cam lobe in spite of this!
Click to expand...

Not to be argumentative, but for what I spent on rebuild of this engine, I will side with those that recommend the higher zinc, including my cam grinder.

But I know where you are coming from. I have put a lot of miles on worn out flatheads that burned a quart every 100 miles; went through a lot of recycled oil that came in unlabeled quart jars with funnel tops.
 
WOW, thanks fellas for your thoughts & experiences. I've been running 40w Rotella, but can't find it any more. The engine carries 40lbs hot oil pressure at speed & 15lbs @ idle. 180 stats & it stays at 180 even if i run it a little hard.
Love "The Barn"! m
 
Diesel 15-40 because most of my shop DDs use it and it's around in big blue jugs. It's expensive so it must be good... :D
 
Been using Castrol 10w30 for the last 36 trouble free years.. Good to see our trusted experts agree on 10w30 too!
Also use it in my daily driver!
 
Do a search for "Classic Car Motoroil". I have been using it in my 50 Merc and 63 Avanti with great results. They claim to blend it as was done before the zinc and such was taken out of the oil. It is 15W-40. Both cars had good oil pressure before this oil and have not changed.
 
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