Help me choose the best oil for a 41 Ford Flathead

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Hello all, I've recently picked up a '41 ford pu with the original flathead engine. It's been in storage for 25 years and recently brought back to life. The previous owner changed the oil with a straight 30w just to get running. A friend has a simular flathead, although completely rebuilt, he runs Rotella 15/40. Engine starts and runs fine, no noise or smoke. I'm not driving it no more than a few minutes at a time to move it around. Getting some fresh oil in it first and then I'll start sorting out the rest.I do not know any of the history of the past 70 years. Thanks in advance, Randy
 
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I am hoping you can post some pictures of this classic. BrocLuno is the poster with the knowledge of old engines and how to go about getting them running.
 
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Originally Posted By: randytrish
That is a beauty and in great shape.
 

randytrish

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Thanks. It is in fantastic condition. Fully stock exept 12v conversion. Kind of a sad story behind it. The Dad bought it in the mid 60's, drove and enjoyed it. Decided to have it restored in the mid 90's. Got cancer and past away before it was completed. The family kept it stored since '95. I told his son I would get it back going and enjoy it.
 

Astro14

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Originally Posted By: randytrish
I've got Rotella T4 15/40. Wasn't sure about a multi weight. Wanted to get some opions here first.
For an engine as modern as that (metal shell bearings instead of babbit, downdraft carburetor), Rotella 15/40 would be a great choice. Let me know if you get something that’s really old... grin
 
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In these very old (pre-1960) engines, I like Rotella T1 (straight 30 HDEO) or Traveler (Tractor Supply TSC) straight 30 HDEO.
 
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Plain ol HD 30. Supertech comes to mind. We used to have a customer(passed on) who was a huge flathead nut. He knew them inside and out, and collected everything from bone stock to about as built as you could build one. He even had a couple or three Ardun overhead valve conversions. He ran Valvoline 30. Not VR1, just regular conventional.
 
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The old Ford flat head engines will run fine on just about any oil you decide to put in it. The oils available when that truck was built had almost no additives in them. An HDEO SAE 30 or 15W-40 would be a good choice for your engine. I also don't think that ZDDP or lack there of will make much of a difference in the life of the cam and lifters as the engine doesn't use high valve spring pressures and isn't a high revving engine.
 

OVERKILL

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Originally Posted By: 46Harry
The old Ford flat head engines will run fine on just about any oil you decide to put in it. The oils available when that truck was built had almost no additives in them. An HDEO SAE 30 or 15W-40 would be a good choice for your engine. I also don't think that ZDDP or lack there of will make much of a difference in the life of the cam and lifters as the engine doesn't use high valve spring pressures and isn't a high revving engine.
This.
 
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Originally Posted By: 46Harry
The old Ford flat head engines will run fine on just about any oil you decide to put in it. The oils available when that truck was built had almost no additives in them. An HDEO SAE 30 or 15W-40 would be a good choice for your engine. I also don't think that ZDDP or lack there of will make much of a difference in the life of the cam and lifters as the engine doesn't use high valve spring pressures and isn't a high revving engine.
Plus about a 100 smile So I have some experience with Flathead V8's as my first car was a 1950 Vicky. And I have worked on so many flathead tractors and boat engines I can't count that high. Low pressure valve springs and good cam metals mean very few cam failures. So you have to assume the first 40 years of its life was prolly non-detergent 30 grade. Maybe 40 grade if it was down south where it was warm all the time ... These engines have nominal bearing clearances in the 0.002~3 range, so something around a 30 is good. But there is nothing wrong with a quality modern multi. It depends on cold start conditions for your location ... Delo 400 15W-40, Delvac, Rotella, Mystic JT8 (one of my fav's) are all good. One oil you might consider is Delo 400 15W-30 SD (severe duty). No, your motor is not severe duty - but it's a very nice narrow spread multi with plenty ZDDP and a very robust add pak. But so it Shell T1 SAE 30 HD, Delo 400 30, etc. The thing about all these flatheads is they exhaust through the block. The Fords are the worst with long exhaust passages through the block. That adds a lot of heat load to the cooling system on top of nominal cylinder wall transfer that OHV motors do not have to deal with. It also adds to crankcase temp as the passages are low in the block. To counter that Ford had big radiators and two water pumps. So stay on top of the cooling system and you'll be fine smile Does it have an oil filter? What is the nominal oil pressure like?
 
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