Join Our Ford Truck Forum Today

Document your Ford truck project here and inspire others! Login/Register to view the site with fewer ads.

Ford Flathead

I just got a 51 ford with a flat head v8 and cant find the oil specs so if anyone knows what kind of oil and how much it takes i would greatly apreciate your input. i believe its a 239
 

mtflat

Flatheads Forever
2,559
147
Yes it's a 239. You need to get a shop manual - online ebay for about $30 and an operator's manual - about $10 from almost any of the parts suppliers online. 5 Quarts, 6 when you change the filter.

Oil - has the engine been running with detergent oil in the past? If so, any brand and any grade will work. I usually run 10W30 or 10W40 NAPA brand - which is Valvoline. These are very easy engines to work with and they'll absorb a great deal of abuse.

If the truck hasn't been driven a lot recently and was only fed non-detergent oil, running detergent oil may loosen deposits in the system and can plug your oil pickup.

Congratulations on owning a great truck - I can walk you thru most anything you'll come across. Back in '99 I did a complete frame-up rebuild on a 48 that is still a daily driver.
 
well it has a brand new engine but its been sitting for 10 years with the same break in oil so i think its developed sludge. i think im gonna put some non detergent oil in it drive it around a bit to losin stuff up and drain it out before i pass 100 miles and then put whatever i want in it. ill have to get a owners manuel for sure. i just dont want to mess it up its the first car ive ever driven with the flat head v-8 certainly beats the hell out of a model A
 
Oil doesn't develop sludge from sitting... it develops it from heating, cooling, getting contamination in it, water, etc...

If you have a bottle of oil in your garage and you leave it there for ten years, what would you expect to find when you open it?
 
yeah i was just thinking it sludged up cause it had so many seasons and acumulated water from humidity. i think he ran it some times too just not that much. he also left the same gas in it for all those years so i had to get a new tank. maybe only the filter housing had some sludge in it that he didnt clean out and thats all there is
 

mtflat

Flatheads Forever
2,559
147
If it's a relatively 'new' engine I'd just change the oil with regular oil and have fun. Non-detergent wouldn't be necessary in your case - only those with decades of use that have been sitting for several more decades.

Oh, I should mention another controversy that been boiling the last couple of years. EPA in their relative wisdom has forced oil mfgr's to remove zinc from the oil formulations as it's hard on catalytic converters. Engines up thru the 80's used zinc to cushion the flat tappets.

I run a diesel oil in my flathead cause it was the last to have zinc removed, but even that is changing. Check the labels. Do what you want. Oil companies and EPA say it doesn't matter, engine rebuilders have noted several cam failures. (It's most critical when breaking in a new engine - first 500 miles while you're seating the tappets on the cam)
 
ok sounds good. i cleaned the filter housing and will ordering a new filter today so hopefully by this weeks end i can put a new gas tank in. by the way this car has a ford-o-matic you know much about them?
 

1985 Ford F-150

Country Boys Can Survive
7,816
307
Tooele, Utah
If it's a relatively 'new' engine I'd just change the oil with regular oil and have fun. Non-detergent wouldn't be necessary in your case - only those with decades of use that have been sitting for several more decades.

Oh, I should mention another controversy that been boiling the last couple of years. EPA in their relative wisdom has forced oil mfgr's to remove zinc from the oil formulations as it's hard on catalytic converters. Engines up thru the 80's used zinc to cushion the flat tappets.

I run a diesel oil in my flathead cause it was the last to have zinc removed, but even that is changing. Check the labels. Do what you want. Oil companies and EPA say it doesn't matter, engine rebuilders have noted several cam failures. (It's most critical when breaking in a new engine - first 500 miles while you're seating the tappets on the cam)

Yep thats exactly right I use 15w40 rotella year round for that reason but you can also get a zinc addative and run that with any other oil. The only place I can find with the addative is the online places like Jegs.
 

mtflat

Flatheads Forever
2,559
147
ok sounds good. i cleaned the filter housing and will ordering a new filter today so hopefully by this weeks end i can put a new gas tank in. by the way this car has a ford-o-matic you know much about them?

I grab filters at NAPA - their Gold 1006 filter works well and is still used in big equipment and tractors so they're easy to come by. Don't fill the filter housing with oil when you change it. Just drop in the new filter, bolt the canister together and the oil will get there on it's own. (somebody always asks about "priming" the canister)

Sorry, I have no experience with the ford-o-matic trans. Mine are all manuals. I assumed this was a truck, but in looking at the first post, you never said that. When I think of automatics I think of cars. Check with the guys at this website for flathead V8's - great group of guys!

http://flatheadv8.org/phpBB/index.php?sid=5e704df70c2bf7d429e85a9e9330e688

Oh, it's not stock but I also put a clear plastic inline filter just before the fuel pump and change it every 6 months or so. NAPA Gold 3002 has 5/16" fittings and slips into the flex line nicely. You won't believe all the junk you will keep out of your carb! Keep the plastic filter away from the exhaust manifold - I install mine about 2" from the fuel pump which puts it on the firewall and high enough to inspect every time the hood is open.
 
Last edited:
yeah sorry its a four door custom. back then the cars and trucks didnt such a huge difference so i just used this forum. now i have mechanical pumps i can rebuild but it already has an electrical are the old mechanical ones any good.
 

mtflat

Flatheads Forever
2,559
147
Don't be sorry - the shoeboxes are great.

Some guys prefer an electrical pump - as long as they are regulated at 1.5 to 3 lbs. pressure they do fine.

I have used a mechanical pump for the past 10 years since I started driving a flathead daily. I just put in a new mechanical. I have an electric on the shelf, but haven't bothered to install it in the truck.

The best sources for parts I've found is Sacramento Vintage Ford, Red's Headers and Patrick's as well as my local NAPA.
 
yeah sacremento vintage is great. me and my dad rebuilt our model As out of their catalog. i guess ill have to make sure im not crnking out to much fuel pressure. i bet i can find a regulator at the napa or car quest
 

Ford Truck Articles

Top