Oil capacity for the Model T engine.

Post by **jiminbartow** » Thu Mar 17, 2022 5:38 pm

Seems like I have forgotten more than I remember, so I have been reading up on the basics to refresh my memory as I get my car ready to start for the first time in 7 years. The most recent thing I read was in regards to the oil capacity and of course, opinions vary. Some say 4 quarts and more say 3.75 quarts. From what I gather, 4 quarts puts the oil level above the top petcock and 3.75 quarts puts the level just below the top petcock, which is what is recommended by Ford. One recommended 5 quarts in hilly areas to ensure that, on a steep hill, the front bearings will not be starved of oil. Since Florida is basically flat, 5 quarts is off the table, so which is best, 3.75 quarts or 4 quarts? Jim Patrick

Post by **speedytinc** » Thu Mar 17, 2022 5:49 pm

4 quarts for an empty/fresh engine first time.
Dippers will retain about a half quart. Therefore, for an oil change, add back about 3.5 quarts to refill.
4 quarts will be above the top petcock.

BTW your picture's oil level is not correct. The oil level is well above the bottom of the bands @ rest.

Post by **Moxie26** » Thu Mar 17, 2022 8:41 pm

When you pour in four quarts of oil on a change , how much would that half quart that's in the troughs really harm the engine??? For the past 20 years I've been dumping in 4 quarts on every change.. have not had any engine problems .

Post by **DHort** » Thu Mar 17, 2022 8:52 pm

Open the top pet cock, put in 4 quarts, and let the extra drain out. If you put the empty oil bottles under the car it will be a reminder to close that petcock before you start to drive it.

Post by **Oldav8tor** » Thu Mar 17, 2022 9:23 pm

When I change oil I jack the front end up to get more of the oil to drain from the dips. Dave's suggestion to verify level by opening the top petcock is a good one.

If you're worried about getting enough oil to the front bearing you should install an external oil line. The one that has a small funnel over the flywheel magnets is superior to those who modify the magneto post.

Post by **J1MGOLDEN** » Fri Mar 18, 2022 11:47 am

Then there is another old argument of whether you should have enough oil to let it pour out the top petcock with the same gusty that it pours out the lower petcock OR whether it should just barely drip out the top petcock.

On tours, I check the oil every morning, noon, and evening.

In the morning, if nothing comes out the top, I add 1/2 quart.

Then at noon, if some comes out, I just shut the petcock, if nothing comes out, I add the other 1/2 quart.

Then that evening, I repeat the above procedure.

You can run out of gas as often as you like, but you cannot run out of oil more than once, until you buy a new engine.

Post by **Mark Gregush** » Fri Mar 18, 2022 12:23 pm

I have been making it a habit to jack the front up as high as I can and let drain overnight. Then when adding, start with about 3-1/2 with upper petcock open sitting back on the ground, adding till oil comes out of same. Or just add 4 qts and let drain off.
My opinion; Rebuilt engine or not, you can add too much oil and might pump/smoke if over filled, along with find spots to leak out.

I have also found that with some outside oilers, esp ones mounted to side of the hogs head with too big of line, can do the same thing (pump/smoke). Not a deterrent for those, just something to watch for.

Post by **TWrenn** » Fri Mar 18, 2022 3:05 pm

Keep in mind that a little "seep" or drip from the top cock in the morning cold engine will result in a pretty decent flow out of the top cock mid-day after driving. The hot oil swells up more than you think.

Post by **Moxie26** » Sat Mar 19, 2022 10:56 am

Good morning Tim. ..... so does the Ford manual say to check oil level when it's cold or hot? ......

Post by **TXGOAT2** » Sat Mar 19, 2022 11:16 am

As far as I know, they didn't discuss hot or cold. I think they said to check oil, gas, and water before going on the road, and recommended keeping the oil level halfway between the upper and lower petcocks, which implies a cold check. They warned NEVER to run the car with the oil below the lower petcock, and not to run it above the upper petcock, with halfway between the petcocks being ideal. All checks to be made with the engine off and car on level ground. The engine will retain some oil even when the pan is fully drained. Ford made mention of this. My engine seems to retain at least a quart, although half a quart is commonly cited. My engine may have a dam behind the rod dips. A cold engine might take half an hour for the oil to fully drain back into the pan. A hot engine would probably take 5 minutes or less. Running the engine with the oil below the lower petcock brings high risk of damaging it severely. Running the engine with the oil level above the upper petcock will result in excess oil consumption, excess carbon deposition, and increased oil leakage. Power and fuel economy will be reduced. I would follow Ford's recommendation of keeping the oil level above the lower petcock and below the upper petcock. Kits are available to add a dipstick to the T engine. If properly installed, calibrated, and used, these can make keeping the oil level at the ideal, Ford-recommended level a lot easier.

Post by **TXGOAT2** » Sat Mar 19, 2022 11:19 am

It's important to be sure the oil level petcocks not clogged by dirt, mud, bug nests, or lint from the transmission bands.

Post by **J1MGOLDEN** » Sat Mar 19, 2022 11:58 am

Some of the early accessory oil check sticks have a wire about two inches long that swings around to push the dirt out of those oil drain holes.

Others have marks for the gas tank fill levels.

rainer · Post by **rainer** » Sat Mar 19, 2022 12:18 pm

Why not simply add a level viewing glass if you want to know it so precisely?

I had one already installed on my Lizzy when I bought it. Its upper end (and ventilation hole) is on same level as upper petcock.

If I am unsure if it is clogged, I open the lower petcock to see if oil is coming constantly. I catch this oil and fill it back ub at the front of the engine.

VERY SIMPLE and absolutely no need to climb underneath the car. Open the engine hood and you can see the oil level, or you knee down and look from right side for more exact control.

This is the view from right side (sorry, picture is a bit blurry):

I can only recommend this viewing glass. This huge engine has surprisingly little amount of oil inside. So it is preferable to be able to check the oil level without getting oily hands in seconds.

Post by **speedytinc** » Sat Mar 19, 2022 12:57 pm

In theory, you are correct. In practice, dirty oil stains the glass &/or a plugged breather hole can give a false full level when empty. The screw holding it together can loosen & dump all the oil out.
That knowledge & some maintenance can make a sight gauge useful.

Post by **Mark Gregush** » Sat Mar 19, 2022 2:18 pm

You can also do as Steve Jelf has suggested in the past, put a piece of clear tubing over the ends of the petcock, open both valves and check the level. Just be sure to close those valves when done.

rainer · Post by **rainer** » Sun Mar 20, 2022 5:34 am

speedytinc wrote: ↑
Sat Mar 19, 2022 12:57 pm
In theory, you are correct. In practice, dirty oil stains the glass &/or a plugged breather hole can give a false full level when empty. The screw holding it together can loosen & dump all the oil out.
That knowledge & some maintenance can make a sight gauge useful.

Hi, speedytinc.

You are absolutely right, it is no good idea to blindly believe what the glass shows.

About the plugged breather hole... I see that the oil level inside the glass decreases when I open the bottom petcock. This indicates that the breather hole is not plugged. I always have an eye on that. And when no oil comes out from petcock, the reason is also clear - a plugged oil channel inside to the engine.

Which screw do you mean in "holding it together" ?

My viewing glass is inside a brass part. This entire brass part with viewing cutouts can be screwed off. The glass is sitting on a little O-Ring on its lower end and has no gasket on top. The upper glass end is also not cut in 90 degrees, so it touches the brass only on one side and has a little gap on opposite side. THIS is the breathing hole at my viewing glass, there is no hole through the top of the brass part. Air floats up through the little gap between brass and glass, then crosses the upper glass end through this little gap.
On bottom end the glass is sitting on an O-RING. This ring is elastic and also keeps the brass-cover's thread under permanent tension (by pushing the glass upwards), while the brass thread is sitting well in the lower brass block. I wound a little bit of Teflon tape around the thread to make it sit more firmly. The brass part didn't move the smallest bit yet.
It was built like this when I first disassembled it for cleaning (I polished all brass when I got my Lizzy and didn't want to hurt the glass), except of the Teflon tape.

When I got my Lizzy, the glass was looking like graphite (deep black). Even when using a lamp from back side, nothing was shining through it. So I thought the glass is stained and needs cleaning. Finally I found out that the former owner had filled in so much oil that the viewing cutout was completely filled, and the last oil change also must have been long ago. Now my oil is not yellowish brown any more, but still transparent. This is for sure the last remainder of dirt from inside the engine, I will change it earlier the first time, after 5-6 short trips, this will not harm.

Also, I keep the oil level now slightly lower, so I can see it in the glass. This is approx. 10mm below upper petcock. This makes it easier to see the oil level.

babychadwick · Post by **babychadwick** » Sun Mar 20, 2022 10:08 am

I've got a larger one that has a cork and plate in it. Coming off the bottom is a wire to the magneto. IF you run low on oil the cork will drop the plate touches and the magneto is grounded out stopping the car preventing you from killing your engine. Never used it because then I would have to put a magneto back in the car . . .

Post by **speedytinc** » Sun Mar 20, 2022 11:01 am

The pix you provided. Looks like there is a screw from the top cap thru the glass tube to the body. Thas part of typical construction & can vibrate loose & away.

John Codman · Post by **John Codman** » Sun Mar 20, 2022 11:13 am

Every couple of years I drain the oil hot, then put 4 quarts of 10 w 30 into the engine and don't think about it for the next two years. During my first oil change on this car I did the petcock thing; it took exactly four quarts for the top petcock to drip. I always do the oil change in the same side of my garage, so there's no reason to think anything will be different from one oil change to the next. For the first year or two I checked the oil level regularly. I established that the engine does not burn oil and leaks very little. I never check the oil between changes. If the engine ever stops leaking a smidgen of oil I will know that it is out of oil.

Post by **jiminbartow** » Sun Mar 20, 2022 11:17 am

Yes. There is a 3” long brass screw that goes through the top hole, down through the center of the glass tube and and screws into a threaded hole in the bottom and tightened, then a nut screws onto the exposed threads in the bottom and is tightened against the bottom. This basically serves as a locknut, locking the threads in place, preventing the screw from vibrating out. I have had the same one on my T for 50 years and the screw has never vibrated loose. Last time I took it apart to clean it, even though the fiber gaskets looked good, I dried it all out and put some “Right Stuff” on the top and bottom gaskets to seal the glass tube and in the threaded bottom hole to prevent any leakage. Jim Patrick

Post by **Moxie26** » Sun Mar 20, 2022 1:35 pm

A big thank you to you John Codman for your response.. since we both have the improved Ford, it will hold 4 quarts plus whatever is in the dippers... And show very small drips out of the top petcock !

Post by **TRDxB2** » Sun Mar 20, 2022 1:40 pm

1925 Ford Owners Manual on -Engine Oil maintenance - http://www.cimorelli.com/mtdl/1925/1925manual.pdf

Post by **Moxie26** » Sun Mar 20, 2022 1:42 pm

What year copyright is that from?

Post by **TRDxB2** » Sun Mar 20, 2022 3:39 pm

Moxie26 wrote: ↑
Sun Mar 20, 2022 1:42 pm
What year copyright is that from?

The one above was from a 1925 Owners Manual http://www.cimorelli.com/mtdl/1925/1925manual.pdf
The 1926 manual says to use oil instead of kerosene
date 0f 1925 (12/1/1924

The one below is from the 1926 Owners Manual as a reference in the MTFCA Library https://www.mtfca.com/books/1926Inst.htm

Post by **Moxie26** » Sun Mar 20, 2022 7:38 pm

Frank.. John and I have over 20 years of practical experience changing oil in our improved model t's, with the same fill results of just seeing if a few drops from the upper petcock when it's open. If you like saying that we're wrong, well, that's your prerogative...... I wonder how many other improved model owners have the same experience results,... That four dip pan does hold a lot more oil than the three dip pan.

Post by **speedytinc** » Sun Mar 20, 2022 10:25 pm

Moxie26 wrote: ↑
Sun Mar 20, 2022 7:38 pm
Frank.. John and I have over 20 years of practical experience changing oil in our improved model t's, with the same fill results of just seeing if a few drops from the upper petcock when it's open. If you like saying that we're wrong, well, that's your prerogative...... I wonder how many other improved model owners have the same experience results,... That four dip pan does hold a lot more oil than the three dip pan.

I have a drain plug in #3 dipper, so only 3 dip pockets hold leftovers. Add back 3.5 quarts. I do not fill to the upper cock. Between the 2. You may realize, after running & splashing, the oil level @ the petcock rises. Thats 40 years + experience. Less leaks & oil burning.

Post by **Steve Jelf** » Sun Mar 20, 2022 10:50 pm

I don't care whether it takes 3¾ quarts or four quarts. I just fill until the oil reaches the top petcock.

I agree with John that a sight gauge can easily give a false reading and make you think that no oil is plenty of oil. Even worse is that it replaces the bottom petcock, so that if the gauge gets knocked off or broken you lose your oil. This is not good.

This is the oil sight tube Mark mentioned. Open the petcocks to check the level, then close them. If the tube gets knocked off, no harm done.

Post by **jiminbartow** » Sun Mar 20, 2022 11:10 pm

Great idea Steve. I like that! Jim Patrick

Post by **TRDxB2** » Mon Mar 21, 2022 12:07 am

Moxie26 wrote: ↑
Sun Mar 20, 2022 7:38 pm
Frank.. John and I have over 20 years of practical experience changing oil in our improved model t's, with the same fill results of just seeing if a few drops from the upper petcock when it's open. If you like saying that we're wrong, well, that's your prerogative...... I wonder how many other improved model owners have the same experience results,... That four dip pan does hold a lot more oil than the three dip pan.

Perhaps you have me confused me with someone else's response.

"I" said nothing about changing oil, the amount of oil to use or how to check oil level. All I did was reference Ford the Owners Manuals for 1925 and 1926 because they mention the frequencies to change oil and cleaning out the crank case. I have re-read the Ford Owner Manual references I posted and don't see how it contradicts or conflicts with anything you or John have said. These references do not mention how to check the amount of oil or how much to use as well. Perhaps you can point out where the Ford Owners Manual contradicts what you have posted.

Post by **Moxie26** » Mon Mar 21, 2022 9:39 am

Good morning Frank.. if you don't respect what I say go argue with somebody else. Have a great day.

Post by **TRDxB2** » Mon Mar 21, 2022 10:14 am

Moxie26 wrote: ↑
Mon Mar 21, 2022 9:39 am
Good morning Frank.. if you don't respect what I say go argue with somebody else. Have a great day.

Just so you know... I do have the fullest respect for what ALL you guys posts on the Forum. I'm not trying to argue anything, just trying to understand how I may have offended you. I apologize just the same.

Scott_Conger · Post by **Scott_Conger** » Mon Mar 21, 2022 10:16 am

Frank, I've re-read the entire exchange 3 times and agree that none of your posts was in conflict with Bob, nor any information or opinion he has expressed. If posting information directly from the Ford Manual with no commentary or opinion associated with it is taken as argumentative, well, that reflects on the reader, not the poster. For some reason, you are the guy he's going to have a pizzing contest with in this thread. It's not the first time, nor will it be the last. Forget about it and don't spend time waiting for an apology.

Post by **TRDxB2** » Mon Mar 21, 2022 11:24 am

Thanks Scott. I thought I just responded to his posts on what the Ford Manual said about draining the oil hot or cold and a second about what edition the 1st Referenced manual was.

Dropacent · Post by **Dropacent** » Mon Mar 21, 2022 12:33 pm

32 posts re oil level, says me in dumbfounded amazement. Why not add type of oil to the thread and make it a real barn burner!

Post by **Steve Jelf** » Mon Mar 21, 2022 1:06 pm

What kind of oil should you use when you're burning a barn?

Post by **speedytinc** » Mon Mar 21, 2022 1:13 pm

Can the fire be put out with radiator coolant? what type & mixture?

John Codman · Post by **John Codman** » Mon Mar 21, 2022 1:16 pm

Steve Jelf wrote: ↑
Mon Mar 21, 2022 1:06 pm
What kind of oil should you use when you're burning a barn?

I am told that Diesel oil works well.
I thought that your computer wouldn't allow you to post on this forum? Didja get a new one?

Post by **Steve Jelf** » Mon Mar 21, 2022 2:16 pm

No, John, it's the old software on my traveling laptop that won't accept some websites. I will get one that's more current before I make another trip. My desktop iMac has current browsers that present no such problem.

Post by **jiminbartow** » Mon Mar 21, 2022 11:49 pm

Earlier, Jim Golden mentioned a measuring stick equipped with a wire to clean out a plugged petcock drain hole. That reminded me of an original Model T combination tool that I found in the trunk of my ‘26 coupe when I bought it in 1970. A 20.5” long petcock opening tool with a 1” long poker that is used to clean out a clogged petcock hole. This is very handy for opening the petcocks without having to crawl under the car. Jim Patrick