You dipstick...

[Woodie UK]

The mechanic who recently carried out the disc brake conversion (plus an oil/filter change) on my '56 Crown Vic mentioned that he thought I had the wrong dipstick in the engine: 312 Thunderbird.

He put in the 5qts as mentioned in the handbook but I was wondering if there are different length dipsticks for the Y block motors. I'd hate to over or under fill the engine with oil....
Colin

[scicala]

I know Thunderbird engines had the dipstick located in the block, and pretty sure passenger cars (your's) had the dipstick at the bottom of the timing chain cover, or vise versa. So there are probably two different length dip sticks at least.
If you are sure there are 5 quarts of oil and a new filter in there, why not just re-mark the dipstick with the car on level ground after the engine has been off for a little while.

Sal

[paul2748]

TBird YBlock dipsticks are longer than the sedans because of the difference where they are located.

The 56 shop manual shows 5 quarts crankcase capacity PLUS one quart if the filter is changed.

[miker98038]

Don't know about the cars, but most spin on filters don't need a full additional quart. At least my bird didn't. When I put the headers on I had to change the dip stick and tube. Put 4 quarts in, started it, and let it drain back. Marked the stick, added a quart and a half, marked it again. Let me close in on "add oil" point. I had the right dipstick to check it against, yours may vary if it's the wrong one, but you'll get close. Over/under by 1/2 qt probably isn't a big deal on a well watched street motor.

[dmsfrr]

Oil level is of course checked cold after being run and capacity is determined by the oil pan, not the engine. I can see spin-on filters holding a bit less than the bigger old bolt-on canisters.
The '55 Ford Car shop manual I have lists the y-block oil capacity as 5 qts, plus 1 for a filter change.
IIRC the '54/'55 thru '62 y-block powered full sized cars all used the same front sump oil pan.

There are (at least) 4 different styles of y-block oil pans, some holding up to 7qts, but the others are rear sump style for Tbirds, light duty and heavy duty trucks.

.

[Daves55Sedan]

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IF (and I say IF) the car has the factory T-bird 312 engine in a full size car, it would have been installed with the standard oil pan commonly installed on all 272/292 engines in full size cars (dmsfrr's photo on the left) AND would have had the dipstick entering the right side of the timing chain cover (whereas T-birds had the dipstick in the middle of the engine block on the side).
Y-blocks have a oil capacity of 5 quarts plus one quart for the oil filter = 6qts (But if you have converted to the spin on type filter, don't put in the entire last quart) because the spin-on filter is smaller than that big canister they originally had.

[dmsfrr]

Originally Posted by Woodie UK

The mechanic who recently carried out the disc brake conversion (plus an oil/filter change) on my '56 Crown Vic mentioned that he thought I had the wrong dipstick in the engine: 312 Thunderbird.
He put in the 5qts as mentioned in the handbook but I was wondering if there are different length dipsticks for the Y block motors. I'd hate to over or under fill the engine with oil....
Colin

What did he see to make him think the dipstick is wrong? Does it somehow not look like a normal 50's Ford dipstick?
The '55 I have came to me with the wrong dipstick, the cap at the base of the handle didn't fit correctly on the top of the dipstick tube.

If the dipstick tube in your '56 Crown Vic has ever been removed there may(?) be a slight lip inside the recess in the block preventing it from seating fully. (photo #1)

Double check the oil level shown on the dipstick when the engine has the correct amount of oil in it. Five & a half or six quarts, depending on which type oil filter it has.
If it's not at or very near the 'Full' mark the dipstick may well be incorrect. You can re-mark it as Sal suggested, or look for a better one.

The *Thunderbird 312* in full sized cars was just a sales option package that IIRC included a 4 bbl carburetor, dual exhaust, hi-perf rocker arms(?) and some decorative items. The option package was very nice, but not some sort of magical mysterious thing. (as the sales & marketing dept would have you believe)
'55/'57 Thunderbird's used the same basic engines as all other Fords of the era. The only differences were some of the bolt-on and optional parts. (and most of those were just to get the engine to fit in the engine compartment)

There is no way to verify the engine is actually a 312 while it is installed in the car. The 292 and 312 blocks are identical on the outside, and the oil capacity is the same.

The same front sump oil pan was used in all the Full-Sized y-block powered cars, to fit around the steering linkage & frame, not for any engine option package differences.
Oil pans in a '55/'57 Thunderbird are the rear sump type, also to clear the frame and steering components, the engine sits lower and farther back in the car.

In any case... the shop manual I have does not list a different oil capacity for Full Sized cars vs. the Thunderbird's. (5 qts, plus 1 more for a filter change.)
.

Originally Posted by Daves55Sedan

IF ... the car has the factory T-bird 312 engine in a full size car, would have had the dipstick entering the right side of the timing chain cover (whereas T-birds had the dipstick in the middle of the engine block on the side)......

Yes, the Thunderbird's have a different dipstick location for their rear sump pan, which won't fit in a full-sized car.
The engine blocks often have both dipstick holes. The right side center position is also used on trucks. The unused hole is closed off with a small plug. (photo #2, block for a T-bird)


.

[Paul Bennett]

The two extremes of too much and too little oil are 1. Too little oil so it doesn't get picked up by the oil pump AND 2. Too much oil so oil gets paddles/splashed by the crankshaft.

Many oil pans have a plate (with a strange name which I've forgotten) in them which helps determine the upper limit of full.

But I'm wondering ... has anyone used a borescope to look into the pan through the dipstick tube peering at the oil surface and compare what they see to the dipstick marks? Share pictures?

[dmsfrr]

Originally Posted by Paul Bennett

... Too much oil so oil gets paddles/splashed by the crankshaft.
Many oil pans have a plate (with a strange name which I've forgotten) in them which helps determine the upper limit of full. ...

Many oil pans have vertical baffles that help prevent oil from sloshing side-to-side or front-to-back, and keep it closer to the pickup tube. They can also have a horizontal windage tray to help keep oil down in the pan and away from the crankshaft at speed or during 'entertaining' vehicle movements.
.

[1967 Camaro]

My 1957 Thunderbird owners manual states for the 292, five quarts of oil plus one more if changing the filter.