Confirming Engine Size

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BinaryData

Member
Joined
Aug 29, 2015
Messages
23
Hey Guys,

I've got some free time now that I've caught on my classes. So, I've decided to put my grease monkey boots on and start mucking around with my truck. I'm going to attempt to replace my Oil Pan Gasket. I'll post pictures when I get home. I know this isn't directly related to Rat Rods, but the other forums I've looked at, come across as if they'd troll the living hell out of me for being a greenhorn.

The Problem!
It has a major oil leak. It burns/leaks oil like no other, I have to put 5 Quarts in ever week. That's $100 / month on just oil.

The Vehicle
1979 Ford F-150 9' Bed Automatic

The Engine
According to the Ford Label on the door; I have a 400 v8 6.6L Engine. Is there anywhere on the Engine I can confirm this? I want to say it's stock, but my brother says he thinks it's a crate engine. I'm clueless, so to the Experts (you guys).

Once I know this, how difficult is it to replace the Oil Pan Gasket? I'm assuming you have to drain all the oil.
 
I'm not a Ford guy so I can't help on the engine id.
As far as the oil consumption, if 5 qts a week is true then you need an overhaul or another engine.
 
Post a picture of the motor - somebody will identify it. Post one from underneath. Odds are, you'll have to lift the motor to get the pan off no matter what it is. Take a couple pics of where you think it's leaking too.

I have to agree with Old Iron, if you're loosing that much oil, odds are the motor is near gone and replacing the pan gasket probably won't do much.

How many miles are you driving per quart?
 
79 pickups came with the 400, so it's possible that's what yours is. Sam is right, you'll probably have to pull the engine to get the pan off, the crossmember is going to be in the way. Doubtful the pan gasket is leaking that much, if it's not burning it through the engine, I'd be more inclined to think it was the front and/ or rear main crank seals leaking. The pan gasket is above the oil level in the pan, so not much leakage there. Valve covers are more likely to leak than the oil pan, running down on the exhaust manifolds and burning off, but it would be smoking under the hood and you'd smell the oil burning. Have also seen the end gaskets on the intake leak, but it would almost have to not have a gasket to leak that amount in a short period of time.

I'd get some degreaser, spray the heck out of everything under the hood, then pressure wash it off real good so you can see where the actual leak, if there is one, is at. If it doesn't have a stream of oil running out somewhere, I'd have to say the guys are right, you need a rebuild or a new engine....
 
Only way to tell the difference between a 351m And a 400 is to measure the stroke.
 
Ok. Here's is the above part. The more I drive the truck, the more oil it leaks. If I drive it to work and back, which is 70 miles, I generally have to replace the oil by the second or third day of driving it. If it sits, it holds oil or leaks minimally.

I've attached a few photos below, I haven't been able to get under the truck yet. I'm really hoping that I won't need to pull the engine. That's a lot more work than I'm capable of. I don't even have an engine hoist.

I can crawl under the truck tomorrow and get a picture or two of underneath. I know we need to get some degreaser, and wash it out. It's a pretty hefty truck, hauled a fully loaded bed of dirt like it was nothing.
 

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Judging by your pictures, I would have to say that your valve covers are leaking. There's a nice black strip about 1" going around the entire bottom of your valve covers so they've been over torqued a time or 2 and are cracked around the bolt holes is my guess. But, covers won't usually lose that much oil so I'd be leaning more towards the rear main seal. The rear mains weren't known for holding up too well on those modifieds.
 
If it was burning that much it would be smoking like mad. Can you smell it burning off the outside of the engine? Sounds more like it needs seals everywhere. Does it smoke?
 
Is your tailgate all speckled with oil or oilmud? This tells you there's a leaky crankshaft seal [front or rear] or a pan gasket, like you thought. If you're burning that much oil your tailgate will be clean but your wake will be blue.
Good luck with the detective work.
 
If it was burning that much it would be smoking like mad. Can you smell it burning off the outside of the engine? Sounds more like it needs seals everywhere. Does it smoke?
Nope. Don't smell oil at all, I can just see lots of it, and I check it on a regular basis. Don't like driving it when its empty.
Is your tailgate all speckled with oil or oilmud? This tells you there's a leaky crankshaft seal [front or rear] or a pan gasket, like you thought. If you're burning that much oil your tailgate will be clean but your wake will be blue.
Good luck with the detective work.

What tailgate? :p But no, none of that is showing. Glad I posted here. The kid who my brother bought the truck from, was an idiot. He screwed up a lot of the wiring trying to install a modern stereo with no experience and messed up some other things too.

Should I degrease it, and then pressure wash it, and then come back to see whats up?
 
That was my suggestion in post #4 above......

You're what I'm referencing. I go back to work tomorrow night, and my neighbors frown upon my late night activities in the garage. Apparently, no one likes to fall asleep to an air compressor :p

I'll buy some degreaser, give it a good spray, and pressure wash it. Then give a nice long drive to and from work, and see where the oil is coming from. Narrow it down a bit more.

You guys rock, I'll make a Build Project for this.
 
Nope. Don't smell oil at all, I can just see lots of it, and I check it on a regular basis. Don't like driving it when its empty.


What tailgate? :p But no, none of that is showing. Glad I posted here. The kid who my brother bought the truck from, was an idiot. He screwed up a lot of the wiring trying to install a modern stereo with no experience and messed up some other things too.

Should I degrease it, and then pressure wash it, and then come back to see whats up?

What do you mean "I can just see lots of it"?
 
Fourth Digit...S...400

Engine Code
The fourth digit of the warranty or vehicle identification number indicates basic engine identification. The chart at right shows engines used in the F-series light-duty trucks (F100/150/250/350) only.
CODE YEAR CYL C.I.D. Carb Type
A '73-'74 6 240 1-bbl. Exc. California
'75-'79 8 460* 4-bbl. 7.5 Litre
B '73-'79 6 300 1-bbl. 4.9 Litre
G '73-'79 8 302 2-bbl. 5.0 Litre
H '73-'76 8 390* 2-bbl.
'77-'79 8 351 2-bbl 5.8 Litre
J '73-'79 8 460* 4-bbl. 7.5 Litre
M '75-'76 8 390* 4-bbl.
S '77-'79 8 400 2-bbl. 6.6 Litre
Y '73-'76 8 360 2-bbl.
1 '73-'76 6 240 1-bbl. Low compression - D.S.O.
5 '74 8 360 2-bbl Low compression - D.S.O.
* 390 and 460 engines not available from the factory w/ 4WD trucks.

SOURCE: 1973-1979 Ford Truck Master
Parts Catalog - Oct. 1979
 
Sarge's info would identify it as a S code 400 all right.
Visually, the 400 has a taller deck height than the 351M, so the intake mounting surface is about 1" taller - obvious if you have a 351M sitting beside it :D
The 400M has a 4" stroke versus the 3.5" stroke of the 351M, it should be possible to measure it through the spark plug hole with a wire, turning the engine manually to find TDC to BDC and comparing the difference.
Regardless of the displacement, most gaskets are the same other than the intake end gaskets.
 
Sarge's info would identify it as a S code 400 all right.
Visually, the 400 has a taller deck height than the 351M, so the intake mounting surface is about 1" taller - obvious if you have a 351M sitting beside it :D
The 400M has a 4" stroke versus the 3.5" stroke of the 351M, it should be possible to measure it through the spark plug hole with a wire, turning the engine manually to find TDC to BDC and comparing the difference.
Regardless of the displacement, most gaskets are the same other than the intake end gaskets.

I'm assuming there is also a sound difference. This 400 sounds really meaty. With a proper exhaust pipe it'll probably sound a whole lot better. Soon as I get my bill for Dental work paid off, I'm going full bore into this. Had to have my wisdom teeth pulled :( $2,000 ouchies..
 

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