[EchoOfGecko]

Not sure if there is a better place for this, but you Mustang guys seem to have all the best info on small blocks!

This is my first SBF, and I'm hoping someone could help me identify a few holes that were open on my engine. It was rebuilt around 1k miles ago, but not by me, and it was partially stripped down when I got it.

1st Pic - There are a couple holes that look to be drain holes on the heads, along the channel where the intake manifold meets up. Are these drain holes, or something else? Should they be plugged? If they are drains, where to they exit?

Also, I thought Windsor motors had 18mm spark plugs, but mine are 14mm. The block code is D4DE-6015-BA indicating a '74 Falcon/Maverick, but I guess the heads must be something else? Any easy way to ID these without having to pull the intake off?

2nd pic - There's a hole that looks to be a sensor port or something, along the rear lip where the belhousing attaches.

Are there any good diagrams that might label all of the parts of these engines?

Thanks!

 

[FEandGoingBroke]

1st Pic. That hole is nothing, ignore it. The V/C will seal when you put a gasket on it, this is just designed into it when they made it and is to be ignored for the most part.

ALSO: When mentioning a Windsor motor you are generally referring to a 351. This motor you have is a 302. Whether made in Cleveland or at the Windsor foundry, a 302 is a 302 and not a 351.

Second ALSO: Your heads have markings on them under the valve covers. What are they?

2nd Pic: That's a water drain hole. Plug it.

 

[mustangboy]

Looks like your intake is loose..Can you take a picture with the intake off?..I do not recall seeing those holes on any heads that I have seen...Looks to be right in the exhaust crossover spot but very high up..They would definetely not be covered by the valve cover gaskets....Also that hole in the rear is in all of the smallblocks I have seen..I have never seen it used for anything though..Perhaps is was used during factory assembly or in the foundry or something....Anyway don't worry about it..

On looking at the pics again it looks like an air pump hole in the rear of the heads?...Can you look on the topside of the heads and try to find the date code...It will look something like this 7h15....First number is decade,letter is the month and the next numbers are the day they were cast...

 

[FEandGoingBroke]

frdnut, that's NOT a hole in the head it's the valve cover silly man. Ignore it. It's cast that way.

 

[EchoOfGecko]

Thanks guys, I'll take a look after work and see if I can find those date stamps.

frdnut, that's NOT a hole in the head it's the valve cover silly man. Ignore it. It's cast that way.

Actually, it is in the head. I should have taken a pic with the VC removed, but that hole is about 3/16" down from the VC gasket surface, approximately in the area marked on the picture below (not my heads). Unfortunately I didn't even notice it till I was degreasing it to prep for paint and noticed the marine clean and water was draining in there.

The intake isn't loose at all, the gap there between the head and manifold is the gasket; it's almost flush with the edge of the manifold but it's just too dark to see. I was hoping not to have to take the manifold off, but it's looking like that may be the safest option to ensure there isn't water and marine clean dumping down into the bowels of the engine.

 

[EchoOfGecko]

Hmmm, so I've been Googling my brains out for a few hours now trying to figure out what these holes are, and I stumbled across the following page discussing Thermactor air and the exhaust crossovers in the M-block (351M/400). Looks like they had similar holes:

M-Block 351M/400 Photo Archive

Exhaust Crossover Cooling

Just above the exhaust crossover port on the cylinder head intake face is a blind hole (arrow). It is partially exposed above the edge of the intake manifold when the manifold is installed.

The purpose of this hole is to relieve heat from the cylinder head’s exhaust crossover passage. Some people are tempted to plug it or fill it, perhaps to keep debris from accumulating in it. However, that would defeat the purpose of the hole, and it would aggravate the heat problems inherent in the exhuast crossover design.

Anyone ever seen these on a 302?

 

[EchoOfGecko]

A few more pics. The date code stamped under the VC towards the front is 7D25...

 

[arnoldtx]

The later heads have an extra hole above the exhaust cross over port so nothing to worry about. That hole goes no where.

 

[mustangboy]

Those are some very strange heads you have there..Your date code breaks down to 7th year of the decade april 25th....Now we have to figure out the decade..Since it has stud mounted rail rockers I would normally say 1967...However ford didn't run the small spark plugs until the mid 70s.Also the air ports in the back of the heads would indicate to me that they are newer than that....
They can't be 1977 heads though since ford also switched to pedestal mounted rockers that were stamped steel around 77.....

Edit.....I did some digging and it appears that the stamped steel rockers supposedly didn't start till mid 78...It also appears that the internal air injection ports (holes in the back of the heads)started in 1975 so I guess you have some 1977 heads....I still have never seen that weird hole by the valve cover before..

You also have the worst of the worst combinations if your 1974 shortblock still has the stock style pistons..The 73-76 302 blocks had an extra tall deck height to reduce compression..Then in 1977 they returned the deck height back to what it had been in previous years and increased the combustion chamber in the heads to reduce compression....You have both the tall deck height block AND the big chambered heads....That means you only have about 7.2:1 compression if you have stock style pistons and the deck was not milled when it was rebuilt...

 

[FEandGoingBroke]

It makes sense to me that those are 77 heads on a 77 block. And you're right, that hole is in the head, My eyes were playing tricks, but it's nothing to worry about it's simply a design in the head where the exhaust crossover is located. That hole will not hurt anything.

 

[EchoOfGecko]

Cool, thanks guys! Yea, I kinda knew when I got this motor that it wasn't anything special as far as performance goes. It was in an RV before it was wrecked, so it has some other odd things like a rear sump pan with the dipstick in it, a torque cam, and it had a fixed-yoke short tail shaft C4 which won't really work for me.

But it was rebuilt and it ran really well, and the price was right, so I couldn't pass it up. And it's going in my '54 Ford Customline; I'm really looking more for a smooth cruiser engine thats OK on gas, so I think this should work well for me.

Maybe in a year or two I'll try and find some GT40 heads or some aftermarket aluminum jobs.

Thanks again for the help!

 

[mustangboy]

It makes sense to me that those are 77 heads on a 77 block. And you're right, that hole is in the head, My eyes were playing tricks, but it's nothing to worry about it's simply a design in the head where the exhaust crossover is located. That hole will not hurt anything.

I would love to see a picture of those heads with the intake off of the engine..If that "hole" was part of the exhaust crossover it should leak exhaust out of the top of the exposed hole?..I can only assume the hole is not connected to the crossover or it takes some funky kind of intake gasket to cover the hole.

 

[arnoldtx]

I have some heads that have that hole. It's not part of the cross over but just above it. The hole doesn't go any where.

 

[Montek]

Yes they are built in for foundry use only as they bottom out at near 1" depth. Poke a screwdriver or similar in like you're checking for bees:smile2:
I have same on my 77 351M heads. They do not circulate any water or exhaust, they just bottom out of themselves.
I will use bath/tub caulk and fill them in so they don't collect any moisture or debris.

Montek