Hole identification on the cylinder heads - 302 V8

[sgauvry]

Folks -

What is the hole seen in the picture below?  I've put my lower intake on and about 1/4 of the hole is showing on each side.  Are they used to pry off the intake? Or something vital and a cause for concern?  

[85lebaront2]

Steve, if it doesn't go into the crossover (passage underneath it) then it will not be a problem. If it does, then they sent you the wrong heads on that engine. Is there a casting number on the heads?

[Gary Lewis]

I've seen a crescent-shaped hole there that didn't connect to anything, but not a round one.  But, as Bill says, if it doesn't connect to anything there's no problem.

As for the casting numbers, they are on the bottom of a small-block head and are essentially impossible to see w/o pulling the heads.

[Rembrant]

sgauvry wrote

Folks -

What is the hole seen in the picture below?  I've put my lower intake on and about 1/4 of the hole is showing on each side.  Are they used to pry off the intake? Or something vital and a cause for concern?  

I have no idea what the hole is for, but I can tell you that the stock heads on my '84 302 (D8OE) had these holes, and they were indeed partially exposed above my intake from the factory. They caught my eye during disassembly and I was also wondering what they were for, and why they were half (or quarter as you say) exposed.

[sgauvry]

Thanks, Bill, Gary, and Rembrant! The lower intake manifold is on so I cannot visually tell if the holes go into the crossover passage.  I took and really skinny phillips and gently felt around.  The hole ends and it seems it does not go into the crossover, best as I can tell.  

Do you think the holes are there to make it easier to pry off the lower intake?  I can't figure any other purpose.  

Steve

[Rembrant]

sgauvry wrote

Do you think the holes are there to make it easier to pry off the lower intake?  I can't figure any other purpose.  

If was betting money, I'd say that is was more likely that the holes had something to do with the manufacturing process, and nothing to do with service. A locating hole for a jig or a fixture of some kind either in the machine shop or on the engine assembly line. As far as I know, it's just a blind hole.

I'll take a look at my D8OE heads this morning to check. They're off the engine now, so the holes will be easy to see.

[sgauvry]

Thanks!  Nice looking truck you have there!!

While I've got you, I'm considering priming the engine with oil while it's still in the engine stand. I have a dummy distributor and will use a power drill. Advantages/disadvantages to doing this while still in the stand?  I thought it may be easier to purge the air from the engine with regard to plug installation after the engine is primed.

Steve

[Gary Lewis]

I really like priming the engine via the oil pump.  I'm not sure it makes much difference, but I like having the engine in the vehicle so you can tell when the pressure comes up on the gauge.  However, the drill will slow dramatically when the pressure comes up, so that may be a moot point.

So, in the vehicle or out doesn't matter, and if it is easier for you to do it out then go for it.

[sgauvry]

Thanks, Gary!

[Rembrant]

sgauvry wrote

While I've got you, I'm considering priming the engine with oil while it's still in the engine stand. I have a dummy distributor and will use a power drill. Advantages/disadvantages to doing this while still in the stand?  I thought it may be easier to purge the air from the engine with regard to plug installation after the engine is primed.

I have my 302 pulled out and disassembled now. I'm actually dropping all the pieces off at an engine shop tomorrow morning. Getting them to go over the short block for me, and assemble the rest (GT40 heads, Comp Cam kit, Edelbrock intake, etc).

I was going to assemble it myself, and I was going to do like you and prime the oil system with a drill once the engine was back in the truck. However, now that I'm getting a shop to assemble and break-in/dyno for me, it's kind of a moot point and I forgot about it.

What is this dummy distributor you were going to use? I guess that would work fine, as long as you remove the drive gear from the distributor shaft. I know there are purpose built shafts for priming, but if you have an old distributor you can use, that should work just fine. Make sure to check rotation;).

[Gary Lewis]

Yes, make sure the cam drive gear is off of the distributor you are going to use to spin the oil pump.

[85lebaront2]

I have a real nice one somebody sent me, works for 335 and 385 series engines.

[Gary Lewis]

Yes.  But, which one of us is going to use it first?  

[85lebaront2]

I have already used it when I flushed the cooler lines.

[Gary Lewis]

Good!  I'll probably make another one for my own use.