Block question

[Big10-1978]

Hey guys! I bought a 383 block a few years ago and I’m finally ready to start building it. Upon further inspection I noticed a broke piece in a hole that is underneath where the mechanical fuel pump goes. What is the circled pieces function (1st pic with orange block) and if there is a whole all the way through this….what could be the potential problem? My pic is the unpainted block pic.

Thanks, Derrick

You must be registered for see images attach

You must be registered for see images attach

 

[PrairieDrifter]

I can't recall ever seeing that. But regardless, it should be easy to see if it goes through. Take a flashlight or a ziptie and feel around.

If it does go through, just get a the proper size soft plug, like the freeze plugs on the side of the block and a little sealer and pound it in. If you wanted to you could put sealer or epoxy on top of the plug as well.

 

[Ricko1966]

Show me a pic from the side of the block. Nothing wrong with @PrairieDrifter idea I don't know your skill set,or tool set. I'd be 1/2 tempted to tap it npt and put a galley plug in it.

 

[Big10-1978]

It’s definitely a broken piece and I’m not sure what either bolts into the front or some dowel pin goes into the bottom. I haven’t seen any assembled engines that use either the treaded hole or the opening on the bottom though so I’m not sure. I’m familiar with mostly building modular ford engines.

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

 

[sidschev]

just drilled to deep for threads. no biggy...

 

[PrairieDrifter]

It’s definitely a broken piece and I’m not sure what either bolts into the front or some dowel pin goes into the bottom. I haven’t seen any assembled engines that use either the treaded hole or the opening on the bottom though so I’m not sure. I’m familiar with mostly building modular ford engines.

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

That upper bolt hole should have a bolt in it as it goes through to the fuel pump push rod. You can thread in a longer bolt when changing the fuel pump to hold the pushrod while swapping. These holes could have been used with the heavy truck mounting, which usually uses a horse shoe style mount on the front of the block and a special bellhousing with mounts to the frame. Instead of the end of the trans and sides of the block.

I believe that hole doesn't even touch the pan rail, so it's fine. Unfortunate that it's like that, but no real problem. Maybe slightly more weak than normal? But not a critical spot.

No need to mess with unless looking for cosmetics.

 

[Big10-1978]

Thanks guys! Gonna put in forged crank/rods/pistons soon! Looking to make 450 NA then throw a turbo on it!

 

[Ricko1966]

Okay that shot is from the bottom and the front I want to see the side to see if your block is drilled for a fuel pump pushrod. Not all are.

 

[RustyPile]

Over the years, Chevrolet has looked for ways to lighten the engine blocks. Various areas are now thinner as a result. That hole in the pan rail serves no purpose after the block is fully machined and the engine is assembled. The threaded hole that "empties" into it is used to attach various accessory brackets. One use that comes to mind is engine mount brackets for pre '58 passenger cars..

as PrairieDrifter mentioned, No need for any attention at all.

 

[RanchWelder]

I would suggest, without expert knowledge, this is casting flash which needs to be cleared from the opening.
Use a Dremel or a round file or better yet a carbide end mill and clean that mess up.

At the very least, if this was supposed to be blocked off, and the threads were never supposed to be exposed to fluids or another passageway, you will need thread sealer on whatever bolt crosses the oil/water threshold for this port and the hardware which it intersects on both sides of the casting issue.

Epoxy to the missing metal barrier, may be a solution, with a release agent on the threads of the internal bolt areas and careful repair strategy. I would verify with an expert if this casting is defective before trying to repair it.

Good thing you caught it before you bolted everything up and found a cross-leak contamination or a casting flash issue.

Make certain there is supposed to be metal between this passage, or NOT, and plan to correct whatever is wrong before you move forward.

If the previous builder used the wrong length bolt, (which is very common), the missing metal may be a defect in the block and NOT a simple repair.

 

[RanchWelder]

Accidentally re-posted...