302 cubes for Suburbia

[dave w]

Well, I have a similar not good engine rebuild experience to share. See pics below. SBC 406, 6.0" rods.

dave w

[JeepsAndGuns]

Dang dave, what happened to that thing?

[1project2many]

Thanks for sharing. 406 parts aren't cheap especially with those long rods.

What's the pink stuff?? Obviously something hard enough to do damage. Piece of a bolt or screw that got sucked in?? Is that groove too deep to run?

[dave w]

The engine was fresh from the machine shop, which also assembled the engine. It appears to me, something foreign was in the ring compressor when the piston was installed into the engine. I'm requesting the machine shop sleeve the damage cylinder, at their expense.The machine shop insists the cylinder only needs a hone. Drama, Drama, Drama, I can't say I want to do business with a machine shop that is reluctant to fix the problem the way I think the problem should be fixed.

Anyway the first picture shows how the piston valve reliefs should be installed.

I'm not sure what the pink stuff is, paint from the rings or maybe assembly lube?

dave w

[1project2many]

Dave... Are you saying it's part of a ring compressor?? For 4" bore engines I have a nice, adjustable tapered aluminum compressor that I use. I'll be using it tomorrow if all goes well.

Pulled heads and pan but left the block in the truck. Pistons are installed backward. Rods, however, are installed correctly. So the machine shop assembled pistons to rods incorrectly but I'm still a bonehead for assembling it this way. I built the engine between the time I injured my back and the time I had surgery and all I can figure is the pain killers I was taking had something to do with it. It's no excuse but I can't see any other way I'd let something so obvious go. So tomorrow am I arrive at work early and knock the pistons out. During the day I'll either send the rods/pistons to another shop or try my hand at disassembly / reassembly using a torch to loosen the pressed pins. Hopefully the local GM dealer will have the head gaskets I used in stock so I don't have to wait for those. Part no 10105117 .028" compressed thickness.

Now I have a 45 minute drive ahead of me to get home so I can catch a few hours sleep and be back up at 4:30 to head back to the shop.

List of things to bring in from home tomorrow:
Tapered Ring Compressor,
Coppercoat
Toaster oven for heating rods
Patience, patience, patience.

[dave w]

Dave... Are you saying it's part of a ring compressor??

I'm thinking some debris was on the ring compressor. Who knows where the debris came from, maybe the debris was in a shop towel that was used to wipe the ring compressor? Maybe the debris was on the shop table where the ring compressor was set down between pistons? I don't think the debris is from the ring compressor, most likely the ring compressor picked up the debris from somewhere just before compressing the rings?

dave w

[EagleMark]

Dave... Are you saying it's part of a ring compressor?? For 4" bore engines I have a nice, adjustable tapered aluminum compressor that I use. I'll be using it tomorrow if all goes well.

Pulled heads and pan but left the block in the truck. Pistons are installed backward. Rods, however, are installed correctly. So the machine shop assembled pistons to rods incorrectly but I'm still a bonehead for assembling it this way. I built the engine between the time I injured my back and the time I had surgery and all I can figure is the pain killers I was taking had something to do with it. It's no excuse but I can't see any other way I'd let something so obvious go. So tomorrow am I arrive at work early and knock the pistons out. During the day I'll either send the rods/pistons to another shop or try my hand at disassembly / reassembly using a torch to loosen the pressed pins. Hopefully the local GM dealer will have the head gaskets I used in stock so I don't have to wait for those. Part no 10105117 .028" compressed thickness.

Now I have a 45 minute drive ahead of me to get home so I can catch a few hours sleep and be back up at 4:30 to head back to the shop.

List of things to bring in from home tomorrow:
Tapered Ring Compressor,
Coppercoat
Toaster oven for heating rods
Patience, patience, patience.

That story just sucks... How long has that motor been sitting waiting for a home? What a bummer...

How exactly does a machine shop press these in? They don't use heat do they? Torch on new pistons and rods scares me... Or do you not have a press?

I hate to say this but are the valves OK? Back in 1977... yup I'm old... I bent 2 sets of pushrods and didn't hurt a valve. I even pulled timing chain cover to see if I had it wrong, before I realized I built it wrong .

Man I'm sorry, that is a bummer. Like you said PATIENCE!!! Sounds like your tired to boot... patience...

[JeepsAndGuns]

How exactly does a machine shop press these in? They don't use heat do they? Torch on new pistons and rods scares me... Or do you not have a press?

All the ones I have seen, have either a gas fired or electric heater that heats the small end of the rod enough to ease the insertion of the pin. AFAIK, they still press them in as they are quite a tight fit. I can understand why they are such a tight fit too, last thing I would want is to have a pin walk out once the engine got up to temp.