I tore down the front to get to the cam plate to see what's up. Found these goofy plastic/rubber plugs behind it. Huh? Never seen these before.

The passenger side had a metal cup plug behind it - visible in the first pic above. The driver's side did, too...way back in the hole, blocking the galley. Solved! many thanks too everybody who chimed in, especially Godscountry340.

Here's the driver's side:

Never seen them before either.

weird, a quick googleimage search seems to point to the plugs being in those holes.



are you saying the driver side plastic plug got pushed into the hole there blocking the oil feed to the lifters?

are those 9/32 plugs past the vertical feed in your picture supposed to be there too?

I've torn down many small blocks before and never seen those white plastic plugs.

The metal cup plugs seem to be hit and miss; some engines have them, some don't.

The 19/32 metal plug in the driver's side was installed way too deep - between the oil feed hole and the galley, effectively blocking all oil feed to the galley, and hence the lifters never getting pressurized oil to pump them up. It should have been driven in just to the front edge, with the oil hole exposed behind it.

Agreed, the front edge of the oil hole is ~.297" back from the front vertical face on the pass side & ~.383" on the drivers side. I have some Dorman 555-009 mini cup plugs that are ~.594" dia & look like they might be a hair too big (dia), maybe, not sure but iirc I have used that Dorman # in the past. I shoulda measured the height of that plug.

When I took apart the untouched 340 in my Dart last year. There were no metal plugs installed by the factory behind the cam thrust plate. My understanding that this was common or normal?
The new block soft plug kit had those plugs in it so I installed them in the front ends of the galleys based on advice here. I also remember someone saying to just install them flush with the surface of the block so not to block the passage that leads down to the #1 main bearing.
Again, good learning information here...

Ok, lots of posts but did I miss it - you did nothing to the front of the engine and all of a sudden these plugs move on their own ?

Is that what happened here ?

We bought this engine about a year ago as a never-fired fresh rebuild. I usually build my own but looong story short, we needed one in a hurry.

I swapped out the rear sump truck pan for a center sump car pan. While the pan was off everything looked real good: balanced rods and crank, bearing clearances right on, etc. We buttoned it up, primed it, and fired it. Ran great for about 5-6000 miles before the lifter tick became noticeable.

My guess is that the original cam and lifters were re-used. The lifters must have held their original prime until a couple bled down and wouldn't re-pump up. That's what started this whole mess. The drivers side never got any oil to the galley because that metal cup plug was installed way too deep, between the oil feed hole and the galley, effectively blocking it off.

As far as those plastic plugs are concerned, I don't think they had anything to do with the problem. I've just never seen them before.

Never seen the plastic plugs, something someone tryed for some reason???? Who knows. But the metal plugs started getting used around 1970. Should be flush with front of block. oil pressure supposedly goes up 10p.s.i. with the metal plugs behind the thrust plate. With solid lifters the plug on drivers side is intentionally driven in deeper to turn oil off. Some one might have originally set it up with plans for a solid lifter cam and switched plans to hyd cam and forgot they set it up for solid lifters.

Ding ding ding I do believe we have a winna.

This was bugging me last night, and got me to wondering if that plug was intentionally set in there deep - I mean it's pretty obvious with the oil hole right there staring you in the face.

So, your theory of blocking the galley for a solid cam makes sense. I've never run a solid in a small block, so I did some research and found the modest common method of blocking that galley is to drill and tap the hole from the #1 main saddle and install a set screw. Obviously the plug installed deep does the same thing.

Oh well, at least I know that front main bearing got plenty of oil!

Thanks again to everybody for helping me out.