W/o a gasket, the oil pan sits flat on the block, it doesn't rock at all. However once I put the oil pan gasket in, there is about 1/8" gap on each side of the front and rear crescent moons. The oil pan will "rock" slightly side to side since this gap exists. Once the pan is tightened down the gap is gone, this is a 1 piece oil pan gasket, thick front seal.

Now I also have the multi piece pan gasket kit, with 2 other front seals that are smaller than the one on the 1 piece. All 3 do no allow the oil pan to sit flat. The front seal thickness varies from about 1/8" to nearly 2/3", yet none allow the pan to sit flat on the gasket.

Is this the fault of the oil pan? Or is this okay? I know why the front was leaking, the timing cover I bought did not fit right, I took an old stocker timing cover and it was obvious the one I had bought new and put on the engine was out of whack.

The Z28 SBC Oil pan is 90$ from GM, is it possible the oil pan I bought from summit is junk like the timing cover?

It makes me wonder if the oil pan should sit flat on the gasket, and if the oil leak was the timing covers fault, not the oil pan/gasket. The lip of the crescent moon on the timing cover did not meet the block, it was completely off compared to the stock cover I threw on to compare.

 

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The front two oil pan bolts always had oil on them, so the oil was leaking from up high, not low on the crescent, I'm thinking that it was the timing cover not fitting right as opposed to the gasket. However everyone I talked to said that there should not be a gap like that, but even if I use the thinest front seal the oil pan still doesn't sit flush. When I torque the pan down to the required amount (7 ftlb , 12ft lb in corners) there is no gap, the side rails have the same gap, but the rails never leaked. So I don't know the only leak I had appears to be from the timing cover, but everyone says there shouldn't be a gap like that. I dont' know what to do, I don't want to reuse the pan if it's going to leak, but what else am I supposed to do? The oil pan said it required thick front seal, so I got a thick front seal gasket.

 

i'm thinking that thick front seal is part of the problem.

edit: i see you have tried the thin type seal n/m.

 

that's normal. your "problem" is caused by the gasket materialnot being compressed. after it compresses you have a oil tight seal, if things go well. any more i trash the 4 piece pan gaskets that come in a gasket set and use 1 piece pan gaskets, way better gasket and way better materials.

 

What ede said.....get the one piece gasket. A little more pricey, but it goes in a place you absolutely don't want leaks....best thing since shoe laces!!

 

Normal.

The gasket must not only compress vertically (flat), but also it gets "squeezed" LATERALLY between the main cap and the oil pan's "crescent moon." This squeezing won't happen just laying the pan on the gasket. It takes some force to pull the pan down and squeeze the gasket between the main cap and oil pan.

 

With a one piece gasket, I assume it collapses enough to seal the corners of the timing chain cover and rear main seal housing... but is there any need for sealer?

I was planning on running sealer on the four corners, but I don't know if it's necessary or just a waste. I don't want any leaks, that's for sure... what's my best bet?