The engine is a fresh rebuild with 600 miles. I noticed that the heads were leaking oil between the head and the cylinder. Not much but enough to be concerned. So I pulled the engine and removed the heads. What would cause the head to leak. I also noticed some wear on 2 of the push rods. What would cause this as well?

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Wear on pushrods is from the spring wire holding the tubes. You didn't mount it correctly.

As for the oil, I don't see burn marks on the head to signal leaks between the head and cylinder so where does it come from? Was there oil in the cylinder (rings not seated/broken)?

The oil was coming from the bottom side of the head where the head and cylinder meet. You can see in the first picture. It progressively got worse. I mean it's not like it was dripping oil a lot but it was noticeable when I had the car up on the rack. Cylinders didn't seem to have excess oil in them when I pulled the heads with the exception of number 4 ? I suppose the next step would be to pull the cylinders and check the rings. I would think if the rings were not seating I would also have excessive crank case pressure

I have the same leak issue on my rebuild with 150 miles on it. I'll wait and see what happens when the rings seat. Then re-torque the heads.

My leak looks just like yours, but mine doesn't leave spots on the floor...does yours?

Some mechanics don't lap the cylinders into the head, were these? It's old school, but it ensures there's a clean smooth mating surface, something that you can't guarantee with machined surfaces. I've never had many leaks from machined heads, but never any with a lapped head. I'd be curious about other mechanic's experiences.

The outer rocker stand studs go through the head. I'm not looking at mine now to remember if it's both or just one, but you need to put sealant there to avoid a lead that looks similar to that.

Looks to me a bit of compression leak, especially in the 3rd picture on the right the oil looks blown away from the cylinder/head sealing surface.
The problem with oil there is that there the only source for oil at that sealing area is oil getting past the rings.
Retorqueing the heads may have stopped the compression leak but your rings should have seated by now, so there should not have been oil even with a little compression leak.

Jim

There's always a little oil in the combustion chamber, at least in all the engines I've torn down, and unseated rings aren't gonna cause a compression/oil leak at the cylinder/head join. There are a number of possibilities here: The case spigots have become distorted, the heads weren't properly torqued, the heads weren't properly surfaced (I've never been fond of lapping the cylinders to the heads because it can induce less-than-parallel surfaces), or you're not using head gaskets, which can take up very slight unevenness. My money's on the spigots.

The Cap'n

No spots on the floor, just on the pushrod tubs and a bit on the exhaust.

I don't know what the spigots are? Are you talking about the head / cylinder studs?

Fat performance did the engine work. I'm pretty sure they do not lap the cylinders to the heads. The landings on the case were paralleled. The cylinders were original 94mm cut to 96mm. The pistons are from AA and the rings are total seal. They also rebuilt the heads. New valves, seats, guides, springs. A pretty reputable shop. Heads are going back to Fat tomorrow to be looked at.

This is somewhat common. What usually causes this is an engine that running rich and losing ring seal due to the fuel washing the oil from the cylinder walls.

Those chambers look really rich and the fresh rings probably were not sealed well at all and that lead to this. Rich running on a fresh engine is a cylinder and piston ring killer. Fuel is solvent, not lubricant.

Yeah... That is quite rich. Can we assume you are running carbs?

Yes, And I know the idle jets were way to rich.

Thats exactly what the issue is. The unburned fuel and oil mix has to go somewhere and it finds its way out at the mating surface.

The head sealing surface doesn't impress me on those heads. Who did the machine work on them?

Fat Performance

Excuse my hijack,

But if running rich is the issue (according to Jake) and Lotus Joe knows the idle jets were making it rich, How would I cure my rich issue?

I have a stock 1.8L L-jet system on a 1911cc. Adjust the AFM?

Ok, so I'm going to clean up the heads, put the engine back together; lean the carburetor out and have Fat Performance run it on their dyno to sort out the timing / mixture. Stay tuned

The pics must not have represented the work very well, that looks nothing like Fat's work that I have seen.

Fat are good guys, they are the only competitor that we respect.

I use them exclusively for all my machine work. Fortunately they are 10 minutes from my shop. Great guys

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I use them exclusively for all my machine work. Fortunately they are 10 minutes from my shop. Great guys
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How much is dyno time? Is the engine going to be in the car or out? Can they do both?

I know you don't work there and I should probably give them a call, but I thought maybe you'd know.

Hope it solves your issue.

They use a bench dyno. I think the last engine I had done there was $400.00 for a dyno and tune.

Great info, Thank you!

Any resolve?