Engine tick sound after re-seal

[74er]

I could use a little help identifying the tick sound coming from my engine. Below is a youtube of the sound. Background: Over the past winter I re-sealed the engine. Good news is I don't have any more leaks. It's a 2.7 ROW '75. The changes I made are installing SC cams, SSI, and Bursch muffler. I have Alusul cylinders and I purchased #1 & #4 used cylinders as the originals were pretty bad. I had to install new rings on #4 because I broke one during install. I didn't do any valve work or even disconnect the rods. Tick sound increases frequency with RPM. My thoughts are broken ring (I haven't done a compression check yet) or maybe the new cylinder(s) are slightly set lower and the piston end of stroke lip created in the cylinder is contacting the piston ring. I have disconnected the belt and ruled out the alternator/fan. Has anyone ever encountered this?


20131029184109 - YouTube

[timmy2]

2 new cylinders and only one set of rings? Perhaps the old rings on the new cylinder aren't seating well. (Or new rings on old cylinder on different can)
Did you do a break in as per Wayne's book?
Anything in the oil if you did?

[DohertyCM]

Is the Fan rubbing?

That tick is way too loud...

a rocker might be loose?

[74er]

Thanks for the feedback. I suppose it is possible the new rings are not seating well but I just don't have any background to know what that would sound like. I have run the engine to operating temp. at higher RPM but not for the full 20min. as suggested in the book. I have driven it around the block a couple times getting the rpms up. I am nervous to run it with this sound. I did drain oil once and haven't found anything.
I had disconnected the belt to verify the fan/alternator is not the issue. I don't suspect rockers as I did the valve adjustment with engine out and could get a good feel on those.
Besides a compression check, how else could I go about finding the location of this?

[thumbdoctor]

Maybe its the video but the engine doesn't sound like its firing on all six cylinders. The tick seems to be half engine speed so valve train and distributor drive may be culprits. To prove whether it's a cylinder head or exhaust flange leak, try unplugging spark plug wires one at a time. If the sound diminishes, then its combustion / exhaust gas leaking. Another way the to check it in darkness.

[Jdub]

I hesitate to comment as I know little, but that sounds a lot like a manifold leak I encountered in working with 4-cyl VW engines. Best to you on this and hope you nail it shortly.

[74er]

Manifold leak did cross my mind. I thought I could see some of the shroud caught under the weber spacers but I re-set them and trimmed some shroud away. What's the latest in finding a manifold leak?

[DohertyCM]

I just remembered that I had a plug come out on the bottom of the heads next to the exhaust manifold. I think it was called a fresh air plug...some type of pollution thing....anyway if this plug comes out it will sound just like that.

Look on the bottom side of the heads and check to see if you have these plugs. The heads I had were a 76 or 77 S model...but they were not there with my 74 heads.. The plugs are about the size of a 10 bolt and go in with a hex key wrench.

I looked for a picture of what I am talking about but cant seem to find one...If I find I will post..

[DohertyCM]

The photo shows the plugs I am talking about...

[Flat6pac]

I cant tell from the video but I had worn out rockers in a 77 years ago that sounded like piston slap in the cylinder so much that I bought new P&Cs, installed, and still had noise, change out the rockers and all was good.
Bruce

[74er]

It turns out this was a damaged metal sealing ring between the valve block and the piston cylinder. I have to assume it someone got out of place during install but plan on checking cylinder height over again to make sure all is good.

[74er]

[Dpmulvan]

Bummer but at least you found it before it did any major damage