I haven't run my car down the road since the rebuild (months ago, still not leagal or safe)but I have run the engine alot and run around the parking lot. The problem is I'm getting what I think is blowby coming out of my valve cover breather. When I cover the hole with my thumb and remove it I get a puff of compression.I did a compression check some time back and the cylnders were all about even. I'm useing a Eldebrock timing gear. I just ordered a double roller today in hopes that I have a valve timeing problem.I'm starting to wonder if I screwed up in installing the rings incorectly somehow, either upside down or top ring in the middle or something like that. I think I'm in denial about have a ring problem. Also the cam is a Compitiion Cams 286H. I know it is going to have a low vacuum signal, but it does have some and the PCV is working. Anyone have any ideas.

What kind of rings, file fit etc. What gaps set on top and second rings? What was your compression? Next I would buy a leakdown tester for 69. and this will tell whats going on! ;)

The rings are moly rings, they are not file fit. The rings are matched for the pistons by the factory.If I remember the compresssion was around 125psi in each. It's been several months since I checked it.

Thats a nice big cam in there! Love your website with the ol' Rat Fink! Cool animation too! Seems to me that your compression is low. I'd like to see 160-170psi with a new engine! Do the leakdown test! Goodluck! :D

I've ordered a leakdown guage tonight. The thing is the engine runs so damn good and strong.

Bad Rat, keep us posted to what results you find out on the leakdown test. This test will verify whats going on with your rings, valves,etc!

I say give it more break in time. The rings will hopefully seat better. I wouldn't worry about the compression testing.

try running a a positive vaccum breather to manifold or through air cleaner.

I am useing a PCV valve to the manifold.

rat,
All engines have some blowby, it is impossible to perfectly seal a piston ring. Any engine will build up crankcase pressure if you block off the breather hole like you are doing.
I also think you need to drive it some to put a load on it for the rings to seal. That is why I try to tell guys not to finish and install thier engine until they can either run it on a dyno, or drive the car for 40-50 miles. Letting a fresh engine sit around idleing is the worse thing you can do.

Your right about getting some miles on it, but I've never had an engine I've built do this. It will drip oil out of the valve cover breather after running a while.

Bad Rat 414
My Advice- get that car somewhere you can DRIVE it. Accelerate hard, then de-accelerate hard. Do this several times. What kind of finish stones where used on the walls? Was a deck plate used when honed? If no deck plate was used, the top of the cylinders are not truly round. A true "mirror"
finish on cylinders without deck plate hone is risky for seating rings.
My 427 has NO PCV, just valve cover breathers and there is zero blow by. Load those rings ASAP. Just my opinion.

Oh, I've done a few small burnouts with it, but nothing for any length of time. The block was machined by a machine shop and I told him what kind of rings I was useing (he asked)and he did use a deck plate. The block was .60 over I went to .090.