35k miles isn't a lot for a valve job and blow-by in #5 shouldn't have hurt the valves. You can check relative condition of guides by rotating cam to open valves and check movement at valve head when you push valve head. You can check valve seat for leakage by rotating cam so valves are closed and filling combustion chamber with very thin oil. like WD40 and check for leakage at intake & exhaust ports.

How bad was oil consumption with old engine?

Paul Shovestul


Quote Originally Posted by Dave M
Helo again everyone,

I'm considering some comments made in my last post.

To reiterate, I'm swapping out the bottom end for a rebuilt one and found the head as seen below. Its not a great pic, but what we're looing at is #5 which had big time blow-by (super low compression, normal during wet test). The remainder of the valves have a thin brown coating which can almost be picked off with a fingernail (see the intake on #6). Other than #5 being a pig, there is no indication that the head should require a complete rebuild.

Its also important to note that this head was rebuilt < 50,000km ago, but obviously has a coating due to the high mileage (1/2 mill kms) and the bum rings in #5. What are my options here? Is there a way to clean this up without doing an entire rebuild. If I bring it somewhere can they tell me if the guides and seals are OK without breaking the bank? Can they/me clean this up safely/economically.




Not trying to be cheap, just trying to be cheap

Thanks again,

Dave M