Jump to content

A learning opportunity


Bill Stoneberg

Recommended Posts

I can't wait, I get to learn some now skills in my life. I am so happy about this. (All the proceeding was said with much sarcasim).

Today as I was cruising along at 55 or so in my 64 Riviera, a horrible clatter started and the passenger compartment filled with oily smoke.

Got off the freeway as soon as I could but I feel it is to late. Something in the engine let go and probably took $ 3 - 5000 worth of other parts with it.

So now I get to learn how an engine and assorted other parts comes out then how a built replacement (if it still turns) I have goes back in. I get to search the garage looking for parts

that aren't on that short block I have and what I need to do to make it whole.

First I have to clear the garage floor so I have some room to work. Canoes and Kayaks are once again relegated to the back yard.

Just as it is time of year to drive the car…. What a pain in the butt this nice drive turned out to be.

More coming as I play CSI to find the cause of this all.

Link to comment
Share on other sites

What did the rest of the valve stem look like, diameter-wise? A while back, a guy brought a Pontiac 389-family V-8 to my machine shop associate's shop to get a valve job done. When he pulled the valves out, the stem of one valve, below the guide and above the valve head, was about 1/8" in diameter (basically, an "hour glass" inverted shape). It was not thin enough to bend, but was getting dang close to breaking. Kind of like the subframe bolts in my '77 Camaro were getting (hidden as they are) when they were replaced with grade 8 bolts.

Other failures have been in the area of the upper stem, where the retention grooves are. If the valves are designed to rotate (without the use of dedicated rotator mechanisms), the locks will be a little loose to allow for this. Over time, the grooves will wear and the valve keepers will fail to hold the valve stem against spring pressure.

We've seen what happened to the piston . . . what about the piston wall and the valve seat itself? When replacing "one" OEM-production piston with an aftermarket "replacement" piston, you'll most probably discover the weights to not be the same, especially if an OEM piston might be an oversize piston. Replacement pistons seldom weigh the same as the production pistons they look like. So, in the case of "one" being replaced, you'll need to get a digital scale (in grams) to weigh a good piston of the bunch and then weight the new replacement piston . . . matching the heavier replacement piston to that of the OEM piston's weight. This ensures that "factory balance" is maintained. Not quite so critical if the whole set is being replaced, though.

The question now might become how many of the remaining valves might have been getting close to have a similar problem?

And, of course, it's always nicer for these things to happen reasonably close to home, as in this case.

Please keep us posted on your further expeditions into the NailHead's innards.

NTX5467

Link to comment
Share on other sites

Yuppy. Swallowed a valve. I hate it when that happens. :( You better have the head checked for cracks also. Stuff pounding around inside can do a lot of dammage. I'm with NTX5427. Have all the valves taken out and checked. In fact, tear the whole engine down. Clean and check everything. Leave no stone unturned. You will be all the happier for future reliability. Oh, and Spark plugs are the least of your worries sunshine. ;) Dandy Dave!

Edited by Dandy Dave (see edit history)
Link to comment
Share on other sites

Brian, Yes the same Riv I was going to drive to the Nationals. I am thankful it didn't happen in the middle of nowhere, Wyoming. Would have been and expensive tow home.

My plans are to either go through this engine or replace it with already rebuilt 401 I have. BUT considering this head was a head I had built for afor mentioned 401, do I trust the other head ?

Bad thing is, I don't remember if I replaced all the valves or not when I had the heads rebuilt. I am sure going to look now, no matter what I do.

Going to pull the other head off after church today and see what it looks like and then the motor will be ready to come out when I have a chance. I will say this after working on it yesterday for 5 or 6 hours, I feel it today. My feet and shoulders are sore, not the same as sitting at a computer all day.

Link to comment
Share on other sites

Guest 42buickman

Bill, you have what is called " TWO PIECE VALVES". Just heard about them the other day, and one came into the shop last week, and now another that you have. Must be something new. Good Luck, Paul

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...