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Noticed the engine ticking a few days back, and after tracking the sound down with my engine stethoscope, I popped off the driver side manifold.
Well, uh oh...found that the number three piston exhaust valve seal was burned, AND there were metal shavings around the spring. I just installed new valve seals last summer.
I was stumped on figuring out the source of the shavings thinking that the valve guides were bronze. My research yesterday taught me that these engines used steel guides.
Last night, Hudson and I removed the rocker arm shaft and confirmed that there is A LOT of play with the offending valve.
Damn. A screwed valve guide with the Homecoming show around the corner. I have decided not to take the chance with the 4.5h drive to Lansing and risk dropping a valve or seat into the combustion chamber. We are still gonna go, but we will just drive one of our other cars.
I have read that the factory valve guides can be tricky to remove and the is a risk to cracking the head casting. I am going to have the work done by the engine shop. For those of you that know, would I be better to have original style steel guides installed? Or, replace them with bronze guides? If the heads are a the shop anyways, i may as well have hardened seats installed as well. Any wisdom you can impart on my next steps would be appreciated.
Guess I'd better get a parts list sent off to Fusick for pickup at the show!
Oh well, small inconvenience in greater scheme of the hobby.
The factory heads do not have replaceable guides. The guides are just a hole machined into the cylinder head. Same with the valve seats. The cast iron replacement guides are more than adequate for a stock type engine.
I would not order or purchase any parts for the heads until you have your machine shop examine them. Different shops have different tooling and prefer different types of valve guides. Just like body and paint guys have their own favorite paints etc.
And to be honest with you unless the exhaust valve seats are badly worn I would not waste money on hardened seats. They really are not the problem that a lot of people make them out to be.
Roger that! That's some solid advice.
I will hold off on the valve guides… Just as well, because a Fusick is out of stock on them anyway.
I will just order up the stuff that I know will be correct… Like the actual valves, springs, keepers, gaskets,etc.
I wouldnt even order that stuff. Your valves might be fine with a cleaning and refacing. Your machine shop probably has a box of 1000 of the keepers. I tell my customers not to buy anything until we have looked at the heads. Also you never know what has been done in the past to a 60 year old set of heads that might require different than stock parts.
Let the machine shop thoroughly check the heads first and go from there. X2 on the hardened seats, they are not critical especially on a classic car. Inspect the rocker shafts for wear.
Do a compression test to rule out other problems before pulling the heads.
I wouldnt even order that stuff. Your valves might be fine with a cleaning and refacing. Your machine shop probably has a box of 1000 of the keepers. I tell my customers not to buy anything until we have looked at the heads. Also you never know what has been done in the past to a 60 year old set of heads that might require different than stock parts.
This is why I like to reach out to guys in this forum. Sage advice.
And I will run a compression test before pulling the heads.
Do a dry compression test first, if a cylinder shows good leave the test at that on that cylinder. If a cylinder shows low, do a wet test on that cylinder to see if the compression jumps up notably, if not it is a valve issue, if yes it is a piston/ring issue.
Do a dry compression test first, if a cylinder shows good leave the test at that on that cylinder. If a cylinder shows low, do a wet test on that cylinder to see if the compression jumps up notably, if not it is a valve issue, if yes it is a piston/ring issue.
Well, it was a nice weekend, so I was able to get through a bunch of tasks. One of which was getting the heads pulled off the engine! It was no easy task...thanks goodness for my engine hoist for lifting those heavy buggers out!
Dropped the heads off to the machine shop yesterday. He is going to give them a once-over this week and figure out what they will need and what parts I need to source - Just in time for Homecoming! He saw the metal head gaskets and said that they were the original ones. Interesting that this is the fist time this engine has been open. Testament to build quality.
Before I took the engine apart, I did both dry and wet compression tests. Only one cylinder was low. The low cylinder is the number 3 - which is the one that had the bad valve guide. So, I am hoping that the low compression number comes from the valve issues on that one. Compression test results
Here's a few photos! Intake manifold removed! Hudson is ready to tear into the head removal! Phew! Driver's side off and on the bench The combustion chambers and valves are in decent condition Both heads off!
