How to lap valves on a 1995 Eclipse Talon 420a head (non-turbo)
When my 1995 eclipse timing belt broke I knew that there was a 99% chance that the valves were bent in the process. I searched the internet for a good way to replace them, without having much luck. I figured I would try and come up with something myself, I figured I would document the whole process of valve lapping by video...hope this helps you if you are in the same bind as I was!!!
Cylinder Head 105 - Valve Job Basics
Valves not sealing? Valves not bent? This is how you fix that problem.
In this video I outline the basic valve job procedure. Cleaning the
valves, cleaning the seats, cleaning the combustion chamber and lapping the
valves in to make a better seal.
Here I cover the process start-to-finish. It's the same exact process for
pretty much all non-rotary combustion engines. It takes patience and
perseverance to do this job, but anyone can do it. Reference your service
manual for measurements and service limits. Everything else that's not in
your service manual is in this video.
I apologize for not having broken busted crap to work with in this video.
It's more beneficial to all of you when bad fortune falls on me because it
gets well documented, and many people watching these videos are looking for
answers. If you have bent valves, you will discover it quickly once you
chuck one up in the drill. You'll see the face of the valve wobble around
while it spins. You'll see evidence of this damage on the valve seat. If
it's bad, you may see damage on the valve guides in the form of cracks or
missing pieces where the valve guides protrude through the head ports.
Give all that stuff a good visual inspection. ...and if you doubt yourself,
never hesitate to get a second opinion or consult a machine shop. They
will have access to expensive tools that you wont find in your average
How to Reseat / Lap Valves (Basic Valve Job)
In this video i'm explaining how to reseat or lap valves in a flathead or
overhead valve engine. Also can be called a valve job, but this is not a
complete valve job. I also used to much valve grinding compound, it does
not require a whole lot. Usually when a engine needs this done is when a
engine has low compression that is found to be leaking around the valves,
or sometimes a engine will backfire do to the valves not closing
completely/properly. Thanks for watching.
Testing for Leaking/Bent Valves
--Please Read-- :)
Some of the best advice I can offer you about fixing your car is to search
for an online forum related to your car, or even for your specific engine.
If you have a popular car or engine, this can be an amazing tool in
diagnosing and fixing cars yourself!
1. Get kerosene, gasoline, or break cleaner.
2. Tilt head on its side, with the ports of the valves you're testing
pointing up and exposed.
3. Fill the intake or Exhaust ports
with the liquid you chose, make sure to use enough liquid to cover the back
of the valve head completely inside the port.
4. Look at the valve surface in the combustion chamber for leakage. (Let it
sit for several minutes)
5. If there is a leak, you could have a bent valve or just a bad seal of
the valve to the head. You might have to replace the valve, or just use
some lapping compound to lap the valve/seat to resurface.
6. Repeat for the other side if you wish.
7. This is a great time to replace valve seals if you have noticed they are
worn too much.
8. If you have any questions, please post them here and I'll try to answer
You just tilt the head on one side or the other depending whether you want
to test the intake or Exhaust valves.
I'm testing the intake valves in this video. I did this way because I
didn't have the leakdown test equipment, but also because I wanted to
replace my head gasket anyway. I wouldn't say this is the best way to test
initially if you suspect leaking or bent valves because it requires you
remove the head. Try just a regular leakdown test first. But if you're
taking it off anyway it's pretty nifty and doesn't require the leakdown
test tools. There are several methods to do this, this is just the one I
chose in my situation.