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.
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
Cylinder Head 201 - Radius Cut Valve Job
This video covers the complete valve job process that your machinist might
perform. If the 100 series videos didn't help you identify and correct a
problem with your cylinder head, then this is the next step. This video is
brought to you with permission from my machinist in full 1080HD, and covers
cleaning up the head inside and out, preparation and setting up a radius
cutter, cutting all 16 valve seats, valve grinding, and spans 3.5 hours of
actual work in under 30 minutes. There's nothing like this anywhere else
THANK YOU BALLOS PRECISION MACHINE. Thank you for the professional
explanation and execution of a job excellently-done, and un-precedented
access to your facilities.
A valve job is done by re-grinding or replacing valves, and then having new
seats cut to match the faces of the valves you're using. There are several
different machines that might be utilized to achieve this result, but the
process is the same no matter how it's done. There are seat cutters that
utilize cutting stones. There are valve seat cutters with 3 separate
angles installed 120° out-of-phase, and there are single cutters with all
3 angles (radius cutter) that cut with one blade in one pass. The machine
demonstrated here is a Sunnen VGS-20 Radius Cutter. This machine (now out
of production) produces a gradual curved seat that's superior to the shape
of a traditional 3-angle seat. While a radius cutter does contain the 30,
45 and 60 degree angles, it does so without leaving any sharp edges between
My valve selection includes Supertech 1mm oversized nitride-coated
stainless steel undercut and back-cut intake valves, and 1mm oversized
Inconel back-cut Exhaust valves.
Inconel is a high-temperature alloy utilized in marine and forced-induction
performance engines that can handle more abuse than steel can without
melting. The other characteristics of the valves which are discussed
typically yield bigger gains in airflow than simply using a bigger hole and
a bigger valve.
Why I did this to a perfectly-good cylinder head:
I changed cams. Because the valves were previously recessed during another
valve job 9 years ago, my valve installed height was increased and this
raised the operating positions of my rocker arms. My new camshaft
selection dictates using the stock valve install height. The only
solutions to this valve install height problem are to either replace the
valve seats, or install oversized valves. I opted for the latter.
EASY, HOW I LAPP & GRIND VALVES. THEY DONT TEACH THIS TRICK IN SCHOOL, ONLY OLDSKOOL.
Automotive technician since 1991 I show how I do a valve grinding job
(Lapping Valves) at home using a vacuum hose, drill & compound, don't over
think it and don't assume it cant be done. learn how and save money on your
project with out taking your cylinder head to the machine shop. Valve
guides must be in good shape ( with no significant play or bent Valves
before you perform this task, but this procedure works very well if done
with care & quality. Go get it! and God bless.
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!!!
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.
Valve Lapping with Air Assist
Demonstrating of Valve Lapping on cylinder head (1.8L 4-cylinder head for
MGB) with Air (pneumatic) drill. Could not get good suction with Hand-Lap
Tool as some valves had small pits (no problem).
Upon inspection (after lapping), had a solid 1/8-inch concentric landing
A broad landing area (contact surface) is good for heat flow from valve to
block, to prevent "burnt valves". In the long run, valves with broad
landing areas will last longer and seat better.
How to polish a crank ( crankshaft )
Engine-Guru.com Presents a video on how to polish your crank shaft. Any
questions call 616-430-3114 ask for KYLE. We are located out of Grand
Fitting new valve guide seals without removing the cylinder head Suzuki Vitara
This is how you can remove and replace valve guide seals with the head
still on the engine. Normally you have to have the head off so you can fit
the valve spring compressor on to the head of the valve. I had heard of
this method but never tried or seen it done before. The only special tool
is a piece of string.
Watch the video and see the "Essex Red Neck" at work :-)
cylinder leak test how to check for bent valves
i did this video to help some of you not get ripped off when buying a
i will be doing many videos of how to test parts and what to look for.
please email me if you have question or what to learn how to test something
else firstname.lastname@example.org or email@example.com