kenneth d lewis wrote:
in part
are the heads are differant in the 1.9 and the 2.1 waterboxer engines

Kenneth and the list
Im not on the list right now but I have been reading it and I have read
a couple of threads about the AMC waterboxer heads and wanted to share
some thoughts frist its not uncommon for shops and importers to sell
just the 2.1 heads and say that they are the same AS 1.9 and thats ok as
long as they are replaced in pairs you could even go the other way and
use a 1.9 head on a 2.1 but that would be considered a downgrade

the other question I had read was asking what problems there have been
with the AMC
heads.I strip 2.1 engines every day and some come threw with used AMC
heads and those are the only ones I save to reuse. when I remove the
springs on the used heads I must file the intake valves at the three
grooves in the stem to get them to go threw the valve guide. in some
cases the three gooves in the stem are gone and the retainer has moved
to the point that the spring pressure is affected. the valves that are
installed in the new AMC heads (In this country by the only importer)
Suck
with that said you should also know that I personaly use 6 to 10 AMC
heads a week on long blocks. I have in the past had to fix heads for
customers because of the valves stem problems before I started replacing
valves. I have for some time changed the valves in every head I install
as does AVP. the AMC heads are a much beter casting and have a less
corrosive alloy. I have had no other problems with them other than when
shops install the exhaust system with a 8x25 bolt and a flat washer its
just to short and it strips the thread in the head. a 8x30 with a flat
washer is a must
I currently have pair of used AMC heads at a local shop with a flow
bench to see if we can improve the flow. I am also testing a differant
cam grind using reground stock cams that have more duration. stock cams
are much harder than aftermarket cams and are much less likely to fail
I hope to offer these as upgrades in the near future on my rebuilt
engines. I will keep the list posted as to when this will be offered.
for now please dont call or email me to discuss the upgrades I wont have
anything to say.
Bob Donalds
http://www.bostonengine.com