RE: [Chrysler300] J cylinder head exhaust seats

["'John Grady' jkg@xxxxxxxxxxxxxxxxx [Chrysler300]" <Chrysler300@xxxxxxxxxxxxxxx>]

Really does sound like valves were destroyed , due to not sealing/cooling,
but only when very hot. Like the propane engine. Exhaust blowing out of head
vent had to be a wildly wiped out guide(s) , beyond wiped out, destroyed, as
burned exhaust seats would normally  leak into exhaust system , not valve
cover ; one guess/postulate is exhaust valves were red hot due to not
seating (held off head for whatever reason, including seat recession into
head, or seizing in guides,  although more likely when hot,  first, they
grew in length (as they do, for sure) and took up clearance if solids, hung
slightly open, meaning no valve head cooling (which cooling happens only
when on seat, like the machinist said). The red hot valve (from whatever
reason) then also expands sideways, especially at bottom,  either locking in
valve guide or chewing up guide really bad if at all tight in guides..maybe
even if it was a correct fit in guides, at normal high temps, and also burns
up the oil that would lube it .. might bend push rod , or let push rod fall
out.

 

Some have commented that perfect circle type valve seal add to this, by
letting too little oil into exhaust valve guide ; Bob Walker at Hot Heads
says put no aggressive seals on exhaust valve . There is pressure in there
will tend to push oil pack, unlike intake

 

That guide having wiped so bad,  kind of points at guides eventually
hanging up valves , they were not able to close fully, hot stem did not go
back into lower part of guide when really hot, wrecking them. That damage
could happen on one several minute run. But first cause could have been
lash, too. If valve head did not get so hot , due to the not touching seat,
would not have stuck /hung off seat, or damaged the guide. 

 

That the car was apparently running OK before this running at full / high
output, says valves were obviously  not cooling , only when made very hot,
not that they had leaked all of a sudden that day,  due to slow recession
over a long time, or engine would have been running poorly before the  high
speed runs..it does not recede into head in 20 minutes? ..but maybe a combo
of those two things..some recession ,=  results in some too tight valve
lash, if solids. Before this, when was last time lash checked if solids? (
do not know what cam is in it) . How often did Chrysler say to check? Have
no idea.

 

Whatever, all these things are factors in a decision, which remains an
individual thing , no right or wrong . Anyone know if George's J or Don
Cole's K had hard seats? ( both never went fast!) ; I wonder if max wedge
heads have hard seats? nascar? NASCAR probably do, you really need it there
.

 

While on this, last series of posts on setting B block solid lifter valves
seemed to end that the person doing work, sorry forget who, was going to set
them hot. If set hot , it would be really good to post here the resulting
cold clearance before closing up valve covers, just to get a feel; for how
much , and which way it changes..

 

All good stuff..

 

John

 

PS, hydraulics do not get excessive lash, so they will touch and will cool,
even if seats recede  ; so a failure of exhaust seats w hydraulic cam points
right at seats/recession, the issue in question-- or ? sealing issue due to
material or gas problems of some kind?? . Hard to sort out what happens/ can
happen  with solids, lots of variables can hang the valves slightly open no
matter the gas is. Checking lash on solids periodically is even more
critical,  if gas quality causes recession.you can catch it. 

 

From: Michael Moore [mailto:mmoore8425@xxxxxxx] 
Sent: Thursday, May 22, 2014 11:55 AM
To: John Grady
Cc: Jamie Hyde; Chrysler300@xxxxxxxxxxxxxxx; bob marco; Jim; Paul Sebring
Subject: Re: [Chrysler300] J cylinder head exhaust seats

 

Here's my experience-My 300H had a major rebuild in 1984 done by Lee
Hamilton Racing Engines in Quincy Illinois.A top notch rebuilder of the day.

 

My wife and I flew back to Quincy and ferried the car back to California
with no drama. I was burning leaded high test gasoline at the time.

 

>From 1964 until then, it had been our family car, making several cross
country trips. After a paint job and a Gary Goers interior, we began taking
the car to shows on the West Coast and Canada.

 

Gradually, leaded premium disappeared. The engine then had 10000 miles since
overhaul. 

 On one trip to a WPC show in Victoria, we were driving the car especially
hard. It was very hot and we were trading off using the busy coast route or
the hotter inland route . Much of the trip was mountainous. I was driving
well over 90 going uphill in very hot weather.I was even trying to see what
the speed coming out of second gear was on a full out acceleration. I think
it was around 100. 

 

I noticed a change in exhaust note eventually, and by the time I got to the
show, I had exhaust gas coming out of the oil breather and the valve cover
paint was blistered. After the show, I began the long trip home back to Los
Angeles. I called Ray Doern, or he volunteered, or I volunteered him, but we
ended up in his back yard in Portland. Several local members of the 300 Club
dropped by to look and offer suggestions. I finally decided that no matter
what, the problem was the head(s), and it had to come off. Ray had offered a
bed for us. We began in the late afternoon to pull the heads in his back
yard. By 9 pm, we had the heads in a Portland machines shop Ray knew. It was
a big automotive machine shop whose chief machinist seemed very
knowledgeable. The valves needed hardened seats he said as the valves were
burned from inadequate cooling caused by lack of lead, poor sealing and hot
gasses blowing through the exhaust valves and guides  etc. 

 

The heads were promised by 2 the next day. Ray left me with a car to run
errands in and the next morning Connie and I cleaned up parts, repainted the
valve covers, got a gasket set and prepared the engine for the heads. As
soon as the heads were ready, we painted them and the intake manifold the
proper color, let the paint flash a bit and carefully installed the still
wet heads. Later that afternoon, we were running again. We cleaned up and
took the Ray and Cindy Doern out to the best steakhouse they knew of,
celebrated success. We departed the next morning and returned to LA without
incident. The most significant damage was a valve guide worn completely
through the guide and kissing the head casting. The theory was that once the
exhaust valve was burned enough to leak, hot gasses traveled up through the
guide leading to the guide damage. The message I got from the shop manager
was that  the 413 in hot weather, uphill, driving hard as I was really
needed hardened seats. I accept his opinion as god knows he has replaced
enough of them to see what's going on.  And, why would I NOT have had the
hardened seats installed at that point?  I recall the job cost me $400
including new valves and hardened seats.        

 

 Mike Moore

 

On May 22, 2014, at 8:12 AM, 'John Grady' jkg@xxxxxxxxxxxxxxxxx
[Chrysler300] <Chrysler300@xxxxxxxxxxxxxxx> wrote:

 

  

 

Hi Jamie, despite the mad rush to put these in, has anyone on server
experienced that failure (which is specifically, what? ) on B engine exhaust
seat without inserts? Can be an issue , I would expect,  on marine or truck
engines under high loads, but car engines,  I have some trouble buying it.
Do not have those in any heads on cars I have built or owned, never had any
problems since 62(!) , and inspected engines with 100k + on them at
teardown, no evidence of anything. I suspect it is a rumor grown large, from
the 283 camp, but emphasize I have an open mind, would like to know of
someone who had this happen. What DOES happen??,(! Facts, from examination,
not magazine or machine shop opinions)??   If not perfectly done,  in terms
of fit ,  they DO fall out, totaling the engine. I do know of that happening
to a friend's engine . Leads to lots of mouth movem ent at machine shop
about why, blame you (somehow)  which does not bring back rare heads,  even
if made whole on $. Further, from engineering view, there is an inefficient
seam in heat transfer from inlaid seat to cast iron, solid iron transfers
heat better, and heat is the enemy. Plus,  amount of iron to water is
reduced, I think making it far far easier to crack it.  Not "breaking
through" but leaving .060 of iron is far worse in fact than breaking
through, as you do not know that.. Your machinist is a very smart guy.
Antifreeze leak takes out whole engine. (just went through that , cam was
round, all rockers totaled inside at shaft) . To answer your specific
question, there are ultrasound devices that can measure depth to water
jacket, but do you REALLY want to reduce that safety factor over group
think?

 

With respect to burning of exhaust, only engine I know of,  personal
experience,  that that happened on was on propane, and it was valve-- not
seat that was badly grooved and burned, that also makes common sense, plain
cast iron seat was perfect, not even needing grinding, new valve and Ok
since  . That seat REALLY surprised me, expected what you talk of,
especially with radially grooved valve right against it..but there you have
it. Destroyed valve,  seat fine.   Seat is surrounded by a large mass of
iron backed by water. Yet, apparently??  Valve has nothing to worry about,??
yet seat gets hurt, per rumor? Right. 

 

Some quality engines have induction hardened heat treated area around
exhaust valve, more for recession or wear than (?" No lead failure-which
specifically, is wha t??"?)  , Putting in seats probably nicely removes the
elaborate heat treat**  . B block might have that , they did something to
improve hemi, as early ones had factory stellite hard seats , believe on
later ones they deleted it.--- Without problems--- but maybe a really good
heat treat. For high performance engines, for sure they would not have
forgotten 55-58 hemi racing experience  in 59-64. Plus no exhaust seat
history on B blocks , (to my knowledge) unlike cheap brand x that does not
even have valve guides (except hole drilled in cast iron) , their heads may
burn. And they outnumber us.

 

All of this assumes correct adjustment of solids,--- too tight you burn
everything, all bets are off if valve is hung off seat when hot. 

 

My .02, ----do not listen to "everyone knows" BS, think it through.as you
are doing. Your thinking is right on. Further if worst prediction happens(it
won't) you do a valve job at 75-100k, still have your J heads, unlike
antifreeze and cracking worries.

 

** had that happen, machine ship proudly turned perfect C or D crank .010 to
"clean it up"  (read charge you)  which removes thin marine/  industrial
heat treat the 300 hemi cranks had. Something like nitriding, read that long
ago, as a costly feature of 392 letter car cranks . Took me a week to get
over that. Not sure I ever did.

 

John 

 

From: Chrysler300@xxxxxxxxxxxxxxx [mailto:Chrysler300@xxxxxxxxxxxxxxx] 
Sent: Thursday, May 22, 2014 9:39 AM
To: 'Chrysler300@xxxxxxxxxxxxxxx'
Subject: [Chrysler300] J cylinder head exhaust seats

 







Hello group, The machine shop that is working on my J heads asked me if
there is enough casting meat to put hardened exhaust inserts in the
combustion chambers with the large 300J 1.74 valve diameter? They are
reluctant to t ake a chance on not knowing if anyone has done the inserts on
the 557 J head casting and then ruining my rare parts by breaking into the
cooling jacket.  The senior guy in the machine shop has some experience on a
413 max wedge engine when they went to a 1.81 valve (he does not recall the
casting number of those heads) and broke into the jacket when they did the
inserts, since the heads were not as valuable to him, He just sourced a set
of 915's that were of a later casting and installed the large 1.81 seats
into them without a problem. The factory had apparently changed the mold
casting by then to provide more material in that area that allowed them to
install the hardened seat.  I do not want to run any type of fuel additive
as I would like to have the inserts added to my heads but of course will not
do the inserts if there is a chance that the 557's will be damaged during
the process.  Has anyone on the server installed hardened seats in a J? 

 

 

Jamie  Hyde

585-466-0067 cell

 







 



 



[Non-text portions of this message have been removed]



------------------------------------
Posted by: "John Grady" <jkg@xxxxxxxxxxxxxxxxx>
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