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Not a bad price for an old car. These were Chrysler's response to the Ford
GTHO and Holden GTR XU1
http://www.australianmusclecarsales.com.au/muscle/91880
Wally
Is that really a reasonable price? What year is that?
It's really nice though; really clean...But are 3 carbs really necessary?
lol
http://www.australianmusclecarsales.com.au/image/91889x500y420.jpg
chris_knows
Yes they had to have triple webers to get the 280hp (the E49 had 302 hp)
which was more than the 340 small block V8 option. It could do 14.8 seconds
way back in 1971 and that was with a three speed. The E49 could do 14.4
out of the box. The engine was locally developed/built and was probably
Chrylser's best ever hemi six.
Wally
Hell yeah! :drool:
SlipKnoT
Wally you live in Australia right?
You guys always got such cool cars. And from the looks of it, your guys'
Chargers were far smaller than ours. :thumbs:
SlipKnoT
It's a funny thing with human nature... you always want what you can't
have. Yes the Aussie cars were generally smaller footprints than the US big
arsed cars.
Wally
:laughing: Well you know what they say, "Where theres a will, theres a
way".
SlipKnoT
and you generally have what you don't think you want :mrgreen:
windsonian
Wally, I don't know anything about this engine, but in the pix that Chris
posted, it looks like the intake and exhaust are on the same side of the
head. All the hemi 6's I have seen, had intake on one side of the head and
exhaust on the other, which straightens the airflow across the
cylinder.
What makes this a hemi? Can you explain airflow through that head
please?
Inquiring minds want to know.
jcutsh
A rhetorical query I'm supposing:wink2:
The general arrangement on many of the sixes here in that era was for
counter flow heads. I think the idea was for colder climes where there was
some advantage in heating the intake manifold for better cold idle, but I
really don't know the reason. Of course the Ford six crossflow head made
here is prized in the US as a must have upgrade (I know cos I made a motsa
selling one :mrgreen: )
I guess a hemispherical head doesn't really care if the valves are
crossflow, counter flow, canted, etc as it's more a combustion chamber
shape than process.
Here is a bit of a yarn
(http://www.fastlane.com.au/Features/Charger_NZ_USA.htm)
Wally
Would there be any issues with non-homogeneous pressures with that setup?
Or does the compression stroke sort that out? I'd have thought that with a
cross-flow engine, you'd get a fairly even pressure gradient to get the air
in/out, but that one would be a little more complex. But then again, I
guess, the valves are (for all intents and purposes) open on diff'rent
strokes..... hmmm
sorry, just kinda thinking out loud ... or on the keyboard as it were.
windsonian
I'm sure there's all soughts of reasons for counter flow (casting ease,
production, etc). I never really understood the comment that crossflow flow
reduces blow through on overlap, because the bigarse valves were generally
close together no matter what the flow design.
Advantages I can think of for cross flow would be the obvious entrainment
of residual exhaust gas pocketed across the cylinder during overlap (i.e
"crossflow"), more even cooling of the exhaust valve so less radial
cracking, less lead oxide buildup, better swirl efficiency, etc. Canting
the valves is probably easier too, although I seem to recall the reverse
flow hemi had valves at a fair angle to the bore's centreline.
The old heads with one inlet and one exhaust valve had limits on the size
and lift. Valve to bore area ratios on these were often 0.22 to 0.25, while
twin valve setups can comfortably be up around 0.32 to 0.35. Average flow
on single valve heads is pretty poor, although it doesn't stop the
aftermarket suppliers sprouting how good their peak flows are on near
absolute vacuum.... strange really because invariably someone using these
heads will have the mother of all cams that limits maximum vacuum to around
12"hg (terrible dissapointment to some when the dyno, even with the
monotonous rigged figures, doesn't "flow" the hp touted. :wink2: )
Production twin valve heads are nearly always crossflow with some sought of
pent/hemi chamber. With the pent roof the flame front can accelerate easily
into the 30+ m/s, with just a couple of small quench pads and appropriate
squish height. With smaller valves the engine can rev harder, has less
rotational mass, the heat conduction on the seat/valve is much better and
of course bowls/ports are less confined to available cross section.
Preheating the fuel/air is no longer a desirable condition with injection,
so keeping the intake runners away from the exhaust manifold is beneficial.
Wally
Yes Wally I suppose it was. There are so many “wives tales” about the
hemi, I thought a little of your expertise would be nice. You did well.
The hemi has nothing to do with where the intake or exhaust are located on
the engine, as so many people think.
It is totally the shape of the cylinder portion inside the head itself.
Its main advantage, allows for more area to provide larger valves.
However, as you so expertly pointed out, those larger valves required
extreme canting which required drastic engineering in the valve train.
Many think Chrysler invented the hemi, because they patented the term. Not
so, I believe the first hemi came along in about 1903. BMW, Ford and
others all produced engines with hemispherical heads.
I believe Fiat had a marvelous little 500cc engine in the 30's with hemi
heads.
The six cylinder, which you Aussies built was a great engineering feat.
Not only for the heads, but the crank and rods and oiling are excellent in
that engine. That engine will accept amazing abuse. A job well done.
Yes, I used you my friend, forgive me, but maybe the little ones learned
something. Lol
jcutsh
