Matt! I'm crushed!! The article you scanned for the web site has some info
about the timing chain setup on the 4.7 and a picture. Basically there is a
chain thats driven off of the crank and goes to an idler in roughly the same
location as the cam would be on a pushrod engine. That idler then drives two
chains that power the camshafts at the heads with automatic tensioners. "Both
cylinder heads use a .443"/.429" split-lift intake/exhaust; 244/254 degree
split duration intake/exhaust camshaft with 18 degree overlap. " But it is not
a double in that there is not a double thickness of chain for each driven
sprocket. The cams each operate a set of needle-bearing roller rocker arms,
with opposite-end hydraulic lash adjusters acting as the fulcrum. The intake
and exhuast rockers are opposite each other almost like a Hemi. The intake
valves are 1.89" and the exhaust are 1.46". The pistons are moly coated to
reduce break-in scuffing with cylinder roundness being held to .00015" and
taper to .0006". There is an integral windage tray and there are no main
caps. Instead the crank is held in place with what Dodge calls a 'deck plate'.
A large cast iron assembly that bolts to the crankcase base with about 20
bolts thereby clamping down all 5 main bearings at once.
Sorry, went a little over-board there... I can see that once this engine
gets more popular, you will probably see some pretty wild performance gear
available for it!!
-------- Previous post -----------
Date: Tue, 29 Feb 2000 12:14:24 -0800
From: "Barret, Matt" <MATT_BARRET@earthtech.com>
Subject: DML: RE: Forged Pistons question-Sam 4.7L pistons
4.7L pistons are Cast Aluminum, Moly rings, compression ratio is 9.3:1!!
I haven't seen any info on the timing chain , don't know if its single or
double?
__________________________________
Sent: Tuesday, February 29, 2000 3:02 PM
To: 'dakota-truck@buffnet.net'
Subject: DML: Forged Pistons question-Sam
Sam, do you know the pistons in the 4.7 are forged or not? And the timing
gears-single or double?
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