http://cgi.ebay.com/ebaymotors/aw-cg...325480&r=0&t=0


I sooooo wanna click on "buy now" ?
:confused: :lol:

 

Only if you're building a "drag race only" engine. You don't want
to run aluminum rods on the street (they fatigue, even in drag
motors, and need to be changed periodically).

Dan

 

hehe...I dunno about aluminium rods...I'd be afraid they'd bend or something. I know they are used in no2 engines cause they absorb the shocks...but humm...I dunno. Starts at a nice price tho.


[Modified by Lohkay, 11:56 AM 1/14/2002]

 

hehehehe ;). Well if they are for nitrous.. i'm assumin they don't bend easy.. is anyone actually running Al rods? :lol: :boxing I'm crazy.

Fatigue? :(

 

Danno hit it right, Jenny, you don't want aluminum rods unless you drive for a few seconds at a time and want to change them at the end of the season.

Forged steel is our friend :)

Cory

 

awww but they are so pretty... ;)

 

Jenny the problem with aluminum rods is that they are stretching as your motor runs and they do get to the point where they end up snapping :( . Sure would be cool though ;) .

 

Yup, they do look cool. Any idea what they weigh? I'm just curios about how light they are.

KM

 

C&A website listed the stretch at something like .003-.005" not much more than regular steel expansion? They're just so cool :)

 

Then buy them and keep them on your coffee table. That way you can
continue to enjoy how cool they look even after you've finished your
new engine. (I'm sorry - couldn't resist :lol: )

 

lol :( not a single yea... not lookin good

 

Jenny, you would not be happy with them in the long run. They do
look cool (ok, pretty). Aluminum rods are exotic as far as engine parts go.
I've built a number of engines over the years with aluminum rods (including
blown alcohol drag boats and a "qualifying only" engine for a road
racer). So I've had some hands on experience with them.

What I meant by fatigue is that because of the properties of aluminum
(expansion, stretching, etc.) the strength of the rod degrades over
time and it will eventually break. They aren't good for engines that decelerate
under load (like in downshifting), because that tries to "pull" the rod apart.
This is why they are not used in road racing or endurance racing, only
in drag racing, and the racers change them frequently.

Also, because of the stretching and expansion, you have to run more
"piston to head" clearance (which means a wider quench gap) and more
valve to piston clearance to accomodate the aluminum rod. One of the ways
to "squeeze" more hp from an engine is to reduce the clearance between
the piston and head at the quench area, and you can't do that as well
with aluminum rods.

You also have to run a little more rod bearing clearance, again because
of the properties of the aluminum. This is not condusive to a realiabe,
long running street engine.

The other problem is they are very bulky (albeit still lighter than steel).
This extra bulk means you have to grind clearance in the block around
the pan rails and bottom of the cylinders. And since they are much lighter
than steel, you'll pay more to get the crankshaft balanced because it
will require more work.

Admittedly, it's very difficult to be objective when selecting engine parts
for a new combination (I have the same problem). I'm building a new engine
for my '85 and am using 6.0" Crower steel rods, and they are very "pretty."

Check it out:

http://home.austin.rr.com/dancurrie/ProjectVette.htm

It might be wise of you to call C&A, tell them what your objective is, and
ask them about running their rods in a street engine.

Dan :)

 

Somebody bid on them, so can't to the "buy now". :sad:

I re-read the seller's description of the rods and noticed they are
for "small journal" crank pins, which is the 2.0" diameter rod
journal. This is again popular to do in drag racing, but hasn't
been seen on factory cranks since 1967 on the 327. You definitely
don't want small rod journals for your engine (I think I remember
you're planning a 383?). In fact, you can't buy a 383/400 crank
with small rod journals, you'd have to have them ground down
from 2.1" to 2.0", which is .100" under, and most people balk at
going more than .010" under on the rod journals (although I'm
perfectly comfortable with .030").

Dan :)

 

lol yeah re-rad and saw that too... oh well patience. :) i'm getting myself into more trouble though.... CF:1 Jen:0

:)

 

:lol: :lol:

 

:lol: :lol: :yesnod:

 

Several of the top drag racers sell pistons and rods out of their engines after they have been used. You can pick up a pretty, used, signed one if you were really interested. Makes a hell of a conversation piece too. Someone even sells them with a clock in the "crank" end.

Cory