cheap ARP rod bolts

[rick@brubakerbox.com (Rick Alexander)]

Steve,

There are two components to balancing, rotational mass (crank, timing gear,
pulleys, flywheel already shaved or lightened as per your preference, and
pressure plate) and reciprocating mass (rods with bolts and nuts, wrist pins
with retainers, and pistons with rings). The rotational mass requires the
special tool that your machine shop has. It supports the main bearing
journals and spins the assembly. Each bearing support is independently
locked out so that each end can be balanced by itself. The crank is done at
each end then the next piece is added and balanced then the next etc. until
the entire assembly is balanced. This should take your machinist less than
an hour but remember you will be paying a little for the machine and his
overhead as well. The reciprocating mass can be done with a good gram scale
and a die grinder or dremel. Weigh each piston (with rings, wrist pin and
clips but not necessarily assembled) and compare. Slowly remove material
from the heaviest until they are all the same or at least 0.5g from each
other. Use a fine cutting tool as you would like to have a smooth finish and
polishing later might upset your balancing. The rods are done the same way
except that you will do one end and then the other while trying to get their
total weights equal. The trick here is to support the end you are not
weighing in order to get a consistent measurement. I have found that hanging
the end that you are not weighing from dental floss to be the best method
for me.

It's not hard assuming you have at least a little patience. Good luck and be
sure to have fun.

Rick Alexander
http://www.brubakerbox.com
http://clubs.hemmings.com/hams/
http://clubs.hemmings.com/vwsrus/

----- Original Message -----
From: <jester@westfailure.net>
To: "Rick Alexander" <rick@brubakerbox.com>
Cc: <scirocco-l@scirocco.org>
Sent: Saturday, March 09, 2002 7:58 AM
Subject: Re: cheap ARP rod bolts


> On Fri, 8 Mar 2002, Rick Alexander wrote:
>
> > Seems steep to me. I had my rotational mass done for $62.50. I did the
> > reciprocating mass out to 0.3g which took me maybe an hour and a half. I
> > sure would like to make $111.67 an hour.
> Okay,
>
> Maybe i need an education here... I was going to take him pistons, rings,
> rods, crank, flywheel, pulleys etc. and have the whole lot spin
> balanced...
>
> But if they cant spin balance pistons & rods, i can do that myself &
> having just the crank balanecd would be a lot cheaper i'm sure, and i'd
> prefer it that way :)
>
> so, what to do here?
>
> thanks,
>
> Steve
>
>
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