Balancing
TerryB
Should the piston and rods be balanced together as a unit or is it better
to do each individualy?
Where do you remove material on a rod?
Where do you remove material on a piston?
I tried a google search and did not find clear answers.
--
Terry B
AKA VDUBBS
Buggin in Bama
http://vdubbs64.tripod.com
Shag
>How close should the rods be in weight to each other?
>
>Should the piston and rods be balanced together as a unit or is it better
>to do each individualy?
From what I've read (and I'm sure I'll be corrected if I'm wrong),
"together." And you can even match up heavier pistons with lighter
rods to make combinations of pistons/rods that are closer in weight to
each other that way, making it so you don't have to remove as much
material. I've read the answers to your questions that follow, but
don't recall clearly what they are so I'll shut up for now. I mean
I'll shut up for this one particular minute in time. :-)
>
>Where do you remove material on a rod?
>
>Where do you remove material on a piston?
>
>I tried a google search and did not find clear answers.
---
"There's nothing wrong with a little shooting as long as the right people get shot."
- Inspector Harry Callahan
Steve
"TerryB" <Remove...@yahoo.com> wrote in message
news:Xns96289F202D2EARe...@130.133.1.4...
> How close should the rods be in weight to each other?
> Should the piston and rods be balanced together as a unit or is it better
> to do each individualy?
> Where do you remove material on a rod?
> Where do you remove material on a piston?
> I tried a google search and did not find clear answers.
http://www.aircooledtech.com/
Some info here you might find helpful. look at engine building/short
block/static balance
--
Steve Hewitt
67 Bug
Jan
Factory spec: 8 grams
MY spec: 1 gram, 2 g is easy to achieve with a cheap scale.
It's also important to know WHERE the weight is on a rod, lenghtwise.
They should match that way too.
> Should the piston and rods be balanced together as a unit or is it better
> to do each individualy?
Makes no difference. Shaggie had a good answer regarding mixing amd
matching pistons and rods to get a decent set with minimal work, but
since they ALL have to be SAME weight, and the weight should be
located in the same area...
... the only way to do it right is to weigh each piece separately, and
remove material from the heavier ones to match them with the lightest
one. I do rods and pistons separately. New pistons today are pretty
accurately the same weight, you rarely need to touch them.
Weights on a used set of stock rods are all over the place, I've seen
24g differences in a set of rods that came from the same engine.
(Surely it was rebuilt by someone in a hurry before)
> Where do you remove material on a rod?
This would require a picture. The Bentley book has one.
I might scan it and put it up on my website tonight. or maybe not :)
> Where do you remove material on a piston?
inside the piston, there are a couple bumps and bulges you can shave
to 1/4 of their original height. But you have to remove a LOT of
aluminum to lose 1g of weight. Luckily with good quality pistons (like
Mahle) this is often not necessary. I wouldn't worry about that unless
you find a difference.
If you see a 5g difference in piston weights, you need a new piston. I
don't think removing that much material would be safe/possible.
Jan
Jim Adney
>How close should the rods be in weight to each other?
Depends on how well you want them balanced. Your manual will list the
factory spec, but you can actually balance them much closer than that.
>Should the piston and rods be balanced together as a unit or is it better
>to do each individualy?
Balance all the pistons against each other. Balance all the rods
against each other. Rods should be balanced not only for total weight
but for weight distribution (known as end-for-end balance.)
>Where do you remove material on a rod?
The correct places are shown in your manual.
>Where do you remove material on a piston?
Inside the skirt you will see cast on bosses which have been turned
down on a lathe to balance them.
>I tried a google search and did not find clear answers.
I gather you don't have a manual. Get the correct Bentley for your
model. There's no point in trying to do anything like this without
proper guidance.
-
-----------------------------------------------
Jim Adney jad...@vwtype3.org
Madison, WI 53711 USA
-----------------------------------------------
TerryB
>>I tried a google search and did not find clear answers.
>
> I gather you don't have a manual. Get the correct Bentley for your
> model. There's no point in trying to do anything like this without
> proper guidance.
>
> -
> -----------------------------------------------
> Jim Adney jad...@vwtype3.org
> Madison, WI 53711 USA
> -----------------------------------------------
And you gather correctly! Whatelse would you guys be doing if we all had
manuals? It is on my list of things needed, but you guys are still a great
source of info.
TerryB
news:NVo2e.112151$vK5....@twister.nyroc.rr.com:
Now that is getting answers to questions and then some!!!!!!!!!!
THANK YOU STEVE!!!
I have just spent some time looking around that site and it has answers to
questions I did not know I had questions for.
--
Jan Andersson
http://www.kolumbus.fi/janandersson/VW/rods.jpg
The one on the left is *overkill*, and made for a race engine where long
life never was important.
Jan
TerryB
news:424C1A45...@rocketcom.mail:
> http://www.kolumbus.fi/janandersson/VW/rods.jpg
The thoughts of drilling holes had come to mind, but I knew it was probably
not good for a long life. LOL
What happened to the rods that were drilled? Did they bend or distort in
that area?
Jan Andersson
>
> Jan Andersson <bug...@rocketcom.mail> wrote in
> news:424C1A45...@rocketcom.mail:
>
> > http://www.kolumbus.fi/janandersson/VW/rods.jpg
>
> The thoughts of drilling holes had come to mind, but I knew it was probably
> not good for a long life. LOL
>
> What happened to the rods that were drilled? Did they bend or distort in
> that area?
These were carefully selected from used stock rods, magnafluxed, and
machined *considerably* lighter, plus carefully balanced to less than 1g
weight difference.
They lasted several seasons in an autocross car that saw dirt and
pavement mix on track,
140hp and over 9000 rpm regularly. Each race lasts about 20 minutes and
it's pure hell.
10+ races in a season, not counting winter season.
After that they lasted 2-3 years in my street bug, 8000rpm redline. (and
a heavy foot).
After that they were shelved for a while, and then I built another
8000rpm streen engine with them...
At which point, during break-in, one of them finally died. Taking a
case, piston, 2 cylinders,
and a head with it to vw parts afterlife.
http://www.kolumbus.fi/janandersson/VW/snaprod.jpg
Still, pretty good considering these only needed to survive one race
day.
Like I said, these were not designed to last. They were designed to be
lightweight and cheap. :)
Jan
Jan Andersson
Oh yea, the rest of them still checked out ok, but I discarded them
anyway.
Jan
tricky
Jan Andersson wrote:
>>Like I said, these were not designed to last. They were designed to be
>>lightweight and cheap. :)
>>
>>At which point, during break-in, one of them finally died. Taking a
>>case, piston, 2 cylinders,
>>and a head with it to vw parts afterlife.
Not so cheap then ;-)
Rich
TerryB
>> What happened to the rods that were drilled? Did they bend or
>> distort in that area?
>
>
> http://www.kolumbus.fi/janandersson/VW/snaprod.jpg
>
> Still, pretty good considering these only needed to survive one race
> day.
>
> Like I said, these were not designed to last. They were designed to be
> lightweight and cheap. :)
>
> Jan
I would think that you could use smaller holes and still retain most of the
strength. A street engine would/should last pretty well. Considering you
ABUSED these rods on the track and the street. Most of us do not go that
hard on our engines, as you do. LOL, no offense intended. My thought
would be that they should last under close to normal use and with smaller
holes and you could even add another hole or two and still hold up as well.
But, I will not volunteer to test this theory until I am financially set
for life, and at the current rate, that will be 10 years after death. LOL
I am just happy the wife has allowed me to expend what I am on my current
engine. It would be different if I were single, but the benefits are not
quite the same. Ahh well, enough on that subject. LOL
Juper Wort
> I would think that you could use smaller holes and still retain most of
the
> strength. A street engine would/should last pretty well. Considering you
> ABUSED these rods on the track and the street. Most of us do not go that
> hard on our engines, as you do. LOL, no offense intended. My thought
> would be that they should last under close to normal use and with smaller
> holes and you could even add another hole or two and still hold up as
well.
> But, I will not volunteer to test this theory until I am financially set
> for life, and at the current rate, that will be 10 years after death. LOL
>
> I am just happy the wife has allowed me to expend what I am on my current
> engine. It would be different if I were single, but the benefits are not
> quite the same. Ahh well, enough on that subject. LOL
>
>
Know that feeling very well !!! LOL. Just had the ' Either Bus or Bug has do
go'...speach... Managed to get away with selling the ICT's :-( for
now...
james
Jan Andersson
The rest of the RACE engine is pretty worn out after one or two race
days, so it should be rebuilt anyway.
Imagine what happens when you run 20 minutes flat out on a dirt track, 8
cars at a time, with no air filters. The cylinder walls alone will get
eaten away FAST, so the engine after a couple of races is no longer
competitive.
Also race rules include "must sell" clause, cars are sold for a fixed
(very low) price if there are any bidders after each race. Bidders each
get one "bid", then the winner is drawn. Price is less than what you'd
spend on a competitive engine. Team members often bid on each others'
cars as protection, so the car stays in the team. Bidders must have
valid racing license.
So.. minimum budget, maximum power, with strict parts limitations.
(heads must be based on stock heads, no welding allowed near ports...
not allowed to use true dual carbs, maximum of one carb throat per two
cylinders.... displacement is limited to 1649cc in "foreign bodies" and
1800cc in beetles..)
Jan
Jan Andersson
>
> Jan Andersson <bug...@rocketcom.mail> wrote in
> news:424C4410...@rocketcom.mail:
>
> >> What happened to the rods that were drilled? Did they bend or
> >> distort in that area?
> >
> >
> > http://www.kolumbus.fi/janandersson/VW/snaprod.jpg
> >
> > Still, pretty good considering these only needed to survive one race
> > day.
> >
> > Like I said, these were not designed to last. They were designed to be
> > lightweight and cheap. :)
> >
> > Jan
>
> I would think that you could use smaller holes and still retain most of the
> strength. A street engine would/should last pretty well. Considering you
> ABUSED these rods on the track and the street. Most of us do not go that
> hard on our engines, as you do. LOL, no offense intended.
Non taken :) These risks are taken knowing full whell what might happen.
The street engines I used these in were my "experimentals". I.e.
expendable,
if I learn something in the process.
I've learnt a whole bunch of stuff... of what not to do ;)
> My thought
> would be that they should last under close to normal use and with smaller
> holes and you could even add another hole or two and still hold up as well.
> But, I will not volunteer to test this theory until I am financially set
> for life, and at the current rate, that will be 10 years after death. LOL
hehe, same here...
I'm sure many will be tempted to try this, and I say go ahead if you can
afford
to lose what you have invested in the engine. never gamble with more
than what you can afford to lose...
And don't come blaming me if something broke. I'm telling you right
here, that something most likely WILL,
when you push the envelope hard enough.
> I am just happy the wife has allowed me to expend what I am on my current
> engine. It would be different if I were single, but the benefits are not
> quite the same. Ahh well, enough on that subject. LOL
That's what I'm facing now, so I hear ya :)
Jan
Joao Eliseu
>> I am just happy the wife has allowed me to expend what I am on my current
>> engine.
Yep...the same with me...and I'm lucky guy, because my two soon are very happy when
we all go for a ride on it...
Joao
72 Super 1302