[Icelander]

Hello, im in a kind of a trouble here and i really could use your help here.
my case is that im rebuilding a Chevy 350, and the plan was to replace the rods and pistons, the new pistons weight 565gr plus piston pin and rings, don't know what they weight and rods that mesures 565 grams as well. so can anybody tell me if this is far away from the OEM weights ? will the engine vibrate like a rattlesnake on cocaine ?
Thanks and best regards. Kristofer.

[Notorious]

Anytime you replace parts in the rotating assembly, the engine should be rebalanced. It shouldn't be too expensive and if you don't, odds are you'll be sorry.

[Icelander]

I am afraid there ain't anyone here in Iceland that has got the equipment to balance the internals. but thanks for the answer.

[dawg]

sure there gotta be a machine shop around somewhere.
first off you gotta try and get the lest weight in your rotating assembly
crank-rods-pistons.
having the crank balanced is the most important
I have seen some just weigh the rods and pistons to get within a gram of each other.
you can take away some material in non critical areas to get within a gram.

[Icelander]

There sure are machine shops around but none can balance the internals, they all say the equipment is to expensive and the market to small, and shipping the internals to the us for balancing would be more expensive than buy a new 383 stroker kit from Summit, and why don't i just do that, i would if i could find one with pistons for a supercharger, i need the compression low, i want to run with the boost somewhere between 6 and 9 psi. I would use a 327 if i could find the right stuff for it, only pistons i found where the TRW L2441F and they fit with a rod that measures 5.8 in. ?? and where do i get a rod for a small Chevy that measures that, and then im back in my old shoes and need balancing.
But thanks for your interest guys and best regards. Kristofer.
P.S. The best thing for me to do is get the green card and move my butt over.

[dawg]

try performance automotive warehouse
http://www.pawinc.com/

[Notorious]

Originally Posted by Icelander

I am afraid there ain't anyone here in Iceland that has got the equipment to balance the internals. but thanks for the answer.

Admittedly I know little about Iceland beyond it's geographical location. But obviously they have cars there, which means they need their engines rebuilt sometimes. Therefore you must have automotive machinists there somewhere!

[oldbogie]

Originally Posted by Icelander

Hello, im in a kind of a trouble here and i really could use your help here.
my case is that im rebuilding a Chevy 350, and the plan was to replace the rods and pistons, the new pistons weight 565gr plus piston pin and rings, don't know what they weight and rods that mesures 565 grams as well. so can anybody tell me if this is far away from the OEM weights ? will the engine vibrate like a rattlesnake on cocaine ?
Thanks and best regards. Kristofer.

Stock chevy 350 pistons range from 500 to 550 grams, stock pins from 132 to 145, stock rod from 630 to 655. You weights of 565 for piston rings and pin are a lot lighter than stock and 565 grams for the rod looks a bit off, all in all though if your figures are correct the total is 1130 against for your parts against a range of 1205 to 1130. If your shaft is countered for the middle of 1167.5 you'd be a little overbalanced by about 3.3% on the shaft which isn't bad especially if you push the upper revs under hard acceleration.

Bogie

[Stroke]

only pistons i found where the TRW L2441F and they fit with a rod that measures 5.8 in. ?? and where do i get a rod for a small Chevy that measures that

You want aluminum, or steel?

http://www.rrconnectingrods.com/

[Icelander]

Hi, thanks for all your help guys i really appreciate it.
I did contact those rod makers and they are looking into it for me, thanks.
And then i started thinking....what if i buy a new crank and deal with some good shop in the us and get them to balance it for me ? ! if i weight the rods,pistons,pins and rings and tell them the total weight ? do i weight the big and small end of the rods separately ? or does it not matter ?
Again thanks for your time and help. Kristofer.
P.S. This web site shows what we ride in Iceland.http://www.bilavefur.net/album/index.php

[oldbogie]

Originally Posted by Icelander

Hi, thanks for all your help guys i really appreciate it.
I did contact those rod makers and they are looking into it for me, thanks.
And then i started thinking....what if i buy a new crank and deal with some good shop in the us and get them to balance it for me ? ! if i weight the rods,pistons,pins and rings and tell them the total weight ? do i weight the big and small end of the rods separately ? or does it not matter ?
Again thanks for your time and help. Kristofer.
P.S. This web site shows what we ride in Iceland.http://www.bilavefur.net/album/index.php

This fellow is in the state of Maine and contributes to this forum regularly: http://www.cncblocksnortheast.com/ I'd log on send him an email to see what he would suggest, he's a continent closer to you than I am.

My recommendation would be to get a balanced crank set consisting of the crank, bearings, rods, pistons, pins, and rings at a minimum.

For the rod, yes the big end and the small end are treated differently. The big end weight is considered rotating weight along with the rod throw and the counterweights. The rod's big end and rod throw portion of the crank is usually accounted for in the counter weight at 100% for a 90 degree engine. The weight of the upper end of the rod, the piston, pin and rings are accounted for by the counterweight at 50% of their weight. One of the first procedures in balancing is to get the each end of the rod and the total rod to the same weight for each rod. This holds true for the pistons, pins and rings. The counter weights are then adjusted to reflect the counterbalance needed for the common adjusted component weights swinging on the rod journal end of the crank.

We're actually talking masses here not weight per say. Mass is a weight times acceleration thing yielding G-force.

Bogie

[ap72]

ya got that backwards... wieght is mass X acceleration...

pounds is the standard equivalent to Newtons
slugs is the standard equivalent to kilograms

on earth gravitational acceleration is considered to be 32ft/s^2 or 9.81 m/s^2

Also, mass for any given object cannot change without modifying the volume or density of that object

Weight of an object can change anytime you move it in relation to another object, especially one of considerable mass (like a planet)

basic engineering 101

[oldbogie]

Originally Posted by ap72

ya got that backwards... wieght is mass X acceleration...

pounds is the standard equivalent to Newtons
slugs is the standard equivalent to kilograms

on earth gravitational acceleration is considered to be 32ft/s^2 or 9.81 m/s^2

Also, mass for any given object cannot change without modifying the volume or density of that object

Weight of an object can change anytime you move it in relation to another object, especially one of considerable mass (like a planet)

basic engineering 101

Tories, whigs; weight, mass; ying, yang it all gets so confusing.

Bogie