300WHP Supernatural 3.XX Coming Soon! (Page 8/54)
La fiera MAR 17, 10:48 AM

Some progress!!
Now to the balancing act. The top 4 pistons are exactly match @ 435g each. The lower 2 are a bit higher so I'm working my way down.
You can see the amount of metal taken out from all six so far.
The wrist pins are much easier to balance, the first 2 are @ 107g the other 4 are @ 106g. They'll be easy to match.

Stock piston= 488g
SN piston= 435g
Stock wrist pin= 142g
SN wrist pin= 106g

[This message has been edited by La fiera (edited 03-17-2018).]

mender MAR 17, 10:58 AM
The lower two are quite a bit heavier at 444 and 446 grams, so 9 and 11 grams over respectively.

I'm a little surprised at that discrepancy, most piston sets I get are not more than a couple grams either way. I match heavy pins to light pistons to reduce the amount of adjusting needed. Where are you taking material from for balancing the pistons?
Blacktree MAR 17, 01:11 PM
If I did the math right, that's over a pound (in total) removed from the pistons and wrist pins. Nice!

[This message has been edited by Blacktree (edited 03-17-2018).]

engine man MAR 17, 01:43 PM
with all the weight you have shaved off the pistons and rods I think you will need to have the crank balanced or you might end up with a bad vibration good luck it is a cool build
La fiera MAR 17, 02:31 PM

quote
Originally posted by mender:

The lower two are quite a bit heavier at 444 and 446 grams, so 9 and 11 grams over respectively.

I'm a little surprised at that discrepancy, most piston sets I get are not more than a couple grams either way. I match heavy pins to light pistons to reduce the amount of adjusting needed. Where are you taking material from for balancing the pistons?



The problem was that these pistons come in set of 4 and I bought 2 separately. The package of 4 were within a gram or two but the other 2 are off by a lot, 11g like you mentioned. But I'm getting there little by little.
To answer your question I drill little holes at low depth under the crown. I do it a little at a time and what I do in one side I repeat at the opposite side.

To answer Engine Man, The next step is to get the crank knife edged and balanced based on the weight taken off the rods and pistons and then the Pistons and rods will get Cryo threated.

Other advantage of these pistons is that they use a more robust set of ring thickness.
Stock rings
Top= 1.20mm
Second= 1.50mm
Oil= 3.00mm

SN rings
Top= 2.0mm
Second= 2.0mm
Oil= 4.76mm

[This message has been edited by La fiera (edited 03-17-2018).]

La fiera MAR 17, 03:29 PM


I'm a visual person and like the saying "A picture can say a thousand words" this is how much weight I saved on the pistons and rods combined and not counting the crank shaft after it gets knife-edged and balanced.
Will MAR 17, 03:54 PM

quote
Originally posted by La fiera:


Other advantage of these pistons is that they use a more robust set of ring thickness.
Stock rings
Top= 1.20mm
Second= 1.50mm
Oil= 3.00mm

SN rings
Top= 2.0mm
Second= 2.0mm
Oil= 4.76mm




I wouldn't call heavier, less conforming ring an advantage...
La fiera MAR 17, 07:13 PM

quote
Originally posted by Will:


I wouldn't call heavier, less conforming ring an advantage...



You lost me Will!!
La fiera MAR 17, 07:29 PM

This is an example of how I lighten the pistons. Some have more and some have less.
La fiera MAR 17, 08:14 PM
I have to re-match the rods because some how the ARP bolts threw them off balance!