Author |
Message |
Yehan73 Samba Member
Joined: June 18, 2008 Posts: 648 Location: Fort Collins, CO
|
Posted: Thu Oct 14, 2021 12:26 pm Post subject: Cutting off piston skirt |
|
|
I accidentally broke off one of the skirts from a piston in my 94mm x69 build. Are there any negatives chopping off the skirts from the other 3? I know this is done often for long stoke, but not sure anyone’s done it for standard 69? |
|
Back to top |
|
|
VWporscheGT3 Samba Member
Joined: September 01, 2006 Posts: 2073 Location: Gardnerville, NV
|
Posted: Thu Oct 14, 2021 12:35 pm Post subject: Re: Cutting off piston skirt |
|
|
the little slipper tip is what i imagine you are saying broke.
the Profile of a pistons skirt extends all the way to the bottom, if you look at on a profilometer or measured on a cmm, they have a whiskey barrel like finish to them , the slipper tips give the piston stability... so in short... dont friggin do it.. further more the force it took to break the tip off like put a big flat spot in the finish of the skirt....
i know it sucks, but do yourself a favor and buy a new set, AA's are cheap enough to not worry... save yourself the headache .
Second thing you brought up, skirt length and such on stroker pistons... its more out of necessity... the piston is less stable and will rock more but you need that skirt to be short to clear the crank counterweights at the bottom of the stroke. everything has its trade off.
-Trevor at UEM , no affiliation with AA.. FWIW |
|
Back to top |
|
|
FarmerBill Samba Member
Joined: July 25, 2017 Posts: 762 Location: New England
|
Posted: Thu Oct 14, 2021 3:49 pm Post subject: Re: Cutting off piston skirt |
|
|
Some parts vendors will sell you a single P&C, I know Aircooled.net will. |
|
Back to top |
|
|
74 Thing Samba Member
Joined: September 02, 2004 Posts: 7374
|
|
Back to top |
|
|
nsracing Samba Member
Joined: November 16, 2003 Posts: 9437 Location: NOVA
|
Posted: Thu Oct 14, 2021 7:09 pm Post subject: Re: Cutting off piston skirt |
|
|
How much of it broke off requiring a new piston??
YOu can trim off but you gotta do them all to all of them. Rebalance after. |
|
Back to top |
|
|
Jason37 Samba Member
Joined: April 21, 2004 Posts: 1027
|
Posted: Thu Oct 14, 2021 8:26 pm Post subject: Re: Cutting off piston skirt |
|
|
AA might also sell you just a piston. |
|
Back to top |
|
|
dogmeat Samba Member
Joined: September 08, 2021 Posts: 146
|
Posted: Thu Oct 14, 2021 10:31 pm Post subject: Re: Cutting off piston skirt |
|
|
yeah... how much broke off? and if its not too much and you are desperate, you don't have cut them all... only the piston in the opposite bay. the other thing to consider is the thrust face of the piston skirt. when it comes over center on the power stroke one side of the skirt gets more force against the cylinder than the other due to the angle of the rod on the crank pin. the wear pattern is easily seen on worn pistons. btw... opposite bays have opposite thrust faces... that means you piston may be better on the other side
but really... pistons are so cheap... |
|
Back to top |
|
|
Ohio Tom Samba Member
Joined: February 09, 2006 Posts: 1657 Location: Marshallville Ohio
|
Posted: Sat Oct 16, 2021 6:25 pm Post subject: Re: Cutting off piston skirt |
|
|
Weigh one of the good ones completely bare.
AA brand I assume?
I will dig thru my stash of singles and see if I have one close.
PM me the weight, and I will reply.. |
|
Back to top |
|
|
Yehan73 Samba Member
Joined: June 18, 2008 Posts: 648 Location: Fort Collins, CO
|
Posted: Mon Oct 25, 2021 9:13 am Post subject: Re: Cutting off piston skirt |
|
|
Thank you so much for everyone’s response. Tom thank you for your offer. I did have two new sets of AA’s, but was trying to see if I can get away with using the old ones. just got the new ones painted and ring gap checked yesterday. They are ready to go in. |
|
Back to top |
|
|
dogmeat Samba Member
Joined: September 08, 2021 Posts: 146
|
Posted: Mon Oct 25, 2021 10:35 pm Post subject: Re: Cutting off piston skirt |
|
|
painted???? |
|
Back to top |
|
|
Pruneman99 Samba Member
Joined: February 22, 2012 Posts: 5013 Location: Oceanside
|
Posted: Tue Oct 26, 2021 11:53 am Post subject: Re: Cutting off piston skirt |
|
|
If you paint them black, they run cooler. |
|
Back to top |
|
|
bw65vw Samba Member
Joined: August 04, 2020 Posts: 149 Location: Tennessee
|
Posted: Tue Oct 26, 2021 11:58 am Post subject: Re: Cutting off piston skirt |
|
|
Pruneman99 wrote: |
If you paint them black, they run cooler. |
Hmmm I always use hot pink. No really is this true?? Wouldn't the paint just peel off over time and with heat? |
|
Back to top |
|
|
dogmeat Samba Member
Joined: September 08, 2021 Posts: 146
|
Posted: Tue Oct 26, 2021 9:55 pm Post subject: Re: Cutting off piston skirt |
|
|
I've dealt with Glyptal, both applying and removing it, but that was on engine cases..... never seen paint on a piston. is that a thing??? |
|
Back to top |
|
|
evanfrucht Samba Member
Joined: July 24, 2016 Posts: 2180 Location: Laurel Canyon, CA
|
Posted: Tue Oct 26, 2021 10:58 pm Post subject: Re: Cutting off piston skirt |
|
|
Painting the cylinders makes no cooling difference whatsoever. It simply keeps the surface rust from showing...
Whatever helps you sleep at night people _________________ 1967 Bug ( the daily rod )
1964 Fury Wagon ( the pavement shredder ) |
|
Back to top |
|
|
|