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modok Samba Member
Joined: October 30, 2009 Posts: 26740 Location: Colorado Springs
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Posted: Sun Oct 07, 2018 11:59 pm Post subject: AA pistons still not very good |
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So I'm an idiot. Even though I already know these things are shady I ordered another set of 92b pistons. Same deal.
The top rings are still the soft pose-able material.
Skirts are still .001" too big, even though the size is marked on top, they aren't that size.
Then I realize the pistons pins aren't cut square. yeah that's right the ends aren't 90 degrees. The worst one .006 runout on the end. I ground them square. So the pins are 2.480-2.487 length.
I check the pin end play in the piston, I have .016-.030 in the pistons with the longest pin, it's supposed to be less than .016"
What the heck am I going to do??? |
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fastone Samba Member
Joined: August 16, 2010 Posts: 211 Location: So Cal
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Posted: Mon Oct 08, 2018 12:08 am Post subject: Re: AA pistons still not very good |
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Stock up on old school cima's ? :) |
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modok Samba Member
Joined: October 30, 2009 Posts: 26740 Location: Colorado Springs
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Posted: Mon Oct 08, 2018 12:52 am Post subject: Re: AA pistons still not very good |
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I've been doing that.
AA's c-clips are .040 thick, empi ones that are .045, and they kinda fit in there, that improves it somewhat. |
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Zed999 Samba Member
Joined: March 04, 2018 Posts: 1240 Location: UK
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Posted: Mon Oct 08, 2018 1:19 am Post subject: Re: AA pistons still not very good |
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My cheapest type available AA 104's came with a chrome top ring which has sealed really well. I guess it's lucky dip with AA which is a shame as some of their stuff seems pretty good |
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bugguy1967 Samba Member
Joined: January 16, 2008 Posts: 4338 Location: Los Angeles, CA 90016
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Posted: Mon Oct 08, 2018 1:45 am Post subject: Re: AA pistons still not very good |
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Wonder what would happened if you shimmed them.
I guess you could always machine down some std pins to the length you need. _________________ "A petrol engine can start readily, run smoothly and give every appearance of being in good order, without necessarily being in good tune." - Colin Campbell, "The Sportscar Engine" |
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modok Samba Member
Joined: October 30, 2009 Posts: 26740 Location: Colorado Springs
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Posted: Mon Oct 08, 2018 2:09 am Post subject: Re: AA pistons still not very good |
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yeah replacing the pins seems most reasonable
Another choice is machine for double clips.
For now I... will probably put them back in the box and let them age a few years. Strange stuff. |
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Alstrup Samba Member
Joined: July 12, 2007 Posts: 7178 Location: Videbaek Denmark
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Posted: Mon Oct 08, 2018 4:16 am Post subject: Re: AA pistons still not very good |
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Well, not especially good. On the other hand, I have seen the same issues with Mahle units apart from the rings though |
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nsracing Samba Member
Joined: November 16, 2003 Posts: 9437 Location: NOVA
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Posted: Mon Oct 08, 2018 10:17 am Post subject: Re: AA pistons still not very good |
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How many times does it take for someone to learn their lessons is beyond me.
I used them once before when the AAs came out first time at the insistence of someone - cause the parts were sent to me free to try out. I was not impressed when I machined them - pot metal material looked to me then. Never again have I ever used them. There were some I have been sent to balance but they were not mine. I just do as I am told to do w/ the parts.
I love Mahle or CIMAs - that is it! The Brazilian Mahles so far have not changed the quality. I hope they never stop making them. |
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Hustlers67 Samba Member
Joined: September 21, 2011 Posts: 263 Location: Sydney, Australia
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Posted: Mon Oct 08, 2018 2:09 pm Post subject: Re: AA pistons still not very good |
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Whats the issue with the rings Modok? |
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Matthew Samba Member
Joined: January 29, 2004 Posts: 1760 Location: Eastern Tennessee
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Posted: Mon Oct 08, 2018 3:05 pm Post subject: Re: AA pistons still not very good |
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Are these the slipper skirt pistons? I had the weird rings with my 90.5 slipper skirts. _________________ 1965 Beetle sedan
Click to view image |
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vugbug68 Samba Member
Joined: June 25, 2006 Posts: 2696 Location: sacramento
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Posted: Mon Oct 08, 2018 3:12 pm Post subject: Re: AA pistons still not very good |
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Just pulled apart my friends engine that started making a noise on decel, (piston slap) they were brand new thick wall 92's, those are #2 and #4, 1 and 3 look fine. This engine couldn't have more than 4000 miles on it. I guess I got lucky with my 94's
_________________ 71 Super - Backroad Thrasher
66 Corvair - Weekend Cruiser
90 4 Runner - Muddin
Last edited by vugbug68 on Mon Oct 08, 2018 3:14 pm; edited 1 time in total |
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jpaull Samba Member
Joined: February 22, 2005 Posts: 3456 Location: Paradise, Ca
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Posted: Mon Oct 08, 2018 3:13 pm Post subject: Re: AA pistons still not very good |
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Regarding the rings being "Pose-able". I had the same issue with one of the AA Piston Pin retaining clips. It was Pose-able also. I could bend it into all kinds of shapes and it had no spring pressure whatsoever.
Scary. |
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mark tucker Samba Member
Joined: April 08, 2009 Posts: 23937 Location: SHALIMAR ,FLORIDA
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Posted: Mon Oct 08, 2018 3:15 pm Post subject: Re: AA pistons still not very good |
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why the fuck arnt they just forging them?? dont say china dosent have a forge....of corse it would take a few years to get those right if they started doing that. or they would be 1 forging and machine it for all 3 big bore sizes...94 sure would be heavy.... the forge cranks they forge polenty of chevy pistins, and the new ls& ford shit is small bore...wtf? just another reason to use v8 pistons in our vw's. |
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modok Samba Member
Joined: October 30, 2009 Posts: 26740 Location: Colorado Springs
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Posted: Mon Oct 08, 2018 4:57 pm Post subject: Re: AA pistons still not very good |
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Slipper skirt 92
I don't have anything against AA, I'm just reporting the facts.
Piston pins not being square or not fitting the pistons right is a rare enough problem in this century that nobody is looking for it, so, just a heads up.
I don't know why the rings are soft, or if it's good or bad, just very unusual. |
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esde Samba Member
Joined: October 20, 2007 Posts: 5927 Location: central rust belt
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Posted: Mon Oct 08, 2018 5:03 pm Post subject: Re: AA pistons still not very good |
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mark tucker wrote: |
why the fuck arnt they just forging them??. |
AA do make forged pistons, in addition to the hyperutectic I have a set here, and am going to look them over shortly. I'll post some pics if anyone is interested. FWIW the price for the AA forged is about the same as the Mahle. _________________ modok wrote:
Bent cranks are silent but gather no moss. I mean, ah, something like that. |
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modok Samba Member
Joined: October 30, 2009 Posts: 26740 Location: Colorado Springs
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Posted: Mon Oct 08, 2018 5:15 pm Post subject: Re: AA pistons still not very good |
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vugbug68 wrote: |
Just pulled apart my friends engine that started making a noise on decel, (piston slap) they were brand new thick wall 92's, those are #2 and #4, 1 and 3 look fine. This engine couldn't have more than 4000 miles on it. I guess I got lucky with my 94's
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The fact that the scuffing is heavy on the -edges- means it could have been overheated and/or not enough clearance. Also called "four corner scuffing". Just handy hint. A lot of people they see ANY scuffed piston and assume it was too hot or too tight, but often times that's not the case, tho in this case I'd say it's likely. |
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theKbStockpiler Samba Member
Joined: July 07, 2012 Posts: 2316 Location: Rust Belt
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Posted: Mon Oct 08, 2018 5:36 pm Post subject: Re: AA pistons still not very good |
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Why not ask the seller to send out extra pins or other kit? Makers/distributors of some products ; I don't know if piston kits are like this, ship extra parts with the big order for this reason.
Would the Teflon buttons work? _________________ My beetle is not competing with your beetle. I have the yellow beetle in my town. There is a red one, a green one ......
Use all safety devices including a mask. |
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67rustavenger Samba Member
Joined: February 24, 2015 Posts: 9663 Location: Oregon
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Posted: Mon Oct 08, 2018 5:49 pm Post subject: Re: AA pistons still not very good |
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theKbStockpiler wrote: |
Would the Teflon buttons work? |
Not on slipper skirt pistons. The Teflon buttons would just fall out of the pistons and get chewed up by the spinning mass in the case. _________________ I have learned over the years.
Cheap parts are gonna disappoint you.
Buy Once, Cry Once!
There's never enough time to do it right the first time. But there's always enough time to do it thrice.
GFY's Xevin and VW_Jimbo! |
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modok Samba Member
Joined: October 30, 2009 Posts: 26740 Location: Colorado Springs
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Posted: Mon Oct 08, 2018 5:56 pm Post subject: Re: AA pistons still not very good |
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A piston pin is a 10-15 $ part.
The simplest solution is the best one, which would be to make a 2.5" piston pin that is 2.5 inches long. Measure twice cut once? jeez |
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67rustavenger Samba Member
Joined: February 24, 2015 Posts: 9663 Location: Oregon
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Posted: Mon Oct 08, 2018 5:58 pm Post subject: Re: AA pistons still not very good |
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esde wrote: |
mark tucker wrote: |
why the fuck arnt they just forging them??. |
AA do make forged pistons, in addition to the hyperutectic I have a set here, and am going to look them over shortly. I'll post some pics if anyone is interested. FWIW the price for the AA forged is about the same as the Mahle. |
esde, Does AA manufacture their own forged pistons?
When I ordered my TW 92's. I was admittedly a little buzzed.
I ended up ordering, AA TW 92 barrels and JE forged pistons.
When I checked the order the next morning I discovered the error.
Now that I see this thread. I'm glad I fucked up my order.
I did however change the rings for a set of Grant rings. They look exactly like what was on the JE pistons. I wonder if JE pistons come with Grant rings.
When I tore my engine down. I did find light scuffing on one piston. But nothing to cause me to be alarmed. _________________ I have learned over the years.
Cheap parts are gonna disappoint you.
Buy Once, Cry Once!
There's never enough time to do it right the first time. But there's always enough time to do it thrice.
GFY's Xevin and VW_Jimbo! |
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