AA Pistons

[mike]

Hey Guys,

I got a 2110 and I'm looking at upgrading it to 2276. I've been reading up on the AA pistons and was just curious what the general consensus on their quality today.

I know there were a few threads last years that slammed their quality, but has it gotten any better? I'm looking at their true forge sets as I might go with nitrous down the road.

Thanks,
Michael

[martin]

I got the cheaper AA set and the pistons are nice, but the barrels badly needed honing to be straight.

[fifty-five]

I wouldn't trust them. I bought a 500 mile 2276 long block and it had aa pistons in it, that prompted a full tear down and rebuild. Is the money you save worth the peace of mind you won't have with the aa's?

[fifty-five]

Oh yeah there was nothing wrong with the engine. It was one of my good buddy's. So I was around for most of the 500 miles.

[gkeeton@zbzoom.net]

The shop I work at, Jim's Custom VW's, has used lots of AA sets with good success. We've used the 85.5's all the way up to the Stroker 94's. With some shops charging as much as $300 for a set of Mahle's these days, more, and more people are using the AA's. As far as quality goes, I don't think they have changed anything from when they first came out. 99% of the people that gave them a bad rap on the net were using them for what they were NOT intended for, i.e. trying to run 25+ lbs. of boost, or a 100HP shot of N2O. Mahle's would not have held up to that abuse. If you are at all considering using N2O in the future, don't fool around with inexpensive pistons. Just bite the bullet, and buy some Wiseco's or something better, then you will never have to worry about it. We all try and save money, but most of the replies I've read about that gave the AA's a bad rap were the people trying to cut corners with an inexpensive piston when they should have been using a race piston.

[Sam]

I have had the cheap AA kits in seveal engines I built for folks, one is my wifes engine. Never had a problem, but like others mentioned these were 2000cc area strokers   (2054, 1976, ect) that were set up to run 6500RPM or less, less than 140HP.   

My engine building philosophy is a little different than some:,
If a guy starts with a $200 crankshaft, may as well run $80 rods, $145 P&C, $350 heads, $250 carb, and so on. 
 If you start with a $1200 crankshaft, I'm gonna run $350 rods, $300 P&C or so, $1200 or so heads, SLR Cam/lifters, $800 carbs, and so on

So IMO, assess what you have so far for an engine and build on that with parts of similar quality!

[mike]

Thanks for all the feedback guys.

The honing of the cylinder I've heard is a must when getting these kits which I've already talked to a local machine shop that have done several. He mentioned that most of them needed a few thou opened up to provide the proper clearance.

fifty-five, Do you know if the set you had in your 500Mile motor was a forge kit or the standard kit?

I understand the risks of running N20 which is why I'm looking at the forged set. I would imagine this has significantly more strength over even the so called "forged" cimas.  I don't intend to run anything wild here, I'm just looking for a 50-75 shot. I'm more in it for the experience of building a nitrous motor, not looking to set any records at the track.


From people's experience, what's the average cost of getting a set of Wiseco done up for an aircooled engine? everything said and done with cylinders, pistons, rings, machining costs. $600?

[Ohio Tom (DdK)]

I have used many sets on different motors. Both for myself and others.
I have a set on my main race motor (forged version) that sees 8,000rpm every pass down the track. 3yrs on the motor so far.

I have had to hone them a few thou on some sets. Espeically if I'm building a turbo motor, weather Mahle or AA's I hone for .005"-.006" clearance.
I have had to hone both kinds.

Quality seems good and most sets are very close on balance right out of the box.
I like all the size options and upgrades you can get with them.

I also agree that if you really want to make some HP, you buy Weiscos or better.

I got a buddy who is having Weisco make a speical set of 92mm pistons that he's gonna use in those AA thick wall 92 barrels.
perfect for a turbo race motor.

[fifty-five]

I don't remember. I think may have been cast, but not sure.

[mike]

Thanks for the feedback guys! I'm going to shop around and see if Weiscos will still fall within the budget. I'm pretty sure it will as the forged AA aren't too far off.

[VW NOT V8]

I have had the cheap AA kits in seveal engines I built for folks, one is my wifes engine. Never had a problem, but like others mentioned these were 2000cc area strokers   (2054, 1976, ect) that were set up to run 6500RPM or less, less than 140HP.  

My engine building philosophy is a little different than some:,
If a guy starts with a $200 crankshaft, may as well run $80 rods, $145 P&C, $350 heads, $250 carb, and so on.  
 If you start with a $1200 crankshaft, I'm gonna run $350 rods, $300 P&C or so, $1200 or so heads, SLR Cam/lifters, $800 carbs, and so on

So IMO, assess what you have so far for an engine and build on that with parts of similar quality!

I would agree with Sam, for the most part. HOWEVER, take into consideration the cost of machining a case, whether it is new ($600 +) or used ($200 +). I would perform a search on this site for: AA Piston or AA Performance. Let the information you read be your guide.

Have fun,

Chris Andrews - The Mailman

[RhoadsVW]

I have used many sets in motors with no issues. In fact on start up they seem to have less crank pressure than with Mahles. Seal up very well.    Dave Rhoads

[Ohio Tom (DdK)]

I think that has to do with the ring package that they come with.
They do seal up but can take some time.
I perfer to use cast rings on all my builds.

[RhoadsVW]

Also the AA are better balanced than Mahle.  I have had Mahle's sometimes as much as 5 grams off straight out of the bax.  The AA's have never been more than 2 grams.  The Mahle's are a good piston but qualty control is down as far as getting sets closley matched.  Seems like AA uses a low tenison oil ring.  When I worked at building endurance off shore racing engines we always used low tension oil rings with our ring pack. I also agree with the Grant rings for rebuilding.  Very good rings.    Dave Rhoads

[cal 67]

I heard from the rep a while back that some of AA problems people were having had to do with using AA pistons and Mahle barrels. AA's are larger than Mahles so when they heated up they were seizing in the barrels and causing catasrophic damage. I've had three experiences so far with AAs and they've all been great. My personal pistons for my 1776 came within .5 grams of each other. The shop didn't even bother messing with them.