AA Performance P&C kits, Anyone have experience? Options

[Kansas 914]

I have a 2.0L motor sitting around that was water siexed (rusted) ao this weekend I pulled it apart.

Needs new pistons and cylinders so I was looking at this big bore (no machining needed) kit.

Anyone have experience with this particular kit?

http://aapistons.com/index.php?main_page=p...;products_id=58

[Jake Raby]

I've had a couple people ask why I haven't responded to this post, so I figured I would.

The AA pistons haven't met our expectations for about 3 years now, I pulled all of them off the shelf except the 1.7 and 1.8 sets because nothing else is available for those engines.

The pistons had lots of issues and the ring pack wasn't impressive for high mileage use. I found variances in piston weights that were greater than the amount of material that could be removed safely. Deck heights were everywhere. Piston/cylinder clearance wasn't adequate and etc. I DID give this feedback to AA and their response was "many engine builder use our part without problem" (I talked to Thomas, the Owner and thats exactly what he said!)

Since then the cylinders themselves have been recast and are nice. We couple these cylinders with the KB pistons and Hastings rings after going through lots of steps to ensure they are compliant, have proper ring gaps and have proper skirt clearance.

The VERY FIRST set of the KB pistons I ever used were applied to my 912E engine. See this page on my site for a complete tear down of this engine after 160,000 miles of hard service with almost no maintenance and extended oil drain intervals
http://www.aircooledtechnology.com/index.p...&Itemid=112

Now.. remember that these were the prototypes of this 2.0 KB piston, being the first set that was ever made and usually the first set isn't the best set no matter what we are working with.

Here are the KB pistons from this engine after those 160K miles.
(IMG:http://www.914world.com/bbs2/uploads_offsite/www.aircooledtechnology.com-1095-1284474617.1.JPG)

When measured the rings gaps had only opened up .003, skirt clearance had worn less than a measurable amount and the pistons were simply cleaned up via our corn cob blasting technique, re-ringed with a new set of Hastings rings and resused. We honed the cylinders .0003 to clean them up (they were original 039 cylinders that now have over 260K miles on them) they were bored to 96mm when I built this engine the first time in 2002.

Here the pistons and cylinders are prior to reassembly with the new Hastings rings fitted.
(IMG:http://www.914world.com/bbs2/uploads_offsite/sphotos.ak.fbcdn.net-1095-1284474618.2.jpg)

Now the application of some "Snake Oil" engine assembly lubricant
(IMG:http://www.914world.com/bbs2/uploads_offsite/sphotos.ak.fbcdn.net-1095-1284474619.3.jpg)

Nice tight deck of .036 was attained on all but one cylinder, which was .035, achieving .001 variance between 4 cylinders is very hard to attain! Try that with AA pistons! Len decked my case perfectly which helped in the ability to get these deck height results, my registers were sagging very badly, like most. The engine is set up at 9.83:1, as I am looking to capitalize on the 37 MPG average this engine gave previously. I'd like to attain over 40, which I have done in the past with this engine in the previous state at peak.

And here it is completed and ready to test the prototype throttle body on the engine dyno, before going back into my 912E for another 150K+ miles of service!
(IMG:http://www.914world.com/bbs2/uploads_offsite/sphotos.ak.fbcdn.net-1095-1284474747.1.jpg)

Once I complete the engine dyno evaluations, install the engine into the car and get chassis dyno results I plan to make an extensive thread describing what needs to be done to "rebuild" a RAT engine after high mileage.. I'll share all the details of this engine there.

The bottom line is the AA pistons provide service for entry level engines and those that don't have high expectations for building high mileage, or super well blueprinted engines. For their cost they are a viable alternative for low performance applications. As with any Chinese made component you have to understand that the attention to detail isn't their biggest attribute and that should you have issues with them gaining technical support could be a challenge. If I had to choose one primary grip about these pistons it would be the ring packs that they use out of the box.

Don't take this post as an advertisement, because we are not the only people that sell the KB pistons.. We also don't have the cheapest price on them, because of what we do to them thats "extra" that may not be necessary.

We have used KB pistons in applications that far exceeded what the pistons were designed for and were advertised to do. This includes using a set in a Road Race engine turning over 8,000 RPM for a full season! To date I have NEVER had a KB piston fail that wasn't the fault of some other primary failure, like heat or oil starvation. I can't even say that for the JE pistons, because I have had them rip pin bosses out for no reason on the street and track!

KB pistons are very tough, resilient to wear, don't rattle at start up and generally consume around 1 qt of oil in 1500 miles, which is normal.. They are very hard to beat, 90% of what I build run them because they just plain work.

Does anyone have any pics of AA pistons with extreme high miles on them??

This post has been edited by Jake Raby: Sep 14 2010, 08:39 AM