AA Performance Products & GEX Options

[Craigers17]

It looks like AA Performance in Covina might have acquired the old GEX company that built air cooled engines. Please correct me if I’m wrong, but I don’t think GEX had a great reputation. My question is, … can anybody confirm this acquisition and has there been any quality control upgrades on the engine building side of things?

[Chad911sc]

I am building a 2056 right now with AA forged rods/AA pistons/AA biral cylinders/AA performance heads. I have gone over each and every piece with a fine tooth comb. The rods I actually bought from LN engineering because they are the AA brand, but they have been resized and checked. I weighed each rod and they were within .02 grams of each other. The pistons were also within .02grams of each other and look very nicely made with skirt protection. One of the pins was 1.8 grams heavier than the other 3, but it ended up helping me do my final balance because I had to take off .002 from the top of one of my pistons which I ended up using that pin on. The cylinders look beautifully made and were all exactly the same height.
Now the bad….the cylinder heads are a different story. My best friend owns his own performance cylinder head shop, so I’ve been able to make them work. I inspected the heads when they came in and I thought they looked good. I gave them to him to port and polish them and do a better angle cut on the valves for better flow. Also had them fly cut to get my compression in the 9:1 area I was looking for. I got the heads back from him and set them up to do my valve geometry, when I noticed that the rocker arm studs fit horribly in the head itself. When the stud is completely threaded into the head you can wiggle it back and forth. I am now disassembling them again to do time serts into the head so that it has a much better gripping ability to keep the stud into the head. I also upon a deeper look into the surface, found about an inch long crack on the outside edge of the head.
So my summary of the AA quality will never be fully known until I start it and hopefully have a long life with this engine, but everything looks very good to me except the heads. I think they will be fine now after all of the port and polish work/welding/Timeserts. But most people don’t have my connection with a cylinder head guy and all that work would be very pricey.