AA piston cylinder kit

[Left_coast*9]

Has anyone used the AA kit below (or any of the AA products for 911s)? Any feedback or info is appreciated. I am assuming these are not Nikasil but not sure.
AA part # 008 911 92S JE
Porsche 911S 2.7L 92mm JE P&C kit C/R 10.5:1 Cast Iron liner $1595.00

[Left_coast*9]

https://aapistons.com/products/porsche-911s-2-7l-92mm-je-p-c-kit-c-r-10-5-1-cast-iron-liner

Ok obviously not Nikasil, but seems like a decent option for rebuilding my 1974 7R case and making a nice street driver? Could one turn around and have these plated in Nikasil? Apologize if this has been beaten to death.

[lvporschepilot]

Very controversial topic of course, but many have used the above setup and been just fine. Run what you think is best. AA sells a ton of these things so someone is using them well but obviously not reporting on Pelican.

[Catorce]

Avoid the cast iron cylinders on 911 motors. I have used AA cylinders on 356s no problem, but a cast iron cylinder does not belong on a 911. Pony up, get a used set of cylinders, and send them to US Chrome to be nikasiled. You'll be far better off....

[Trackrash]

The set in the link has a CR of 10.5 - 1. AA apparently used to have a set with 9.5 -1 CR AND biral cylinders. That sounds like a better setup.

I agree with Catorce. Get a used set of aluminum Porsche cylinders, Have them refurbished add new pistons and have a motor that will have lasting value.

Trying to save a few dollars on a 911 rebuild is false economy.

[lvporschepilot]

I'm not going to get into this discussion noting metallurgy or thermodynamics, nor where heat in an engine is primarily housed and dissipated post-combustion, and where engineers decided water-cooling was required first, I'm just plain not getting into any of that, but I will say from a business perspective AA has sold hundreds of sets of 911 cylinders.

A group of businessmen's collective livelihoods in this small and fickle industry depends on selling a product of a certain quality, albeit an ambiguous one to some. AA would be the first to know if something is of such substandard quality that none could be safely sold to a point they would be extremely foolish to continue selling given that the favorite American pastime is indeed the lawsuit. Word-by-mouth to others in any businesses is the most powerful tool to build-up or destroy one's business, and AA is still standing and doing well. Just saying.

[Catorce]

You should ABSOLUTELY get into the metallurgy here and go find out why Porsche stopped useing Biral cylinders when they moved from the 356 to the 911. From that point forward, all 911 cylinders have been light alloy.

Biral is simply not an appropriate material for a 911 cylinder; it doesn't matter how many of them have sold, and it doesn't make it right. No serious 911 build will be accomplished with Biral cylinders.

[lvporschepilot]

Nope. Not going down this rabbit hole. I can only advise you review engine overall heat transfer, turbulent convection in an IC engine, and radiative heat transfer and environments that experience the most significant heat. MIT and University of Illinois did some great work on this in the 80s.

[Catorce]

Give me a break. I hold 3 patents on air cooled porsche motors and I make the only reproduction cases on the planet. There is very little I don't know about the motor.

If Biral cylinders were so good, Porsche would still be using them.

[Left_coast*9]

Thanks everyone. I can see from this and other threads that this is a controversial subject. I hope that my budget doesn't force the issue. As I get closer to needing to make a decision, I'll be in here much more picking your collective brains.
Here is another thread on the subject:
2.2E DIY Rebuild

[Catorce]

Originally Posted by Left_coast*9

Thanks everyone. I can see from this and other threads that this is a controversial subject. I hope that my budget doesn't force the issue. As I get closer to needing to make a decision, I'll be in here much more picking your collective brains.
Here is another thread on the subject:
2.2E DIY Rebuild

It's not controversial at all. You can buy a good pair of core Alusil Kolbenschmidt pistons for 500 bucks. US Chrome can coat them with Nikasil for 1000. Then, the JE pistons you are looking at cost $850 or so by themselves.

So for $1595 you could have the wrong cylinder for your motor or for $2350, which is a mere $750 bucks more, you could have the right stuff.

If you already have core cylinders, the price is basically a wash.

And as I said, I ACTUALLY OWN a set of AA Biral Cylinders. They are on my 356, which had Biral to begin with. Quality is good for that application.

[Trackrash]

The reality is Porsche used iron cylinders up to 2,4 liters on its bottom tier motors, the T.

My take is for a street driven, mildly tuned motor up to 2,5 liters, iron cylinders with 8.5 to 1 CR would be OK.

For a 2,8 liter with 10.5 to 1, probably not the best choice IMO.

I only mentioned birals, since I read that AA used to offer them. The link above is about iron cylinders.

[lvporschepilot]

Originally Posted by Catorce

Give me a break. I hold 3 patents on air cooled porsche motors and I make the only reproduction cases on the planet. There is very little I don't know about the motor.

If Biral cylinders were so good, Porsche would still be using them.

I will preface this by saying I own an automotive component manufacturing company. I exclusively manufacture A LOT of Ferrari components. I have to be extremely careful with regards to materials and components considering the liability and how particular FNA/Ferr UK (Ferrari North America, and Ferrari UK) are.

But this, my friends, is why this rabbit hole will go unbothered. I like everyone here too much to unpack this thing, but I will agree the best option with longest service life potential is indeed what you suggest, but you should see what old Ferrari F1/312 and Dino/Boxer engines run, and what modern made turbo VW bug (OLD bug engines running silly bar pressures) engines are running, just saying we might not shut out what everyone else has deduced as well.


Old 911 engines are not cutting-edge technology, nor were they when they were new considering the F-1 liquid oxygen rocket engine was around (thing is so cool, 1.5m lbs of thrust), I digress. I have no doubt Porsche had not the ability to produce isothermal images of their various heated engines, nor have access to many other tools available in the last decade or so which are particularly helpful in deducing what materials are best. BMW clearly used this tech well as they very successfully brought back magnesium blocks, which was only possible by way of knowing precisely where it needed to be strengthened. The N54/55 blocks from BMW actually use cast iron cylinder sleeves, while the B58 uses a ferrum plasma spray which creates a thin layer (.3mm) or iron on the cylinder wall surface eliminating the need for a sleeve. Awesome tech, and those engines crank all manner of power.

I commend Porsche for moving to a tech which undoubtedly proved to be more efficient for the consumer and ultimately Porsche with fewer warranty issues (until emissions Mag cases that is), it was the right thing to do, but honestly, how many of us drive these things enough to really have to worry if the thing will go 300k miles? Racers maybe? I've never placed more than 150k miles on any engine let alone a sports car engine, period. But that's just me.

Enjoy your day all

[Catorce]

I have nothing against iron cylinder sleeves. Your mention of them in this thread is comparing apples to alfa romeos. My 997 Turbo that's punched out to 3.8L with big turbos uses a Darton style ductile iron sleeve. It's the only way to make big boost.

What we are talking about here is cast iron cylinders, which is an entirely different discussion. They are cheap and heavy, which is why Porsche used them on their T engine. When it was time to move the performance bar higher, they moved to an alloy cylinder.

That move alone speaks volumes....

[Left_coast*9]

First off, thanks to our host for this site. No disrespect for considering parts not offered here (at least I didn't see them available on Pelican but I am new here LOL). Next, a set of Mahle or LN Engineering PCs are like $3.5-6k. That to me seems exorbitant . Granted, this is my first Porsche, a 1973 911T Targa, so I guess I am not quite up to speed with how much these cars cost. My car will be a weekend driver, occasional long distance freeway and backroad driver here in the Pacific Northwest USA. I will never track it, never abuse it. If I put 50,000 miles on this car after I complete the restoration in my lifetime (I am 45 now), it would be a miracle. I have other cars that I enjoy driving too so I presume I will be spreading the leisure time amongst them (3 total). I am not loaded but we do OK and I can afford a Porsche as long as I do most of the work. Given all that, I really don't see how I can go wrong with AA PC kit at 90mm or 92 mm with the 9.5 compression ratio. I realize I might suffer in the resale dept. But I bet when the potential buyer sits in the seat and drives this car, they won't be able to tell the PC are not Mahle LOL.
My plans for the rebuild are a '74 2.7 case, the AA 90 or 92mm 9.5 CR kit, and basically stock 70.4 crank, rods, etc., Weber 40s, and not sure on ignition yet.
So am I being a naive newbie?

[lvporschepilot]

You’ll be fine. Drive her in good health. Cheers

[Catorce]

Why don't you do what I said and have US Chrome recoat your current cylinders and then buy the JE ones?

And your thought is to use iron cylinders in a mag case????

[Trackrash]

Originally Posted by Catorce

Why don't you do what I said and have US Chrome recoat your current cylinders and then buy the JE ones?

And your thought is to use iron cylinders in a mag case????

Isn't OE for a 2,4 T iron cylinders?

Problem is if the OP goes to 90 or 92mm cylinders he will have to bore the case and heads to match.

IMO if he stays with the stock, or near, bore for the 2,4 the AA cylinders should be fine.

[Catorce]

Maybe I misunderstood.....is he making as 2.7 mag case motor or is he making a 2.7 from a T motor??

[Left_coast*9]

Originally Posted by Catorce

Maybe I misunderstood.....is he making as 2.7 mag case motor or is he making a 2.7 from a T motor??

My car is a '73 911T Targa. Long story short, the case I plan to use for my rebuild is a '74 2.7L 7R mag case, which I acquired in short block form. So I have no 2.7L (or 2.4L for that matter) cylinders. The 2.7L short block has the used stock CIS pistons still installed. I was looking at the AA kit with 92mm PCs to fill the need, with a slightly larger bore (than the stock 2.7L 90mm) for a few more hp. Just thought of something I need to consider.....since I am planning on 40 webers I am wondering if the AA kit will work.
You guys have me thinking though....the newbie is wearing off slightly LOL if I can source good used parts and have them refurbished/recoated, even it if was slightly more $, it would give me the right set up (in the spirit of doing things right).......