AA piston cylinder kit

[boosted79]

Deutz used cast iron and I think Biral later for their air cooled diesels that run forever. Wouldn't be my first choice for a Porsche but there is no question it will do the job.

[Catorce]

Originally Posted by Left_coast*9

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).......

OK, that clears it up a lot. With a mag case, I would definitely get some stock cylinders and have them recoated at US Chrome.

I am not just talking out of my ass here, I have actually done this numerous times. Also, I did this in the 2.7 that is in my 914-6.

You will find that the cost of recoating a set of cylinders and buying the same JE pistons as in the AA kit you looked at will cost not much more than the total AA kit.

[Left_coast*9]

Another option:
https://www.qscusa.com/collections/porsche/products/qsc-porsche-911-90mm-aluminum-nikasil-coated-cylinders-set

QSC Nikasil-plated cylinders, 90mm, $1568.


Obviously not Mahle, but this might take the hassle and headache of buying a used set of Mahles (who knows how many heat cycles, miles, whether in spec, etc) and having them recoated at US Chrome, etc. Any feedback or experience with QSC or opinions otherwise?

[Left_coast*9]

After a brief search, there are obviously a few threads out there. I am a good distance away from needing to make a decision, but definitely intriguing. Still interested in hearing from folks who have used these with success. There is apparently a vendor who sells these after evaluating/ measuring them - would be interested to chat with them too. Thanks all!

QSC Quality Specialty Components

[lvporschepilot]

Henry used to sell them and do QC with them and built a number of engines with them. I do not know his status with them now, but I recall him nothing the out-of-roundness is the issue with having cylinders replated, the replaters cannot guarantee under .001 and neither can new Mahle stuff, when he actually stated the iron liners he went through tested at about .0002 out, which is really good.

[75 911s]

^yes In my QSC research I would buy from Henry at Supertec as I saw a thread that stated he buys in batches and then quality control sorts them into same height groups. Obviously it is a chinese made cylinder if that matters to anyone.

Catorce, ::edit:: I guess nikasil is a type of chrome?

[Henry Schmidt]

I no longer use or recommend QSC cylinders. Too many quality issues. Ovality and flaking Nikasil just two of them.
I discovered a design error in one of the sets they sell and after informing them of the issue, they continued to sell the product without a redesign. This cylinder design caused catastrophic failure within a very short time/mileage.

The issue with both AA and QSC cast iron cylinders is that both companies use the same Chinese factories to manufacture the cast cylinder (conjecture based on previous experience with both companies) and both are way too soft.
We have/do use the AA biral cylinders (86mm) but we have them sized and Nikasil coated before they pass our QC.

[lvporschepilot]

Thanks Henry!

[Henry Schmidt]

As for using cast iron cylinders on a 90/92 mm engine: Bad Idea
Air cooled Porsches use the cylinders (fins and fan) to cool the heads.
Cast iron is a terrible heat sink when you're trying to transfer heat from aluminum.

You can use Biral cylinders if you limit the horse power and provide adequate oil cooling.

[Left_coast*9]

^Thanks Henry. I like the idea of good used Mahles and having them recoated. I see I just missed a nice used 90mm set in the classifieds for $700 ish. Is that a good price? How does one visually diffentiate between the Alusil and Nikasil cylinders? According to Wayne I don't want the Alusil, and in the early 2.7L years the Alusil and Nikasil cylinders were used interchangeably. How does one measure or evaluate whether they are out of spec? Buy from a reputable source? LOL

[Trackrash]

The rule of thumb is that Mahles have 11 fins and KS have 10. Almost all Mahles are nikasil.

The only way to know if they are in spec is to measure them with the appropriate tools OR have a machinist you trust, who knows these engines, measure them.

Both types can be re-coated with nikasil. BTW, nikasil is nickel silicon carbide.

Here is what my cylinders looked like on the motor I just finished building, that were in spec with the original finish.

[Henry Schmidt]

Originally Posted by Left_coast*9

^Thanks Henry. I like the idea of good used Mahles and having them recoated. I see I just missed a nice used 90mm set in the classifieds for $700 ish. Is that a good price? How does one visually diffentiate between the Alusil and Nikasil cylinders? According to Wayne I don't want the Alusil, and in the early 2.7L years the Alusil and Nikasil cylinders were used interchangeably. How does one measure or evaluate whether they are out of spec? Buy from a reputable source? LOL

Our experience is that Alusil when Nikasil coated is a better cylinder.
The higher silicon ration in the Alusil material is more stable at temperature.
Nikasil will bond to Alusil cylinders without issue.

Call Ken @ 911 Vintage for reconditioned 90 mm cylinders. I think they sell a fresh set for around $ 1,600 with no core cylinders required. 760-731-4911
911vintage@earthlink.net

[Left_coast*9]

Really good info, thanks for the replies everyone.

[Southbay356]

is US Chrome the only shop in the USA that does Nikasil-plated cylinders ?

is there only one grade of Nikasil ?

and when you get them back are they ready to use, and if not what do you need to do ?

Thanks for the info

[KTL]

Millennium Technologies in Plymouth Wisconsin also does the Nikasil plating

Yes they’re ready to install when you receive them back. AFTER you clean them to make sure there is no honing grit or blasting media debris on them