Pistons QSC 2,7

[crummasel]

Hi There,

while normaly i am involved in high performance applications, actually (strangely) i have a LOW performance application on a 2,7 CIS 165 HP.

Just crusing, short distance among usage, daily, even if in Germany almost no High speed highway need, just reliable daily usage. Is this (strange solution) an option on approx 8K miles/year?:

Porsche 911 92 mm Cast Iron Cylinder & Piston Kit | eBay

Anyone experience?

REAL experience appreciated.

Thanks and Greets,

Robert.

[Raceboy]

Andrew (Lapkritis) recently rebuilt a 2.7 with these cylinders, seems to have great results. Prepare for reading, this will take a while: Specific Question - ARP Head Studs on 2.7 Magnesium case - Insane?

[Henry Schmidt]

We caution against using substandard (read low quality) parts when building Porsche air cooled engines.
Our experience with QSC may be as comprehensive as any.
When we evaluated QSC cylinders we found that with Nikasil cylinders, we had to mix and match 3 different sets to find 2 usable sets.
With the cast cylinders, our biggest concern with quality was a very low Rockwell (hardness) reading. (real numbers not conjecture)
When fitting, the cylinder fins needed to be trimmed to before installation.
The most important issue is cooling. Cast iron offers inferior heat transfer which leads to cooling issue.
The Ps&Cs you are questioning come with cast pistons which are generally considered inferior when compared to forged pistons.

Could they work in a limited performance application? sure
Will they last as long or cool as well as Nikasil cylinders? absolutely not

[crummasel]

Absolutely clear and true.

As mentioned on 911 engines i do usually work on high performance applications for which i would never consider these for.

Here i am talking about a LOW performance application which can probably come up to working temperature much quicker, as the car will mainly be used for short distances. Environmental teperatures are moderate not higher than 30°C. So here i am looking for LESS cooling.

Sounds strange but its so.

[Henry Schmidt]

Originally Posted by crummasel

Absolutely clear and true.

As mentioned on 911 engines i do usually work on high performance applications for which i would never consider these for.

Here i am talking about a LOW performance application which can probably come up to working temperature much quicker, as the car will mainly be used for short distances. Environmental teperatures are moderate not higher than 30°C. So here i am looking for LESS cooling.

Sounds strange but its so.

Although I understand your position on cooling there is also the question of quality.
Fit and finish as well as low hardness numbers make these a poor choice if you want it to last even moderately well.
If you elect to use these cylinders, fit them before assembly and I would recommend Nikasil plating. This will ensure low friction numbers and extended ring and cylinder life.
Cheers

[crummasel]

Good point, Henry i will check that.
Usually when making engines the focus is the impossible between high performance, extreme long lasting and good fuel economics with good results.
This particular application will have the same criteria but more all weather short distance than performance, which is also a challenge kinda houswife's SUV.
So we are thinking more of condensate, daily use, mild summer but winter as well and cold periodes where the engine probably never meets its proper working temperature plus longer standstill times. WPC (Worst possible conditions). But longevity to be a must.
I absolutely do not trust the QSCs so anyone here with high mileage experience including winter use?
Unfortunately (and i mean only THIS particular application) these seem the only ones to feature steel barrels and we have a lot of high performance stuff in germany but not such.
BTW: i would plan to run them at some 9..9,5 CR for 98 pump gas.
Engine is a 165HP US non California Sportomatic and left mildly improved but standard and all old steel headbolts, no cams, just SSI's.


Thanks,
Robert

[Lapkritis]

Hello Robert,

I do have a few miles on these but with JE pistons to accommodate a higher lift cam. The pistons you will receive are CIS-E replica with snap ring cir-clips and not the symmetrical example you see in their catalog photos.

They are very well packaged; as my experience shared above shows along with many pictures, the width of the cooling fins was too great to allow installation. The fins likely have to be trimmed before fitting which is about an hour of time. I did send notice to the retailer of the defect in design but I expect that may or may not have reached the production floor.

Cooling - I added heat sinks to billet valve covers with milspec hard black anodize and also ceramic thermal barrier coatings on piston tops, combustion chamber of the cylinder head/exhuast port/valve and into the exhaust header pipe to assist with shedding heat that Henry was sure would be present. The only issue I found was getting enough heat into the engine when the temperature was below 45F. The warm-up time to 180F oil temperature was over 20mins and never exceeded 200F in cooler weather. The highest maximum temperature observed during the hot summer months was 215F in New England region climate which is similar to Germany. The vehicle is equipped with a fender mount oil cooler. I have now stored the vehicle for the winter but if I were to continue operation during the cold weather I would fit regular turbo lower valve covers to keep heat in the engine.

Henry has a bit of a personal quest against QSC which is apparent when he shares adjectives to dissuade any potential purchaser. The QSC iron have superior characteristics of thermal expansion more suited to an air cooled engine relative to the inferior aluminum that destroys the delicate engine cases with poor inherent design. If you tune fuel mixture properly and use a quality motor oil then you should expect service life from the cylinder which is the same as millions of regular vehicles with iron combustion chamber surface... which is to say quite a long time.

[crummasel]

Hi Andrew,
thank you, i have seen your thread. Interesting.
I understand you were wanting to compensate the mediocre cooling properties of the cast iron barrels.
I have been working on lots of T engines as well and i always have been astonished about the good wear and out-of-round readings of the old cast barrels even in completely worn out engines.
However, honestly i have to say on any engine i increased performances in significant values i have changed barrels to nicasils or birals and i will continue to do so.
The application i will be working on is completely different. Here i need the quickest possible temperature rise to operation temperature and it will almost never see full-throttle für longer than 10secs. It will unlikely ever see more than 150 Km/h (what a pity in germany :-) ).
But a good and stable all-day application with a majority of short distance, standstill over days, winter, and mostly inner city rides, one weekly longer ride on country roads at crusing speeds of some 120Km/h.
So i am thinking about cast iron barrels (i also like the idea of a slight increase of cc), 5 blade fan and a reduced oil filling.
Completely different from what i am doing usually.
I did not really catch what you were saying about the pistons which come with it. They deliver different ones than the ones displayed? Can you post a picture of the actual pistons, please?
I have noted the dissonances you had with Henry and i have to admit i understand his position: Since i am also doing engines since decades sometimes my lectures to others seem to sound quite arrogant. I try to keep an open mind though..
Also i understand your position, you do not like the stop-thinking-attitude which i like.
Henry has posted a lot of helpful input to this forum as you are doing also.
Different opinions on a hobby... ;-)

[KTL]

If looking for steel barrels/liners instead, you could look into the JB Racing cylinders

JB Racing - Porsche Engine Components

I realize you said you're looking for longevity and not looking to have max cooling, given the working environment. I mentioned the JB Racing cylinders only because you spoke of steel liners.

[crummasel]

Thank you, i know these but i am really looking for all steel barrels incl. the fins.
As far as i know the QSCs are the only ones on the market?
That they do them all-steel i assume is for budget reasons.
So i ask myself: How bad are they really? ;-)
Anrews experiences sound promising, Henrys input sounds prohibitive.
Any further experiences with these?

[Lapkritis]

Here are photos of the 92mm QSC:








Mahle RS and qsc side by side:


Qsc 92mm 9.5:1 911 piston:

[Henry Schmidt]

I’m not sure why but these threads quite often turn into personalities over substance.

I don’t have a personal stake in any of these products other than my head studs.
The information I post is based on observation not supposition.

The reason I don’t like some of the QSC products is the specifications of the products not the name.

When I say that the Rockwell is low, it’s because we measured it.

Mahle Biral or cast 84mm 96B 911
QSC cast............. 86mm 76B 356
QSC cast .............. 90mm 76B 911
AA cast .............. 86mm 82B 356
AA cast.............. 86 mm 86B Heat treated 356 (we heat treated them to try and improve the product, we also tried Cryo)
AA Biral ............. 86mm 92B 911
We like this product but feel the Rockwell is still too low so we Nikasil the cylinder reduce ring wear (friction) and increase cylinder life.

Another product we wanted to use but don’t is their aluminum oil filter housing w/steel screen filter.
It looks like a nice product but the filter element is rated at 45+ microns and I prefer 25 but no more than 35 microns.

Like many of their product, it’s not a horrible product it just doesn’t suit my specifications.

[crummasel]

Good info on hardness (pretty soft, the stuff) and thank you for the Photos! :-)

What do you think about their CE - gasket delete?

[Lapkritis]

Originally Posted by Henry Schmidt

I’m not sure why but these threads quite often turn into personalities over substance.

I don’t have a personal stake in any of these products other than my head studs.
The information I post is based on observation not supposition.

The reason I don’t like some of the QSC products is the specifications of the products not the name.

When I say that the Rockwell is low, it’s because we measured it.

Mahle Biral or cast 84mm 96B 911
QSC cast............. 86mm 76B 356
QSC cast .............. 90mm 76B 911
AA cast .............. 86mm 82B 356
AA cast.............. 86 mm 86B Heat treated 356 (we heat treated them to try and improve the product, we also tried Cryo)
AA Biral ............. 86mm 92B 911
We like this product but feel the Rockwell is still too low so we Nikasil the cylinder reduce ring wear (friction) and increase cylinder life.

"There is no Rockwell scale for tests on cast iron, nor is there one for steel sheets thinner than 0.15mm. In order to close this gap, there are devices that work with the Rockwell procedure (with pre- and total test loads), but with much larger (or smaller) and thus non-standardised test loads."

"Cast iron: always use HBW x | 3000. Due to the smaller homogeneity, it is recommended to use the highest total test load of 29,420 N."

"The steel ball penetrator is used for softer materials. The softer the material, the larger should be the diameter of the ball and / or the smaller should be the total test load. For instance, the materials that can be tested with the HRB scale (ball 1/16" – total test load 980.7N) are harder than the materials tested with the HRL scale (ball 1/4 "- total test load 588.4N). "

If you're on testing using Rockwell on the b scale you did this wrong.

Guidelines to hardness testing

[Lapkritis]

Originally Posted by crummasel

Good info on hardness (pretty soft, the stuff) and thank you for the Photos! :-)

What do you think about their CE - gasket delete?

Check my reply. Soft without comparison to a control... and experiment claims contradictory to correct methods. Bzzzz, try again Henry.

[Henry Schmidt]

Mechanical Properties of Gray Iron - Hardness

Hardness is the most commonly determined property of metal because it is a simple test and many of the useful properties of metal are directly related to its hardness. Within a class or type of gray iron, hardness is a good indicator of its engineering properties, but this relation is not useful between types of gray iron because differences in graphite structure have more of an effect on tensile properties than on hardness. Specifying the hardness at a designated place on each casting is an excellent method of establishing consistency of castings in production quantities where the type of iron being used has been established as satisfactory for the application. Compression strength does correlate very well with hardness for all types of iron because hardness is essentially a compression test. Hardness usually gives a good indication of tool life in machining, however, the presence of free carbides in the microstructure will reduce the machinability much more than it increases the hardness.

The Brinell hardness test is used for all irons because the Brinell test impression is large enough to average the hardness of the constituents in the microstructure. Rockwell hardness B or C scale tests can be used satisfactorily on machined surfaces where the supporting surface is also machined. Several Rockwell tests should be made and averaged, but extreme values should be discarded because of inordinate influence by a graphite flake or a hard constituent.

Quick question for you Andrew: how did you test your cylinders?

[Henry Schmidt]

The Application of Hardness Tester for Metal Casting

Rockwell hardness tester

Rockwell hardness tester is also commonly used in the inspection to cast iron. All the parts with smaller grains, if there is not enough space for the Brinell hardness test, can be tested by Rockwell hardness tester. For pearlitic malleable iron, chilled cast iron and steel castings, HRB or HRC scale can be used, and if the material is heterogeneous, several readings should be measured to get the average value.

Rockwell hardness test is quick, convenient and has small indentation, which can be used to directly test the finished piece. It is suitable for testing mass production of finished or semi-finished parts piece by piece.

[Lapkritis]

Originally Posted by Henry Schmidt

The Brinell hardness test is used for all irons because the Brinell test impression is large enough to average the hardness of the constituents in the microstructure. Rockwell hardness B or C scale tests can be used satisfactorily on machined surfaces where the supporting surface is also machined. Several Rockwell tests should be made and averaged, but extreme values should be discarded because of inordinate influence by a graphite flake or a hard constituent.

The Brinell hardness test is not a Rockwell test; they're very different. Not sure what you were doing or what setup you had rigged but the experiment description is already changing. First you said it was Rockwell test... now Brinell test? Which is it? It can't be both tests. If it is Brinell then we will discuss the integrity of the result.

Originally Posted by Henry Schmidt

Quick question for you Andrew: how did you test your cylinders?

Fuel, fire, miles and smiles. Thanks for asking.

[Lapkritis]

Originally Posted by Henry Schmidt

The Application of Hardness Tester for Metal Casting

Rockwell hardness tester

Rockwell hardness tester is also commonly used in the inspection to cast iron. All the parts with smaller grains, if there is not enough space for the Brinell hardness test, can be tested by Rockwell hardness tester. For pearlitic malleable iron, chilled cast iron and steel castings, HRB or HRC scale can be used, and if the material is heterogeneous, several readings should be measured to get the average value.

Rockwell hardness test is quick, convenient and has small indentation, which can be used to directly test the finished piece. It is suitable for testing mass production of finished or semi-finished parts piece by piece.

LMAO, you're reading me the catalog of a tool. Do you recall which machine, tool head and measurement method you used? I want to help you out here to understand what you did. Too funny.

[crummasel]

C'mon guys, I got the point.

Lets say QSCs are softer.

They do do not meet Henry's specs but Andrew's.

I would not use them on high performance applications but may be well off using them for a houswife's SUV application.

As to Henry i am concerned about tolerances, Andrew, whats your experience?

Any comments on CE-ring delete?
Any further experience concerning mileage?

Thank you.