A&A Piston Durability

[rick m]

I spent Saturday helping a friend tear down a motor that was smoking badly in a Bay Window bus. It was a 1915cc Type 1 with an Engle 100 cam, dual ports and stock carburetor.  No full flow, no filter on the motor, no additional cooler (just the dog house), no knowledge on why the air/fuel ratio is so critical to heat.  You can see the results.  They had a 34 pict on the 1915 with a 140 main jet but had made no other mods to the carb.

The owner drove the bay window from Reno, Nevada, to Phoenix. He stated that several hours of the trip he had to keep it in 3rd gear with a strong head wind against him. During that time the motor as losing power but he still got it into the Phoenix area. When called over to take a look at it, it still ran when I got to listen to it before tearing it apart.  The motor had all new parts so we were able to salvage the case, cam, lifters and miscellaneous parts.  

The A&A piston #2, literally melted but did not explode, crack, or come apart.  The wrist pin was dark blue from the heat.  The small end of the rod was blued as well. Was running some of the aftermarket "I" beam style 4340 rods (vw length).  

We are in the process of going through and redoing the motor with new 94's.  I am replacing the aftermarket heads with original German heads as the casting is much cleaner as is the airflow that can get through the head. We are also converting it to dual carbs.  Could not talk the owner into allowing us to full flow the motor (which I feel is his mistake) along with another remote cooler and fan. Also suggested adding a deep sump to give the motor some additional capacity while we have it down. May still win that battle before we re-assemble it for him.

All in all, seeing what the A&A Pistons went through in a heavy Bay Window camper bus....I would not hesitate to run them in a properly built street engine of any kind.

Rick M

[rick m]

Here is anothe angle of the A&A Piston after being punished for hundreds of miles.

Rick M

[Zach Gomulka]

Could not talk the owner into allowing us to full flow the motor (which I feel is his mistake)

I wouldn't build the motor then. It's got your name on it, if he blows it (which isn't out of the question, it sounds like he has zero sense of mechanical sympathy), guess who is gonna catch the blame?

I would build an indestructible anvil of an engine. Go thick wall 92's, Kadron's or maybe a single Zenith, something simple carb wise. And over cool it to death, but retain the factory thermostat.

[Cheesepanzer]

^^^   agree 100%.  A full-flow set up doesn't cost much to do and just makes good sense, especially for an engine that will be worked pretty hard across its service life.

I also completely agree with increasing the induction.  The 34 pict set up should be "sunsetted" in that beautiful Arizona sun, and small dual carbs added.  36 DRLA's would be great, or 40 IDF's.  K-dogs are fine as well.

Just my $.02.

[rick m]

We already talked the owner into dual carbs.  Single pict on a 94 bore motor is rediculous. Crazy what some of the bus people try. The motor needs more air. As for the rest, I am not building the motor...just giving input as well as some strong recommendations which I hope the owner heeds or he is headed for repeat trouble. Will post some shots when done helping the friend who is assembling it.

I am a fan of the K-dogs for low end grunt on bus motors too. I have used them on inexpensive builds and they work great!

You can lead a horse to water but you cannot force them to drink.  I have seen VW people repeatedly take the cheap route and they pay for it over and over.

RM

[Torben Alstrup]

We already talked the owner into dual carbs.  Single pict on a 94 bore motor is rediculous. Crazy what some of the bus people try. The motor needs more air. As for the rest, I am not building the motor...just giving input as well as some strong recommendations which I hope the owner heeds or he is headed for repeat trouble. Will post some shots when done helping the friend who is assembling it.

I am a fan of the K-dogs for low end grunt on bus motors too. I have used them on inexpensive builds and they work great!

You can lead a horse to water but you cannot force them to drink.  I have seen VW people repeatedly take the cheap route and they pay for it over and over.

RM

Single carbs on a 1914 is absolutely doable, BUT it takes quite abit of carefull selection of parts to make it work. That engine was a disaster even before it hit the roads. I´m sure that on top of it all it ran lean. If the cam and lifters are salvageable, the Kads are a nice and easy solution to the induction problem.

As for the durability of AA pistons. IF those pistons are older than approx. 3 years, the AA pistons were sub quality to Mahle. Today I really dont think there is much of a difference between Mahle as we knew it and AA.

But its a cryin´shame to waste such a bunch of parts due to a low quality build by someone who aparently did not know what he was doing. I see it all the time here too. - Cheap engines from companies with big shiny ads, loaded with ALL the crap parts. In fact I just finshed such a 1914 last week. Had to replace about half of the engine after only 5000 miles. And if I have had free hands I would not have stopped there (!)

T

[dragvw2180]

 I wonder what the compression ratio was ?  Mike McCarthy

[65bug]

Was he by chance running a 009 Distributor with that 34 pict carb?

[modnrod]

Nice to know the quality of the AA stuff isn't bad, I agree with what Torben said about the lack of quality in most of the shiny ads. Those pistons had a short and unhappy life for sure.

A quick one though Rick. I'm not disagreeing with you as such, but my observations are with small carbs, especially single barrel carbs, on large motors is that they don't run the motor lean at all, if anything they tend to go really rich when held flat at full revs. The let the motor rev until it gets too rich, not lean, due to the lack of airflow, and this causes a natural rev-limiter function. In the past I have built engines for family (with no mechanical sympathy!), using parts safe to 6000, then used a single Solex or Stromberg so the motor won't rev past 5000/5500. Obviously this one wasn't jetted or tuned well to begin with, but I've used single barrel Solex and Stromberg carbs on everything from 1300 Suzki's up to 3.3L 6 cylinders, and often the only thing I need to check is actually the idle cct, not the mains or power cct. Are you sure the Solex 34 was the cause of the "lean-and-too-hot" blow-up, or could it also be timing/oil quality/dizzy tune?

Perhaps putting the twin Kads on there will merely let him rev the bloody thing 1000rpm higher than before in the same conditions, but without the natural rev-limit function of the single Solex. I'm glad you're not building the thing for him, it will end in tears again probably.

[rick m]

The sad thing TORBEN is that it had a lot of good parts in it. New case too. We saved most everything. Turned out to be a bad brass distributor drive gear that went away and kept screwing with the timing on the motor.  Unfortunately the owner kept driving it...which was astonishing it would even run.  I think this was a combination of the brass gear going away and the owner who knew little or nothing about what not to do when the motor starts to run bad.  Anyway, most of the parts are good. We are full flowing the case, modifying the carb and setting it up correctly.

I have never run anything but dual carbs so I am somewhat bias towards more air to begin with.  It will all work out. We will take pictures showing all the stuff we are redoing before re-assembling. One thing I would not do is run the MEXICAN dual ports. These heads almost had no air flowing through them around the intake and exhaust ports due to the really poor casting. We are replacing the heads with original german dual ports and doing some other work on the heads as well. It will run better, have more oil and cooling when we get done.

RM

[benlawrence]

the aa pistons are good, after hearing all the horror stories about them failing i was dubious about putting them in my motor, roll on a year and my good freind has run his motor with the non forged stroker 94s for a full season, they have seen 7000-8000 rpm everytime the car is on the track and they have stood up perfectly, needless to say i have no issue with using them for my street car.

[BeetleBug]

As for the durability of AA pistons. IF those pistons are older than approx. 3 years, the AA pistons were sub quality to Mahle. Today I really dont think there is much of a difference between Mahle as we knew it and AA.
T

Is not AA and some other brands just re-labeled Chinese parts easily available for those considering to import parts themselves? Some guys in Norway bought a pallet of cylindersets from China and got the following info:

Offset wrist pin:                                          Off set as original
Forging, alloy type /                                     T6 aluminum
Production process/                                     Hypereutectic Casting
Tolerances                                                  +/- .02mm
Quality of rings ,                                           Chrome top ring/ Cast iron, USA brand
Maximum RPM range                                     7,000rpm

Same piston and barrels is delievered to several US dealers.

Price is 289 USD including freight and Norwegian VAT of 25%. They offer the following sets:

P/N          OEM #   Description
VW9000T4E   029-37-90   90x66 mm   1700cc  Dome Top
VW9000T4F   021-198-075   90x66 mm   1700cc  Flat Top
VW9300T4   021-198-075A    93x66 mm   1800cc    
VW9400T4   021-198-200     94x71mm    2000cc Dish Top
VW9400T4E   021-198-200 FT   94x71mm    2000cc Flat top Piston
VW9500T4S71   021-198-200 95   95x71mm    Big Bore Slip-in
VW9600T4S71   021-198-200 96   96x71mm    For 2.0 Case
VW9600T4S66   021-198-075 96   96x66mm    For 1.7 & 1.8 Case
VW9600T4B66       96mm    For 1.7 / 1.8  Aluminum Biral P&C Kit
VW9600T4B71       96mm    For 2.0  Aluminum Biral P&C Kit
VW9800T4BL       98mm    For 2.0  Aluminum Biral Cylinder Set

[Torben Alstrup]

AA pistons ARE made in China.

AA claims that they do the final honing on the cylinders in the US. Wheteher that is correct or not, I do not know. What I do know is that at least for the last approx 2 years the piston quality has been good, and the quality of the hone and roundness of the cylinders better than Mahle. It is about over now, but out of the last approx 11 set of 94 Mahle´s I dealt with, I was only able to make 8½ set with perfect cylinders. The last 6 cylinders went on the shelf for rehone to JE pistons.

Rick. OK. I may have painted the ugly one on the wall a little too early. Good to hear that most of it is salvageable. I agree that dual carb engines are way easier to set up. Its the maintenance part that make them a PITA for some people. Like I wrote earlier, the large cc. single carb engines are much more difficult to get to run perfect than most would expect. you simply have to think different.

´nuf said. Getit running again  

T

[65bug]

The 34 pict carb was a major problem when paired with a 009 distributor. After changing the timing for the 009, you had to back down the idle screw on the carb so low, it shut the idle circuit down. This would let the engine get so little fuel, it would not idle correctly. If you can get it to idle, it would not transition to the next circuit properly. Even with a good accelerator pump.
     I went through that crap years ago on a 1600. Of course, dual carbs solves that problem alltogether! Motor ran nice and cool then. No big flat spot either..........

[modnrod]

The 34 pict carb was a major problem when paired with a 009 distributor. After changing the timing for the 009, you had to back down the idle screw on the carb so low, it shut the idle circuit down. This would let the engine get so little fuel, it would not idle correctly. If you can get it to idle, it would not transition to the next circuit properly. Even with a good accelerator pump.
     I went through that crap years ago on a 1600. Of course, dual carbs solves that problem alltogether! Motor ran nice and cool then. No big flat spot either..........

To get them to idle and also transition properly with a 009, drill a 2 to 3mm hole in the throttle blade next to the idle slot.

To jet them on a big motor, tune the air bleeds, and keep the main jet as small as possible.

The best thing is a completely stock-looking motor (it's the street-racer in me..........), with amazing throttle response and excellent economy. You can easily double the HP and still use a Solex 34pict.

But dual carbs are the preferred option for most, and make more power.
 

[65bug]

modnrod,
        I hear ya! I did all that crap too. Then when I scraped up the bucks, I graduated to dual kads. I was in heaven! Now I much more prefer my 2165 with dual 48's..........HA!

[modnrod]

Yep, been there myself too! Webers at full noise can be addictive.

But it's really easy for someone to put down $100, not knowing that a single Solex and stock air cleaner can push a standard-looking Bug to 100kph in under 6secs........

Or at least, so I've heard. 

[65bug]

I just know ALOT of motors have been fried that way!!!!! I think it was part of the reason the Holley Bug Spray got so popular! LOL.
       I must admit, I have never owned 48 IDA's. I have Dell's...................but I love em nonetheless! Great carbs! Dial em in and your done!

[modnrod]

Yeah probably. Twins make the power, and the jetting knowledge is plentiful and easy to access.

But I just realised I didn't explain myself properly above.

What I meant is that it is very easy to get someone to put up $100 against you if all you have under the lid is a stock Solex, twin Webers makes them think twice.
Aaahh, the bad old days, how I miss them sometimes! 

[andy198712]

As for the durability of AA pistons. IF those pistons are older than approx. 3 years, the AA pistons were sub quality to Mahle. Today I really dont think there is much of a difference between Mahle as we knew it and AA.
T

Is not AA and some other brands just re-labeled Chinese parts easily available for those considering to import parts themselves? Some guys in Norway bought a pallet of cylindersets from China and got the following info:

Offset wrist pin:                                          Off set as original
Forging, alloy type /                                     T6 aluminum
Production process/                                     Hypereutectic Casting
Tolerances                                                  +/- .02mm
Quality of rings ,                                           Chrome top ring/ Cast iron, USA brand
Maximum RPM range                                     7,000rpm

Same piston and barrels is delievered to several US dealers.

Price is 289 USD including freight and Norwegian VAT of 25%. They offer the following sets:

P/N          OEM #   Description
VW9000T4E   029-37-90   90x66 mm   1700cc  Dome Top
VW9000T4F   021-198-075   90x66 mm   1700cc  Flat Top
VW9300T4   021-198-075A    93x66 mm   1800cc    
VW9400T4   021-198-200     94x71mm    2000cc Dish Top
VW9400T4E   021-198-200 FT   94x71mm    2000cc Flat top Piston
VW9500T4S71   021-198-200 95   95x71mm    Big Bore Slip-in
VW9600T4S71   021-198-200 96   96x71mm    For 2.0 Case
VW9600T4S66   021-198-075 96   96x66mm    For 1.7 & 1.8 Case
VW9600T4B66       96mm    For 1.7 / 1.8  Aluminum Biral P&C Kit
VW9600T4B71       96mm    For 2.0  Aluminum Biral P&C Kit
VW9800T4BL       98mm    For 2.0  Aluminum Biral Cylinder Set

blimey, that'll make a few engines! how many kits in a pallet?

[BeetleBug]

blimey, that'll make a few engines! how many kits in a pallet?

Just enough for one engine and one season on high boost 

I believe  they sold every kit and is now taking new orders.

[65bug]

And very possibly ONE PASS TOO............................

[RhoadsVW]

I was putting a new set of 90.5 Mahle's and one piston had no wrist pin grove.  Guess that one some how made it through Mahle's tite quality control.    Dave Rhoads

[Fast Bug]

Wrong mixture, ignition and oil issues could cause the fried piston but what about ring gap?
Too tight ring gap could help heat up the piston. It’s not normally necessary to check ring gap on the Mahle stuff but maybe you have to check everything on the Chinese. 

[RhoadsVW]

I am not trying to knock Mahle piston sets but when running new engines there is less crank case pressure from AA's than Mahle's. I have checked ring gap on AA's and never a problem. Not trying to sell AA's but I think the quality on Mahle's has dropped. Mahle are good but a little pricey for what they are now. Mahle's don't seam to be a true forged pistons like they used to be. The cylinder quality I think is better than AA but the piston's are lacking.  Also you better balance the Mahle's. Out of the box they are as much as 4-5 grams off. One set I did was 8 grams off.  The most I have seen from AA's are 2 grams. Most all are within 1 gram.  Just some information I have personally found while working with both sets.  Dave Rhoads

[rick m]

Dave....Your feedback is very true. I have found the same with weight and ring gap when comparing between MAHLE and A&A.  I have several different sets of the A&A pistons I will be using.  Preparing a set of thick wall 92's right now for my wife"s 1835 buggy motor.  Will be running a set of their slipper skirt style 90.5s in an 84x90.5 motor I am building for another project.

RM

[Fast Bug]

I am not trying to knock Mahle piston sets but when running new engines there is less crank case pressure from AA's than Mahle's. I have checked ring gap on AA's and never a problem. Not trying to sell AA's but I think the quality on Mahle's has dropped. Mahle are good but a little pricey for what they are now. Mahle's don't seam to be a true forged pistons like they used to be. The cylinder quality I think is better than AA but the piston's are lacking.  Also you better balance the Mahle's. Out of the box they are as much as 4-5 grams off. One set I did was 8 grams off.  The most I have seen from AA's are 2 grams. Most all are within 1 gram.  Just some information I have personally found while working with both sets.  Dave Rhoads

Dave....Your feedback is very true. I have found the same with weight and ring gap when comparing between MAHLE and A&A.  I have several different sets of the A&A pistons I will be using.  Preparing a set of thick wall 92's right now for my wife"s 1835 buggy motor.  Will be running a set of their slipper skirt style 90.5s in an 84x90.5 motor I am building for another project.

RM

Good to hear the positive feedback on the AA pistons. I’m now not so worried about using AA pistons next time. I have never held an AA piston I my hand, but on the pictures I have seen they look thicker and heavier than Mahle pistons, are that the reality? Do you guys know how much an AA 94 mm B piston weight?

FB

[rick m]

We just got the 1915 bus motor back together! In the bus and now on the road.  Open chamber heads. Slight exhaust port work. Stock cam with 1.25 rockers. Modified 34 Pict with 10% more air flow. Merged exhaust, full flowed and boy does it pull and run smooth. Will post some shots later when we download the pictures and video on the engine stand.

Rick M

[Speed-demon]

Can you please describe the carb mods?

[ALB]

Can you please describe the carb mods?

I would like to hear what you did to improve the air flow as well. And thanks in advance. Al