94mm P&C

[S/P4884]

 I know the 94x82 Mahle P&C kits haven't been available for awhile. My distributor told me that there was a change in the management at Mahle and the VW stuff is low on the list of priorities. He said that they are trying to change production from Brazil to Argentina but there will be a substantial price increase. Are the only other options Wisco's and long barrels, and AA? I read both good and bad on the AA sets, but is there plenty of those sets around or are they in short supply?

[1960 ragtop]

Mike I got a really gently used set if you need some. They came off when I switched to wiesco's. Only got a couple passes and a few miles on them.

[gkeeton@zbzoom.net]

Welcome to the new world of decreasing, and discontinuing parts production runs for 30+ year old VW's! Yeah AA's, and the high end pistons, like Wiseco, and JE are the only other options from the Mahles. At the present time AA's are readily available, and I would use them for anything you would use a Mahle for. Any high end use were you would question an AA piston, you would question a Mahle, and would usually end up using a Wiseco anyways. I guess it's getting to the point where we need to be happy there are long barrels, and Wiseco's available. If price on the Mahles does increase, that will surely end production. I can see sales numbers being too low to continue production. Almost everyone needing an inexpensive piston will buy AA's, because of their cheaper price, and everyone else will buy the race pistons. The last sets of Mahles shops were selling in the $270-$300 range. Jaycee long barrels are around $150, and Wiescos around $400, correct? Mahle doesn't have much room for a price increase. Those that don't like the AA's will just say the hell with it, and for a little more, just buy the long barrels/Wiescos.

[bugnut]

I was reading an old Hot VWs or VW Trends from when I was in middle or high school the other day, and was amazed at the prices.  Cases used to be like $200 or $250, and the pistons being discussed were $140 per set... for stroker versions!  Man, them's were the days.

[gkeeton@zbzoom.net]

That wasn't that long ago. I started working at the VW shop, I currently work at, in 2003. Mag cases were $275, and Mahle stroker 94's were $179. The piss poor economy, and crummy exchange rate has really put a damper on the hobby.

[bugnut]

I will likely keep a close eye out for good used sets at swaps... I got a good decent set of 90.5 'B' pistons and cylinders at a swap meet here in Oregon a couple years ago for a song, and they all checked out with a dial-bore gauge.  A good hone job, new rings, and they're now in my new 2017 build!

[Greg G]

I have had good luck running AA's.

[S/P4884]

I've talked to several people that like the design of the AA pistons better than the Mahle's. I'm going to try a set.

[flat top]

Geff..  Would AA stand up on a 2180 budget turbo engine???

Wayne

[fiatdude]

They might stand up to the engine but the boost might be a different question -- Moderate levels of boost OK -- -- But the big difference between pistons is the amount of abuse they can take when something goes wrong -- with a JE piston the engine might have a little time to let you know it is unhappy -- with an AA it will be slag

[Jason Foster]

I picked up a new set of Wisecos yesterday. I'll be using those with Bugpack long barrels

[gkeeton@zbzoom.net]

Geff..  Would AA stand up on a 2180 budget turbo engine???

Wayne

Hey Wayne! What fiatdude said. Any AA problems I've read about in the past were from 20+ psi of boost, or 50+HP worth of N2O. Jim personally spoke with a guy from Michigan that had one let go at 27 psi of boost, but I would think less than 10 wouldn't be an issue. I'm sure Tom did some research before he built some of his Turbo engines, maybe drop him an e-mail.

[flat top]

Thanks Geff....  Is the new CAR going to be ready this year?


Wayne

[gkeeton@zbzoom.net]

Thanks Geff....  Is the new CAR going to be ready this year?


Wayne

No, but the Super may be getting some small "consistancy" upgrades.

[Mike Lawless]

This is from a product review I had on my website a while back, (now unlinked to my main page, but still relevant)

AA Pistons....
I've been using the same set in our race motor on and off since '06. (2332, NA, 260plus HP, 8500 rpm)
After measuring the barrel and pistons right out of the box, the very first thing I did was have the barrels honed. The clearance was only .0015". Enough for a street engine perhaps, but not comfortably enough for a race motor. I had the barrels opened up to give me .006" clearance. This might have been a little much. They clatter a little when cold. Probably could have gotten away with .004"

Here's some point by point observances....
Observation # 1. Opening up the bore that far screws you up on ring selection. There are precious few ring set available that can stand an oversize that much. The standard ring that comes with the set ends up with a gap approaching .040" when the bore is honed that much. They will never seal good enough.
Solution...A total seal gapless top ringset. Made for a "file to fit" end gap. Not many other options available, and a very expensive ringset. Given those two primary problems, (cost to hone and buy a new ringset) it brings the cost up significantly for the total package. There might be other "file to fit" ring sets out there, but it will take some research.

Observation #2. Once this was done (I also drilled eight gas ports into the top to intersect with the back of the groove), the piston set out-performed anything else I tried, which included some high dollar American made custom pistons. Every time I tried some new "whizbang" piston, I ended up reinstalling the AAs.

Observation #3. I received a later set from my good friend Ron Barrett to look at. The barrels were a little larger from the factory, giving a net clearance of .0035". This only makes the bore .002" bigger than "nominal" (3.701" for a 94mm bore) and doesn't open up the ring end gaps too bad. The Barrett's chose to run that set as is without additional honing.

Observation #4. Yes, they are made in China. I find it amusing that they have outperformed high priced American made custom pistons in my application. I think overall, I might have had more peace of mind with an American made set of pistons such as Wiseco, but I didn't like the ring groove sizes in the two off the shelf version of those. 2mm top or 1mm top. The 2mm size's best place in an endurance application. The 1mm doesn't seal well enough without positive crankcase evacuation (vacuum pump). That my opinion based on my experience.

Conclusion: They are probably fine as is for a street motor, but make sure you inspect them carefully for burrs and stray metal chips. And by all means, check the clearance. Don't take anything for granted.

Funny thing happened when I called Wiseco to see about getting their piston with the standard 1.5 X 2 X 4mm ring groove package. The guy I spoke to said I was stupid for wanting that (His words) and the price for the pistons alone would be $600.

I said "OK then. I guess I won't be buying anything."

[bill stipe]

Anyone know how much the AA can be cut for valve clearance?

thanks

[Mike Lawless]

I think .300" might be pushing the outside, but it also depend on valve size. With 48mm intakes, I have valve pockets .260" deep and the closest point of breakthrough would be the top ring groove. I'm still good but I don't think I would be comfortable going much deeper. If the valve was positioned closer to the cylinder wall, you won't be able to as deep.

I wouldn't take my word as gospel tho. All engines are different. The only way to know for sure is mock things up and measure. I will say that if one needs valve pockets .300" deep, they should seriously consider a custom piston with appropriate top ring placement. I have seen Wisecos  and other high end pistons break through at the top ring groove too going .300" deep. So proceed with due caution

[flat top]

Thanks Mike for the great INFO...

Wayne

[WV-VW]

If anybody's looking for a set of long barrels, I have a set of new ones that I bought from Vee Dub Parts a while back but due to the set up of my new motor (Thanks Mike ) I didn't need. They are for sale!

[wayne harron]

Larry, whats the price on the barrels?

[S/P4884]

 Wayne, The long barrels are at my house and Larry is coming down Saturday to pick everything up, so if you want them call me Saturday AM. Larry should be here about 10 or 11.

[WV-VW]

Wayne, I sent you a PM.

[wayne harron]

Larry, I PM'd you back. Let me know what you think.