J&E Piston failure

[fredmeister]

Originally Posted by BURN-BROS

J.E. changed the forging and no longer supply the tapered pins. These two changes were done at the same time, so it is hard to say which one(or both) caused the issue.

What did your pistons weigh in at? Any undercrown milling done to reduce weight. It doesn't look like it from the pic.

Anyone know if the JE piston marking under the crown "97" means this is the improved design? I have a set of 98mm pistons that have the marking in the forging that says "97". Its in the flat area of of the piston dome between the wrist pin bosses. I took this to be in internal JE part number for the forging blanks they use.
I just had these made a year and a half or so ago. No troubles with these pistons yet in my 3.4 liter turbo engine. Its not routinely revved beyond 6600rpm though.

Thanks,
Fred

[65rsr]

OMEGA . Went this route after three different JE wrist pin boss failures on my 3.4....

Originally Posted by 65rsr

Welcome to Omega Pistons

[Mahler9th]

We saw a number of JE piston failures in our Norcal area several years back (mid last decade). Quite a few of them were 98 mm pistons that failed in the wrist pin area. We also saw some failures in larger displacement apps. My own 102 set suffered from cracks in several domes at about 25-30 hours of under 7500 max revs. The cracks got big enough for massive compression loss at RRIV at Laguna in the Sunday Group 7 race.

One NorCal driver/engine builder saw some big ones fail after about a half-dozen hours if I recall correctly.

My engine builder was one of the last holdouts to try various "new and improved" JE designs. But he has given up during the past few years, resorting instead to off the shelf and custom Mahle pistons for many applications.

These experiences were all with racing applications.

[chris_seven]

We have always liked Omega Pistons and have used them in 80 to 85mm diameter in early engines with good results.



For 3.0 litre Engines we have used CPS Pistons with a similar design



For the next engine we build we are going to try a Double Bridge design as we are trying to push revs a little higher.

[Henry Schmidt]

JE has redesigned their shelf piston for exceptional longevity.
Most failures we see in the modern casting are because people refuse to establish a reasonable life for racing parts.

Here is a comparison of the old JE vs the new JE FSR piston. These are 100mm.

[chris_seven]

Does this mean that all JE Porscge pistons now use the FSR Design and are automatically supplied is this form?

[Henry Schmidt]

Originally Posted by chris_seven

Does this mean that all JE Porscge pistons now use the FSR Design and are automatically supplied is this form?

No Chris
It means that they have forgings in some sizes and you can order any piston that can be machined from those forging.

[65rsr]

Zero pin boss failure, 100 hour rebuilds, 500 hour pistons, every shift at 8600+, high compresssion, high horsepower, 3.367 high butterfly / kugelfischer with oil temps <180°F. Possible?

[AlfonsoR]

Walt, with all the things that maybe going through your mind, don't forget to check the oil system to make sure you don't have any potentially damaging metal particulates in the system.

[KTL]

Originally Posted by AlfonsoR

Walt, with all the things that maybe going through your mind, don't forget to check the oil system to make sure you don't have any potentially damaging metal particulates in the system.

I have recently found that to be THE most troubling part of a rebuild after a failure. Is it clean enough is the question always running thru my mind. You can't leave anything to chance and have to disassemble everything down to its base parts, or sometimes dispose of things.

You never know where FOD will lurk. A good example is the timing chain. Lord only knows what debris gets lodged in there when broken parts spew debris. Those chains are FOD collectors and no way should they be reused.

Even when you get stuff back from the machine shop after reconditioning, you have to clean it. I had a reconditioned rod come back with grit in the bolt head recess (think rods with threaded caps like Carillo, Pauter, Arrow, etc.) and it munged the threads a bit. That ticked me off to say the least......

[fredmeister]

Originally Posted by Henry Schmidt

JE has redesigned their shelf piston for exceptional longevity.
Most failures we see in the modern casting are because people refuse to establish a reasonable life for racing parts.

Here is a comparison of the old JE vs the new JE FSR piston. These are 100mm.

The piston on the left looks very much like the forged piston I was referring to with the "97" marking on the crown a little earlier in this post. Its is still a forged blank-not cast so I am hoping it is one of the modified designs and I am not going to have a short lived engine. Its not as nice as the one on the right (FSR) though...thats the top of the line they offer.
FWIW, I don't have a racing 3.4 (98mm) turbo but do drive 50% DE and track days.

JE is supposed to be top notch and recommended by alot of top engine suppliers in Pano and Excellence. This talk of exploding pistons is pretty disturbing.

Fred

[Henry Schmidt]

Originally Posted by fredmeister

......edit.......This talk of exploding pistons is pretty disturbing.

Fred

This noise is old news. JE confronted this issue and corrected it at least 6 years ago. There are some old pistons floating around so if you're not certain of your piston design, don't use it for long life (high hour) racing. Always establish a reasonable life for all racing parts and count that in your budgetary concerns. If you have an old set and you're running it under moderate conditions, make sure you run straight/ thick wall wrist pins not tapered.

[fredmeister]

Originally Posted by Henry Schmidt

This noise is old news. JE confronted this issue and corrected it at least 6 years ago. There are some old pistons floating around so if you're not certain of your piston design, don't use it for long life (high hour) racing. Always establish a reason life for all racing parts and count that in your budgetary concerns. If you have an old set and you're running it under moderate conditions, make sure you run straight/ thick wall wrist pins not tapered.

Thanks man. Looks like I am good.

Thats a load off my mind. And a load off my pistons too, ha,ha.

Fred