1986 325iX 3.1L Stroker + Turbo

[litu]

Cool, i love that ride high, just like how ix should look

[downforce22]

Cool, i love that ride high, just like how ix should look

Thanks, all stock ride height, with bilstein HDs in the rear. Still have to install the fronts.

I tuned a bit more last night and on an open stretch of road its easy to reach triple digits. My boost gauge is showing 5-8 psi so I think my wastegate is cracking open a little early. I might add a boost controller to remedy that but even at 5 psi it is fast.

I love the 3.64 gears on this thing but in 5th gear could almost use some more gearing due to the stroker combo of the engine.

[efficient]

Nice e30. Not a fan of the muffler.

[downforce22]

Nice e30. Not a fan of the muffler.

This one?

[nomansland92]

I run a 10psi spring and they start to open around 7 psi also. I have a gfb electronic boost controller that I dont use anymore if your interested in it. I think I paid like 300 or so for it but if you would like it I'll sell it for 200 shipped.

[litu]

Thanks, all stock ride height, with bilstein HDs in the rear. Still have to install the fronts.

Ok, this is good to know..I have also chrome bumber version..But in very lowered suspension. I have thinking know to but stock suspension to get in in stock ride high.

[downforce22]

I had some more bad luck. The car developed a ticking noise under certain load conditions. It would get louder as the car warmed up and be RPM dependant while disappearing on no throttle conditions.

I was testing and tuning the car and you can hear it in this video. The car still ran great, made great power, and idled smooth so it didn't seem anything was wrong.



I removed the valve cover and checked valve clearances as well as verifying the rockers were in good shape. I wanted to make sure oil was getting everywhere so I checked it with the cover off. The only problem I found was the intake rocker shaft rotated slightly and the retaining pin in the front of the head was not held in place correctly. I thought maybe one of the rockers was 'kissing' the rocker clips or something, but that ended up not being the case. Click to see video and hear sound and symptoms.

WP_20160724_13_35_17_Pro


I decided to take it to the mechanic who built the motor. He was a bit puzzled as well as the sound was not coming from the bottom nd but was coming from up top. We did a few tests. It seemed to be coming from the back of the motor. Then we pulled the spark plug out and started the engine. With number 5 spark plug removed the noise was still there. (Note running an engine with an open cylinder is extremely loud!!) Then we removed number 6 and with a stethoscope, the mechanic noted the noise was no longer a hammering sound and was only a tapping. So it was coming from cylinder 6 and the compression affected the noise.

At this point we thought to drain the oil, but did not find any metal shaving of any sort. We arrived on the conclusion that the wrist pin may have failed but that was the only thing we could come up with and had no idea why it would have failed. At that point, the only way to come to a solution was to open the engine up and see what was going on.

We decided to remove the oil pan and drop the rod bearing out the bottom and pull the piston out the top with the engine in the car. As it turns out, the Forged JE piston failed.

Check out this carnage. Somehow the piston survived with only half of the material holding the wrist pin in place.











As you can see, somehow the piece of the forging just broke off. The scary part is the wrist pin was able to slide around as that 'lock' was no longer holding the wrist pin rigidly in place. It could slide laterally toward the side of the cylinder bore. Luckily, the pistons are so short due to the long stroke that the lower ring actually sits outside the wrist pin bore. And that ring held up as the wrist pin slammed into it laterally. I do not have a picture but the ring had some side loading marks due to the impacts.

Also, where the piston failed, there is a half circle, presumably to access the lock for the wrist pin. It appears there was a stress concentration at that point and that partially caused the failure. I contacted the piston supplier and they asked that I send the piston in for destructive testing so I no longer have it. Ideally they will do something about it but I am not holding my breath. I received a replacement piston and hope to have the engine back together within another week.

I am glad I didn't drive the car further and that the failure did not grenade the engine. It definitely could have if I drove it much more. Once back, I will be dialing in the tune and seeing if anyone has any pointers for my ms tune.

[nomansland92]

Dam dude that's scarry! glad to see it didn't do any other damage, hopefully they improve there design and not give you the bad patch excuse.

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[bradnic]

you dodged a serious bullet. wow
thank you so much for posting about this. I'm sure you'll get things resolved soon with the JE folks.

[digger]

holy s..t was there any striations indicating the crack was a fatigue crack? it didnt look like it from what i saw.

that pin wall looks awfully thin for a FI engine im sure its tapered bore but still for FI dont tick the light weight wrist pin box, part of the job of the pin is to stiffen the piston, it acts like a spine because steel is 3x the modulus of the piston material

was the pin a sloppy fit on the bore on the unbroken side of the piston?

[2mAn]

Damn, that sucks but you doged a MAJOR bullet. I love this thing, but it needs OEM tails badly. Those ones need to be burned to the ground

[ThatOneEuroE30]

That was a close one for sure.

[AWDBOB]

I've seen this before on short skirted pistons with the wrist pin moved up to accommodate a longer rod like these. There is no excuse for that failure, though.

You did good stopping yourself and taking time on the diagnosis, and saved yourself big time in the long run.

[spdracrm3]

Dang dodged a major calamity there.
Those are very short skirt pistons. Never seen narrow skirt on one side and wide on what I assume is thrust side wonder what that does for weight balance side to side, do they shift the pin further to compensate Fancy stuff

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[ThatM20Guy]

Very nice build. How is the front diff holding up? Really want to eventually turbo my ix but people seem to say they are basically made of glass when you start adding power.