Detonated??

[Alerosaint]

So last Wednsday nite i was getting on the highway and while accelerating when i reached 80mph my "SES" started flashing and "trac off" came on my exhaust started sound weird like a poor man subie....it started to bogged down and try to die at lower rpms and at one point it did....white smoke poured out the exhaust....was oil burning.

Next day I pulled the spark plugs...was oil on the spark plug on cylinder 1,2,3,4...yeah...not got good right...so we did a compression check and all the the cylinders and they check good except cylinder 4 which had now compression. So I towed my car to buddy house and we tore into the engine and here is what we found









so Im gonna order a piston and try to have her up and running in couple weeks but I think I detonated not sure....but this is a lesson for me...I kno though the next thing going in her is an AF gauge.

[[ion] C2]

that's crazy man...

improper piston ring installation?

[cherrington17]

noice work!

inverted can of air and a hairdrier will fix that in no time!

[Nate's Alero]

melted piston rings, improper cooling? makes sense waterjacket plugged, did GA_turbo put green in orange??

[jayson_waltz]

i think u ate a ring buddy. it happens, were u runnin the crap out of it when it happened? and why did u tow it? hell when i spun a couple bearings and bent a rod i still drove it a couple miles back to town

[Alerosaint]

I havent pull the piston out yet but im sure the ring is done, but i was kinda hauling.. ok I was hauling ass....was getting on the freeway, 6krpm and going...I also did have water pump issues(was leaking a lil)...gonna change that as well

[jayson_waltz]

u sould order forged internals now...

[[ion] C2]

it is!

that is his freshly built engine with Wiseco pistons and Eagle rods, Clevite77 bearings and the works

someone didn't install things to spec..... 6k+rpms are nothing... mine's seen 6500 a lot lately... i'm tuned and running perfect though. still, that should not have happened. things were not assembled correctly or you used inferior parts.

[Alerosaint]

I probably ran lean and the sh!t hit the fan =S....

[Oldsnut]

Ouch.

[[ion] C2]

Originally Posted by Alerosaint

I probably ran lean and the sh!t hit the fan =S....

that's possible... you know the stock s/c tune targets 13.0:1 AFR at WOT? lol... add the 62mm TB and the 2.7" pulley and full exhaust and you're running 14:1 at wide open...

i saw 14.3:1 one time with my 2.6" pulley and stock tune stock injectors....

[Alerosaint]

yeah and I effed up by not having the proper gauge....but my painful lesson is learnt and i will be picking up an A/F gauge as I can...so i can monitor and i will be getting a tune if not as soon as but with weeks of completing these repairs

[Redog]

Yeah I wouldn't be running a S/C without a A/F gauge

I have on in my car and it's saved me a few times, just when I think about taking it out

[[ion] C2]

you have a narrowband

[Alerosaint]

I was fine stock supercharged but when I started changing pulleys thats when I should have thrown a guage in there...and the narrow band SUCKS

[Spilner521]

Yeah forget the narrowband light show. Get a decent wideband...and a better tune.

[Redog]

Originally Posted by [ion] C2

you have a narrowband

Yeah but that's all you need on a NA motor with the stock cam.

Cammed, different story

[GA_turbo]

Damn man i tought you said you were going to change injectors and get it tuned, plus i know why it happend, you shouldnt been going as fast as you were with out the tune, now it makes sence when you told me that you removed the speed limiter and change the fuel cutout settings also.

The top that you see on the pistons are not the ring its just dirty plus the headgasket its still on, i put everything on according to wiseco and the pic shows that he ran very lean, that piston detonated.

[[ion] C2]

Originally Posted by Redog

Yeah but that's all you need on a NA motor with the stock cam.

Cammed, different story

Widebands are useful for any engine. Knowing the exact AFR is great. For N/A you'd want the most you can possibly get by tuning so a wideband would work wonders to be able to compare the commanded AFR vs. the actual AFR and adjust your VE tables to provide you with perfect fueling.

At higher loads especially and staying wide-open for long on the stock tune, your AFRs get up into the low 14s... I can see why things happened the way they did. Once I saw 14.3 on the wideband I stayed out boost until I got bigger injectors and tuned.

[Alerosaint]

Originally Posted by GA_turbo

Damn man i tought you said you were going to change injectors and get it tuned, plus i know why it happend, you shouldnt been going as fast as you were with out the tune, now it makes sence when you told me that you removed the speed limiter and change the fuel cutout settings also.

The top that you see on the pistons are not the ring its just dirty plus the headgasket its still on, i put everything on according to wiseco and the pic shows that he ran very lean, that piston detonated.

I did tell you that and Was going too and still planning too....the fuel rail is almost ready and i just got in contact with the tuner, but i went faster in my car with you in it after the build w/ the same tune....I could have detonated during that time as well but i didnt... as far as the speed limiter i was at 80mph and was 6 grand......the same speed/rpm i hit everyday going to work nothing out the norm no where near the regular cutout...so pretty much i was livin on a prayer but hey shit happens...it finally caught up to me

That fact is I should have been able to monitor my a/f and I wasnt. I blame myself. I ****ed up lesson learnt. As soon as the engine is fixed next paycheck I will get me one.