Padoo

Alright guys, i am new here, i just bought my first vette in october. 01 c5 base with 41k miles on it. Kooks headers, b&b exhaust, stageII procharger kit with 4" pulley P1SC1. As far as i know thats the mods and obviously it was previously tuned but dont know by who.

I drove the car a few times taking it to speeds upwards of 160+ already and had no issues. Well i did some nic nacs and installed a catch can and was going take it for a spin, and i was climbing to about 140 and the car went limp.. Still going but wouldnt pull any further, then it let go! Smoke everywhere, running rough, long story short, i got home. After some months i decided to pull the heads and i melted 4/8 pistons.

Now my question is some say it leaned out.. Which would make sense, but what would cause it to lean out randomly? Is my stock fuel pump crapping out? Should i invest in a aftermarket fuel pump along with a booster pump? Etc? I need help!

I am looking to build the motor now, stock crank, good rods, good pistons, mild cam, ported 243s... And ofcourse keep it supercharged. So, what would some of you experts say i should do for fuel delivery/ look into??

Thanks in advanced, NOOB! Lol

breecher_7

As far as fuel system questions go, you may want to start here:
https://www.corvetteforum.com/forums...selection.html

But it does sound like the engine just went lean. Do you have photos of the damage? Without photos its pure speculation.

Padoo

U can look at the top side of the pistons and u see material gone, almost looks as if its a shadow..

PEETYZ

Did the spark plug electrode break off? Looks like it might have. Pull the plugs

Padoo

Nope all the plugs looked perfect other than being oily from the oil blowing past the pistons

5 Liter Eater

Without insturmentation you don't even know if you went lean. Could be just too much timing, bad gas, etc. Definitely looks like it detonated.

Padoo

Yea i just didnt want to spend money in building the motor and run into the same problem, but seems as if i will def need put an upgraded fuel system, just was trying to get some different thoughts from some of you experts

Caveboy

helga203

After u build the engine with all the changes u deff have to have it retuned. For sure.A get a afr gauge to monitor if it goes lean to get out of the petal

FourG63 97GST

it's really a guessing game without data, surprised it didn't melt a plug first, that's typically the first "weakpoint" in the cylinder. but at that speed/rpm/loads, it really just needs a split second of error to burn things. what's your power level? boost? fuel setup?

Padoo

Yea i was suprized to see the plugs still in tact. Def will need it retuned once i get the motor built with the changes. As far as power/ boost.. I would say the cars around the 460rwhp range at 8psi.. Stock fuel system except for the larger injectors provided by procharger with the kit..

schpenxel

Put a wideband on it after it's back together. You have absolutely no idea what's really going on without that.

People act like "tuning" is some mythical thing that will ensure your car never runs lean ever again.. in reality, you should keep an eye on things anyways.

Could have been lean, could have been knock, could have been a coincidence. Who knows

I wish dash logic was an option for the C5 guys.. makes monitoring everything really really easy.

Milan

Cracked sleeve?

BLOWNBLUEZ06

Hard to tell with the shadows in the pics, with my computer, but looks like broken ring lands. These motors, in stock form, won't put up with detonation, under boost.

MVP'S ZO6

It is possible that parts just broke. Like most have said its a shot in the dark to try and answer your question on what went wrong. Take a good picture of all of your spark plugs (at the business end) and label what cylinder they came out of. I'm really not a fan of automatically blaming the tuning. It could have been a number of things right down to something as simple as it was just a faulty component. It is a good idea when you do get a new engine to get a quality wideband oxygen monitoring system. (I like my AFR500) aka the old Ngk AFX.

Give us more specs on your car. Supercharger system boost levels , do you have methanol injection and things like that.

schpenxel

I brightened the pictures up some and yeah, I can't tell whether the top piece of the pistons is cracked and still there or missing altogether exposing the top ring.. but either way, same thing more or less

turbocvette

You will likely never find the exact reason it let go. On your next build install afr gauge and a data logger so if it blows again you can see exactly what went wrong. Also pop you pcm out and take it to your tuner and see if there is anything funny going on like timing etc. Most shops will take a quick look for free. I had a bike tuned at a shop before and the guy said she was good to go and that just was not the case. Needless to say I took it to another tuner had to pay twice! But he got it all figured out and running good. Also a data logger is good to watch your boost levels etc. I am not particularly familiar with prochargers but turbo app boost creep can take you out quickly!
So my plan for you.
Call a shop ask about the fuel system and buy it from them if you find they are very helpful. Speedinc is a good place to call.
install a data logger system you want rpm,boost, afr readings all in the same logger. I use innovate with a pocket logger its very small and I can hook up to a laptop for live readings etc. This set up will run you approxamatly $600 for all the gauges etc the mtx gauges are very nice and will even light up red or whatever color you want in an overboost,lean,rpm etc.
As far as your motor goes and how much you want to spend 5.3 are cheap and respond very well to boost. Go to the junk yard and get one ready to rock for $500 swap most your parts over intake etc, Then buy cam, valve springs, etc. Still wont be that cheap after tune extra parts etc but if she lets go again just another 5.3 and swap it in. Im cheap though haha

turbocvette

Also that piston not being out yet don't look that bad. If you pull it and can clean the cylinders up with a hone you can prob get away on the cheap. Ive seen perfectly running motors taken apart with that much detonation on the top of the piston. Your power loss etc prob came from cracked rings. If you stick with stock pistons etc look up tombo piston prep. The guy knows his stuff. Even though he does bikes its all the same when it comes to prepping a boosted motor.
But yeah looks like you just went lean or as others stated gas timing etc all come into play. This is the exact reason I don't like buying toys already boosted you really don't know what all they did to it until it lets go.

schpenxel

I agree.. cylinders are probably close to OK.. I wouldn't put it back together without forged pistons/rods

BLOWNBLUEZ06

Better plan than running a 5.3 IMO.

Using a junkyard motor isn't a bad idea for the people able to perform swaps themselves and save the labor, but paying someone to do the swaps risks getting more expensive than a nice, built motor with first or second failure.