Engine Blow up on Dyno - Questions
 

I just had the tuner vortech supercharger kit installed on my 05 G35 coupe 5MT. My engine internals are all stock. Along with the charger I had a 1/2 inch plenum spacer installed, MRev2, Fast intentions high flow cats on the stock cat back. To hold the power I had a JWT clutch and flywheel installed.

Prior to the supercharged install, I had no excessive oil consumption issue or anything that would indicate the engine is not in decent shape. It does have 90K miles on it.

On the second pull on the Dyno, the engine started smoking badly. Now it won't even turn over. Cylinder 6 spark plug is damaged and cylinder 5 is unscrewed but will not come out of the spark plug hole(end is probably damaged). At the time of the failure the engine was at 5600 RPM and making 367 whp on a Dyno dynamics Dyno.

I am thinking the engine probably threw a rod but looking for opinions on what others think could have happened. I'm just surprised that this happened 2000 rpm below redline. The charger was probably making peak torque at that time but I would think it would still be within the limits of what the stock internals could handle. These centrifugal chargers don't make a lot of torque so I have no clue why the engine failed.

The tuner said all the AFR, timing etc numbers looked fine at the time of failure. Any thoughts from anyone?

Forced induction is always a roll of the dice with these cars.. Sometimes they just give out

Now time for my favorite part. Time to pull the engine!

We put a camera down cylinder 6 and found a bent rod and shattered piston. My option now is to replace with a used engine or rebuild mine. Hopefully I can just rebuild mine with new rods and Pistons. You never know what you will get with a used engine

Wow here I am thinking a stock rod could handle at least 400hp for a few dynos.might as well lower the compression of the pistons and up the boost.

Mine also went kaboom at 367who on a Mustang dyno, i destroyed #6 rod and piston, the rest of them were fine. I belive mine had to much timing causing knock but I'll never know I was at work when it popped.

My tuner is saying all the numbers looked fine but I wasn't there as well. What did you end up doing? Did you rebuild the motor or did you replace it?

Rip

Thankfully I had a spare motor I rebuilt, the motor that blew up would need a decent overbore or sleeved and a new head. If I could do it all again I would have bought a built motor instead of building mine. It's been a huge pain in the ***.

Wow , pretty d__m insightful .......makes me think twice on doing the SC boost so soon , gotta have stronger bottom end . Sorry for your loss bruh.

If I were you I'd go to rebuild it with forged internals. Time to go for bigger numbers now ;)

really odd that both went down on #6 at about the same power level. is there a known oiling issue to that last rod bearing? or possibly you had a clogged fuel injector. hard to believe it just arbitrarily went, and only on one cylinder. there had to be a timing snafu unless the piston was weak to begin with.


did you have a compression/leakdown test done on the cylinders prior to the install?

Yes, get a bigger supercharger and video the result.

Telcoman

Cylinders 5 & 6 receives the most airflow. They will be leanest / hottest. When tuning a stock motor, best to use higher octane fuel (not oxygenated so similar AFR as pump gas, e.g. leaded fuel if no cats to worry about).

OEM parts must be kept cool to survive.

Don't use leaded fuel, even if you don't have cats. You will destroy the oxygen sensors. Exceptions are race gas occasionally but even that is available unleaded.