Cylinder 2 problem

[jkimes]

Well, my car made very disappointing numbers on the dyno this week considering how much money I dumped into the new turbo, fuel, and drivetrain setup. It should be pushing over 640whp at 30psi and capable of 40+ psi and over 750whp. However, since my engine supposedly has issues, the shop says it only made 540ish whp at 30psi and they're afraid to turn the boost up any higher because the crankcase pressure is extremely high even with my calan catch can setup w dual 6an vent lines coming off the valve cover. He also says continued spark plug contamination on cylinder 2 seems to indicate blow-by but also claims that the car isn't smoking (so it shouldn't be bad rings right??). He suggested that the bore on Cylinder 2 may be asymetrical causing blow-by. Does this seem like a valid explanation? Is there anything else i can do other than a complete tear down and rebuild?

 

[JacksonAuto]

Besides the oil on the plug, what other symptoms lead him to believe that the blowby is excessive? When an engine has excessive blowby you will almost always get smoke. What happens is pressure from the compression stroke on one cylinder will pressurize the crankcase and oil will be forced up past the rings on opposing cylinders and into the chamber. I would question whether the moisture on the plug is oil or fuel. I would have your tuner to perform a leakdown test. This would rule out the rings real quick.

As a side note, there is no advantage to deleting the PCV system. An engines crankcase is intended to operate under vaccum (which a proper PCV system creates) and the lack of a PCV system actually encourages blowby. A catch can doesn't do anything except catch the oil and stop it from dripping on the ground. I'd encourage you to install a properly functioning PCV system back on the car.

 

[jkimes]

They did a compression and leakdown test after the valve stem seals were replaced (before the last dyno runs) due to oil puddling on cylinder 2 causing lots of smoke. Afterwards I was told that the compression and leakdown tests were good but I don't have the actual numbers in front of me. If the compression and leakdown results look good what else should I check? Also, how do I determine if the crankcase pressure truly is excessive? He says the dipstick is blowing out but to me that doesn't necessarily mean much.

 

[JacksonAuto]

Leakdown numbers cannot be good if the dipstick is blowing out. It takes a tremendous amount of pressure to blow the stick out which tells me the rings in at least one cylinder are shot. No way it would pass a leakdown test.

 

[JacksonAuto]

Did this same mechanic do the initial fire and break-in?

 

[jkimes]

Did this same mechanic do the initial fire and break-in?

No, I did the initial fire and break-in myself. The engine was built by a machine shop in Springfield MO about 6 years ago (see profile for details). I installed it myself with some help from a friend and a lot of Budweiser. The engine probably has less than 3000 miles on it because I've had the car torn apart almost constantly fixing little things here and there and installing upgraded components. Regardless, it sounds like the car should be blowing smoke if cylinder 2 has a warped cylinder or bad rings correct? He claims the car is not blowing smoke so I'm not sure what to think.

 

[JacksonAuto]

Blowby doesn't always result in smoking. If the dipstick is popping out, then you definitely have blowby, no doubt about it.

 

[jkimes]

Well, it turns out the tuner lied when he said he was "afraid to turn the boost any higher because something might let go". I went to pick up the car from the shop, fired it up only to see smoke billowing out the back and noticed some of the nastiest rod knock I've ever heard. He blew up my engine..it's completely effed.

 

[91mits]

thats messed up man, feel sorry for you. 540whp you were almost there, hope you get it worked out man.

 

[GSTurbo1]

sorry bud... tune yourself

 

[Tiki2777]

Wow that sucks ass, just another reason to tune by yourself or be there watching every single thing they do and scruitinize it. Time to bring out the lawyer and sue their asses. I hate "professional" tuner shops that #### up other people's hard work with time and lots of money into their cars.

DO NOT LET THEM ROLL OVER YOU