Ive been losing about 4 quarts of oil every 3000 miles. Here is the original thread:

Ive finally got time to do a leak down and compression test done and here are the results:
[list=1][*]Cyl 1) LD: 20%, Comp 200[*]Cyl 2) LD 19%, Comp 190[*]Cyl 3) LD 10%, Comp 195[*]Cyl 4) LD 56%, Comp 130[*]Cyl 5) LD 20%, Comp 180[*]Cyl 6) LD 38%, Comp 160 (alot of burnt oil on spark plug tip)[/list=1]

Not sure how this is usefull info for others but i thought id share.

 

Cyliner 4 is toast, and cylinder 6 is marginal.

I am familiar with the COMP, but what is LD% and who do I interpret that number?

Thanks for sharing.....

 

LD is Leak Down. A better way to see what's going on in a cylinder. Think of a compression test as a quick picture and a leak down as a short film.

Any way the number is the percent of air leaking out of the cylinder when pressurized with air. under 10% is good 20% fair/workable 30% and beyond you should fix.
Gary

 

Cylinder 4 is toast. Comp at 130 isn't avg around 180+ also 53% leaking.. Is this a TT or SC? Also what psi of boost if boosted? Sorry for all the question just trying to piece things together.

 

this is horrible news. what happened to burn up the pistons?

 

99.9% of the failed motors are from bad tuning or no tuning at all. People buy supercharger kits, Hitrous kits, and/or Turbo Kits and they put them on with other mods and don't *tune* them. Problem is the kits are designed for a stock car with no additional mods. Then the customer goes and adds a plenum, headers, different intakes, ecu flash, etc and doesn't tune it for the new mods.

Tuning is the key.

Kyle
SGP Racing

 

Nothing a litte "FORGED INTERNALS GROUP BUY" can't fix.

https://my350z.com/forum/showthread....threadid=85958


Honestly, I feel your pain, but fortuantely, your rods didnt snap and break your motor. Blowing through the rings is a relatively "nice" way to kill a motor. Look at the bright side!

 

I had my Greddy kit with no other mods, besides RT cats, and it was pinging at 5psi of boost and 11:1 A/F. Go figure.....I honestly think that most of these kits need a bit of tweaking..even out of the box...for long-term reliable and safe operation. The PE in my opinion, is the safest kit out there, becuase it comes with 4.4psi of stock boost, and more efficient turbos at standard boost levels. (cooler intake charge).

That said, even with proper tuning, I dont think we'll get a lot of miles out of stock bottom end at 8-10psi of boost. There are rods are just too wimpy for those type of stresses on the motor. Yes, you can run your motor at 8-10psi with a stock bottom end, but I'm just saying the reliable and longevity of the motor would be at risk. And you leave no margine of error for a finicky ECU, or a bad tank of gas....etc...

Good luck Enron!

 

Ooops i forgot:
https://my350z.com/forum/showthread....threadid=85175

 

I thought that Nissan spec call for only 10% LD...anything more than that is supposed to be bad. Maybe that was just for the SR20 motor.

I think I will have this test done when I get my car back. How much did it run you Enron?

 

$65 for the compression and $100 for the leak down. I am a tad worried about FI on the stock motor since Nissan designed it for NA, keeping in mind of the light and thin rods. I have 2 cylinders that are damaged most likely formme hydrolocking the motor and 3 cylinders showing some wear, maybe due to FI. Im not sure wth.

 

any mod friendly dealers that could help you by warrantying the labor costs of rebuilding motor? Then you could throw in your shiny new forged rods and pistons.

 

After hydrolocking the motor...those would have to be some REAL friendly dealers.....Anytime you suck water into the combustion cycle expect no help from a dealer

 

if you hydrolocked the motor your insurance co should cover the damages.