Well today the pistons finally came out of the car. On Sunday I was dismayed to find a perfectly good head gasket. That meant it had to be something else causing low compression in #3 cylinder.

And here it is:
http://www.turbochargedse-r.com/0704build5.jpg
That's the #3 piston, the first one I removed. Initially it looked to be in good shape....but wait...what are those tiny cracks on the side?

http://www.turbochargedse-r.com/0704build6.jpg
Cracked ring lands. I knew it. What is odd is that the car drove some 50 miles with these cracks in it, no problems at all. The cylinder walls are nice and smooth, too. Go figure.
I have four #2 DET rods/pistons ready to go in. However, my block is a 'freak' in that it require three #2 pistons and one #1. So I am ordering one #1 DET piston today, and hope to have it for install by next weekend. Until then, all I can do is clean surfaces, etc. to get ready for everything to go back together.

http://www.turbochargedse-r.com/0704build7.jpg
And that's what I did today. I started by honing the #2 and 3 cylinders since I already had the pistons out. I used a generic honing tool that works with a regular power drill. Just coat the walls with LOTS of oil, slide the arms with the honing stones on them down in the cylinder, and let her spin. It only takes about 30 seconds to get a very nice finish on the cylinder walls.
Cleaned the cylinder head mating surfaces, the upper oil pan surfaces, etc. and called it a day. Once the new #1 piston gets here, I'll dive in and put everything back together next weekend.

lookin good, bet ya cant wait to get back into your SE-R! good luck

Hey Greg...the cast Det pistons are just as prone to cracking ring lands. So why not upgrade to some forged ones?

hmm. i have like 4 of those type of hones. i was under the impression that that's the type of thing you want a machine shop to do. hmm. maybe i will order the JE pistons and crower rods after all, i was holding off on it because i didn't want to have machine work done on the block.
lol i thought they only used the spring loaded hones on caliper bores.

Looks like things are coming along really well Greg. What are you refering to when you said that your motor required three #2 pistons and one #1 piston?

Looks like things are coming along really well Greg. What are you refering to when you said that your motor required three #2 pistons and one #1 piston?


Nissan uses a grading system for pistons. #1, #2, etc. On top of the cylinder block each cylinder bore is stamped with a number signifying what grade piston goes in each hole. Mine is 'odd' in that it reads 2-2-2-1.

In the photo of me holding the honing tool...look to the #2 cylinder just to the left; you will see a number '2' on the top of the cylinder between the water jackets. The grade of piston is also stamped into the top of each piston.

As for getting some aftermarket pistons...this engine will not see more than 10-12psi of boost from here on out. The factory pistons lasted 156k miles, two years of nitrous, and two years of 8-12psi of boost. While DET and DE pistons both are known to crack like this....I doubt this engine will see the abuse I've heaped upon it any more. I really ran it hard these last 2 years.

-GP-

What are the differences between the grades of cylinders?

What are the differences between the grades of cylinders?

http://mywebpages.comcast.net/myprojectb13/pistongrade.jpg

lookin good, bet ya cant wait to get back into your SE-R! good luck lol does not look like he even took it out of the se-r :tongue:

I wont abuse it anymore. Right

Looks good GP. Now get it back together.

lol does not look like he even took it out of the se-r :tongue:
I think he meant driving it. :rolleyes: :D
Hey Greg, so you already have another engine?

Nissan uses a grading system for pistons. #1, #2, etc. On top of the cylinder block each cylinder bore is stamped with a number signifying what grade piston goes in each hole. Mine is 'odd' in that it reads 2-2-2-1.

In the photo of me holding the honing tool...look to the #2 cylinder just to the left; you will see a number '2' on the top of the cylinder between the water jackets. The grade of piston is also stamped into the top of each piston.

As for getting some aftermarket pistons...this engine will not see more than 10-12psi of boost from here on out. The factory pistons lasted 156k miles, two years of nitrous, and two years of 8-12psi of boost. While DET and DE pistons both are known to crack like this....I doubt this engine will see the abuse I've heaped upon it any more. I really ran it hard these last 2 years.



-GP-


Interesting Greg. I had no idea that the block was marked like that. I didnt even notice it when i was tearing down the old lowport that came in my car.

http://www.turbochargedse-r.com/0704build6.jpg
Cracked ring lands. I knew it. What is odd is that the car drove some 50 miles with these cracks in it, no problems at all. The cylinder walls are nice and smooth, too. Go figure.


So they were cracked, but held in place by the rings? I'm figuring that because you managed to find the pieces.

What did you find elsewhere to explain the lower compression on the other three cylinders? Was it just worn rings?

Yep, Jason. Look at the first pic of the piston, and that is exactly how it came out of the cylinder. All the pieces were together...just small cracks were visible. I really wish we'd have removed that piston while you were here...just so you could see it.

I only removed #s 2 and 3 today. #3 had worn down rings, no cracks. Looking at Jonathon's FSM scan of Nissan piston grades....I am going to pop a #2 DET piston in the #1 cylinder of mine and check the clearances. There's more wiggle room in there than I thought. :)

-GP-

where did you get that honing tool from? I could definitely use one of those suckers.

and what oil during honing?

I got it at MonkeyZone, Mike. It seems to do a decent job. I used WD-40 oil.

Oh, and to answer an earlier question...I do have a spare engine in my basement. This is the original engine that came in the car, and I want to keep things that way.

-GP-

DET pistons? Up the boost!!

DET pistons? Up the boost!!

put in TTZ pistons....you will be happy :D

^^ that requires overboring the cylinders. not something he wants to do or go buy for that matter im sure