Hole in #4 piston??

[Minimalitia]

Hey guys my tow guy just got a 92 eclipse and it has a 4g63 N/T motor in it but there is a hole in the #4 piston. i was thinking about grabbing the motor as a donor for a build up motor for my TSI or just a spare motor. but i got two questions. first what would cause a hole to blow through the top of the piston? also is the N/T 4g63 the same motor just diff valves as the turbo one? or could i make it work for a turbo one? thanx

 

[Old Mitsu Tech]

Pre-ignition and detonation can cause it. Caused by Carbon, over advanced timing, or poor cooling around the combustion chamber. ETC.

The NT block doesn't have the turbo oil lines. And, the compression is higher and you should change the pistons at least. The turbo oil lines I guess could be "manufactured" Although someone else will have to tell you how. Not in my realm of knowledge.

Good Luck

 

[blackGSX2g]

Hey guys my tow guy just got a 92 eclipse and it has a 4g63 N/T motor in it but there is a hole in the #4 piston. i was thinking about grabbing the motor as a donor for a build up motor for my TSI or just a spare motor. but i got two questions. first what would cause a hole to blow through the top of the piston? also is the N/T 4g63 the same motor just diff valves as the turbo one? or could i make it work for a turbo one? thanx

Just like Old Mitsu Tech said, detonation/pre-ignition killed that piston.

The N/T 4g63 block is cast the same as the turbo block, but it is missing the oil squirters underneath the pistons. The 4g63T blocks have these to keep the pistons cool. While it is argued that you do not need them, I would prefer to keep them or get a block that has them.

The oil lines for your turbo are all external and can be swapped from your existing motor (or purchased seperately) and can be installed on the N/T block just fine.

The N/T 4g63 pistons are 9:1 compression whereas the 4g63T pistons are 7.8:1 compression. I would not recommend running those pistons in a turbocharged car.

As far as the head is concerned, they are all cast the same and are completely interchangeable with one another with the exception of the camshafts. You will need camshafts designed for the 4g63T motor.

 

[herovueboi]

I think if a piston has a hole, your better off picking up a better condition 4G63. I would steer clear of something that has been hit with a problem such as that. Swapping in a turbo motor into a car that used to be turbocharged is so much less of a headache. Though I recall a thread about n/a to turbo conversion. I am sure that that thread contains a list of parts that you could use if you do choose to pick up that motor.

 

[Amazin' Wasian]

I think if a piston has a hole, your better off picking up a better condition 4G63. I would steer clear of something that has been hit with a problem such as that. Swapping in a turbo motor into a car that used to be turbocharged is so much less of a headache. Though I recall a thread about n/a to turbo conversion. I am sure that that thread contains a list of parts that you could use if you do choose to pick up that motor.

Just because there is a hole in the piston doesnt mean the engine is unusable. I melted one of my pistons and all i needed to do was hone and replace and it was done.

-nick-

 

[Eclipxor]

I am in the process of turning my N/T into a turbo. But the hole in the piston is either a predetination or something actually being in the cylinder while the car was running. Either way you should get that cylinder honed because of the shrapnel in the cylinder.
The only real difference between a turbo and n/t with the internals is the oil squirters under the pistons which ultimately turned out to be useless, the pistons, and the intake cam. The intake cam needs to be upgraded and you need to swap the pistons because the piston ring shelves are not set up to hold the pressure of the cylinder. The oil squirters turned out to be useless because they are meant to cool off the pistons and they are not efficent enough. They just wind up burning your oil.

 

[Minimalitia]

Hey i got over to the car today and took the valve cover off the motor and the two valves(total one for each cam) at the very end all the way on the passenger side of the block (rite above the piston with the hole in it) both had the rocker arm not atached.. like they were just sitting in the head not on. one of them was wedged between the cam shaft and the cylinder head. i had to pry it out with a screw driver. what would cause this?

 

[i1nk83]

Jumped timing, causing the piston to hit the valve quite hard. That might be the reason for the hole in the piston.....or maybe its just me.

 

[herovueboi]

Just because there is a hole in the piston doesnt mean the engine is unusable. I melted one of my pistons and all i needed to do was hone and replace and it was done.

-nick-

Sure it would still be usable. I didn't say that it was a total piece of crap after something like that. I just wanted to say that for the price of a 4G63 today, its probably cheaper and less work to get one and build it up rather than a n/a and swap all the turbo parts over to it. But its up to him, I would probably just build a turbo motor to save the headache of swapping part for part that is needed.