I at least blew my headgasket possibly a couple of pistons/rings.

I'm considering replacing my pistons and rods with forged ones
I have 76K miles on my stock motor.

I want to leave my motor in the car to do this. Is it worth it? How much can I do with the motor in the car by taking the head off and dropping the oil pan? How often do main bearings wear out? I won't be able to change them, right? So is it worth the effort?

 

I would take it out of the car and rebuild it on an engine stand

1. you have enough room
2. you may be able to do it faster than with it in the car
3. it give you easy access to other components in the car that would be difficult to reach with the engine in place...

 

Since you can't drive the car anywhere, and the fact that it will take a good amount of time to do this, I would pull the motor.

It'll be much easier to inspect/remove/install things that with the motor out of the car. Just rent an engine crane from a shop (borrow a friend's truck/van).

good luck

 

Main bearings can be replaced with the engine in the car. Just remove the main bearing saddle and the upper bearing halves can be pushed out with an old one. I've done it several times.

 

Don't you have to remove the crank to get to the main bearings? In order to remove the crank don't you have to take out the tranny/flywheel?

 

I'd take it out too. If you've dropped your tranny and done your timing belt before, the rest is a walk in the park.

 

The real question is how is the condition of the cylinder walls? If they are ok, you can rebuild without pulling the engine or tranny. If the walls are out of round, you must pull it to have the motor bored and honed at a machine shop.
With only 76K miles, your mains may be ok and won't need replacing.
If you just replace pistons and rings without knowing the condition of your cyl walls, you may not get the full potential of your motor.

 

So. what exactly will I need to evaluate the condition of my cylinder walls? If the factory honing marks are still there I assume thats a good sign? Do I need a special caliper to test thicknesses?

Also, if I land up doing my pistons and rods, If I inspect my lower main bearings with my engine in the car and they look nice and smooth, is that an ok sign that I can go with the rebuild and be ok?

I wonder if that little vibration I've been having at about 1500rpm has been my internals this whole time.

 

since you are going through all that trouble to do a partial rebuild, why not just save the extra cast and do the whole thing? save you big headache in the long run.

 

Kinda OT, but why do you think your motor crapped out? Did you have any detonation? Looks like you have a nice engine management set up.....

 

I'm not sure. I overboosted to 11.7psi when I was not set up that high in my hondata. According to hondata, i did not get cutoff at 11.2 where I was set because the MAP voltages usually read a bit lower than boost gauges.

Anyway, I don't think I was detonating. I had my wideband in and it was showing good mixture in boost.

I know at least that my headgasket is gone but my outer 2 cylinders have low compression. I may be in for pistons/rings at least but who knows yet. I pull the head in a couple of days!

 

To test for out-of-roundness, you will need a Dial Bore Gauge.

 

No, the lower halves will come out with the main bearing cradle. The upper halves can be pushed out with an old bearing. They can only be pushed out in one direction because of the locating tab. Remove and replace them one journal at a time. BTW, the lower halves take most of the stress so if the lower halves look good the uppers are probably fine.

Yes.

 

oh, thats sweet! I really want to avoid having to drop the tranny. If the bearings look good without wear or hot spots, is it ok to just leave them and just replace the pistons/rods and rod bearings or is it worth it just to replace the mains anyway? Have you done that trick before in replacing the bearings like you describe?

 

If the mains are in good shape I don't replace them unless it is requested. Usually if they are beat up the crank needs to come out to be repaired.

Yes.


[Modified by Chiovnidca, 8:15 PM 6/23/2002]

 

I think you need to change your sig. How can you offer hondata and wideband o2 tuneing and not know these things already.

 

are you aware that a great many car tuners have never touched an engine? Let me just say that a few "experienced" tuners I have come across do a pretty crappy job tuning as well. I consider myself much more mechanically inclined than most people out there. Especially with the Hondata system and wideband tuning on the street (which most people are just too lazy to do), I am quite confident in my abilities.

If I care to ask some reasonably intelligent questions before tackling a job on my engine that I have never done on my engine, I would hope for some reasonably intelligent answers from some caring and helpful people the same way I patiently help others.

Beyond that I need not comment on your post.