Rebuilding 4G64 for low compression.

[727DSM]

I have a 1996 4G64.
I have low compression and Id like to rebuild around main things that can fix it.
I was wondering how much I can rebuild without actually pulling out the motor.
I would like to...
Replace my pistons
o-rings
Valves

If theres any other things to rebuild to fix my compression please let me know.

Any suggested parts?

 

[GSXTasy005]

I don't think anyone on this site is going to tell you how to half-ass anything. if you replace your pistons PULL YOUR MOTOR and take it to the machine shop. have them hone or bore it, then put it back in. I think 99% of the community will stand behind me on this one.

As for suggested parts, can you give us an idea on what you want to use the car for?

 

[92AWDHX40]

I never did a rebuild with a engine in the car, pita, so much easier to accesse everything. Depends on how far you need to build.

 

[BogusSVO]

What o rings are you talking about? OR do you mean the piston rings?

What is wrong with the valves they need replaced?

Yes there are some that have "in frame" rebuilt there engines, low buck builds to be sure, but it can be done.

But first, what is your budget for your build?

What mods are done already?

What parts do you have now?

 

[727DSM]

I plan on turboing it down the road, but definitely a daily driver. maybe 200-250HP.

Cant I just clean it and drop new pistons in?

 

[GSXTasy005]

Yes there are some that have "in frame" rebuilt there engines, low buck builds to be sure, but it can be done.?

My statement was meant to imply that no one would recommend it.

 

[727DSM]

I have pretty much just an intake..
Yeah the piston rings.
Im not hoping for major gains, but to just fix the compression to regain lost horsepower.
Medium range budget. I just don't have the time to leave my car overnight at a mechanic for work.

 

[DSMAvenger]

Pull the motor. We pull the motors even if we are just replacing the transmission depending on the setup. Pull the motor. If you pull it... They will come.


Chris

 

[broken_eclipse]

You can do a rebuild in the car, but like SVO and others have said and I completely agree, it'll actually be more of a burden than a blessing.

The cylinder head is going to have to come off of the block just to get the pistons out, so you're already half way there.

Then you're going to have to unbolt the rods from the crank which requires the oil pan to be off.

If you're doing pistons you might as well throw in some new bearings since you're already there and while you can try to plastigauge them, readings won't always be the same for plastigauge with rod bearings..True readings require a variety of mic's.

You're going to have to be under and leaning over the car doing all of this.. Spend the extra 2 hours and pull the motor and thank god you did.

 

[daniel dee]

You can do a rebuild in the car, but like SVO and others have said and I completely agree, it'll actually be more of a burden than a blessing.

The cylinder head is going to have to come off of the block just to get the pistons out, so you're already half way there.

Then you're going to have to unbolt the rods from the crank which requires the oil pan to be off.

If you're doing pistons you might as well throw in some new bearings since you're already there and while you can try to plastigauge them, readings won't always be the same for plastigauge with rod bearings..True readings require a variety of mic's.

You're going to have to be under and leaning over the car doing all of this.. Spend the extra 2 hours and pull the motor and thank god you did.

Fully agreed X2!!