Compression Loss

[Dweet]

Ok here is the deal. I have a 6 bolt 4g63t out of a 91 Talon. I had a leak down test done to it. Piston 3 has a 70% compression loss and piston 1 is about to go. The guy that did it seems to think its either leaky piston rings and/or valve problems. He said more than likely valve problems. Anyways I talked to ERS and they seemed to not really know how much it would cost to get the engine rebuilt. I was wondering if anyone here may know common problems regarding these engines and if so what the rebuild cost would be. Any help is appreciated.

[Iwishiwascool]

how much do you have to spend is a better question.

[DSM614]

pm me.

[Dweet]

well this engine is for a daily driver so i dont want to do a rebuild to make it stupid fast... just reliable

[talon guy]

well this engine is for a daily driver so i dont want to do a rebuild to make it stupid fast... just reliable


lol he said reliable

[Mike C]

Isn't the purpose of a leekdown test to determine whether the leeking is coming from the valve seals or the piston rings? I thought thats what differentiated it from a normal compression test?

[KentStateTsi]

i believe you can get an entire rebuild kit from slow boy racing....its made by Top Line...for around $500 i think.....thats with new stuff......i bought piston and rod combo's off of mitsubishi graveyard for $15 each....ALWAYS us new rings...i paid $72 for those...have a machine shop check to see if the head is straight......anything more than that is totally up to....such as APR head studs...$70.....Mitsu headgasket $??......there are so many variables its making my head spin trying to post about them....dont be affraid to ask what you may think is a stupid question..thats what we're here for

[Dweet]

what do you think about this rebuild kit
http://www.machv.com/comenrebkit.html

[DSM614]

That's the same kit he is talking about Nick...

[Iwishiwascool]

That will work IF you have the time and the space to do a rebult project

You MUST have torque wrenches and patience... not to mention a warm place to do all this. It is not a quick thing to do.

[biglipps66]

well by looking at it, it contains the good stuff to get the motor back in working condition. Depending on the condition of the block, you could get a light hone and do stock rings and pistons or just do a .20 over bore and get 20 overs. Not bad.

And what Ken says... building a motor is NOT an easy task. There are the smallest details you need to pay attention to that could be the difference between your motor lasting 1 day or years of fun.

[Iwishiwascool]

and by tiny he means thousandths of a mm.

When we open the tech archives shortly you will be able to see all that is involved in building one.

[WikdTSi]

I'm not sure how MACHV or others can sell a generic "rebuild kit" for Any Turbo 7 Bolt.

:confused

:nono

Maybe they just take a good guess at what your block #'s might be.
:bash

[birdsfoot]

reliable??????

ive never heard that word before :p

[DSM614]

I will be helping on this project. No worries guys.

[JayC]

You may just be looking at new rings and head gasket to get her up and running. The thing is, if you are goin start into the engine you are going to want to get bearings, gaskets, seals, timing belt, tensioner, so on a so forth. That looks a like a pretty good deal for all of that. If you were to price that stuff alone it would be much more.

[KentStateTsi]

and by tiny he means thousandths of a mm


PLASTIGUAGE!!!! you cannot express how important the bearing to surface clearance is......and yes, it can be thousandths of a mm

[Iwishiwascool]

correct. Plastigague.

Does Everybody posting here use plastigauge??

[DSM614]

I do now... 1 f**ked up crank we thought was ok. Lessioned learned.

[gsxtacy01]

i highly recommend if you dont want problems down the road use a micrometer and not plastigage. plastigage is more of a resourse for when an engine is in a car and measure bearings for a rough reading for the cause of a problem . ill tell you dont be lazy and use a micrometer !! measure in the journal housing and than the journal and subtract for your oil clearance. 2) use a dial bore gauge or telescoping gauges and an outside mic to check the cylinders for taper and out of round AFTER you hone them because you can replace rings that will never completely from minor damaged cylinders you cannot see from 1 to 4 thousandths that new rings wont fix and you'll still loose some compression need help email me at gsxtacy01@yahoo.com i work on blocks alot as a hobby and soon to be ase certified just too young :(