90 4g63 turbo rebuild

[dj99877]

hey everyone. I just recently bought a 1990 4g63 turbo engine and wanted to rebuild it. it has about 100,000 miles on it and from what i understand it jumped timing and blew the head gasket warping the head slightly. besides the fact that i am getting new valves, milling the head and possibly the block. and honing the block and cleaning it. i was wondering if there was anything that should be replaced or modified right off the bat. I am interested in building the motor slightly, nothing extremely expensive though. any suggestions would be greatly appreciated! thanks

 

[nlzn]

If you're looking for mods on the head and don't want to have to do it twice a nice set of ARP's and a quality headgasket would be a good place to start.

 

[Mr PopUps]

hey everyone. I just recently bought a 1990 4g63 turbo engine and wanted to rebuild it. it has about 100,000 miles on it and from what i understand it jumped timing and blew the head gasket warping the head slightly. besides the fact that i am getting new valves, milling the head and possibly the block. and honing the block and cleaning it. i was wondering if there was anything that should be replaced or modified right off the bat. I am interested in building the motor slightly, nothing extremely expensive though. any suggestions would be greatly appreciated! thanks

Dont deck the block, unless you want flatter pistons.....

 

[BogusSVO]

^^^^ x2

but before we get off line too far, What goals do you have for the build? 250? 300? 895?
What is your budget?
How much boost?
Can you tune?
do you have a DSMLink? or a moates chip burner?
what bolt on mods do you have now?

now the machine shop you deal with,
do they have a torque plate?
How will the block/head be surfaced? what equipment do they use?

the build for diffrent goals will need diffrent parts selection.

Fill in a few more blanks and we can help you out on your build better.

 

[dj99877]

well im shooting for around 250 i just have the motor right now. and when im done redoing it i want to find a rolling chassis to put it in. im somewhat new to the 4g63's but i know enough to get started and have alot of dsm friends for guidance. i do not have dsmlink because i just got the motor. if I were to drop it into a car i would want to have a bigger turbo than stock. it seems I have alot more to research. At the moment im not really concerned with a turbo and that YET! but when its all done i will be. hope this helps

 

[Project90Talon]

One thing you will have to do is re-hone the block, Decking the head as said above will only get you flatter pistons, arp hardware all around is a good idea, see if the head is salvageable or get a new one if it is warped beyond repair.

 

[BogusSVO]

Dont deck the block, unless you want flatter pistons.....

what? hoe is decking the block going to give him flatter pistons?

these engines from what I have seen run almost a "zero" piston to block deck, on avarage from what I have measured, the piston is .002-.003 in the bore

a shop with good/accurate milling equipment can mill that amount giving a good surface finish for a MLS HG

The Mitsu Factory repair manual sets a total of .008 to be removed total from the head and block, not each but combined total

AERA, Automotive Engine Rebuilder Assoc. states .015 off the head between New Heighth and service limit.

That can be adjusted with a thicker HG to maintain factory set compression ratio.

When the block is honed, make sure that a torque plate is used, and the main caps are torqued to specs too.

250hp should be fairly easy to achive with the 4g, Do some reserch on other builds and all should go smoothly for you

 

[dj99877]

alright that sounds pretty good. apparently the head is warped beyond repair so if anyone knows where i can good a nice used or new 1g awd head for not a hole lot of money that would be awesome!
Also I was just wondering if you can make 350 to 400 horsepower on a stock engine and a larger turbo? if so what sort of components would i be looking at?

 

[e85_4g63]

The heads for the 4g63 are all the same (noted between fwd and awd). You just need to find a good 6 bolt head from a May 92 or older 4g63 engine. (Turbo or non turbo also doesn't matter in your case).

 

[BogusSVO]

alright that sounds pretty good. apparently the head is warped beyond repair so if anyone knows where i can good a nice used or new 1g awd head for not a hole lot of money that would be awesome!
Also I was just wondering if you can make 350 to 400 horsepower on a stock engine and a larger turbo? if so what sort of components would i be looking at?

Just how warped is the head? a good shop can fix it short of it being carcked into 2 pieces

I have "fixed" 4g63 heads that had appox .030 of warp

just takes a little time and some extra effort and some good know how.

 

[dj99877]

Just how warped is the head? a good shop can fix it short of it being carcked into 2 pieces

I have "fixed" 4g63 heads that had appox .030 of warp

just takes a little time and some extra effort and some good know how.

i think the shop guy said about .015 im not sure. the bad thing is its the only machine shop around. i bet its not the greatest place.

 

[Joshuah Stedman]

alright that sounds pretty good. apparently the head is warped beyond repair so if anyone knows where i can good a nice used or new 1g awd head for not a hole lot of money that would be awesome!
Also I was just wondering if you can make 350 to 400 horsepower on a stock engine and a larger turbo? if so what sort of components would i be looking at?

You can make that much power on a stock block, but you'd better have way to tune it..
You would need to upgrade the ballz out of the stock fuel system (fuelpump, rewire, injectors, afpr, etc, etc) as well as a tuning system as i said b4.

 

[BogusSVO]

i think the shop guy said about .015 im not sure. the bad thing is its the only machine shop around. i bet its not the greatest place.

.015 is close to the norm for what I see on the 4g63 foe warp with a blown HG.
A decent shop should be able to strighten it, if the cam tower warp is not too bad, it may be able to be milled, then use a thicker headgasket.
if a stock HG is .040 thick and the head is milled .015 look for a HG that is .050 thick or so.

Ask the shop what equipment they use, for surfacing and Valve jobs.

here is some info you should read.
this is a great write up on general machine work , written by DSMT Wiseman Big Woo

http://www.dsmtuners.com/forums/articles-engine-fuel/303225-engine-machine-work-explained.html


http://www.dsmtuners.com/forums/new...face-4g63t-cylinder-head-mls-head-gasket.html

http://www.dsmtuners.com/forums/newbie-forum/341288-why-have-your-valves-back-cut.html