1990 sunbird gt help - Second Generation Forum

Forum Post / Reply
You must log in before you can post or reply to messages.
1990 sunbird gt help
Friday, July 20, 2007 6:39 AM
hey all, i picked up a sunbird yesterday as a project car. 1990, 2.0 turbo, 122k, auto the outside is in immaculate shape as its a one owner car and was garage kept. well anyway, while i was driving the car home after picking it up, the oil pump when out and it threw a bearing, i never heard a rod-knock so loud in my life. so my question is this: new engine or new bearings? which would be easier? changing the bearings would be cheaper though and i don't think i'll find a 2.0 turbo engine anytime soon. how hard would it be to put new bearings in this dam thing? and i'm assuming i have to lift the engine out of the car to change the bearings? god i hate them 2.0 turbo motors such an unreliable piece of $hit and i've had many people warn me they were nothing but trouble. and they're not that fast. i think my mothers sunfire gt is a hare faster. well thanks for the help guys


People say that what doesn't kill you in this life
will make you stronger. I'm not sure if that is true
or not, but i do know one thing-You have to learn from
it and it has to make you better.......it has to.......


Re: 1990 sunbird gt help
Friday, July 20, 2007 9:43 AM
Quote:

so my question is this: new engine or new bearings?


The proper answer: Pull engine, disassemble, then evaluate. If the crank isn't too terribly scored, you may be able to get by with just bearings. Opportune time for some go-fast goodies, if that's your slice of pie.

Quote:

i've had many people warn me they were nothing but trouble


They're higher maintenance, but no less/more unreliable than many other GM I4 engines.

Quote:

i think my mothers sunfire gt is a hare faster


You probably have a very, very ill LT3. In it's stock form, the 2.0L-T has 20HP over a stock LD9.




1989 Z24 Convertible - Dust Covered
2006 tC - Dust Covered, but driven more
Re: 1990 sunbird gt help
Friday, July 20, 2007 10:09 AM
ZlineDavid- yes u are right, i do have a very ill LT3 engine lol and yes i know if it was in top running condition it would rape a 'fire gt. i had an 89 sunbird gt as my first car 5-speed, intercooler boost control, etc. and it was pretty fast but also high maintance. but they say speed costs lol but i'm thinking i'll pull the engine and drop in a used one for the time being and then tear down the old engine and do a rebuild and possibly throw some extra power at it should be able to build a mid 14 second motor for 1500.00 or less the problem is finding another motor since gm didn't produce all that many. i see a few in the boneyard from time to time but theyre usually hammered kinda like mine lol


People say that what doesn't kill you in this life
will make you stronger. I'm not sure if that is true
or not, but i do know one thing-You have to learn from
it and it has to make you better.......it has to.......

Re: 1990 sunbird gt help
Friday, July 20, 2007 2:57 PM
you could get a 2.0 TBI block/crank, those were the same IIRC, its been a long time since i looked into LT3 stuff, as well get an intake mani from a 92-94 sunbird MPFI they apparantly flow better i know for sure between na and turbo the pistons are different, probably rods but i coulda swore i've seen that the block and crank are the same between the two and 92+ cam shafts have a better profile/lift
Re: 1990 sunbird gt help
Saturday, July 21, 2007 10:13 AM
Seanski-u are right, the pistons are different, hypterpeutic or however u say it. i think the rods and crank are different too but don't quote me on it. but anyways, i pulled the motor out last night and into this morning and tore the motor apart. the crank is scored just ever so slightly, but not near bad enough to need a new crank. so new a set of new bearings it is.and a new oil pump since that was the cause of this mess lol. if i was smart i would just beef up the whole bottom end so i can run slightly higher boost and for reliability issues. but i don't have the money at the moment because i had to put yet another tranny in my daytona. i think thats the sixth or seventh one now. and plus i have to get the pontiac back on the road by the 5th of august


People say that what doesn't kill you in this life
will make you stronger. I'm not sure if that is true
or not, but i do know one thing-You have to learn from
it and it has to make you better.......it has to.......

Re: 1990 sunbird gt help
Saturday, July 21, 2007 10:51 AM
take the crank to the machine shop and have it polished, or if its bad enough just get it utrned .010" under. it may be ok to look at but it may be out of spec and even slight scoring will tear bearings out of it.

there are quite a few guys running over 15psi on a stock short block, they are a pretty stout motor. one this i would recoemnd is getting the cometic head gasket for it. its a multi layer steel gasket and will last much longer than a stock replacment. if you go this route make sure you get a can of copper spray sealer and coat the gasket in it so it doesnt leak.



Re: 1990 sunbird gt help
Saturday, July 21, 2007 2:00 PM
Sharkey-yeah thanks for the heads up on the cometic head gasket. i hear nothing but good things about it so it must be a quality product. do u or anybody else have an idea where i can get a cometic head gasket at? and people running over 15 psi on a stock block thats kinda impressive i guess the bottom end is stronger then i thought but doesn't that require an intercooler? and one more thing, how many lbs of boost does the 2.0 turbo put out stock? i'm guessing 12? i try to read the boost gauge in the car while i was driving it but the gauge isn't precise enough to know exactly how much boost u r getting


People say that what doesn't kill you in this life
will make you stronger. I'm not sure if that is true
or not, but i do know one thing-You have to learn from
it and it has to make you better.......it has to.......

Re: 1990 sunbird gt help
Saturday, July 21, 2007 11:06 PM
you should be able to get it from a parts store that deals with performance stuff, aside from that may have to order it online. it may be listed for a c20xe or c20let, those are the european versions of the motor, but its the same short block.

the bottom end is fairly strong in these motors. the weak point is head gaskets. stock is 5-8psi depending on the year and transmission. if you are turning the boost up i would highly recomend an intercooler and a blow off valve. a couple cheaper sorces for that would be e-bay, the cheap intercoolers (i think its jdm sport) are actauly decent for the money. 1st gen dsm blow off valves are also pretty good, and fairly cheap.

the factory tuning limits boost to 12psi, anything higher sustained for 2 seconds it will cut the injectors till the boost drops off. with a chip this can be removed, but to go higher than 14 you will need a 3 bar map sensor. before you get to this point though you will want some supporting mods. im not sure how much the injectors will support, same deal with the fuel pump. you would also want some decent exaust, 2.5-3".



Re: 1990 sunbird gt help
Sunday, July 22, 2007 7:14 AM
Sharkey-i'm pretty much with you with everything you said except for one thing. my sunbird has an auto tranny so can i still install a b.o.v? and how exactly do u install them? i have a turbo xs b.o.v. sitting in my garage that i was going to install onto my daytona, will it work on my sunbird too? i'm a guru w/ mopar turbos but when it comes to the gm platform i'm a little lost so i'm sorry if i ask so many questions lol. and i've decided i'm only gonna go with 12 lbs boost no higher. with 12 lbs, an intercooler, 2.50 inch mandrel bent exhaust, header, mild cam (which i already have) and a ported head i should have a fairly quick car lol. and lastly, how do u turn the boost up (safely) on these cars? wouldn't i need to buy or make a grainger valve like i did for my daytona? and will the stock turbo be able to put out 12 psi? thanks for the help and sorry for all the questions.


People say that what doesn't kill you in this life
will make you stronger. I'm not sure if that is true
or not, but i do know one thing-You have to learn from
it and it has to make you better.......it has to.......

Re: 1990 sunbird gt help
Sunday, July 22, 2007 9:29 AM
ive witnessed the stock turbo putting out 19spi. it isnt efficient at that boost, but it will do it. you would need a form of manual boost controler to up the boost. basicly anything you know about turbo mopar stuff transfers over.

you would have the bov flange welded into the charge pipe close to the throttle body. a blow off valve is designed to release the pressure in the charge pipe when you let off the throttle. now you dont let off the throttle to shift, but you do have to let the throttle at some point, and without a BOV, you would get compressor surge and can possibly bend the blades in the compressor.



Re: 1990 sunbird gt help
Sunday, July 22, 2007 2:43 PM
Sharkey-thanks for all the help. and i never knew u could install a b.o.v. onto a car w/ an auto tranny, guess ya learn something new everyday lol. i've decided to yank another motor from the junkyard and throw fresh gaskets on it since i took the crank to my local machine shop and they said they wouldn't feel comfortable working w/ it and giving it back to me as it is actually hammered pretty good. i guess a few scratches on a crank really is a big deal lol. plus the rod did a number on the block so i'll yank the head and the turbocharger itself and ditch the block.


People say that what doesn't kill you in this life
will make you stronger. I'm not sure if that is true
or not, but i do know one thing-You have to learn from
it and it has to make you better.......it has to.......


Re: 1990 sunbird gt help
Monday, July 23, 2007 3:07 PM
I have both a fresh 2.0 turbo bottom end - .5mm over with new forged mahle pistons, fully balanced, no miles. I also have a cometic headgasket still in the palstic. I'd be happy to meet you halfway if you are interested.
I got rid of my race car and got a new 3rd gen project car again. LOOOTS of performance goodies for the 2.0t if you are interested.
Just to get rid of them, I'd give you the short block and headgasket for $400.



Cardomain|Myspace

Forum Post / Reply
You must log in before you can post or reply to messages.

 

Start New Topic Advanced Search