Another rebuild thread
 

I'm removing the DOHC form my SC2 right now. I was driving to work a few weeks ago. I left my driveway and was accelerating up the road when I heard or felt a pop under the hood, the car immediately died and I pushed it back to my driveway where it sat for a couple of weeks while I got my garage ready for what I figured was going to be a long project. Well it's underway now and I'll be looking to this forum for help as much as possible. I'll make postings as I can for the duration of the project.

The car isn't perfect cosmetically, with 180k on the clock, but over the last couple of years I have replaced a lot of the mechanical stuff, front end suspension, brakes, struts, control arms wheel bearings, CV shafts, tires, alignment, AC compressor, you get the idea, I can't bear the idea of scrapping it anyway.

Looking forward to seeing this. Post some pictures if you can throughout the way!

Today wasn't a good day for work, I put in about 13 hours at work today. Spent a lot of it tuning a main rotor for vibration control. Planning to finally get the saturn engine hanging tomorrow. I had trouble with the exhaust flange nuts! Soaked them with mousemilk for a cople of days and used a half inch drive 6 point 13mm socket and they came right off. I was afraid I was going to have to cut the dang things off with a torch, but mousmilk did the job. The rubber on the upper engine mount was almost completely torn away, looks like that,s on the order list. Based on the way it looked, I'm ordering all new mounts.

Any rhoughts about poly mounts?

Well off to sleep, lots to do tomorrow.

Ive heard good things about poly bushings for the s-cars.
Im sure someone who actually drives one has a better input though

Got A little more done today, still not quite to the point of having the engine hanging but very close, radiator is out, alternator is out, power steering pump is loose and set aside. being really careful bagging and tagging parts as she comes apart. I had my two of my sons turning wrenches today, but had a church event and a photo session (helping my wife with lighting) that took up a good chunk of the afternoon. Tomorrow is church in the morning then my youngest son's 11th birthday. He's getting his first rifle, a ruger 1022. I expect we'll be out shooting in the back yard a little bit. Maybe get back to the car in the evening.

Progress today, started late, and still at it taking a break to make this update. I thought I was ready to pull the engine and separated the block from the transmission when I realized that unlike my automatic SL that I did and engine remove and install before, My SC2 Manual has to come out with the engine, clearance is not there to get the clutch past the bell housing. so I put the top engine mount bolts back in and started working on pulling the suspension apart. In retrospect, I had not seen much online about Manual trans idiosyncrasies regarding engine removal issues. I've decided it's not as straightforward as others I've done in the past and have started using a manual like a good aircraft tech should.

The cool thing is that my son, even with his shiny new rifle, still was determined that we would have the engine hanging before he left for his mother's house. Alas, he had to leave about the time I discovered the impossible clearance issue. Another work week starts tomorrow, but I have some days off coming up, should be into the teardown by then. My boys will both be here for Christmas break and hopefully still exited about making the car go.

I seriously thinking about all of this work and that if I'm doing all of this, some upgrades are justified. Now what upgrades? Clutch? Definitely. Higher compression pistons? Boring over? milling, porting and polishing? hmm. Just praying my daughter's car doesn't break down before I'm done. It needs some front end suspension work...

Well back to the CV Shaft extraction, more tomorrow.

Thank god for my heated garage!

I'll take a few more and see if I can post them.

As far as mounts go, I've been OEM stock for 18 years on my mts for my 97 SC2.
In fact, have never needed/bothered to change any but the upper TAM (torque axis mount), which, on these cars, is a consumable. And I just rolled 250K. I'm sure the tranny mount is squashed, but until I have a reason to work down there and it's causing problems, the song remains the same.

From what I've read,
--Aftermarket normal rubber TAMs suck and transmit too much vibration to the cabin
--Poly bushings are great if you are absolutely fine with trading slightly enhanced handling for a harsher ride
--Twistec motor mounts are either the greatest thing since sliced bread or they shear right off from the forces exerted on them. It's hard to tell what the consensus is because you will never hear back from the positive reviewers whose Twistecs became TwistOffs 3 days after they praised it. Hell, don't know if they even still make them. Make sure you follow the proper procedure for the torque axis mount system. It is actually 2 mounts and he lower must be loosened while the top is tightened up.

Had two really rough days at work, VEERRRYYY long hours and a lot of miles on the sunfire dealing with a helicopter that was stuck away from home in bad weather. Playing taxi driver for pilots. Anyway, after Sunday's post I fished with the removal of the engine and transaxle as a unit. I got it to the point of hanging on the cherry picker. I wanted to go remove the trans and mount the block to the stand tonight but Its been a long day and I'm thinking break time.

First off, I am DUNN with using microsoft Edge for forum viewing. I've typed the following update twice and had the window inexplicably close on me each time before I finished the posts. Firefox is now my primary browser in window 10.

Anyway, back to work on the overhaul tonight. I separated the transaxle from the engine then mounted the engine on my stand.

I then removed the air conditioner brackets, the water pump and pulley, the thermostat and nipple, and the exhaust manifold.

Then I ran into some trouble with the balancer. I could not break that bolt loose with a 14 inch breaker bar. It isn't a left hand thread is it? I doubt it, but I've been wrong before.

I was very surprised how small the exhaust ports are! Lots of room for porting, but how much can I safely remove? If using the gasket as a guide, about an 1/8th inch all around. removing that much scares me! I'll look for threads on the subject here before I do anything with it. As I suspected, lots of antifreeze in the seam of the head. Pretty sure now that the blown head gasket is the correct diagnosis, but I'm going to do everything I can to freshen this engine while it's apart. Tired of burning oil.

I figured I would post here, instead of in the new member section...

As far as head porting goes, anything you can do to correct flow issues would have a net gain, but I would get a junkyard head to practice with, lest you hit a water jacket on your only head... As far as port size goes, however, it won't hurt to enlarge the ports, just make sure to blend the opening back into the runner for optimal flow... i would give the exhaust ports a mirror finish, and leave the intake ports at an 80-120grit finish to prevent fuel puddling...

you are too young to know this kinda stuff.

Stop surfing and go......I dunno.....just ....go

In all seriousness, I see you 5-10 years down the road building up your own custom performance engine design business or speed shop. I know production cars are always getting more powerful, and you can always buy an engine in a crate, it's totally different when you improve on something that;s already been optimized.


as long as your boost solenoid can open the bypass

today's progress: the balancer, removed oil pan, timing cover, I take manifold, cams, and finally the head.

Turns out the balancer retaining bolt is a normal right hand thread. I had to have my wife stand on the opposite corner while I leaned on my torque wrench that was set to 250 ft lbs. that did it. It finally came loose without clicking. It then popped off the shaft rather anti climaticly. Was expecting a bit more of a fight with the puller, the timing chain tensioner was pretty much all the way out indicating that the timing chain has been stretched quite a lot. I was planning to replace it anyway. Injectors looked fairly clean but I might get them tested anyway or just replace if not too costly.

Whas rather surprised to see that there was not an intake gasket. I guess I'll have to make my own template to port the intake side of the head and match it to the plastic manifold. Thinking cardboard or some clear acetate sheet ir something like that would work.

The chambers and piston faces were pretty well carboned up and there was a lot of carbon in the intake runners indicating intake valves not seating very well.

The valves were also carbon covered, I haven't checked to see if they seal well. I'll check that before pulling the valves out.

Tomorrow will be all about cleaning parts and measuring for bearing clearances as I pull apart the block.i can't order my kit until I have those measurements. I'll also measure the bores although they look pretty darn good. I can still see the factory crosshatching and it looks evenly worn with no discernible ridges at the top.

The head gasket- I could not find a place where I could say it blew out, but the gasket was very well corroded at all of the water jacket openings.

To be honest, my dream is to run a speed shop... The issue is that there isn't that great a demand for a speed shop in my area...

All I can do is read, learn, and dream, because the reality is that it'll never happen...

I had the SDA TAM mount and dogbones in mine after my rebuild. Vibration and rattles were up but it did help control wheel hop. its been awhile since ive had it but i did like those mounts. never had issues with them, too bad SDA is dead and gone.
Never got around to doing poly bushings before i crunched the front end

In reference to the pulling the trans. It is possible to remove trans from motor, but it will have to come out of the bottom/drivers side wheel well. I dropped the cradle to do my manual swap, but honestly, its more pain than its worth and I found it easier to pull the whole assembly (which i found out when the diff pin fairy visited me a handful of months after the swap was done) then you can clean everything nicely and replace seals easily if needed.

The guy who opened the one by me didn't think it was going to take off, so he built a storage facility into the building as well (for classics/high dollar cars)
He claims he made his money back just on performance work within the first 6 months of being opened. I would've of believed it if I didn't see several customer projects sitting there
G6 getting a 1900 put on with all supports, tuned, dyno
Vette was getting built, turbo'd, and stripped for the track
They were doing something with an sti
GTR came back for a fuel pump upgrade because it wasn't enough for whatever was done to it.


To think, these cars are in my area, but I have NEVER seen em on the road. It is beyond crazy.

Still, the speed shop thing isn't gonna happen for me, for an extra couple reasons:

1. I don't earn enough money at work to save meaningfully toward anything at all like that, and the wife would kill me for not spending the money on a house...

2. Other people in the area are just as broke as I am, preventing their being able to pay(not that they wouldn't want work done)

Movin' to the country,
gonna eat a lot of peaches
Movin' to the country,
Gonna eat me a lot of peaches

Get outta dodge when you can, THEN start chasing the dream

Helomech,

sorry for derailing the thread.

Where are you at in the rebuild?

He called me, decided a fully built motor, with a big turbo. Estimated goal of 500 whp.

might as well do rear wheel drive while you're at it. LSJ swap or DOHC?

Gonna need some beefy torque axis mounts for that puppy

got little done over the Christmas break, was at the in-law's all new year's weekend. I hope all had a merry Christmas. I was kind of bummed, my father in law had moved his 79' Corvette to storage and I didn't get to see it. We are buying it from him making monthly payments until it's paid in full. Will be a couple of years before it moves to my own garage, but my garage isn't ready for it yet anyway. But I digress.

Got a lot done on my cylinder head in the first week of the new year, still a long way to go. Wondering what kind of valve spring compressor works best on these heads, I got the keepers out of the valves well enough but not sure how I'm going to get them back in. none of my valve spring compressors fit.

On the subject of valve springs, I don't know how I did it, but I lost one spring somewhere between home and my hanger at work where I am doing most of the work. It's probably lying in my back yard under the snow. I'm sure someone has a few lying around, but I need to find out who. ebay was no help.


Anyway, I have done a mild port and polish on the head. Lots of casting lines and rough areas removed without enlarging any chambers. With all of that garbage in the way of the flow, I can't believe I won't see a least some modest gains for the effort.

With the help of my boys, will be lapping the valves later today. No fancy three angle grinds are planned, I expect that would be useless effort and not at all effective given the rpm this engine turns.

While you have the head apart:

Earlier model(93) valves are flat faced(not dished like the late model valves are), but same size, length, keeper as the late model... Installing these in your engine with the late model pistons will give a modest bump in compression... Supposedly, the 98 crank is lighter too...

There are lots of 1.9 builds over on sixth sphere, and I would also guess there are owners with spare parts...