Misc Car Projects, What Are You Working On?

Not a performance project this time, but I am saving my Father-in-laws Caddy. It has the 32 valve Northstar, which is a great engine, until... About 70 % of them will at some time develop head gasket failure and start overheating. Dealerships want up to $5500 to do this job, so I took it over as he is on disability, etc...

There are some interesting aspects to this one so here is my photo essay of the project so far.

The patient:


No clearance to access anything. Very tight quarters prompting the dealership mechanic to state he'd rather put his fingers in a meat grinder than do this job! Rear head, of course the one with high leakdown #'s is against the firewall, so engine removal is the best way to do the gaskets.


Ok, now I can get to everything. This was about 6 hrs into the job, only 45 minutes of that was actually structural work, the rest is stupid unhooking stuff. Comes out the bottom on a cradle, JUST like a Ferrari. I'm sure the GM design engineers were mad at the service techs for some reason when they designed this and located all the clamps and fittings.


Finding TDC before dissassembly. Chains, JUST like a Lamborghini:


Intake and head off. Note starter location, unusual for a domestic car. Cleaning and rebuilding things like that while at it and have access to avoid headaches later on:


Heads fresh back from the machine shop. Fresh valve job. Milled flat, but were not too bad despite some serious cycles of overheating. The car saw 260 degrees a couple times but has a limp home mode so it can run without water, randomly selecting cylinders to fire while air cooling the others.


Here is the Northstar issue. With only 10 head bolts into the aluminum block, a loss of clamping power by stressed threads, corosion, etc... causes combustion air to enter the nearby water passages. They don't leak or use water, just the burn overheats the water, then blows it all out the overflow tank. Here the gasket show rust on the cylinder sealing rings indicating water has been there. The engine showed good compression on a gauge because the leak is so tiny, but the leakdown test indicated this is one of a few cyls that had a problem. The car would idle ok for hours, but drive it at speed or up a hill and she would puke.


The solution, install a "Timesert" thread repair system in every hole. This job is so time consuming that you want to do all 20, even if the threads look good, because you'd cry if it failed again in 5K miles. This will make it better that new. First a special bit with a stop and stepped profile cuts a new hole thru a centering jig plate and bushing:


Clean out the new hole:


Tap hole with threads to match the O.D. of a new thread insert with aggressive outside threads. Run tap in until groove on tap reaches the top of the alignment bushing:


Next, Mrs. SMS (SMS by the way stems from my days of running Sewall Motorsports, turning wrenches and restoring cars) calls from the house and says to look outside, 2 deer are working down toward the garage. I guess my language and air tools don't scare them off. I needed a break here anyway.


Back to work, STEEL insert on driver, Loctite on threads:


Run it into drilled hole. Flange on top of insert seats on shoulder left from special bit. Idiot proof.


Biggest dissapointment so far, this picture doesn't show very well what a cool little device this is. Oh well, finished hole, steel thread ready for a new head bolt. Like on the LSX motors, bolts are torqued to a low setting (30 on this one) then twisted 60 degrees of rotation 3 times for final tightening, rather that to a torque setting. This more accurately stretches the bolt properly to achieve ultimate clamping power.


Mocking up for valvetrain alignment:


More later after some more shop time.

thats amazing
must be a blast and a pain in the ass all at the same time

how many miles are on the engine?

Good question. Around 114K. Cyl walls are perfect with cross hatch still present.

Next step. I tried a short cut, but as usual, it did not work. I tried to compress the chain tentioners with a long hooked pick so I could put the chain on the cam sprocket, then slide the sprocket onto the cam. No luck, so I finally had to pull the front cover and set it all up. First the balancer must come off. Since I did not have the trans separated, the usual way of locking the engine from turning via the flywheel was unavailable, so here is a trick. Use a chain wrench, like plumbers use to position big pipe, to hold the balancer and engine from turning while you loosen the center bolt. It takes air or a 4' pipe extension on the chain wrench handle and breaker bar to get that bolt loose. Then a regular puller completes the task.


Here is the left bank (front when in the car) all set up. The tensioners are pretty slick, they are a ratchet mechanism that uses oil pressure to take up the slack and provide tension appropriate to enging rpm.


Since the head bolts are stretched during installation as noted above, they are a one time use item. GM and ARP sell bolt kits and come pre lubed and sealed.


That's all I got done last night. Hope it has a happy ending now that I've started this thread!

I'm completely lost but that looks awesome .

One of the first engines I took apart was a Northstar engine back in high school....and we ended up with a few extra bolts here and there

How's progress on the rebuild?

Hey Mark,
Slow due to my trip and catching up on a few things. I did get both heads torqued down and all cam timing set and chains on, plus front cover, balancer and some water passage stuff not shown here. Plan to have it back in the car this weekend if all goes well.

I forgot about your "shopping" trip. Did you find what you were looking for or are you still on the hunt?

Enjoying watching the progress. This winter, I really want to do a full rebuild of an extra turbo motor I have.

If you like wild projects, take a look at this: http://www.zcar.com/forums/read/1/1839421/1839421#msg-183942...

The base of the project is the same L28ET I have in my car = Single cam, single turbo, 2.8L inline 6. This guy took 2 dual cam heads, cut them up, pieced them together and put them on the block bored to 3.1L. Added a crank from a Maxima Diesel and Rods from a 240Z to stroke the engine, built an exhaust manifold for twin turbos. Built and moved the air intake to the passenger side. The engine is now sitting in a RHD first generation Z. We're still waiting for dyno numbers. Tuning still needs to happen and his Borg Warner T-5 Tranny blew up. The car recently went on an 1000 mile drive and the head held together. Amazing what this young guy has done. Bonus, he's in the family machine shop business.

Found what I was looking for. Anxiously awaiting a certain transporter.

Do tell...

I already know what it is And it is gorgeous

SMS...now that's just rude...Andrew knows and can say its "gorgeous" but you didn't share with everyone? There's got to be a digital picture there somewhere...come on...don't tease...share!

Well if you look at his owned cars...

Although, i do want some pics

I wasn't sure if that was from his past, or the present/future...

So until he let's us in on it, I'm forced to use my imagination...

His is black...i think.

Also, the second one and the second to last one are 328's i think.

The deep chin spoiler is why i think that.

Or maybe they are Euro-spec...

No, those are all 308s, but it looks like you got every color except the one Bill got

I love to see 308's as track cars! The Gulf color car is soooo cool. Thanks for the pictures.

Patience grasshopper, current pics are poor, need that truck to show up...

OK, back to the project:

Front end reassembled, composite intake manifold on.


Fully assembled. Hard to imagine all the stuff under that plastic cover.


Without a lift, here is how to do a drop out engine. Hook the engine hoist to the front frame rails,


And set the car down on the engine cradle.


Tight, but it should fit, as it did come out of there!



And keep lowering/checking until the unibody is settled on the 6 subframe mounting points. Now all that remains is hooking up the exhaust, steering coupling, wiring and vacuum lines, fuel and water systems, brakes and bleed, wheels and turn the key.

Cool thanks for the update!

Great job SMS. That Cadillac engine bay looks my 300tt engine bay... tight, tight, tight. And if I'm deciphering the other members messages, looks like you picked yourself up a 308 Quatrovalve. Very nice! Always loved those cars when I was young. Look forward to seeing you pics and hearing out it's performance.

Last pic and happy ending.
Got the Caddy all together Saturday, put Robin in the drivers seat to fire it up while I checked everything out, turned the key....nothing. Crap. She said, "Is it's theft deterant activated since you had the battery out?" Ah ha, nice to have a clear thinker around. Cycled the door locks with the key fob, turned the ignition switch, and vvrrooom!
100 miles shake down run and all is well, problem solved.

I also now believe the dealers earn every penny of their fee on doing these N* Cads.

Thanks for the story. Congrats on the successfule completition!

Ya I bet they do, not a fun job at all!