Just a bad wire

[Camino LS6]

Heads are about ready to come off, but I'm just too beat. The exhaust manifolds where much easier than I expected, and interestingly, the most rearward bolt on both sides was simply absent. Those two would have been the toughest to remove, but I wonder why they weren't there, and why I had no exhaust leaks. The other cool thing is that once I remove the dipstick tube, I can slide the whole exhaust rearward and out of my way. I have already pulled the rockers and pushrods from the driver's side head but I stopped so that I can get a shot as is to show you guys tomorrow. Given about an hour, both heads should be on the deck.

My biggest worry at the moment is being able to actually lift them out of the engine bay - the physics are all wrong. Trying to pull such heavy pieces out of what amounts to a deep hole should be an experience.

Edited November 1, 2011 by Camino LS6

[67impss]

When I had the engine out of the SS454 P/U I was working on I did most of the lifting with the hood off & radiator out,standing on the sway bar. But you don't have that option right now.

[Camino LS6]

I was going to wait until both heads were off to post these, but since the site will be down tonight I'll do it now. I ended up having to remove the driver's side exhaust manifold after all. And the Driver's side head gave me an unexpected fight. The head bolts were really, really, tight - as if someone overtightened them to hide a head gasket leak? Who knows, but the previous owner was a real tool so it could be. At any rate, here are some pics:

[67impss]

It might be just a shadow but the darkness between Cyl's 3 & 5 makes me think you should check both block & head for parallel one or both may be warped. Good news is that blocks rarely warp but I've seen my share in my 4.5 years machining and 35 years wrenching. Those two pistons look like they've not been firing also could've been the popping and miss

[Camino LS6]

It might be just a shadow but the darkness between Cyl's 3 & 5 makes me think you should check both block & head for parallel one or both may be warped. Good news is that blocks rarely warp but I've seen my share in my 4.5 years machining and 35 years wrenching. Those two pistons look like they've not been firing also could've been the popping and miss

I think that's a good bet, I also think coolant was making its way into several of the cylinders on this side. If the block is warped, I'm going to find out the hard way. As for the heads, they will either be replaced or re-done.

[Justin Bimmer]

For an engine rebuild n00b what does all this mean?

[ocnblu]

Well, Camino decided to run with the big dogs on this one. Awesome.

[A Horse With No Name]

She should be sweet when done!

[Camino LS6]

For an engine rebuild n00b what does all this mean?

Well, what I'm doing is essentially what people call "top end" reconditioning of the engine. The intake manifold and head gaskets were shot and allowing various gases and liquids to ge where they should not. Also my timing chain was very worn, allowing the valves to be slightly out of posisiton relative to the crankshaft. All of these things combined into a undriveable condition. Usually, at this point the heads would be rebuilt before going back on. In this case, I am going to be buying a pair of heads with only a few thousand miles on them instead. This is not a full rebuild by any stretch, but it does bring the upper half of the engine to the same result which should more than solve the problems I was having with it.

It also means a boatload of work.

[Camino LS6]

Pics from last night:

And I finally found a use for the Jaguar

[A Horse With No Name]

With the amount of junk in your barn you pretty much could turn the jag into the next 007 special effects car and make a bundle renting to movie companies.

Good luck on the rebuild and keep us posted.

[Camino LS6]

Picked-up a set of very low-mileage heads last night, Now it is just clean and re-assemble, clean and re-assemble...

[Camino LS6]

Gah!

Cleaning and prepping is taking forever.

[A Horse With No Name]

Glad to know your still at it, my friend...

[Camino LS6]

Cleanup mostly done, heads will be going on very soon.

Pics later.

[Camino LS6]

Heads are back on!

They aren't torqued-down yet, but it's nice to see them in place. The new head bolts were a good call - they come pre-coated with sealant. A friend from Maine is in town, so this is where it stops for today.

Pics:

[SAmadei]

I completely forget what vintage the Tahoe is, except that its sometime in the '90s... so if its towards the end of the '90s, I'd say new head bolts are a good idea, as GM started using those Torque-to-Yield ones... but I completely forget when that started.

[A Horse With No Name]

Good to know....things are going well...

[Camino LS6]

It's a '95, Samadei.

[Camino LS6]

Heads are torqued, valvetrain is installed and adjusted, intake going back on soon.

Pics later tonight or tomorrow.

Oh, and the damn thing needs an exhaust!

[ocnblu]

Will open headers pass PA inspection?

[67impss]

Not trying to hijack the thread but Reliable ROPOS's fuel pump died on me. I got it home w/o a tow. I've only got the truck to drive so had to borrow moms LeSabre to run parts. The damage was fuel pump, filter, tank strap bolt, rear U joint. I worry about the fuel lines they're 2x as big as new due to rust, good shape for 330K mi though

[Camino LS6]

Ocn: I somehow doubt it.

67: Sorry to hear about the Fuel pump hassle - been there.

Here are some pics that actually look like an engine:

[ocnblu]

You've invested a lot of sweat and time into this. Soon you'll be back on the road and up to speed once again, sir.

[Camino LS6]

I sure hope so.

[Drew Dowdell]

OMG teh pushrods!

[Camino LS6]

OMG teh pushrods!

In all their glory!

[Camino LS6]

This piece of plastic just cost me 3 hours:

So there I was, re-attaching everything at the rear of the engine, and everything is going well. At least as well as can be expected when you are under the hood and kneeling on the engine while trying to work. With all of the down-low-and-in-the-back stuff done, I moved on to the re-installing the distributer. After all of my hyper-caution about timing and all that affects it during this whole job, I'm about to verify that all is indeed good.

Full stop.

The distributer will not go down into the engine the final 1/4".

WTF?

So I second guess my self and pull the valve cover again and re-check TDC. Everything is fine.

Again, WTF?

I remove and re-lube the distributer and even try to fit it in in ANY position (it should slide in in two positions 180 degrees apart). It won't go in. So I pull it back out and set it aside, grab my penlight and shove my face up against the firewall so I can look down the distributer hole to see what's going on. Down there, in the black abyss, leaning against the oil pump rod, is the plastic bit pictured above.

OK, that has to come out.

But just how in the hell am I going to accomplish that? That thing is way down deep inside the newly-assembled engine. After trying to catch it with a long screwdriver, and failing, I devised a new method. I clipped off a piece of electric fence wire at about 2' in length and created a hook at the end. Then, with my face against the firewall, my knees on the engine, and my butt in the air, I grabbed the panlight with my left hand, and the wire with my right and somehow managed to snag the offending part. Holding my breath, I then carefully extracted it straight up and out of the engine. I could easily have fallen-off and into the lifter valley where it would be unreachable without pulling the intake all over again - but I got lucky.

Whew!

So then the mystery of what the hell this thing was, and what (if anything) it did as part of my engine, became my new concern. I sure didn't want to open the engine up again, but if this was a critical part I didn't know about, I wanted to get it to where it belonged. It didn't look like anything I'd ever seen inside a Chevy V8, but I needed to be sure. So I jumped into the wagon, and paid a visit to the local Chevy dealer. No one could positively identify that little, white,PITA. But both the mechanic and a group of parts guys agreed with me that it didn't belong anywhere near where I had found it. Good enough for me. What a bizarre sidetrack this has been for my project. I still don't know what the thing is (our collective best guess is a valve seal), but it seems it was just some automotive flotsam a careless mechanic allowed to drop into the engine at sometime in the past.

Edited November 10, 2011 by Camino LS6

[Z-06]

Bob, this thread is an awesome step by step guide. Keep it up.

[Justin Bimmer]

I nominate this as thread of the year.

Great chronology. Can't wait to see the Tahoe 4x4ing over some snow.

I also suggest that everybody select at the top the the thread. "Follow this topic"

[z28luvr01]

Agreed. I seriously got kind of anxious earlier in the week when there wasn't any updates for a couple of days.

[Robert Hall]

Yes, been a great thread...educational...Camino is a braver man than I (I'm afraid if I took an engine apart I wouldn't be able to put it back together in a workable form).

That mystery part reminds me of an old ceramic insulator from a power line..

Edited November 11, 2011 by Cubical-aka-Moltar

[Camino LS6]

Wow!

Thanks guys!

It almost makes all of the stress over this worthwhile.

How about some more pics?

[Camino LS6]

Agreed. I seriously got kind of anxious earlier in the week when there wasn't any updates for a couple of days.

I was doing boring, can't-show-it-in-a-pic stuff. Cleaning parts, and torquing bolts, and adjusting lifter pre-load.

[SAmadei]

That mystery part reminds me of an old ceramic insulator from a power line..

Yeah, it looked the same to me. At first, I thought it might be a piece of broken spark plug insulator, where the insulator snapped off cleanly and was not bonded to the core. But plugs typically do not break that way, and I'm sure Camino would know ceramic from plastic.

It that a o-ring or just black paint. It tough to get a sense of scale on the part, but it's nothing I can identify as an engine part or even a GM part from the '90s.

Just another idea for the future, Camino... if the little hook didn't work, I'd suggest a stick dipped in some really sticky bearing/axle grease. Great for picking up non-ferrous items at a distance.

BTW, the work is looking great, Camino. I wish I had the motivation lately to get my projects pushed forward.

Edited November 11, 2011 by SAmadei

[Camino LS6]

Thanks, Samadei.

The part does indeed have a tiny o-ring, and it is about 3/4" long overall, with a diameter of about 1/2".

I thought about the "sticky" approach to getting it out (I have some butyl tape onhand).

[67impss]

Camino take a look at all fuel line fittings that looked like a valve seal but should have been black for that. The fuel line seals on that 454ss I did looked suspiciously like that item

[Camino LS6]

Camino take a look at all fuel line fittings that looked like a valve seal but should have been black for that. The fuel line seals on that 454ss I did looked suspiciously like that item

The only fuel line fittings I've seen on the Tahoe are the two at the throttle body, and they are just o-rings on metal - no plastic.

[Camino LS6]

Re-assembly should be complete tonight.

Pics later tonight or tomorrow.

[Camino LS6]

It's all back together!

I don't yet know if it will run for me as the battery was just too dead from sitting, and I'm too tired to wait for it to charge. I expect to have to fiddle with the timing, and maybe take the computer out of the loop while I'm doing it. Tomorrow's another day.

Here are the pics from tonight:

[Camino LS6]

No joy yet - spins beautifully, but refuses to start.

Been through all of the preliminaries, and am all but certain that the old lifters have made the valve adjustment moot. Working from that premise now.

[Drew Dowdell]

Getting Spark?

Getting Fuel?

[Camino LS6]

Getting Spark?

Getting Fuel?

Yup.

And I've already tested the old 180 degree out thing with the distributer (had it right from the start)

I'm fairly convinced it is all valve adjustment. If that's not it, I'll have to re-think.

[Drew Dowdell]

stick a compression tester in every other spark plug hole

[Camino LS6]

This stuff is tough to do solo - could really use another set of hands so I can watch the engine while it's cranking.

Oh well, off to fight another round.

I'll update when I find something.

[Drew Dowdell]

Maybe it's just a bad wire

[Camino LS6]

Maybe it's just a bad wire

Funny guy, you are...

OK folks, need some help here. Can anyone think of a cause for a weak spark other than the coil?

The weak spark is the only thing I have found that doesn't seem right.

I'm currently stumped.

[SAmadei]

Maybe it's just a bad wire

Funny guy, you are...

OK folks, need some help here. Can anyone think of a cause for a weak spark other than the coil?

The weak spark is the only thing I have found that doesn't seem right.

I'm currently stumped.

Problem I was having with my '76 Blazer was the spark indexing in the distributor... which was causing the cap and rotors to burn out too quickly and gave me a habitually weak spark. I bought a new (cheap) distributor for it, but have had issues getting it installed... I think the replacement unit has a bad coil in it. This is the only thing I can think of, except bad wires, bad coil or the presence of a resistance wire (not a problem here) that would affect the spark quality.

[Camino LS6]

Hmmm, the old HEI distributers with the coil in the cap...

The main outer body if those coils was grounded, wasn't it?

I may have an idea.

[Camino LS6]

No effect.

It is, of course, entirely possible that the cam/lifters are simply toast.

This is why I hated the idea of diving so deeply into such an old, high-mileage, engine.

I guess I'll start at zero and go through the whole valve/lifter pre-load procedure again and give it one more shot.