Rebuilding an engine - what precision instruments to do measurements

[PlayingWithTBI]

A couple years ago I had a link to a site that had a degree wheel in a .pdf so you could print your own copy. Unfortunately, I lost that link when I upgraded to Windows 11 and Foxfire redid their bookmarks

I looks like yours should work

 

[0xDEADBEEF]

This is an LQ9? Honestly, every LS cam I've ever installed was done dot-to-dot. You don't need no stinkin' degree wheel.

 

[stutaeng]

This is an LQ9? Honestly, every LS cam I've ever installed was done dot-to-dot. You don't need no stinkin' degree wheel.

Yes, a Gen III. Well, now I'm confused. I had seen a video where the guy degreed the camshaft, but he had an adjustable camshaft sprocket. All of the videos I've seen of the Bob or Jose cam swap special on the driveway, they just do the dot-to-dot install and go. The guys with the engine on stands w/o heads are the ones doing the degreeing.

Is degreeing a cam only for like when you manually add timing? On the stock ECU there's no adjustment for timing, unless you override the VE tables (for wild cam or turbo, for example) or whatever you call that, right?

Looks like I'm too early to be worrying about cam, so I'll hold off on that thought.

 

[0xDEADBEEF]

Yes, a Gen III. Well, now I'm confused. I had seen a video where the guy degreed the camshaft, but he had an adjustable camshaft sprocket. All of the videos I've seen of the Bob or Jose cam swap special on the driveway, they just do the dot-to-dot install and go. The guys with the engine on stands w/o heads are the ones doing the degreeing.

Is degreeing a cam only for like when you manually add timing? On the stock ECU there's no adjustment for timing, unless you override the VE tables (for wild cam or turbo, for example) or whatever you call that, right?

Looks like I'm too early to be worrying about cam, so I'll hold off on that thought.

It lets you move the power band around. Retarding the cam moves it up in the rpm range, and advancing it moves it lower. And to do it properly you need a special timing set.

I think in the days before CNC machines and all that goodness you also needed to check that the cam matched the card so you would have to verify it.

 

[Schurkey]

Given the propensity for bottom-feeder replacement parts to not be made correctly, I think a person is nuts to not verify the cam/crank synchronization.

This is different from verifying the cam sensor/crank sensor synch.

 

[0xDEADBEEF]

Which cam are you using? If you're re-using the factory cam that came out of it, there's no point at all in degreeing it.

I agree it is best practice to degree the cam, but I never do it. Never had a problem and never had one not perform as expected.

 

[stutaeng]

Which cam are you using? If you're re-using the factory cam that came out of it, there's no point at all in degreeing it.

I agree it is best practice to degree the cam, but I never do it. Never had a problem and never had one not perform as expected.

Probably the factory cam. I added a pic on post #25. It "looks" okay. I will be checking against specifications. I don't know how I came across this reference, but this thing has all of the specifications! Even has some "production" and "service" specs.

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Well, it's a PDF and too large to post. Here's the link: https://www.gmheritagecenter.com/do...ts/Express-Van/2006-Chevrolet-Express-Van.pdf

 

[stutaeng]

I used the cheap HF 3 stone hone to clean up the cylinders. There's some staining, but otherwise they feel smooth. I see a tiny bit of vertical scoring on some cylinders.

What now? Does this look salvageable?

 

[Schurkey]

I used the cheap HF 3 stone hone to clean up the cylinders.

What grit? Better be pretty fine as I'm sure you'll be using moly-filled rings.

When it's me, I cram a 240-grit Flex-Hone through the cylinders for a couple strokes, followed by a 320-grit Flex-Hone for several strokes.

And then, a normal green Scotch-Brite pad lubed with kerosene or Diesel fuel, scrubbed vertically up 'n' down the bores. That's something I picked-up from David Vizard. Supposedly removes any folded-metal left by the honing; smooths-out the peaks of the metal, and thus reduces friction during assembly and initial break-in.

Then clean, clean, clean!

My machinist uses a different sort of flex-hone after honing to size. His has abrasive plastic fingers. rather than silicon carbide dingle_berries.

There's some staining, but otherwise they feel smooth. I see a tiny bit of vertical scoring on some cylinders.

What now? Does this look salvageable?

It "looks" terrible. Whether it is terrible or not, I'm not qualified to say. It "don't look nothin' like" what I'm used to, which is a pristine, uniform-color cylinder with cross-hatch hone marks.

 

[Schurkey]

Further consideration: I'm not used to using a 3-stone hone. Since my hones are different from your hones, I don't know what's normal for that style tool.

Is it possible that the "staining" you're showing on those cylinders is where the stones aren't touching the cylinder wall, due to some wear in the cylinder bore?

I'd really like to see you haul that to a machine shop for a professional opinion. I lean toward spinning a rigid-hone through some of those cylinders to see if they clean-up visually.