New 87 GN (Topic merged with "It's On!" post)

[SuperSix]

w00t!

THDP finally showed up. 1st shitty seller on TB.com so far.

[SuperSix]

<boner>

Motor is OUT. Had to get crafty with the hoist - the boom wasn't near as long as it needed to be to get it out from the front. I was contemplating removing the bumper, header panel, front support, etc - then decided it would be best to do a bit of Googling. I ended up having to take the left front wheel off to get the hoist close enough, then run the chain out of the end of the boom, not out of the bottom. With a tiny bit of persuasion with a pry bar, she popped loose. I had gone to Harbor Freight to get an engine stand - but don't have any bolts long enough to mount the motor to it. I will get some bolts from Home Depot tomorrow.

Got the info I needed from this thread:
http://www.turbobuick.com/forums/engine-tech/279719-pulling-engine.html#post2452200

Same hoist, and same engine stand.

[SuperSix]

Well, got the motor on the stand today.
 
 Pulled the heads and oil pan. Not as bad as I thought it might be, but it was definitely worth me pulling it to check it out.
 
 #3 main bearing is bad, and the crank journal is scratched. The others look OK to me. Crank has been cut .010 already, not sure if it needs a polish or to be cut again. Isn't .020 pushing it? The thrust bearing surface looked great - I guess that's a positive thing. 
 
 I have pulled 3 rod caps, they look OK. I did the fingernail test on them, there's a few scratches in them - so I guess I need to get the crank cut. I need to ask Julio Don who he can recommend for a machine shop around here.
 
 The head gaskets looked OK. A few cylinders had pushed the orings out a bit, doesn't look like any were broken. I am pretty sure it was an RJC HG kit - I see remnants of silicone. I can't tell f the valve springs have been replaced - so I plan to get the machine shop to deck the heads, and I will put new springs in too. Are the LT1 springs good with a 202/202 cam? Apparently it's  an older Poston cam.

The cylinder walls look good, #2 (front right) has some rust/pitting, not sure if it's that bad though.
 
 Please take a look at the pics - let me know if you need a hi-res of any of them.
 
 I am kinda bummed - I really hoped the bottom end would be fine, I guess not. 

Overhead shot (note scratch on #3)


Main caps:


Main caps again:


Thrust bearings:



Scratched #3 Journal:


Close up of #3 main bearing cap bearing (I haven't pulled the crank yet to get to the top one)


Rear main:


Front main:


#2:


Right Cylinders:


Left Cylinders:


Cylinder #2:

[Charlief1]

Looks like stock replacement gaskets like felpro to me. As far as the main bearing, I've seen it on the Buick V6 quite often myself. Even though it's frowned on I still enlarge the oiling holes for the mains some to help out on the number 3 bearing. I've got 1 crank out of a 4.1 that failed on #3 and took both rod bearings out to the point I use the crank for an anchor.

[Steve Wood]

Not too bad looking from here.   Only a machine shop can really tell how round the journals are.

I have no problem whatsoever going as much as 0.030" under.   I have seen more than one ten second car running 30 under cranks..you could make an argument that such is better due to reduced bearing speed.  I normally like about .0015" clearance on a street engine both for rods and mains


Oops, I left a zero out...Thanks Dave!  Corrected above

[Scoobum]

Pistons are .030 over...hopeful ly just a scuff with the "black balls" for the new rings to seat. Have the big ends on the rods checked for size...cuz if they're "tight"...you'll spin a rod bearing on startup...no sense taking a chance. Grumpy has cracked the 9's with a 20/20 crank...and I pound the shit out of my current engine with a 20/30 crank...so no worries there. Have the mains checked for size as well. You don't have to do this...but...h ave the rotating assembly balanced...you won't believe how smooth the engine revs out.

[SuperSix]

Looks like stock replacement gaskets like felpro to me. As far as the main bearing, I've seen it on the Buick V6 quite often myself. Even though it's frowned on I still enlarge the oiling holes for the mains some to help out on the number 3 bearing. I've got 1 crank out of a 4.1 that failed on #3 and took both rod bearings out to the point I use the crank for an anchor.

They make be stock or FelPro - but there's silicone holding them on. I pulled a few pieces off. In one of the cylinder pics, you can see some hanging down into a cylinder. Which is odd, because it looks like some of the pressure rings were pushed out a bit. I am starting to think they were new gaskets, and somehow when the head was torqued, it pushed them out a bit. The silicone I did pull out was right along the top of the cylinder wall. No way that would have survived even a few firings. That - and the pistons are too clean to have been fired.

Not too bad looking from here.   Only a machine shop can really tell how round the journals are.

I have no problem whatsoever going as much as 0.030" under.   I have seen more than one ten second car running 30 under cranks..you could make an argument that such is better due to reduced bearing speed.  I normally like about .015" clearance on a street engine both for rods and mains

Good info. I need to find a good machine shop. Turns out Don Cruz is local, and I hear he does that type of work.

Pistons are .030 over...hopeful ly just a scuff with the "black balls" for the new rings to seat. Have the big ends on the rods checked for size...cuz if they're "tight"...you'll spin a rod bearing on startup...no sense taking a chance. Grumpy has cracked the 9's with a 20/20 crank...and I pound the shit out of my current engine with a 20/30 crank...so no worries there. Have the mains checked for size as well. You don't have to do this...but...h ave the rotating assembly balanced...you won't believe how smooth the engine revs out.

More great info. I hadn't planned to pull the pistons and re-ring - but shit - I might as well, right?

[SuperSix]

What is the reason for the 2 little notches in the pistons? Is that just to indicate orientation?

[Scoobum]

What is the reason for the 2 little notches in the pistons? Is that just to indicate orientation?

Orientation... correct. I'm old and my eyes are just about shot...but I think I can still see crosshatch marks on the cylinder walls...so this engine likely has fairly low miles on it.

[Steve Wood]

Looks like stock replacement gaskets like felpro to me. As far as the main bearing, I've seen it on the Buick V6 quite often myself. Even though it's frowned on I still e

Looks like stock replacement gaskets like felpro to me. As far as the main bearing, I've seen it on the Buick V6 quite often myself. Even though it's frowned on I still enlarge the oiling holes for the mains some to help out on the number 3 bearing. I've got 1 crank out of a 4.1 that failed on #3 and took both rod bearings out to the point I use the crank for an anchor.

They make be stock or FelPro - but there's silicone holding them on. I pulled a few pieces off. In one of the cylinder pics, you can see some hanging down into a cylinder. Which is odd, because it looks like some of the pressure rings were pushed out a bit. I am starting to think they were new gaskets, and somehow when the head was torqued, it pushed them out a bit. The silicone I did pull out was right along the top of the cylinder wall. No way that would have survived even a few firings. That - and the pistons are too clean to have been fired.

Not too bad looking from here.   Only a machine shop can really tell how round the journals are.

I have no problem whatsoever going as much as 0.030" under.   I have seen more than one ten second car running 30 under cranks..you could make an argument that such is better due to reduced bearing speed.  I normally like about .015" clearance on a street engine both for rods and mains

Good info. I need to find a good machine shop. Turns out Don Cruz is local, and I hear he does that type of work.

Pistons are .030 over...hopeful ly just a scuff with the "black balls" for the new rings to seat. Have the big ends on the rods checked for size...cuz if they're "tight"...you'll spin a rod bearing on startup...no sense taking a chance. Grumpy has cracked the 9's with a 20/20 crank...and I pound the shit out of my current engine with a 20/30 crank...so no worries there. Have the mains checked for size as well. You don't have to do this...but...h ave the rotating assembly balanced...you won't believe how smooth the engine revs out.

More great info. I hadn't planned to pull the pistons and re-ring - but shit - I might as well, right?

nlarge the oiling holes for the mains some to help out on the number 3 bearing. I've got 1 crank out of a 4.1 that failed on #3 and took both rod bearings out to the point I use the crank for an anchor.

They make be stock or FelPro - but there's silicone holding them on. I pulled a few pieces off. In one of the cylinder pics, you can see some hanging down into a cylinder. Which is odd, because it looks like some of the pressure rings were pushed out a bit. I am starting to think they were new gaskets, and somehow when the head was torqued, it pushed them out a bit. The silicone I did pull out was right along the top of the cylinder wall. No way that would have survived even a few firings. That - and the pistons are too clean to have been fired.

Not too bad looking from here.   Only a machine shop can really tell how round the journals are.

I have no problem whatsoever going as much as 0.030" under.   I have seen more than one ten second car running 30 under cranks..you could make an argument that such is better due to reduced bearing speed.  I normally like about .015" clearance on a street engine both for rods and mains

Good info. I need to find a good machine shop. Turns out Don Cruz is local, and I hear he does that type of work.

Pistons are .030 over...hopeful ly just a scuff with the "black balls" for the new rings to seat. Have the big ends on the rods checked for size...cuz if they're "tight"...you'll spin a rod bearing on startup...no sense taking a chance. Grumpy has cracked the 9's with a 20/20 crank...and I pound the shit out of my current engine with a 20/30 crank...so no worries there. Have the mains checked for size as well. You don't have to do this...but...h ave the rotating assembly balanced...you won't believe how smooth the engine revs out.

More great info. I hadn't planned to pull the pistons and re-ring - but shit - I might as well, right?

see my correction above...  0.0015" on the rods and mains

[SuperSix]

Update - 08/14
 
 Took the rest of the block apart toady - Here's all of the pics:
 http://s1184.photobucket.com/albums/z337/Supersix231/87%20Grand%20National/Repair%20pics/Short%20block%200814/
 
 If you see anything out of whack in the pics - please let me know.
 
 Of course, some questions.
 
 All of the lifters looked goo, one or two had some vertical scratches, most showed signs of spinning in the bore, which is good. I didn't see any noticeable wear on the tappets.
 
 Is this a normal lobe wear pattern?
 
 
 
 Front cover and timing chain look new - is this basically a stock replacement chain set? Is that a double roller? If so, should the tensioner be used?
 
 
 All of the cylinders look good, I can't see a cross hatch though. #2 is the one that has the rusty area - and the piston looks rough. Looks to *me* like it shouldn't be a huge issue, a hone and cleaning should fix it up. Block is 030 over, don't think I can cut much more...
 
 
 That lighter area isn't a ridge..
 
 
 Cam bearings look kind of suspect - Is it normal for the front bearing to get a ridge in the middle where the cam oil channel is? I might have dicked up the others removing the cam.
 
 
 Bottom of #1 crank journal had damage, just like the top. 
 

[earlbrown]

Yes, that's a double roller. It looks like you can get away with using the tentioner as it's smooth on the outside. That chain has a lot of slack in it too. That means the timing set has "stretched" or the block was incorrectly line bored and the crank moved up too far. I'd really investigate that before going back together.
  The front cam bearing is beat up pretty bad and I noticed some smearing on the mains. Does that engine have real stiff valve springs and have you measured the clearances in that chinese front cover yet?

[SuperSix]

Yes, that's a double roller. It looks like you can get away with using the tentioner as it's smooth on the outside. That chain has a lot of slack in it too. That means the timing set has "stretched" or the block was incorrectly line bored and the crank moved up too far. I'd really investigate that before going back together.
  The front cam bearing is beat up pretty bad and I noticed some smearing on the mains. Does that engine have real stiff valve springs and have you measured the clearances in that chinese front cover yet?

EARL!!!

I'm not sure about the springs yet - I read somewhere that they are aftermarket. They have the stock-looking shrouds on them though. If the crank had oved forward, wouldn't the thrust bearing be beat up?

No, I haven't measured the clearances. Ugh. I was hoping it was just a really clean GM cover. Is it odd to have the marks on the cam button given that it's a roller?

Funny - I was thinking about getting in touch with you to see about getting a front cover from you.

Just took a closer look at the cam - #3 exhaust lobe has damage at the top. Fuck! It's a Poston GN110T cam.

[earlbrown]

The thrust bearing would have to be beat up to let the crank move forward. I was talking about pic you posted showing the upper main #1. Material has been smeared on the front half and covered that portion on the oil hole.
  With clearances tighter than .002 there's no room for material transfer like that and getting away with it.

Hey I see my oral sex smily made it over here too!

[SuperSix]

Hehe. Yep - it sure did. Been here for years. 

I was referring to your comment about the chain stretching - you said it can happen when the crank walks - If the thrust bearing surfaces show very little wear, then one can assume that the chain just stretched?

Can you still buy factory camshafts? Or am I worrying too much about that mark on the lobe? 

The previous owner thought he had a GN107T cam, it's stamped GN110T.