Tear Down in Progress...

[S10xGN]

Hi All,

Since experiencing mega-knock and pushing a bit of coolant in high boost situations, I decided to start troubleshooting. First thing I found was the wastegate line rotted in pieces! That said, I figured it's time to check the engine out. A retorque of my ARP studs in place (my truck's engine bay) is out of the question, so the engine is now out.

So far, so good! The headgaskets (2 pairs of old GM shims + silicone) were intact with no obvious damage to the heads or block. Check the pix and see if you think they're stretched. Only two anomalies: The breakaway torque on several studs was on the order of 30 - 40 ft-lbs, similar to a bellhousing bolt and the two lower studs on cylinder #2 were corroded with (leaking) coolant. I'll see if ARP will send me a couple...

My Comp roller cam & 853's look great, pushrods are like new, Comp 941 springs look good. Tomorrow, the pan comes off and parts get ordered...

 

[SHADOWII]

You may.....

have just been lifting the head where the stud torque was low, if it only happened under high boost. The only other places coolant can enter, barring a crack in the block, head or intake, is the head or intake gasket. And you're running a non-water cooled turbo.confused

You probably would have to check w/arp for the proper length of the studs to verify that they haven't stretched, but I think that to be unlikely.

 

[slimtastic]

the pistons youve taken pics of look good over all. id measure the head bolts and see if you can find any real difference in length (this is really just for any bolts in question) in genneral tho if you have mutiple "head lift" prblems... id just buy a brand new set of head studs

 

[S10xGN]

Pistons and rings are great. Rod bearings are all showing signs of detonation and I'm definitely not liking the looks of my #3 main bearing. Not sure what happened there, the crank journal has a matching groove about 90° around the circumference. Hope it's not a crack! Parts to the shop first thing Monday morning...

 

[Chuck Leeper]

My $.02...

Russ, looks like # 3 took a major chunk of dirt thru it.
Cap faces look to have a bit of fretting on them.
Strange that the distortion on the gaskets is only on the top studs, inner cyls...
Studs corroded??? WTF are you using for coolant, branch water???

 

[bison]

When I used those gaskets 12 years ago they worked excellent but needed at least 2 retorques. Use sealant on the studs where they enter the block. You better figure out your detonation problem.

 

[S10xGN]

Russ, looks like # 3 took a major chunk of dirt thru it.
Cap faces look to have a bit of fretting on them.
Strange that the distortion on the gaskets is only on the top studs, inner cyls...
Studs corroded??? WTF are you using for coolant, branch water???

Hey Chuck! All I can figure on the #3 main is residual crap inside the crank, I thought I had got it clean enough. Something else strange, 5 of the 6 wrist pins are tight... Would detonation cause that? Are my pistons trashed now? I can't figure those two studs being corroded, my coolant looks perfect (distilled water, a PT of RMI, and just enough green coolant to for 10° or so) enough that I've saved for refilling.

When I used those gaskets 12 years ago they worked excellent but needed at least 2 retorques. Use sealant on the studs where they enter the block. You better figure out your detonation problem.

Bison, I can only retorque ALL of them if the motor comes out, I might get to the top row and front couple lowers after a day's worth of removing stuff. Did I mention this S-10 bay is tiny? :frown: Initial problem was figured out 20 minutes into the tear-down, my wastegate hose was rotted into pieces. That won't happen again, new one is insulated with fire-shield fabric covering...

 

[Chuck Leeper]

$.02 more....

Hey Chuck! All I can figure on the #3 main is residual crap inside the crank, I thought I had got it clean enough. Something else strange, 5 of the 6 wrist pins are tight... Would detonation cause that? Are my pistons trashed now? I can't figure those two studs being corroded, my coolant looks perfect (distilled water, a PT of RMI, and just enough green coolant to for 10° or so) enough that I've saved for refilling.

** Sounds like the detonation has hammered the pistons/pins pretty hard. Were they pin fitted when you built the engine? Being an off center design puts "weird" loading on the pins, even without det.
I'd have them taken apart, and see what the bores look like. Press or floating?
Take a feeler ga to the ring grooves, B4 you remove the rings. Detonation damage there, = new pistons.

** There have been some "discussions" about the use of distilled vs plain tap water. I've not seen a definitive conclusion as to yea or nay on it. Maybe others have more info??
Head lift, coolant is trapped in beside the stud. It stays there, and eats the oxide finish off the stud? Could also be wicking of coolant, due to loss of sealer adhesion on the threads.

Bison, I can only retorque ALL of them if the motor comes out, I might get to the top row and front couple lowers after a day's worth of removing stuff. Did I mention this S-10 bay is tiny? :frown: Initial problem was figured out 20 minutes into the tear-down, my wastegate hose was rotted into pieces. That won't happen again, new one is insulated with fire-shield fabric covering.

**I have no experience w/ the "trik of the month" head gaskets...Never used them.
However, I have done several torque checks with new studs /bolts, while engine is on the stand...In all cases, I've found that rechecking showed loss of torque during the first 1-2 checks. Once it repeats, I stop checking.

 

[turbofabricator]

The TRW/Sealed Power pistons are known to have tight clearances, then add to that the press fit, and you have an issue. (because the pin usually galls a little during the pressing operation.)

 

[S10xGN]

Machinist is a bit concerned about the pin fits, he'll try and hone the bores but I may need a new set. They are galled some, anyone with experience on honing the pin bores? They would all "flop" when I first put it together (damn, 8 yrs ago!).

Crank needs turning and I'm hoping it doesn't get into the fillets. I have a line on another crank if need be..

Rings and ring grooves all looked good, I'm gonna reuse the rings if the pistons are OK. I will definitely be doing multiple retorques on the stand, and Jace said he goes to 85# with the ARP studs. Still waiting on word from ARP about the corrosion issues...

 

[its2qik]

Since you're going through all this trouble, just put some new head studs in it and call it a day. Don't skimp at this point, 'cause it will bite you in the butt.

 

[S10xGN]

Since you're going through all this trouble, just put some new head studs in it and call it a day. Don't skimp at this point, 'cause it will bite you in the butt.

Just got my ARP "package" today; 3 new studs, 2 new washers, and one new nut for $20.10 shipped. Ready to go back together as soon as the block is honed. Crank was turned another 010/010 for a total of 0.020" on rods and mains.

 

[S10xGN]

Got the motor back today! So far I've got the block painted and the crank clearances checked and installed. Now I sit and wait for my (2nd) set of ring pliers from Jeg's. I have a set - somewhere, just can't seem to find them... The crank still shows good fillets even after going 0.020" under on both rods and mains. The wider CP1443 rod bearings fit perfectly...

 

[S10xGN]

Got the shortblock finished yesterday, 24 ft/lbs "breakaway" torque to rotate it. Put my RJC headgaskets on today, I'm thinking these are a step up from the old (no longer available) stacked GM shim gaskets! The sili-goop also went on my studs as well as the gaskets. Jace's torquing procedure is pretty intense, go to 50# in 10# increments then to 85# in 5# increments. One reason to be glad there are only 8 bolts per side!

 

[Squid4life]

Looking good, you move fast! Are you guessing the main cause of knock is from the wastegate line? I would replace all the vac lines, and zip tie them since you have it all apart. Nice work man!

 

[mybuick]

i just installed those head gaskets from rjc in the begining of this winter. and when i put on my intake manifold the bolt holes didnt line up at all, and i already put the gasket and the rtv on the ends of the block. had to take the intake off and have it machined so the bolts will line up. check yours first before you get to far.

 

[Turbo-Archie]

What did you do about the pin bores?


..

 

[S10xGN]

Looking good, you move fast! Are you guessing the main cause of knock is from the wastegate line? I would replace all the vac lines, and zip tie them since you have it all apart. Nice work man!

Thanks, Squid. It's great being retired. All the other lines are great. The WG line (on mine) is almost "pinched" between the oil outlet and the compressor because I have my compressor clocked at 45° instead of 90°. Too much heat with too little airflow...

i just installed those head gaskets from rjc in the begining of this winter. and when i put on my intake manifold the bolt holes didnt line up at all, and i already put the gasket and the rtv on the ends of the block. had to take the intake off and have it machined so the bolts will line up. check yours first before you get to far.

I wallowed out my bolt holes on the first build. Between milling the block and heads, I "lost" a few thou's. I'm going back with SS bolts and washers this time. When I tore it down, half the intake bolts were finger-tight. I know I torqued them, so I'll be checking these (among others) more often.

What did you do about the pin bores?
..

My machinist ran a light hone on them and gave 'em his blessing. Only thing I'm NOT liking at this point is the rod side clearance (which is the same from the first build) at 0.025" average. My oil pressure was pretty good in spite of it. Also degreed the cam and even with the key in the +2 slot, I'm still 1.5° retarded. Again, this was the same as 10 yrs ago...

 

[Kid with a toy]

Well.....

I guess this means I can't get behind the wheel.

I'm sorry about our last outing.

Erik

 

[S10xGN]

I guess this means I can't get behind the wheel.

I'm sorry about our last outing.

Erik

Hey, at least I got the problem figured out! Now I'm in the "fixin" stage. Might still be for sale when done, I could have pulled the engine in my LS/Maverick in the time it took to put the DR side header on this thing! I'm too d@mned old for this...