NTXCAMARO

Hello TGO, I'm going farther into an engine than i ever have before so looking for advice,hints, tips etc. I want to stay low budget, do the work in my garage and learn as i go. I'm not going for big power just want to get this engine healthy again.Will go for a crate engine later down the road. 1982 Z/28 Pace Car Car, has 144K miles was parked in a garage since 1996 until last year when i got it started and put about 10-20 miles on the car. Just drove it around the neighbor hood a few times. It has a rough idle so checked the Compression, Compression test were good on all cylinders except #6, it was zero. Dove in to the engine and the #6 appears to be 'washed out,(term i just learned) see photos below. I believe this cylinder would need new piston rings based on the wash out. So while i have the heads off I'm going to replace the valve seals and lap the valves(no machine shop work). When i do pull the engine my plan is to dingle ball hone #6, install new rings on #6. Button it all back up and drive for a year or so until a possible crate motor swap.
Would the steps i noted be enough based on the all the other cylinders showing good compression or should i hone all the cylinders and replaces all the rings and possible all the rod bearings? Look forward to your advice, opinions, hints, tips etc. Thanks

sofakingdom

iTrader: (1)

If it only got 10 - 20 miles put on it in that condition, I'd suggest repairing the zero compression problem (probably a valve train malfunction of some sort), and LEAVE THE SHORT BLOCK ALONE.

In case I didn't make my point clearly, LEAVE THE SHORT BLOCK ALONE. Any questions? Pop quiz: what should you do to the short block?

Orr89RocZ

iTrader: (20)

Sounds like it has 144k miles on it, was parked for a number of years and then only recently he tried driving it 10-20 miles but had issues?

Seems odd to have 0 comp. on only 1 cyl. Are there any broken valve seats or bent valves or are they not seating all the way due to some odd preload adjustments?

NTXCAMARO

Sofa,,,the quiz sounds like a a trick question.. LOL ...more info. i checked the #6 combustion chamber of the head by filling with water and had it held steady with out leaking for 24+ hours. Oils smells like it has gas in it.. When you say leave the short block alone are you saying no honing of #6, just replace the #6 rings and reassemble ?

jczoka

If in fact you really have 0% compression. (Not anything at all on the guage) there is almost a 0% chance its a cylinder sealing problem. Very likely a valve sealing issue as others have said.

sofakingdom

iTrader: (1)

I'm saying, LEAVE THE SHORT BLOCK ALONE. No rings, no pistons, no bearings, no teardown, no NOTHING. Leave it alone unless you're SURE it's fornicated, and if it is, accelerate your plans for a motor swap, to cure the car's 305 problem; since EVERY PENNY you spend on that turd, just puts your bank account ONE PENNY FARTHER from the correct answer. If it ain't broke, don't "fix" it. Other people might say, if it ain't broke, "fix" on it until it IS. Let's not go there.

I'd expect that something was stuck... most probably, a valve sticking open due to rust or just the schmutz of old age. For that matter, it's entirely not impossible that just the mere act of messing with the head has already cured it, and if you just stuck it all back together, it would be fine again.

A cyl with "zero compression" is almost impossible to be due to rings, without it showing up BIG TIME in the cyl wall. If the rings failed sufficiently hard to cause "zero compression", it's virtually certain that the wall would look like somebody took a pickaxe to it. Plus of course, while running, it would have had blowby from Hell; probably enough to blow the valve covers off, pop the front seal and the PCV valve out, push oil out through every gasket, etc. I'm putting the odds of a ring problem at some number so close to zero that it's less of a chance than 1 second out of the total number of seconds this universe has been in existence.

When you ran the compression test, where did the compression GO? Where was the hissing noise? Back out the carb? Into the exhaust? Into the crankcase? ??? When you looked at the heads after you took them off, what did you see? Was there a valve sticking open? Does the piston move when you turn the crank? Does the cyl wall look about the same as all the others? Any gouges, cracks, signs of MAJOR LEAGUE destruction? Why did the car get parked 25 yrs ago and forgotten until now? Where did this car come from before you got hold of it?

NTXCAMARO

i checked the #6 combustion chamber of the head by filling with water and had it held steady with out leaking for 24+ hours. Oils smells like it has gas in it and there is no carbon build up in the cylinder or piston top(see photo). the cylinder wall has almost a mirror finish..

jczoka

The clean cylinder is the symptom of the real cause. Because there was no compression or combustion, the fuel washed the cylinder clean. But even if the cylinder is “washed down” as you say, you should still have some compression on a test. A check for this is to squirt oil in the cylinder and retest the compression. If it goes up, it’s a ring seal issue. If not it’s most likely a valve problem, but you’re past that point now.

NTXCAMARO

Sofa, I'm starting to get the idea you don't think the piston rings are the issue...im quick like that :-) the cylinder wall doesn't have any real damage that it an see, it is different than the others as it has a shiny finish, the others are dull. (see original photo i posted in first message). I've disassembled the head and nothing looks broken, the #6 combustion chamber held liquid for 24+ hours without leaking. photos below of what the cylinder head looked like when i took it off. Oh the PO turned into a hermit and just quit driving..

Orr89RocZ

iTrader: (20)

You sure the gauge was connected to the tool in the spark plug hole? Lol i had to ask. Or did you accidentally hold the relief valve down while doing it?

NTXCAMARO

Ha ha ..fair question though. No i did the other cylinders and even went back and rechecked it more than twice to make sure...Maybe it's a bad lifter? not sure how to check a lifter .. guess i can try to google that too.

sofakingdom

iTrader: (1)

Could be a lifter stuck in the bore, in the "up" position. Easy enough to verify by hand.

Does that piston move when you turn the crank? Why did the car get parked? Do you have any connection with it going back that far?

NTXCAMARO

Guess i could reinstall the heads after i replace the valve stem seals and check the compression again, if its still shows Zero I could use "oil in cylinder" test..

jczoka

The part that is throwing us all off is the “0 psi” part. No movement at all on the gauge?

sofakingdom

iTrader: (1)

Right: I don't think, even if it WAS a cyl wall / ring problem, that oil would fix it, at "zero compression". That trick is good for testing one when 7 have, say 165 - 175 psi, and one only has 120 or something; then if you put oil in and it comes up to maybe 150, you could attribute the low reading to ring sealing. Usually though, virtually always, if there's a ring problem, it leaves vertical scratches in the bore, and THAT'S the actual leak, not the rings proper. The oil trick fills in the scratches at least somewhat and thereby affects the reading, is the thought process. The fix then is to bore out the block past the depth of the scratches, which then of course requires new pistons AND rings. There's NO WAY it makes sense to do that to a high-mileage LG4. That's economic suicide.

Does the piston move when you turn the crank? What do you know of the car's history?

NTXCAMARO

I really appreciate everybody chiming in with thoughts suggestions etc. Y'all make this forum a great/valuable place for novices like myself. I will check to confirm if the piston is moving and report back.
Some background on the vehicle..I'm the second owner, i don't know a whole lot but the PO parked in 1996 and basically turned into a hermit and quit driving anywhere. What i did notice when i had the car back home is the Trans had brand new trans fluid in the trans( it was from 1996 but it was still bright red). Apparently they forgot to reconnect the linkage bracket back up cause I found the linkage was not connected nor was the bracket bolted in place. So the PO may have just thrown his hands up after it would not go in gear and decided to go hermit. ... Ill report back on the piston moving..

jczoka

Based ONLY on all the info so far... this is my guess:

you may have misdiagnosed the problem. It happens OFTEN, especially with drivability problems.
It COULD be that it was a simple dead cylinder from an ignition problem, plug or wires. Common on smallblocks. It then washed the cylinder down, lost compression, and the guage you're using is not very accurate and looks really low when it's just a little low.
All speculation. But just an educated guess.?

NTXCAMARO

Confirmed, the piston does move when i turn the crank..HOWEVER, I pulled the intake lifter, it was a little tough to pull out, seemed to catch when it was almost pulled out...it finally did release and now moves in and out with out catching. I did find several scratches on the sides of the intake lifter(see photos) the other lifters did no have these scratch marks...Could it be the root cause of the issue? Based on everyone's input I'm going to assume it's not the rings causing the ZERO compression. I will replace the valve seals and reinstall the heads. Should i replace just the one scratched lifter to eliminate that as a possible cause or do you need to replace all lifters if you replace one?

zman1969

iTrader: (9)

well you could re-install the head and pressurize the cyl with air and see if you can hear it leaking out tailpipe or in intake or crankcase - this does seem odd with no easily visible failures that this would have ZERO pressure in #6 - tou can tell that the cylinder isn't firing

BIRD91ZRAG

iTrader: (1)

For an engine that sat that long, there's probably a lot of parts varnished up that can stick. Take each lifter out one at a time, polish the sides up with some 600 grit wet/dry paper and some light oil, clean them up and put them back in the same hole they came out of. Do the same with the valve stems, then lap them to see if they will seat ok. Once that's all good, put it back together with some new gaskets and see what happens. I think I would get some new steel shim gaskets as to retain the correct quench... is this carbureted?

NTXCAMARO

Bird,
Yep, all the lifter have a varnish build up on them. Thanks for the suggestions, i will do that to each lifter. I have lapped the valves on one of the cylinder heads and and I will start removing the second head to do that one as well.
Yes, It is a carbureted Engine(refurbished Qjet) . I removed the ECM, CC carb and CC Distr and went regular carb and non CC HEI Distr... I just bought a basic rebuild set of Felpro Gaskets, would the Head Gaskets in that kit not be sufficient?

sofakingdom

iTrader: (1)

That's VERY GOOD. It's entirely possible for a motor with a broken rod to still RUN albeit not very good. In fact, in the mid-late 70s / early 80s when times were hard, my late little bro who didn't have a job sometimes, used to put his phone # in laundromats and C-stores and such. You might remember, back in the day you'd write (they hadn't invented printing yet) what you would do, child care or home improvement or personal services or car repair or whatever, on a sheet of paper, and then make like a "fringe" of little strips on the bottom with your phone # on them. D00d pulled one of the strips, wanted an engine swap in his truck. He pulled the truck up into the driveway, ran like s*** but still RAN, pulling a trailer with a motor and this big-a$$ hairy 4-speed out of a school bus, and wanted the motor put in his truck. Turned out his truck had a broken rod, with the piston jammed up against the head and (of course...) not moving, but it still RAN. So, ummmm, … yeah. It could happen. Glad yours isn't that bad off.

Believe it or don't, the SINGLE MOST POPULAR repair he got calls for, was AC. I'd go out and help him sometimes after work. I bet he did DOZENS of AC systems, start to finish, over that period. Maybe 50 or more. We got REAL GOOD at making the little old ladies happy because their cars weren't sweatballs any more. They'd GLADLY pay whatever he charged them, plus a nice tip, because we'd get their air blowing COLD, in an afternoon, and it would STAY that way. Sometimes even invitations to meet their granddaughters. Which I guess is a decent enough work spiff, even if some of em weren't exactly my type. I certainly enjoyed it to the fullest regardless. After awhile they started referring their friends and he didn't even have to post on the CORK bulletin boards anymore. Lots of granddaughters. We did 4-speed transmissions too (my specialty, especially T-10s) and got LOTS of Vette business. Stories for another time.

Anyway, enough of that. Let's hope cleaning it all up and unsticking everything restores it to happiness.

WD-40 will dissolve that varnish reasonably well, and of course leaves it well lubed and waterproofed, for a short while at least. It's good at unsticking stuck rings too. Great stuff for neglected motors.

skinny z

That's awesome! Thanks and I may use that at my next troubleshooting meeting. I'll give you credit in the footnotes.

EDIT: This isn't to make light of the OP's situation. It sounds like he's on to a fix though and I wouldn't have anything to offer beyond what's already been suggested. But sometimes a reply just writes itself!

BIRD91ZRAG

iTrader: (1)

The head gaskets in the kit are probably Fel-Pro PermaTorque. They're good gaskets, on an engine that's been blueprinted for them. Their compressed thickness is .039" which makes the head sit about .020" farther away from the deck, which increases the quench area. Some motors don't care, but some will ping like a beiotch, even though you actually lower the compression ratio a little bit. Use them at your own discretion.
some reading for you...
http://www.superchevy.com/how-to/eng...learance-guide

If you're just trying to make it run long enough to save for a crate engine, go ahead and use them, just listen for spark knock once you get it driving.

sofakingdom

iTrader: (1)

Skinny, I'm a mathematician and physicist by training, even though I'm not that by trade now... it wasn't a marketable skill at the time, so now I have to scrape by some other, less mentally satisfactory way. Although I still enjoy intellectual advances (what other kind is there?) in quantum mechanics.

But our universe is young; only 13.7 some-odd billion years. Not all that many seconds if you really think about it and compare to some of the other numbers of interest. Avogadro's number for example, or the # of electrons in a coulomb. Just an eyeblink really.

NoEmissions84TA

iTrader: (1)

Make sure every valve, and every lifter goes back into the hole from where it came.
I would also clean out both lifters for cylinder #6. What do the lifter bases look like?
I hate to even mention this, but now is the time to replace the timing chain and gears, esp. if the factory plastic toothed gear is still in there. You can got a partial look at it through the 2 round oil drainback holes at the front of the lifter valley.

NTXCAMARO

NoEmission, Thanks i will make sure to put them back in each hole The lifters have a coating of varnish on the bottom quarter of them(car sat for 20yrs+). i will check out the the timing chain and gears...thanks for you input and the tip!

NTXCAMARO

Thanks Bird, yeah just trying to get it to run on all 8 for at least a year or so until i can hopefully upgrade to a little higher performance engine. I'll listen for the pings.

sofakingdom

iTrader: (1)

Excessive pinging is not likely to be a problem with the LG4, fortunately. The compression is in the low 8s.

NTXCAMARO

Does it matter which way the valve springs go back in? I'm referring to which way is up .. i have them labeled to cylinder they go back in but noticed they inner spring orientation is a little different as far as how it seats at each end.

sofakingdom

iTrader: (1)

No, those are the same, both ways.

A broken spring can cause zero compression, since a valve can fail to close... are they all OK? Roughly the same pressure required to remove them all?

sofakingdom

iTrader: (1)

Incidentally, the thing in the center that looks sort of like a ribbon isn't exactly a "spring"; it's a damper. Purpose is to control the spring's sideways sproinging motions.

NTXCAMARO

Thanks, I think they are good, They were all equally a PIA to compress..lol...

NTXCAMARO

Ahh ha....thanks for the information. i was wondering what it was and why that was there..

NTXCAMARO

On another note would it be fine to reuse the head bolts? As we know this 305 is not a high HP engine and I've read two different thoughts. One to always replace the bolts and others have said only replace them on high HP applications ...thoughts?

sofakingdom

iTrader: (1)

Stock head bolts in these motors are not torque-to-yield. They can almost always be re-used. Clean up the threads THOROUGHLY. Lacquer thinner and a wire brush are your friends. Run a thread chaser (like a tap, but not a tap) through the bolt holes to clean them up, and spray the threads with carb cleaner. Use the Permatex / Loctite hi-temp thread sealer with Teflon on the threads and under the heads of all the bolts; every one goes right straight into the water jacket. Torque them in stages, like, fully tight with a ½" ratchet (40 ft-lbs or so), then 50 ft-lbs, then 60, WITH THE BOLT TURNING. By that I mean, NOT the "breakaway" torque, but the torque AFTER it has "broken away" and then while the bolt is moving after that. DO NOT UNDER ANY CIRCUMSTANCES exceed 65 ft-lbs!!! and DO NOT use a "clicker" type wrench or a "torque stick", since both of those are subject to the breakaway vs rotating problem. Use a beam or dial type.

BIRD91ZRAG

iTrader: (1)

Also there's a pattern to follow to tighten the head bolts in. Basically it starts in the center and work your way to the ends.
http://www.gtsparkplugs.com/SBC-Head...-Sequence.html
Personally I've used a clicker torque wrench for every one of the few dozen engines I've built and have never had a head gasket problem. I think the trick is to use a bigger spread between stages (25,45, then 65.) to ensure the last turn is to the final torque. With those head gaskets you won't have to re-torque them hot either.
Here's a little video of the last 454 I built, Solid roller making about 550 horsepower...

NoEmissions84TA

iTrader: (1)

Take a 2x4 and drill some 1" holes in it as shown (not all the way through). Label with a Sharpie. Put your lifters in it (in order) upside-down (flat sides UP) and take and post the picture. There is no sense in doing any of this work if your camshaft and lifters are worn.

8Mike9

You did what?

NoEmissions84TA

iTrader: (1)

He filled the combustion chamber with water while the head was off, sitting upside-down.

NTXCAMARO

Yes what he said ,

NTXCAMARO

Will do that this afternoon....BTW are y'all able to see the photos I've posted in the thread? I can see them but want to make sure I'm posting correctly for all to see.

NTXCAMARO

Thanks for the link and beautiful car...sounds awesome,,I had a 70 Chevelle back it the mid 90s nothing like yours but it was clean and fun to drive..I loved it and as many other say...wish i would have kept it!

8Mike9

NTX, where are you located at?

I've a set of FP head gaskets here, new, with .039? compressed you can have if you're going to be bolting on and re-bolting things.

Not feeling like shipping them, but if nearby you can come grab them.

GeneralDisorder

iTrader: (1)

I vote for loss of compression due to a dead ignition component or an injector that's stuck partially open, etc - washed all the oil off the cylinder. I have seen engines not able to start due to cylinder wall washing and I've cured it with some oil down the plug holes to seal up the rings and get it firing again.

GD

cuisinartvette

Agree....doent look like that cyl was firing at all. plug wire?

NTXCAMARO

Well...found something i didn't expect ..not sure if the photos shows the details well enough but, take a look at intake lifters 1 and 2..chewed up! they have a significant dish to them ..All other appear good, other than the varnish build up. Some scratched in the varnish in the sides of # 6 lifter so guess it stuck open giving the ZERO Compression. Is it salvageable if change the cam and lifters? Again just trying to get it running well enough to drive for a year of so before swapping. let me knwo yalls thoughts!

BIRD91ZRAG

iTrader: (1)

Yup, that cam's toast. All that metal went through the engine. Flat tappet cams are pretty hard to keep alive anymore.
I suppose you could bolt it all back together and run it til it dies... I wouldn't waste the money on cam/lifters only to have them get destroyed by all that metal that's gonna be getting washed around by fresh oil moving...
Good luck!

sofakingdom

iTrader: (1)

1 & 2 intake are WAAAASTED. DESTROYED. #6 exhaust isn't far behind.

You can't put that back in a motor. It's already full of metal chips.

Stop where you are RIGHT NOW. That needs to go in the trash. Hate to tell you that, but... it is what it is.

Even changing out the cam & lifters, which "nominally" seems like it ought to restore the motor to function, is probably going to fail. ALL of that metal that used to be on those lifters, PLUS a bunch that used to be on the cam, is now in the oil. The filter ALMOST NEVER catches all of it.

Sorry to be the bearer of bad news, but that thing is TOAST.

You can try replacing the cam & lifters but I don't see a year there. If you want to try that, get the cheeeeeeeeeepest cam you can get, and accept whatever comes after. I'd suggest this one https://www.summitracing.com/parts/sum-k1102. Not because it's so "good"; but because it's CHEEEEEEEP, and it's OK for the motor you have, and it's probably not going to matter anyway. But in case it DOES work, you'll probably be happy with it.

If the timing set still has a chinesium sprocket with phenolic (plastic) gums, replace that too. Otherwise it'll be the next thing leaving you sitting by the side of the road.

NoEmissions84TA

iTrader: (1)

Unfortunately, this is exactly what I expected to see. Sorry.
You will find that the 2 lobes where those lifters were are now round.
All of that cast iron has been circulated through the entire engine - damaging EVERYTHING. Ask how I know.
Your bearings are now destroyed, at the very least. The smart thing to do at this point is not to put any more time into this engine.