Frustrated

[TWO LANE BLACK TOP]

Wrongway..

You can use an old spark plug and knock the ceramic center out of it with a hammer and a punch and grind or cut the electrode off and weld a Male fitting to the remaining outer part of the plug...That fits your chuck on the air hose and use it for pressurizing the cylinder..

Did the original valves have a three or four degree angle valve grind on them..?? What about the valve seats..??

It's not too late 

[Wrongway]

Yes, I do still have the broken valves. I did think about punching out the center of a plug. Wasn’t sure if it would work. Glad to know it will. I’d much rather do it that way. I’ll let you know what happens. BTW, why would it only be affecting the #5 & 6# cylinder? Shouldn't all the cylinders be having the same issue since I replaced all of the exhaust valves?

Edited July 1, 2020 by Wrongway

[BearGFR]

1 hour ago, Wrongway said:

Yes, I do still have the broken valves. I did think about punching out the center of a plug. Wasn’t sure if it would work. Glad to know it will. I’d much rather do it that way. I’ll let you know what happens. BTW, why would it only be affecting the #5 & 6# cylinder? Shouldn't all the cylinders be having the same issue since I replaced all of the exhaust valves?

Well, "should" and "should not" at this point are both out the window.  You already know through direct testing that you've got two dead cylinders that aren't making any compression so what "should have happened" no longer applies here      The question now is - why?  What's going on with those two?  In order to make compression, the intake valve has to open and allow air to be drawn in.  Both valves have to close, the piston has to riise in the bore, and everything has to seal so that air can't leak out.   In your case, on two holes, at least one of those things isn't happening.   The intake isn't opening - or at least one of the valves is never sealing - or the seal in the piston + rings isn't capable of holding pressure - or the piston isn't moving at all.   If it was just "bad" or worn rings, you'd see some pressure rise in those holes, they'd just not make as much pressure as the others.  IN youc case you've got zero pressure rise.  That tells me something is broken.  Intake isn't opening, or at least one valve (or valve guide) is never sealing, or the cylinder can't be sealed (broken piston, cracked/holed cylinder wall, something major.     Breaking those exhaust valves was a very catastrophic event and very likely to have caused more damage than just the valves. 

Could you walk is through in detail exactly what was done to repair things after the problem you had with the valves?

Here's on possible scenario:

   Heads break off exhaust valves.

   One or more of those heads gets caught between the intake valve and its seat the next time it opens and tries to shut

   Intake valve is bent but not broken, and no longer seals on its seat.   Viola - no compression in that cylinder

[Wrongway]

Ok, with details bro. I'll start at the beginning. Hope I don't bore y'all.

After reassembling I took it for a ride. 2 miles in the transmission went out. I sent the trans in for rebuild. While waiting I put in the wiring harness. Got trans back, finished the wiring and built a new drive shaft (why is another story). Finally about 6 months later I started the engine again. Took her for a ride. She was over heating. Tried multiple thermostats. Had local radiator shop test radiator. Said it was good to check heads. Pulled the passenger valve cover to remove heads. Found a broken lifter. Called COMP cams, they said it was out of warranty by now so ordered a new lifter. While waiting for lifter I pulled heads and found that the head gasket was blown. I was told by the guys at the radiator shop that this happens sometimes during break in on Pontiacs. (Yes they specifically mentioned Pontiacs). So I replaced the head gaskets, installed new lifter and reassembled the engine using ALL new gaskets.  I don't ever reuse a gasket. I used my book for all torque specs and per comp I tighten the rocker's down to 20lb just like the 1st time. Started the engine and took her for a ride, no over heating. Got home, popped hood to check for leaks and such and heard something. I removed the valve covers and found 2 damaged pushrods. (1 of the only parts that were reused). I thought maybe with the rebuild maybe the old pushrods couldn't handle it. Yeah, pretty stupid in hind sight. But I ordered new pushrods. Installed new pushrods tightened rockers down to 20lb & reassembled. Figures crossed I started engine.it turned about a 1/2 turn and I heard a loud noise. The engine was locked up. The breaker bar would only move about an inch either way. I started tearing it down again and found the 7 broken exhaust valves. Called comp and was told that their tech gave me the wrong info. So I ordered new valves. On my bench using a spring compressor I removed all of the old locks, springs and everything. I did not remove the intake valves since they didn't seem to be involved. I used break cleaner and a nylon and a brass bush to clean it all up. No drill or any power, just the brushes. I used assembly lube on the stems of the valves reinstalled each valve with new locks. Reinstalled head, timing and everything else with a all new gasket set. Started it up and it sounded good. So I thought. Just had vacuum issues and tuning. Then I reached out to y'all and here we are bro. Hope that's enough detail, if not just ask whatever you need to know & I'll happily answer if I can. Also, when I rebuilt the engine I did have the machine shop check the block to make sure there were no cracks and bore it 30 over. I did use +30 pistons and rings. 

Edited July 2, 2020 by Wrongway

[64 kiwi boni]

You can use an old spark plug and knock the ceramic center and the metal electrode out of it with a hammer and a punch and grind or cut the electrode off the bottom and weld a Male fitting to the remaining outer part of the plug...That fits your chuck on the air hose and use it for pressurizing the cylinder..

i like two lanes idea above !!!👍

what i did wrong way was i used a compression tester gauge that had a hose and fitting on it , chopped off the gauge and shoved a 3/8 hose tail into the flexible hose with a clamp and screwed a air coupling to that 3/8 thread. easy .... here is a picture of it

hell, if you lived around the corner i would give it too you mate!...🙄...but i am a little bit further away!🙄

[Wrongway]

I see, good idea. Thanks bro

[64 kiwi boni]

3 hours ago, Wrongway said:

Ok, with details bro. I'll start at the beginning. Hope I don't bore y'all.

After reassembling I took it for a ride. 2 miles in the transmission went out. I sent the trans in for rebuild. While waiting I put in the wiring harness. Got trans back, finished the wiring and built a new drive shaft (why is another story). Finally about 6 months later I started the engine again. Took her for a ride. She was over heating. Tried multiple thermostats. Had local radiator shop test radiator. Said it was good to check heads. Pulled the passenger valve cover to remove heads. Found a broken lifter. Called COMP cams, they said it was out of warranty by now so ordered a new lifter. While waiting for lifter I pulled heads and found that the head gasket was blown. I was told by the guys at the radiator shop that this happens sometimes during break in on Pontiacs. (Yes they specifically mentioned Pontiacs). So I replaced the head gaskets, installed new lifter and reassembled the engine using ALL new gaskets.  I don't ever reuse a gasket. I used my book for all torque specs and per comp I tighten the rocker's down to 20lb just like the 1st time. Started the engine and took her for a ride, no over heating. Got home, popped hood to check for leaks and such and heard something. I removed the valve covers and found 2 damaged pushrods. (1 of the only parts that were reused). I thought maybe with the rebuild maybe the old pushrods couldn't handle it. Yeah, pretty stupid in hind sight. But I ordered new pushrods. Installed new pushrods tightened rockers down to 20lb & reassembled. Figures crossed I started engine.it turned about a 1/2 turn and I heard a loud noise. The engine was locked up. The breaker bar would only move about an inch either way. I started tearing it down again and found the 7 broken exhaust valves. Called comp and was told that their tech gave me the wrong info. So I ordered new valves. On my bench using a spring compressor I removed all of the old locks, springs and everything. I did not remove the intake valves since they didn't seem to be involved. I used break cleaner and a nylon and a brass bush to clean it all up. No drill or any power, just the brushes. I used assembly lube on the stems of the valves reinstalled each valve with new locks. Reinstalled head, timing and everything else with a all new gasket set. Started it up and it sounded good. So I thought. Just had vacuum issues and tuning. Then I reached out to y'all and here we are bro. Hope that's enough detail, if not just ask whatever you need to know & I'll happily answer if I can. Also, when I rebuilt the engine I did have the machine shop check the block to make sure there were no cracks and bore it 30 over. I did use +30 pistons and rings. 

Wrong way !!! oh my gees! you have certainly had it ruff mate ! you must have pulled your hair out with this on going saga!!!!

at this point, stop .... have  a beer and do the basics, this little air test will be important.

bear is bang on, these things are just a compressor. nothing to teck about a engine but everything has to work in harmony  or it gets way mess ! haha

 

[BearGFR]

Ok great! Thanks for the explanation.   So, if I understand correctly - after the exhaust valve problem you replaced them all yourself right?  Congrats on being not afraid to jump in and do things yourself.  That's getting rarer by the day.    If I've understood right, that does open up some possibilities.  The 'fit' between the valve head and the valve seat is critical and must be precise.  When those valves let go it's very possible that you also bent an intake valve.  It wouldn't take much of a bend to destroy its fit to the seat so that it can't seal even though you wouldn't be able to see it even if you tried.  You -might- be able to spot it if you shined a light at the back side of the valve through the intake port and did that in a completely dark room - maybe, but you'd have to know to look for it.  It's also possible that during the "loud noise" you heard when those valves let go, the exhaust valve seats on those cylinders got nicked.  Again it wouldn't take much damage to destroy the sealing ability and cause the problem you're seeing now with no compression.   Also new valves need to be "fit" to the seats.  That's what a valve job that a machine shop does is all about.  They use fixtures and matched grinding stones to match both the valves and the seats together so that they'll seal.   You can approximate that at home using a valve lapping compound and a hand tool, but that's usually only done as a final step after the valves and seats have been ground, otherwise it can take a very long time and a lot of work to fit valves to seats and you won't be able to control the width of the seat very well.

So what now?  At this point considering what we know, I think it's a done deal that the heads need to come off and everything looked over, but I'd still do that air pressure test first to try to isolate where the leak is.  

In fact, if it were me I'd probably pull the engine and do a complete tear down, remove all the oil gallery plugs at both ends of the lifter gallerys, tear down the oil pump, and do a thorough inspection/cleaning of everything looking for damage or scoring.   There's no telling how much shrapnel went into the oil pan when those valves let go or where it is now, and it'd be a shame to get it all back together and running, only to have a piece of metal circulating around in there take out a bearing, seize a rod, and destroy the engine.  Failing that, at least stick a bunch of very strong magnets on the oil pan, passenger side, rear, and hope that they'll trap and hold onto whatever's in there before it can get sucked up into the pump.  Leave them there until you have a chance to pull it and go through it for cleaning.  Also change your oil, including a new filter - cut the old filter apart, cut the element out of it and spread it out, inspect it to look for metal that it may have already trapped.

The same process I told you about earlier on how to make a piston stop using an old spark plug, you can duplicate to make your own air fitting - but I think I remember you said you'd already ordered one.  After you figure out where the leak is, I'd recommend you pull both heads, take them to a machine shop, and get a full valve job done on all 16 valves.  Make sure they check the all the valve guides too because they could have been damaged when the valves went.  Something else to be careful about when dealing with machine shops:  unfortunately there are some 'out there' who tend to have an opinion like "Oh, it's only a Pontiac so it's not important to be precise".   I've got the engine out of my '69 right now with the block at a different shop as a direct result of that kind of thinking (grrrr - long story).  

Another thing to check since you've got some aftermarket valve train parts:  Pushrod length.   Back off a few rocker arms so that you can see the tops of the valves, and look for the wear pattern on the top of the valve stem where the rocker tip meets the valve.  What you should see is a wear pattern that is very close to being exactly centered on the valve stem.  If it's offset significantly to either the high side or the low side, that's an indication that you need different length pushrods.   That's not going to cause any of the problems you're having now, but it can be a concern for long-term wear on the valve guides if it's not right.   Don't worry about it now, but I wanted to mention it so that you don't forget when it's time to put it back together.

Let us know how it turns out whenever you're able to do put compressed air into those cylinders. 

Cheers,

Bear

Edited July 2, 2020 by BearGFR

[Wrongway]

Well %$#&, ok Bear i'll let you know how the air test goes. Guess ill be pulling the engine and trying to find a machine shop bro. I'll keep y'all posted.

Also, do you guys have a way to flush out the block after disassembly?

Edited July 2, 2020 by Wrongway

[Wrongway]

Ok, so the air test is done. Here's what I used. The end from my compression tester with the gauge and schrader valve removed. I ground off the finger hook on the blower nozzle to my air compressor and 3/8th hose in between. I put 100psi in to both #5 & #6 cylinder's separately. Both cylinder's pushed the air out the exhaust. Just out of curiosity I hooked up to the #8 cylinder at about 80psi and it turned the fan about a 1/2 inch and I stopped.

Edited July 2, 2020 by Wrongway

[64 kiwi boni]

4 minutes ago, Wrongway said:

Ok, so the air test is done. Here's what I used. The end from my compression tester with the blower nozzle for my air compressor and 3/8th hose in between. I put 100psi in to both #5 & #6 cylinder's separately. Both cylinder's pushed the air out the exhaust. Just out of curiosity I hooked up to the #8 cylinder at about 80psi and it turned the fan about a 1/2 inch and I stopped.

oh nice fitting set up mate👍

 and you found your issue👍

[Wrongway]

Thanks bro. 

Edited July 2, 2020 by Wrongway

[Wrongway]

Is it going to do anymore damage to start the car and pull it back up to my garage so I can start tear down? Or should I just figure out a way to push it?

Edited July 2, 2020 by Wrongway

[BearGFR]

3 hours ago, Wrongway said:

Ok, so the air test is done. Here's what I used. The end from my compression tester with the gauge and schrader valve removed. I ground off the finger hook on the blower nozzle to my air compressor and 3/8th hose in between. I put 100psi in to both #5 & #6 cylinder's separately. Both cylinder's pushed the air out the exhaust. Just out of curiosity I hooked up to the #8 cylinder at about 80psi and it turned the fan about a 1/2 inch and I stopped.

 

Well alrighty then.  Sounds like you got two exhaust valves that aren't sealing.  That explains the rough idle and the wonky/low idle vacuum.  Count your lucky stars it's not worse, although I think you mentioned at least one piston had a pretty good divot in it.  I'd get that checked out and try to determine how thick the metal is there before reusing it.  

You'll "probably" be ok driving it back inside - cross your fingers    

The best way to clean the block is to remove all the gallery plugs, then use copious amounts of good old hot soapy water combined with a collection of bottle brushes.  There are two plugs in the front behind the cam gear, and 3 in the back.  Unless they've already been redone, the two in front are like mini-casting plugs ("freeze plugs") that have been staked in.  On the back drivers side, there's a screw in plug.  On the passenger side, there's another pressed in plug "behind" the distributor and another screw in plug in front of the distributor.  That's the famous Pontiac "hidden" plug that people forget to put back in and then have no oil pressure on startup, so don't forget that one.   

Use bottle brushes to chase all the holes --- lifter galleries front to back, lifter bores, lifter oil feed holes, oil pump passages, main bearing feed passages, all the passages in the crank --- everywhere you see a hole, clean it.  Take the end plate off the oil pump and look for damage/scoring on the gears and in the housing.  Open it up and clean out the passage where the check ball is and make sure there's nothing in there that might jam the ball.    It's boring, time consuming, somewhat tedious work but it's oh so important to make sure everything is clean.

Make sure you keep everything "in order" so it can be reinstalled in exactly the same place.  Examine all your bearings for signs of damage/scoring. Same with cylinders, piston skirts, etc.

Hopefully everything is fine and you'll be able to re-use everything, but you won't know until you look.

Good luck!

 

Bear

[Wrongway]

Thanks Bear, can I leave the cam bearings in? Will the hot soapy water hurt them? Or can I just regrease them? I don’t have the tool to remove or install them is why I’m asking. I no that’s basic but I’m not taking anything for granted this time

[TWO LANE BLACK TOP]

As Bear mentioned you might have gotten lucky and only have the exhaust valve sealing issues...Since you're going to have to pull the heads anyway..It would be a good idea after the heads are off...To roll the engine over by hand to make sure that all the pistons are coming up to the same height in the bores... If they all don't  have the same distance from the deck to the top of the pistons that would be a sure sign that you have a bent or kinked rod...Pay special attention to #s 5 and 6....if they are all the same height (none of them lower in the bore than the rest of them)...You're more than likely  good to go as far as the bottom end goes....

Edited July 2, 2020 by TWO LANE BLACK TOP

[BearGFR]

32 minutes ago, Wrongway said:

Thanks Bear, can I leave the cam bearings in? Will the hot soapy water hurt them? Or can I just regrease them? I don’t have the tool to remove or install them is why I’m asking. I no that’s basic but I’m not taking anything for granted this time

They won't be hurt by soap and water. Just look then over to make sure they aren't damaged.  You mentioned grease.  All the bearing surfaces need  liberal amounts of assembly lube when you're putting it all back together. 

Edited July 3, 2020 by BearGFR

[Wrongway]

Wow man, hadn't even considered a bent rod! Damn I hope not bro.

Yeah Bear, I was referring to assembly lube when I said grease. Just kind of at the end of my rope right now and misspoke bro. Thanks, here's what I've got in house. I bought it when I installed the valves. Never used this brand until then. will this work or should I order another brand?

[BearGFR]

Any of the name brands work well. 

[BearGFR]

I just had a thought (yeah, sometimes it happens - even to me - lol). When you put air into 5 and 6, did you turn the engine to a point where you were sure both valves were closed on those cylinders, I hope?   

Edited July 3, 2020 by BearGFR

[Last Indian]

Wrongway, if you’re going to pull the motor, & if it were mine I would, than I would at least take it down to the short block! Clean everything really well, as Bear describes! The one thing you can’t check without disassembling is the pistons and rings! When the valves broke, if that caused enough movement in the rings or pistons that could have caused an issue with either one. So once you have it all apart, move each piston through its full stroke and inspect each cylinders bore carefully for scaring! Then if you do send it to a shop see if they have solid stress plates or some variant of that to pressurize each piston assembly to check the ring sealing. It’s just one more of those things that you would hate to assume is ok, put the whole thing back together and have another hiccup!

Edited July 3, 2020 by Last Indian

[Wrongway]

I'll double check it before I tear it down Bear. 

Indian, I really hate tearing it down again bro. lol. But y'all say it needs to come out so its coming out bro. I've got a really busy day ahead of me but I am going to start on it today bro. I'll send pics of the progress.

Thank you again guys! 

[Wrongway]

Yeah Bear, looks like they were open just a bit. I did the air test again and had my neighbor double check me at the exhaust (not much feeling in my hands now a days). If there is any air coming out it's extremely faint. But that could also be that I'm running an H pipe on my exhaust. My plan is to pull the engine anyways per y'alls recommendation and I'll do the test again on the stand with just the headers hooked up.

[BearGFR]

That recommendation to pull the motor came from your report of definitely hearing leakage at the exhaust.  I'd hate for you to go to the trouble of pulling it and that not be the problem.  If you have the chance to test those cylinders again before you get too far along, make sure both valves look completely shut and apply air.  Listen for leakage - at the carb, at the oil filler, at the exhaust - hopefully you'll be able to hear it hissing from at least one of those three spots.  Also remove the radiator cap and listen there - look for bubbles while you've got it hooked up to air. Listen around the tops of the valve stems on those cylinders and see if you can hear it hissing there around the guides too.   With zero compression, it's got to be going -somewhere-.

[Wrongway]

I can do that Bear. I did hear what sounded like air in a tunnel coming out the carb but couldn’t feel anything. All I meant by “y’all’s recommendation was to clean out the engine and look for debris. Figured I should still do that. But I’ll stop until I let u know bro