Nex Posted June 27, 2011 Share Posted June 27, 2011 After months of generally learning things the hard way, and making very slow progress, we've finally got the engine back in our Z, and gotten it started. After ~30 minutes of idling the initial smoke (header paint) had subsided, and left us with just a bit of oil smoke drifting from the valve cover vent, which isn't currently attached to anything. After we let it run, we pulled off the valve cover to do a hot lash adjustment, and saw this: My camera skills are lacking, but those two lobes, #4 Intake and #5 Exhaust, look different from the others - quite a lot darker and drier. I should probably mention that we had the cam reground by Delta, and are using OEM rockers resurfaced by same. When we first got the head apart, the lobes, rockers, head, and cam towers in that area all looked over-heated to some degree, and those two lobes looked the worst. We figured that this was due to the rogue spark plug tip conveniently left to rattle around in cylinder #4 by the previous owner. In any case, after this first 30 minute run, all of the lobes, save the two in the center of the attached picture, looked more or less freshly-machined, with the occasional bit of wear just starting to form, but also uniformly and completely coated in oil (Valvoline VR1,) while the two questionable lobes were dark around the entire surface, and completely dry where they contacted the rocker. When I pulled the valve cover off, there were a few wisps of oil smoke still drifting off them, leading me to believe that they were the source of the smoke observed while running. I've got two theories as to what the problem is, both of which I'd rather not have to deal with. A) These two lobes over heated before the rebuild, enough to damage the heat treating. That could cause increased friction with the rocker, heat things up, and boil off the oil. There are a couple clogs in the oil passage within the cam, reducing or stopping oil supply to those two lobes. I fished around inside the oil ports in the cam with a length of wire, and couldn't decide whether anything was blocked or not. The wire came out with a bit of black gunk on it, which didn't seem to have any smell. We do, by the way, have a decent oil pressure, though the gauge leaves something to be desired in the precision department - I'd guess it was indicating around 60psi. Hopefully someone out there with a bit more experience can tell that I don't actually need a new cam shaft. Quote Link to comment Share on other sites More sharing options...
duragg Posted June 27, 2011 Share Posted June 27, 2011 Should there be more oil slathered around in that area? Does it look a bit dry? or is that how it goes? If you crank the engine now with the coil lead and/or plugs removed you should see oil barfing out from each cam lobe, no? I've learned the hard way in other engines that pre-lubing can be valuable in a new engine. If those lobes aren't cumming oil you need to know asap. Quote Link to comment Share on other sites More sharing options...
Nex Posted June 27, 2011 Author Share Posted June 27, 2011 Should there be more oil slathered around in that area? Does it look a bit dry? or is that how it goes? If you crank the engine now with the coil lead and/or plugs removed you should see oil barfing out from each cam lobe, no? I've learned the hard way in other engines that pre-lubing can be valuable in a new engine. If those lobes aren't cumming oil you need to know asap. Yeah, all of the other lobes are well-lubed, and I applied generous amounts of moly grease before firing it up. I don't particularly like the idea of cranking it with the cover off, but that might be what we need to do to eliminate some possibilities... Quote Link to comment Share on other sites More sharing options...
Noddle Posted June 27, 2011 Share Posted June 27, 2011 looks like lack of oil, to me those head bold should be full of oil... crank it over, with coil disconnected, see how much oil comes out. Nigel Quote Link to comment Share on other sites More sharing options...
mistah mofro Posted June 27, 2011 Share Posted June 27, 2011 I dont know if you noticed or just detached it for the pic. One of the mouse trap springs (2nd to the left) isnt on completely, also is the cam internally or externally oiled? Im no expert but small things can be a big cause. Quote Link to comment Share on other sites More sharing options...
Nex Posted June 28, 2011 Author Share Posted June 28, 2011 I dont know if you noticed or just detached it for the pic. One of the mouse trap springs (2nd to the left) isnt on completely, also is the cam internally or externally oiled? Im no expert but small things can be a big cause. Wow, I didn't notice that, definitely not intentional. I doubt that it'd do much to the neighboring lobes, but it's probably bent a bit out of shape... I'll have to make a note to check all of them. I'll try cranking it with the cover off when I get a chance to work on it, this weekend most likely. Quote Link to comment Share on other sites More sharing options...
Lazeum Posted June 28, 2011 Share Posted June 28, 2011 (edited) Don't forget to crank with no sparks Once you've checked oil pourring, you should remove the cam and spray some air in it to make sure everything is clean before you start the engine again. I would also remove the oil pump and inspect it carefully inside out. Same goes for your rockers, I would check the pad wear on them (especially the one from the blueish lobes). Your oil looks new but what about the filter? (99% of chance that question is dumb) Good luck with the issue, I'd got the same issue with a Braap's head and Rebello cam. I found it when a rocker broke and spread metal pieces everywhere in my engine Edited June 28, 2011 by Lazeum Quote Link to comment Share on other sites More sharing options...
Nex Posted June 28, 2011 Author Share Posted June 28, 2011 Your oil looks new but what about the filter? (99% of chance that question is dumb) Good luck with the issue, I'd got the same issue with a Braap's head and Rebello cam. I found it when a rocker broke and spread metal pieces everywhere in my engine Yeah, the oil filter is new as well. Did your metal debris get into your oil pump / did you still have oil pressure? We sort of neglected to do much to the oil pump during the rebuild, because it rather stuck together, and we eventually gave up getting it apart when the trusty rubber mallet got us nowhere. Plus we had good oil pressure before the rebuild, so we just sort of hoped that it was alright. There is (unfortunately) a decent chance that we put everything back together with some sort of debris in an oil passage, and it's now lodged somewhere important... Oh well, we'll see if we're getting oil, then move on from there. And yes, I'd already realized that there should be no spark. Just our luck that'd be the first time it decides to fire up on the first try, and the oil would be flowing just fine... Quote Link to comment Share on other sites More sharing options...
Lazeum Posted June 29, 2011 Share Posted June 29, 2011 Yes, my oil pump is shot and debris when right into it. I had a thread about it, you can check it out. Oil pressure was always showing good number on my gage (stock sender, stock gauge), it was getting low at idle but it has always done it. Regarding oil, after the damage, oil was pouring just fine out of every cam lobes as well. Question for everyone: Something I would try is to remove the cam shaft, clean it with solvant and air (I remove the hood, remove the cam sproket, tilt the engine with a jack and pulled the cam). Then crank the engine with no cam shaft, no spark, no spark plugs to pour oil out of cam tower, you'll have no more restrictions to get debris away from the systems. Can it be done??? The chain will have to go before attempting something like this, so the front cover that holds the oil pump.... A lot of work but it might be worth it if it could save an engine for major failure and full disassembly. Quote Link to comment Share on other sites More sharing options...
ezzzzzzz Posted June 29, 2011 Share Posted June 29, 2011 I'm in a similar predicament. I replaced the camshaft by unbolting the passenger side motor mount, loosening the driver side mount and lifting the engine using a hoist attached to the passenger side mount. The old cam came out without pulling the hood and the new one went in. I haven't checked the oil pump for damage but will probably replace it outright. A new filter and oil will go in. The rockers will be left out and spark plugs pulled. The external oil bar will be left off and a bunch of rags placed strategically to catch squirting oil from going everywhere or draining back into the engine. I'll turn the engine over until I get fresh oil coming out of the towers and cam lobes. It's just a matter of cleaning up and reinstalling all of the bits and pieces, adding more oil and another oil filter. There was no indication of a knock in the engine prior to discovering my wiped #4 exhaust lobe. If debri is embedded in the bearings it will have to stay there until I get around to tearing the engine down or it trashs the crankshaft. I'm hopeful that any particles worthy of causing damages were trapped by the oil filter. I've seen plenty of wiped cams in high mileage SBC's way back. Each time a cam was swapped in, oil/filter changed and the car driven down the road without any other problems. I'm hoping for the best this time around. Quote Link to comment Share on other sites More sharing options...
Nex Posted June 29, 2011 Author Share Posted June 29, 2011 Question for everyone: Something I would try is to remove the cam shaft, clean it with solvant and air (I remove the hood, remove the cam sproket, tilt the engine with a jack and pulled the cam). Then crank the engine with no cam shaft, no spark, no spark plugs to pour oil out of cam tower, you'll have no more restrictions to get debris away from the systems. Can it be done??? The chain will have to go before attempting something like this, so the front cover that holds the oil pump.... A lot of work but it might be worth it if it could save an engine for major failure and full disassembly. Since you've got to remove the timing chain, this level of tear down doesn't seem like much fun at all to do in the car. You'll have to remove the radiator, and probably some bits of the front of the car, depending on what you've got up there. And then there's the crank pulley... I think if we find any oil supply issues to the cam, we're going to pull it and the cam towers (already did that once to add spacers, won't be a problem) and see what we can see. Quote Link to comment Share on other sites More sharing options...
Lazeum Posted June 29, 2011 Share Posted June 29, 2011 (edited) Let us know! As far as I'm concerned, I ended up tearing apart the whole engine since metal flakes were everywhere... my crankshaft needs some polishing on journals at least, the block needs a full cleaning treatment prior to put all the bites together & the head did a round trip between Paris & Oregon to be fixed with fresh new parts from Braap & Rebello . The whole oil system has been upgraded (oil restrictor increased, HF pump, spray bar and internal oiled cam went back in) Engine is waiting for some funds to go to the shop... I have also the "while I'm in it" syndrom so I've got tons of stuffs to do now (front & rear suspension overhaul process but also steering and braking) Edited June 29, 2011 by Lazeum Quote Link to comment Share on other sites More sharing options...
KiwiCowboy Posted July 1, 2011 Share Posted July 1, 2011 Did you clean the main oil journal that runs along the side of the block? When I rebuilt my L28E that had thrown a rod bearing, there were fragments all through the engine. I pulled the journal plugs (front & rear) to clean out the main journal and spent 3 - 4 hours cleaning every oil weep hole on that engine. If you can't clean an engine before rebuilding it, it's a waste of time to rebuild it because it won't last long. Follow your mothers advise "Cleanliness is next to Godliness!" Quote Link to comment Share on other sites More sharing options...
Lazeum Posted July 1, 2011 Share Posted July 1, 2011 Did you clean the main oil journal that runs along the side of the block? When I rebuilt my L28E that had thrown a rod bearing, there were fragments all through the engine. I pulled the journal plugs (front & rear) to clean out the main journal and spent 3 - 4 hours cleaning every oil weep hole on that engine. If you can't clean an engine before rebuilding it, it's a waste of time to rebuild it because it won't last long. Follow your mothers advise "Cleanliness is next to Godliness!" If it is an answer to me comment above, indeed, I've removed the plugs from the block. I'm also wondering if I should not get the crankshaft plugs out as well to get a real good clean up I've got great support from Braap and my machinist did the crankshaft of the Renault turbo F1 back in the 80's Hopefully I'll get a perfect motor afterwards, I would freak out as soon as I would hear a noise of the engine once it would be redone. I'd rather do it right! Thanks for your advice though, it's always great to have support to do the right thing Quote Link to comment Share on other sites More sharing options...
KiwiCowboy Posted July 2, 2011 Share Posted July 2, 2011 Sounds like you're doing it right and good luck. Quote Link to comment Share on other sites More sharing options...
Tony D Posted July 2, 2011 Share Posted July 2, 2011 I don't know how many cams and heads I've seen ruined by idiots putting RTV on the head gasket... That silicone likes to break off and plug orifices. Swarf? That's what you get when you rev the engine like a dummy while the engine is cold, and you succeed in lifting the oil filter bypass valve and everything being sucked up from the bottom of the sump and pumping it up topside to wreak havoc some time later. I have opened compressors with machining chips that fluttered in the oil system and caused vibration problems for literally 20 years until I start looking REALLY REALLY closely, and go 'hey, give me some welding rod, let me stick it in here, something doesn't look right with this spray pattern - poke poke - WOW lookie there!' Quote Link to comment Share on other sites More sharing options...
Lazeum Posted July 2, 2011 Share Posted July 2, 2011 to clog engine lube system because of RTV would suck Thanksfully, not the problem in my case, all gaskets were installed dry (and no leak!). Quote Link to comment Share on other sites More sharing options...
Nex Posted July 4, 2011 Author Share Posted July 4, 2011 Alright, we made a bit more progress on this. Cranking with the valve cover off got us no oil out of the cam, and we pulled the cam pulley bolt, and found next to no oil inside. Then we pulled the oil filter, and cranked it, and didn't get any oil there either. I suspect that we tilted the engine too much after installing the oil pump, and we managed to dump the oil we used to prime the pump out. So we pulled off the oil pump, re-primed it, and then we got a good amount of oil from the oil filter while cranking, but still no oil from the cam (after reinstalling the filter.) We replaced the valve cover and fired it up again, and by removing the oil filler cap, could see that some oil was coming from the visible cam lobes, in droplet form, without enough force to actually come out of the filler hole. I don't really know what to expect, but I feel like that wasn't the proper amount of oil flow. We let it warm up for a bit (still some white smoke from the valve cover vent,) and pulled the valve cover again, and things looked better than they had the first time - the lobes that were dry and burned were at least a bit lubricated, and the dark / burned color had lessened significantly. I decided to go ahead with the hot lash adjustment, and discovered that a few things probably went wrong during my initial adjustment (The rocker springs were moving things around a bit, and I didn't press the rockers to the lash pads / valve stems, so who knows what I was adjusting,) because some rockers were quite a ways out of tolerance. I didn't measure just how far, but I think I'm lucky that I didn't lose a lash pad. The worse-adjusted rocker happened to be one of the previously over-heated lobes. Question: Could significantly out of whack lash settings have been the difference between the burned lobes and the others? Next steps are probably to drop the oil pan and see if we managed to clog the pickup strainer, then replace the oil pump. Quote Link to comment Share on other sites More sharing options...
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