Sorry, what I meant was a cracked spring might make contact with the bucket, not a cracked bucket contacting the spring. Anyway it's not that as I've had the cams out and there looks like rubbing on the followers but no cracks. Springs are fine and head has no damage. I'm now going to investigate oil flow rate to the lower exhaust camshaft, because the inlet followers look far less worn. Ok here goes yet another bloody theory, bet you are fed up with these. Question, why are the Exhaust buckets chattering/squeeking and showing excessive wear when inlets look good? 1. Restricted oil flow, result being that the oil drains away to fast and so the buckets don't get bathed in oil as they should. Exhaust cams have a drain, the inlets don't so the oils pools in there. 2. Or followers are just plain worn out, that simple and they are starting to bind. Engine has 45,000+miles on it, or maybe oil even an starvation damaged them in the past. The oil in there was an unknown but the oil I put in there was Mobil 2000 10W40. Cheers Bell ;-)
exhaust valves get hotter then the intakes, more heat conduction and thus greater expansion rates, hence why clearances are different. oil.... lots of debate on brand, grade etc... you're over the pond so Liqui Moly is easier to get I assume. In my opinion their oil works like magic to quieten up a valve train, the Mineral based stock is a good choice for a stock engine with factory seals. Mos2 is a good choice, all the low speed crank turning over you've been doing is absolutely brutal on the cam lobes btw, may I suggest using some high pressure assy lube, Gibbs, redline etc.. better then dry or splash oiling. these are obviously flat tapped cam'd engines and require an anti-friction additive no longer found in oils as it's been determined to be caustic to catalytic converters. Lots of additives out there, personally I use either a diesel oil that still has high enough levels of zinc, or racing oil or if I can get it without too much hassle Liqui Moly. each depends on the build and use. I'll try and get a pic of the cracked bucket, need to locate it in the old parts bin. If and when you decide to pull the cams out again, I know a pita. Go a bit further and pull the cam gears and plugs off the back and flush the cam oil holes clear, sometimes they can get clogged with sludge and debris. the bolt that holds the cam gear on should not have any type of sealant on it, there is an 'O' ring to seal that end, same goes for the other end for the diizzy drive with the roll pin, it drifts out and is sealed with an 'O' ring too. exhaust cams have a taper plug.
Bell ---- I just now watched your latest video ('A 3 Pipe Problem' -- part 4), and I noticed something that is possibly VERY significant. At approximately 6:21 run time in, you appear to put your hand down underneath the rear bank header (by the #4 cylinder). EXACTLY what did you do / grab / touch there at that point ?
Hi Guys, I can put any old oil in my Aston, Lambo or Lotus and I've never had any issues like this. The old Lotus Excel SE has 300,000 miles and has been given a seriously hard time, thrashed to bursting point mostly, and without so much as a squeek, absolutely unbustable that engine. Even the old Aston V8 will hit 7000rpm on every gear change. All 3 cars use the same cam follower system as the Ferrari. By just changing the oil I feel I'm masking a problem rather than fixing it. Nobody here has repoted this problem and folks here must use all kinds of oils without issue. I do like to take all my cars to the red line, but with the Ferrari I've been much kinder and only do it occasionally. I think just changing the oil will always leave a nagging doubt that the engine might seize at any time and blow itself to pieces and that's no fun to have in your mind when driving hard. The other thing I'm thinking is only one bank is making this noise, if it was bad of wrong oil, both banks would be doing it, and that smells very fishy to me. Hi Finnerty, I was seeing if the exhaust manifold was blowing. The microphone is directional hence the change in sound. One way or another I will get to the bottom of this Guys, All the best, Bell. ;-)
Hi Simon check it out here:https: https://www.ferrarichat.com/forum/308-328/449992-bad-mystery-engine-noise.html Latest Video Here: https://www.youtube.com/watch?v=ZIFmlYAKxlY&feature=youtu.be It's been tough but I'm gradually getting there. Regards Bell.
Okay, here is what I am observing. At about 5:28 and again at about 6:21, the squeak is heard. At both these times, you no longer have the mic pointed anywhere specific in the engine bay (as you were doing before). So, I am assuming (and correct me if it's wrong) that the mic is somewhere off to the side and in the same location and pointing direction during both times...... That being the case (?), the volume of the squeak appears to be very different ---- much lower at 6:21 when your hand is down by the header. If you are not actually touching anything down there, then either your hand or your body is blocking some the sound pressure traveling between its source and the mic. 1) Does this car have the exhaust gas sample tubes / ports in the rear header ? 2) Are there any heat shields on that header ?
if it's an air leak then it would happen cold or hot, and usually sounds like a 'tapping' noise as the valve events are amplified. This sound is more of a cyclic interference type, i.e. loss of oil film layer from shear or low pressure, valve stem clearance to guide, loose guide but that would result in oil consumption and deposits on the plug. outside the box here... possible inner spring interference issue.. hmm how thin are the shims on the exhaust of cyl#4 to get the proper gap?
Hi Guys, All set-up clearances were a breeze all shims were within a few 100ths of each other across the whole engine, just like a new Honda. Here is the problem Guys, (see Pictures) now I have to work out why, and my bet is oil starvation, or maybe this wear is normal for this milage but I doubt it. One on the right is kind of OK but the left is not, the head is undamaged not even a scratch. Honing the buckets would get the oil sticking to them again, or even new ones but that is fixing the symptom and not finding the illness in my opinion, which means it will happen again. My next step now for sure is to varify oil flow rate to the cams via oil ways and cross check. Both camshafts are clear and were checked last time. Cheers Bell. ;-) Image Unavailable, Please Login Image Unavailable, Please Login
Well found. Those buckets must have been starved of oil to look like that. Lots of people use 10W40 without issue (though personally I use 0W40) so I doubt very much its anything to do with the oil you put in it
Looks like you found it --- nice job ! Even if that is not the "squeak" problem..... it is its own problem, and it needs to be fixed anyway --- so still a good catch.
OK now you're getting somewhere. the buckets are made of a very hard alloy steel, the heads are of course aluminum, if the wear on that bucket has marred or cut into the steel then something has gotten into the bore, 9 times out of 10 it's when a rebuilder, everyone sitting down? ...... Good. puts the head thru a freaking sandblaster, yep to make it all clean and nice -gives me nightmares thinking about it. The guy I use has a large 'washer' heated to 240*F and degreased for anywhere from 10mins to a couple hrs in 1hr intervals. cleans without leaving behind sandpaper! OK looking at the bucket notice the bottom of the bucket has no wear. that is the exposed part under the skirt of the bore, the dwg above is not accurate. There is something at the skirts edge that is chewing into the bucket. If you have some 000# steel wool polish the bucket and see if catches anywhere indicating a crack, if not then you want to see if the wear marks polish off easily or if they are cut into the bucket. the buckets are splash oiled so it's not a pressure issue, but if there is low flow it can be. something is loosing it's tolerance at temp, more then likely it's the bucket. I went to find the cracked bucket at stopped after sorting thru 150+ used buckets, it's somewhere I just don't recall where I put it. however I did run into a couple that are not true to round, you can feel the internal chuck marks from when they were cut and possibly polished. In the defense of ferrari I don't think they're OEM ones as they are the only ones to have that feature and you can clearly see the 3 point marks, the bucket should be center-less ground for true a concentric part. how does the valve tip look? does the valve 'wiggle' more then others? the crack is axial to the part starting at the bottom and going up ~5mm on the bucket I pulled from a QV last yr. that engine had over heated and was warped a bit.
Hi Smg, just to say nothing has ever been though a sand blaster on my cars and no engine parts ever go through bead blasters either or any kind of abrasive cleaners. The car also has not been overheated. and heads have never been off. OK Crowndog you devil what do you think it is and why ;-)
I wasn't saying that you did or that it has, just a possibility. have you owned the car since new? I've seen many a so called original or untouched engine that has indeed been apart or repaired improperly in the past, it happens. Not saying that this is the case for yours. I've seen that wear before on a bucket, just trying to help.
Agreed, 999/1000 replacing the oil with synthetic won't hurt. But that 1/1000 is always lurking. I've personally seen it happen. That's why I'll never run synthetic in my 308. In this case we will never know. Best that can be done is to put it back together right and move on. Your choice on what oil to use. Good luck moving forward.
Good grief, I don't have a clue. You shouldn't listen to me as I was in the air/oil squishing noise camp. I'm still wondering why three chirps from this discovery. Truly glad you found the real cause. So what's next, checking the bore for roundness, replacing the bucket and insuring proper oiling? When all else fails read the damn manual. - wife
Hey Smg, sorry didn't mean to offend, was in a hurry to get on set when I wrote. it. Just to say, I've done 8000 miles since having the car. Nothing to say anything major done to the engine. In fact all tolerances are so spot on I would say it has never been tampered with. Much thank's regards, Bell
okay couldn't resist. Quoite OK some interesting thoughts there 166&456, firstly I can check cams for true and will but only the cap was affected and only 1. I don't think a cam could bend at that one point only (i maybe wrong) and if it did it would affect the head part of the bearing. I think in my case this cap was put on the wrong way or somthing like that, I don't know but it seems like an isolated incident. More interestingly however you talk of valve clearances, I have just done mine exhaust ones only because they were set to the incorrect set-up of Mondial QV: Exhaust: 0.30-0.35 My book says: Mondial QV: Exhaust: 0.35-0.40 So I set the exhaust for 0.38, now I havn't checked but if one was really loose say 0.40 or even 0.42 could that really make that kind of noise? I'm out today but will re-check clearances when I get back. Cheers Guys, Bell. so could the wrong clearance set before cause this condition? Then, correcting it have revealed it?
Either I'm not seeing it or it's in another thread, what was the problem with one of the caps? To the question on clearance, 0.40~.042 isn't going to cause damage or noise like that. when it gets loose enough it'll 'tap'. too tight and then you can burn the valve, reason being as it heats up the expansion closes the gap and then some when too tight as it never fully closes.
Interesting info in section 6 of this paper ( with pictures) of damage assessment of buckets. May help with ideas.: http://www.schaeffler.com/remotemedien/media/_shared_media/08_media_library/01_publications/automotiveaftermarket/brochure_1/downloads_5/INA_Tec_Brochure_Valve_Train_Comp_en.pdf When all else fails read the damn manual. - wife
here's a screen shot from doing some cam profile engineering on 4L QV build. notice the 3 acceleration peaks on the left graph. Image Unavailable, Please Login
very possible, the bucket galling and scoring can make noise if the clearance is too tight. given that the bucket is moving under the cam and the cam has that acceleration curve, I'd say it's almost a given.
