Okay yea that's what I was thinking as well, maybe replace my oil even, just to start all fresh. But also before I do anything I just wanted to share this video of the bike currently so you can hear what it sounds like. I have the oil pressure gauge hooked up and I bring it to 5400 rpm briefly and then I bring the camera close to various parts of the engine. Lemme know if anything else seems odd. One thing I did notice while using my mechanics stethoscope, is that the whine "seems" to be originating from the right hand side of the engine, idk if that's just because it can resonate more on that side (due to the big open area around cam chain and clutch) or what. The sound doesn't go away or change if I relieve the pressure off of the CCT a bit (loosen just enough to hear the chain begin to make some racket) so I'm really hoping that replacing these buckets do the trick........

Anyways, here's the vid:

 

Hi , just looking back over the first few post, and looking at the buckets I'm just wondering why the contact between the buckets and the cam lobes should be so aggressive to cause that marking, its almost as if there is constant contact, not sure what could be causing that

 

I've been scratching my head on this one too...

I would have assumed oil starvation as well but it looks like wear is just on the buckets, which is pretty weird. Aside from draining the oil and cutting up the old filter to check for chunks of metal or other undesirables, as Cabaret says maybe drop the sump and check the intake strainer too. OP's probably getting a little sick of taking this thing apart though

It almost seems like contact between the pistons and valves - maybe a timing issue causing minor contact right while the piston is near the top of the cylinder? Does it turn over smoothly by hand? Is it possible that the cam lobes are bottoming out (even for a fraction of a second) against the buckets as it runs?

I can't think of many other reasons for those buckets to be seizing up, especially for all of them to fail at once on a fresh head

Also you'll definitely want to mic the cams on reassy, and inspect the lobes for premature wear. They'll flatten out surprisingly quick. Might also want to check the runout while you're at it

Hopefully you get it figured out - if it were me this bike would probably have put me in the loony bin

 

See that was my initial thought, that there was zero clearance between the cam lobes and buckets somehow but the cams show zero sign of wear on the "base" of the lobes. The old cams (that are now on my bench) show some faint faded circles on the sides and tip but not the bottom of the lobes, and there is the correct clearance between the buckets and cams as well. Idk how there would be a timing issue involving valve/piston contact without leaving any sign of contact on the valves or the pistons, but thats definitely a new angle to approach this from. One thing I did notice with the mechanics stethoscope upon a cold start up (roughly 50 degrees F right now in the garage) is until the bike gets to about 100 degrees F, there is a slight "thack thack thack thack" sound coming from the top of the cylinders but not the head. you can only really hear it from the left side as the whining is very loud on the right. You guys have any input on that?

 

These are pictures of the old head (current head didn't really change anything, just has less time on it with the problems I'm having) this was on the bike for quite a while while I was trying to figure out what was wrong. As you can see the valves look untouched (by the piston anyway) unless I'm missing something here. The other 3 pics are of the old cams showing the tip, side, and base of the same 2 lobes on the intake camshaft. All the lobes are consistently the same across both cams as far as wear. I switched out the buckets 2 or 3 times in this head before switching the head entirely. So the wear on these cams is from about 80-90 cumulative miles, plus some of idle time as well. I have not pushed this engine past 6000-7000 rpm since the initial rebuild due to the break-in process and all of the problems I've been having. Hope these help some.

 

Agree. I still think oil starvation is the most likely cause. If you've fixed the pressure, hopefully new buckets and fresh oil will be the last of it. I'd be generous with the grease too

 

Okay sounds good, I ordered some more buckets. So while I'm waiting for them, I'll do a tear down again to the cams and Ill measure all the clearances again and post them so you guys have that info as well. Do keep in mind that I did not re-shim the valves in this head as it "came off a perfectly running bike" and the clearances all seemed okay enough not to worry about for the sake of eliminating the variable of me screwing something up. This time around I'll re-shim it to get it perfectly in spec after receiving the new buckets, and I'll thoroughly inspect the cams as well. Hopefully with perfect clearances, new buckets, fresh oil, and correct oil pressure my problem will be solved......UGHHHHHHHHHHH please let this work

 

Early morning here in Blighty , just caught up , your having a mare with this kiddo , while your at it would check those other things strainer ,relief valve and pump, you've done good sticking to this and I know you will find the cure. Just a thought are the oil passage ways clear to the head (not blocked by gasket) Sorry to add this , not trying to be a know it all

 

Agree with Cabaret. He’s giving good advice here. Check/clean the strainer and relief valve. Groan, I know. But aside from a freak blockage, they’re really the only other possible culprits, and either could cause a low oil pressure condition, especially if dirt/debris fell into the sump during the original topend rebuild or if the oil/filter's been reused at any point in the process

I’m gonna apologise for the monster post, but it’s a slow day at the office and I’ve recently rebuilt one too so this has been educational to me, even if I’m sure it’s been a painful process to experience firsthand. I’m just trying to narrow down the possible causes here so if you’re waiting for parts anyway, I’ve got a couple questions:

Story starts: Bought bike 48k miles. Overheated one day w/ white smoke (assuming head gasket but it’s really not important at this point)

Topend rebuild: head warpage okay, valve job, new gaskets. Whining noise immediate on startup. Rode for 40 miles (probably about an hour of riding). Still making the noise, so parked it to find the cause. *We now know that this is when the bike probably first suffered from oil starvation, so whatever problem occurred, it occurred here*

-Were they OEM or aftermarket gaskets? Any chance that the gaskets obstructed an oil passage? Did you replace the oil filter at this point, or was it later? What oil was used?

Full overhaul: No wear noted, rings done, new gaskets. If the whole engine had been completely starved, we’d probably see some carnage in the bottom-end, but it all looked good. This points to low-pressure, as opposed to no pressure. That’s probably your saving grace. Tappets need a lot of oil, so it’s maybe not unusual that they would wear first. They were replaced. Engine was reassembled and found to still be making the whining noise

Sensibly, you then tried to isolate the source of the sound, disconnecting the gearbox, establishing that it is RPM dependent etc. Checked the cam chain and replaced it to be safe. Replaced the tappets, and that didn’t help either.

At this point we can assume the engine is running with low oil pressure, and it’s been this way since the first topend rebuild (so maybe an hour or two of cumulative runtime). No indications of a blockage at this point

-What oil was used after the overhaul? Was it the same stuff? Did you use moly grease, or any other products in the assembly phase? Some folks pack the oil pump with vaseline etc. – basically anything else to change the viscosity of the break-in oil?

Next we replace the head with a used part. Same result. Now at this point, we check the oil pump operation. We remove the driven sprocket, and turn the rotor with a drill. We get oil from the cams, which rules out a complete blockage. This again points to low-pressure not complete starvation.

-Did you replace the oil at this point? You must have drained it to remove the sump. Anything suspicious? Did you reuse it?

Still making the noise, so we check oil pressure, and find it 10 pounds low. Then you took the bike back apart to measure the guts of the oil pump, and it’s found to be in spec.

-Did you check out the strainer and relief valve at this point? They would have been removed to access the pump so would have made sense but meh - as I say, you’d probably already gotten pretty sick of taking this thing apart so that’s pretty understandable

Now we replace the oil filter, refill the system, and the oil pressure comes back up to spec, but it’s still making the same noise. This is probably from the worn tappets generating way more friction than a smooth one would

-Again, is this the same oil, or was it replaced along with the filter? Is the oil pressure measured upstream or downstream of the filter? I would have thought that a clogged oil filter would cause high-pressure, unless the pressure reading is taken downstream of the filter

So now the course of action is to replace the tappets, check the cams, and install fresh oil. That’s as good a choice as any. Hopefully that fixes the problem, but back to the service manual troubleshooting section, we’ve ruled out everything except the following:

-Clogged oil orifice (possible but unlikely since circulation visually confirmed at cams)
-Incorrect oil being used (possible)
-Internal oil leak (unlikely since the topend has been removed/installed 3 times now and noise originally noticed after topend rebuild not full overhaul)
-Clogged oil strainer screen (not checked)

 

Okay so as far as replacing oil is concerned: When purchased at 48k I replaced the oil and filter, I used a Honda oil filter from a dealership (forget which filter but it was highly recommended) along with castrol full synthetic 10w40, afterwards the bike ran great.

After replacing the head I replaced both the oil and filter (in case there was coolant in the oil from the bad head gasket). This time I again used castrol full sythetic 10w40 and (since it was late, like 3:00am late, at the time of completion) I bought the most expensive filter available at walmart (since they were the only place open). I believe I bought a $15-$20 Fram or Bosch filter..... (mistake #1 haha). After which point the bike started and ran good but was whining and burning a lil bit of oil at high rpms.

So it looks like the rings got a bit crispy after overheating as well. Which prompted the full rebuild. After which point I used Valvoline 10w40 (NOT synthetic) with "Lucas Oil Zinc-Plus Engine Break-In Oil Additive". BUT I did reuse the same filter since it was basically brand new and this engine rebuild was already burning a sizable hole in my wallet..... (wont make that mistake again, nor will I use walmart filters!).

After this point I never was required to dump the oil as I was mostly messing with the top end of the engine or around the clutch. Now one thing to note is that my oil pump is accessed from removing the clutch cover and then the clutch basket. It is located directly behind the clutch. So I do not need to remove the oil pan to access it and the oil pump was well within spec and in great condition. So I have not had an opportunity to mess with the pressure relief or strainer really since the entire rebuild. BUT that said, when I tore the whole engine apart, I did inspect the strainer and clean it. I did not find anything out of the ordinary for a bike with 50k miles but did thoroughly clean it regardless. As for the pressure relief valve, I replaced the O-ring on it with a brand new one and left it at that (so I did not take it apart to inspect the spring and inner components).

As far as parts are concerned I have only ever bought and used quality name brand Honda parts from Partzilla (I've ordered more parts off that site then over the years then I'd like to admit haha) and I triple checked each head gasket (replaced it like 3 times now) with the original one to ensure that all the ports, gaps, and pin holes matched up and were indeed exactly the same, and each time they were.

Also worth noting is that my oil pressure gauge is tapped into the oil line in between the pistons and the head, which is down stream of the oil filter itself. This means that a bad or clogged filter would create low pressure where I was measuring it from and high pressure before the filter. Which makes sense with my measured results. I was reading an oil pressure of 61 psi on my gauge which is the oil pressure going directly to the head and into the cams. After replacing the filter (finally) with a higher end K&N filter, my current pressure read out is 71 psi going to the head, which is spot on with what the manual says it should be.

ALSO another thing worth noting is that the oil passage between the pistons and the head starts at where the pressure gauge screws into the engine (right between cylinder 3 & 4) at which point it travels horizontally to the other side of cylinder 4, where it then takes a 90 degree turn upward and straight into the head. This oil line is about 1/4 inch diameter through and through and has an access point via a bolt at the 90 degree corner mentioned above. I took the cams, the bolt, and the pressure gauge out to check for any possible blockages (such as shop towel or old gasket material) that may have fallen into this port and found nothing via visual inspection or compressed air being blown through as well.

I think that covers just about all the questions asked, please let me know if I missed anything or left anything unclear! I really do greatly appreciate both of your guys' input on this and I dont think you're know-it-alls or anything like that! I've clearly been missing something here (hopefully it was just the filter!) so I need other peoples' perspectives questioning things that I may have looked over or missed! You guys have been an amazing help so keep on doing what you're doing! haha