Honda-SOHC

So an update and a few pics on my unpleasant top end meltdown.

Due to the modded frame I'm lucky to be able to whip the head off in situ as Nurse Julie thought, so that's something I guess.

Before that the oil metering jet on the right did have a damned sliver of the old white gasket seal from the cases the PO used and that I was so careful getting rid of... however a bit was there on the thin end when I took the jet out. The towers seem clear but not blown them out with cleaner yet to see what may emerge.

I sieved the oil through the sump plug and there was one other tiny bit of white sealant and a few globs of jelly like oil and tiny ally swarf from the holders & cam shaft I imagine...

I dropped the oil pan and there was sludge in there but no more sealant, same on the bottom of the pump mesh (none on the pump side though).

So... Roo popped round after my initial post and helped lift my dark and sweary mood with his enthusiasm, knowledge, and desire to help out a brother in need! ...and I've got to say my faith in human kindness has been restored. Cheers mate! Should have been on this forum from the start not the US one 

I've got another cam shaft and tower thanks to Roy but now it's over to you for expert advise on how to now proceed.
I'll thoroughly clean the head, towers, jets in a dishwasher and with steam and parts cleaner afterwards to make sure the oil ways are clear and replace the oil filter but to what do I do with the remainder of the engine.. is there a flush out of the lump I can do with the pump and filter out... pressurised diesel flush somehow maybe?
Am I clutching at straws to not have to split the bloody cases again? 

Wow brave man, and fair play to you!
I'm facing a top end strip down on my 750 after a small disaster cooking my cam... this gives me momentum to get it sorted

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Quote from: Bristolbadger on March 25, 2022, 07:36:56 PM

Quote from: Nurse Julie on March 25, 2022, 05:22:32 PM

I suppose in theory, even though oil is observed getting up to the cam on a newly rebuilt engine at initial start up, it could take a few miles of riding to dislodge any debris that is in the bottom end, such as the dreaded silicone sealer, blobs of glass bead etc, etc.

Julie I reckon you're spot on and this is what happened. I'd been pretty surgically clean and really tried to make sure all oil routes were clear but I guess something somewhere blocked a jet and gave me the two fingers!!

So painful to fall on the last hurdle like this after a couple of years but I guess I'd be looking at ANOTHER tear down of the head etc anyway even if I'd discovered the oil blockage before meltdown. Just this is now even more of a costly one for parts and it now not going anywhere (will cancel my insurance on it now as it's just started) and almost beyond me putting anymore into it, moan moan f@#k s@*t

If when you strip the cam towers off and the oil jet is not blocked then, you have to look at the oilways in the towers. A lot of owners forget to check the oilways in the towers. When you find out what caused the problem and rebuild, when you start the engine do so, with the tappet covers off. This way you can see if oil is feeding the cam 
 
You have not said, if the engine was media blast cleaned.

No media blasting was done just careful pre cleaning of all components with cans and cans of parts cleaner on assembly. When the head and block was off initially I degreased them, washed, then steam cleaned all the hard to get to passageways before spraying out with parts cleaner before assembling

I was double careful of all the tower oil passageways, metering jets ×2.

When I got the engine the bottom end was together just the barrels and head taken off, it had been taken apart by a friend who was a careful and had covered the opening with bubble wrap. I should have probably flushed out the crankcase then somehow but for some reason didn't. I stripped the oil pump completely, there was sludge on the mesh with what looked like possibly a little of rubber hose shavings... I later had to split the cases to get to the gearbox so made sure that whole area was spotless as could be with careful cleaning of the inside cases and with all remnants of the pervious sealant got rid off.

I wished I'd maybe used a cheap light engine oil and changed it after a few initial start ups/miles to help just flush the system then used the decent 15/40... might have spared this pain but maybe wishful hindsight thinking... F*#K!!!!!

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i was told by an old honda guy to turn the engine over with the rocker cover caps off to see if oil arrives at the head. i assume that's a good idea?

F#@#####CK!! I can't think why I didn't do this with the engine in the bike not just on the bench, I assembly lubed everything as i went and was fixed on the pressure being good and having seen the oil getting up there on the bench I assumed all was well..... so moved on to the next thing. TW@T!@!!

Here's that vid:
https://youtu.be/TnXZu-yCPGA

Like you all say rockers 3&4 got starved of oil and just running dry and melting the cam and holders. I don't think, & hope - until I can investigate further - that the head itself is damaged, pray be.

Thanks muchly for the call and support Roo. These are sour times man

Hi folks, I'm properly gutted after I finally finished my k3 750 sohc, got her MOT'd and finally on the road and driving sweet. After 30 or so fairly gentle shakedown miles I decided to pop the cover and check valve clearances and re-torque all the bolts... only to discover the cam seemed off centre on the right side holder...
Low and behold the horror in the pics! I'm mortified to say the least after 2yrs of ground up build.

What could have caused this? Only a bent camshaft that I can think of as I did a full bench check to check oil circulation to the head and all metering jets were clear and oil was getting up to the journals and everywhere nicely. Was getting good running pressure with a gauge attached to the pressure sender initially and also no oil light warning (yes the pressure switch is working) when I was riding it with that back in.

The left side cam holder/journals and camshaft are fine and unmarked as was everything up there when I assembled the engine.

I can't vouch for the straightness of the camshaft when I got the bike so I guess its possible the cam had been dropped or bent and I just had a dodgy one to start with.

Not sure my best course of action now?
 I'll strip all the parts off and take the cam fully off and investigate for any further damage I guess but then best case scenario is me left looking for a second hand camshaft and right side holder and journals. F**k f**k f**k!



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Great stuff, much appreciated. Thanks Phil