smart51
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 posted on 16/4/07 at 08:54 PM |
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You just wouldn't believe it. More engine trouble.
After just fixing my carb related idling problem a few days ago, I thought I'd go for a short ride in my car. But ended up coming home on the
back of a truck. There's never been a time longer than a week or so where everything on the car has been working fully.
The first 3 or 4 miles were just fine. Plenty of power, lots of acceleration, no problems. Then it started making a clanking noise that changed on
overrun. Dipping the clutch made the noise go away. Re-engage and back it came. I stopped and looked arround and everything looks fine. rev the
engine to 2000 or 3000 and it sounds like there's something loose attached to the crank or somewhere.
I drove it gingerly to the nearest illuminated off road parking area and called green flag to take me home. The car drives and the engine seems happy
enough but for the noise.
What could be wrong with the damn thing this time?
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bigrich
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| posted on 16/4/07 at 08:58 PM |
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poss clutch basket come loose or something on the transmission if the noise stops with the clutch in
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ChrisGamlin
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| posted on 16/4/07 at 09:00 PM |
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First thing Id do is whip the clutch cover off and make sure the basket hasnt cracked or knocked a tooth off.
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ChrisGamlin
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| posted on 16/4/07 at 09:00 PM |
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LOL at least we were consistent with the advice  .
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smart51
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| posted on 16/4/07 at 09:08 PM |
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The clutch is easy to look at, as I told someone else earlier today. I think I might even have a spare gasket somewhere.
The prop is tight at the engine end and there's no real backlash in it. Engine bolts are all in place and tight (to the finger). Nothing
appears to be loose. When I rev the engine genlty with my hand on the throttle, the noise does seem to be internal. I hope its nothing expensive.
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ChrisGamlin
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| posted on 16/4/07 at 09:11 PM |
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If cou cant see anything wrong with the clutch, next step would be to drop the sump and hope you don't find any lumps of metal in there
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Dillinger1977
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| posted on 16/4/07 at 09:32 PM |
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no advice but sorry to hear about the bad luck. Im currently hoping for the day mine gets on the road and the build work is finally finished.. but by
the sounds of it, it never really ends!
-Rog
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Hellfire
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| posted on 17/4/07 at 08:12 AM |
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Sorry to hear of the bad run of luck you're having lately... as said, it sounds clutch related. In respect of the gasket, a little advice is to
smear both sides with copperslip that way if you need to remove again the gasket simply peals off of the engine and cover - no need to buy a new one!
It sounds like the engine has lead a varied life.... fingers crossed it is just a temperamental one for now!
Steve
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smart51
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| posted on 17/4/07 at 05:30 PM |
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I've just taken apart the clutch and it all looks good. I've taken off the sump and baffle plate. No chunks of metal fell out with it
and the sump isn't full of swarf. Its a bit dark up in the block so I'll have to get an inspection lamp.
A guy at work thinks that the symptoms point to a worn big end bearing. Does that sound plausible? Is it a big job on an R1?
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ChrisGamlin
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| posted on 17/4/07 at 06:13 PM |
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Worn big ends is highly unlikely IMHO especially in a modern tight tolerence engine like an R1. Big end noise wouldnt go away when you dipped the
clutch and you'd also have very low oil pressure for starters, and if a big end has properly picked up you usually get small bronze type metal
shavings in the sump.
One other thing to look at Ive just thought of, check the ring gear off the crank that drives the clutch basket. You'll need to inspect it via
the clutch cover and if you can try to turn the engine over with is in 1st a wrench on the sprocket (with the plugs out) so you can see it all the way
around. On my old blade I had the crank drive gear shed a few teeth and it sounded awful, much like a big end completely gone, but having said that if
this was the case here I'd expect a few fragments in the sump.
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tks
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| posted on 17/4/07 at 07:21 PM |
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Nah i don't think either it are the big end bearings the reason is simple! The engine would have crashed already! Once there is a bit of play in
suchs a engine it increases rapidly.... until the valve is touching the piston etc...
Did you looked at your clutch actuation meganism? Is there a posibility that you over pull the clutch??? is it possible that the plates and disc are
over there service limit??When they get to thin maybe the springs gets to loose etc..
what is the noise about if you press half clutch?? for example while pulling away??
is it possible that the noise is coming from another part? for example the diff??
the drive shafts?? rear brakes???
Tks
The above comments are always meant to be from the above persons perspective.
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smart51
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| posted on 17/4/07 at 09:27 PM |
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Rolling allong at 30 MPH with the clutch disengaged and the engine idling, there is no bad noise. The noise only occurs when the engine is revving
above 2000 or 2500 RPM, in neutral or any gear. It starts, idles, pulls away and drives normally, just with a loud disturbing noise.
I had a look up the sump with a torch. It all looks OK but then you can't really see too much. It looks like I'll have to lift the
engine out.
Chris, you say that big end noise wouldn't go away when the clutch is dipped. Do you not get big end noise at idle?
[Edited on 17-4-2007 by smart51]
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ChrisGamlin
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| posted on 17/4/07 at 09:31 PM |
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It will sound like a bag of spanners at any revs if the big ends have gone properly, but I guess it might not be as noisy at idle / when not under
load if they were only just starting to wear, but the big sign would be low oil pressure. Do you have a guage?
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OX
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| posted on 17/4/07 at 10:17 PM |
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my brothers first engine was like that .it sounded like a growl when reved up but only at low revs ,after 4000 rpm it was ok. it got worse and worse
and with in 20 miles it sounded like a tractor,dropped the oil and found loads of bronze in it.
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jimgiblett
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| posted on 17/4/07 at 11:01 PM |
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Could be the generator. Mine broke a boss on the crankcase which holds the outer (The inner is attached to the end of the crank).
Can you borrow a stethoscope to identify where the noise is coming from.
Hope not as this was the demise of my old motor due to boss being so close to a main bearing journal.
- Jim
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smart51
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| posted on 18/4/07 at 07:02 AM |
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I don't have an oild pressure sensor. I just use the oil level sensor that comes with the engine.
The generator is a good one to look at. I hadn't thought of that. I'll have to lift the enigne to look at it.
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Bob C
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| posted on 18/4/07 at 09:33 AM |
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re big end failure: I had an old triumph with this feature.....
Engine was quiet when cold (& the oil was thick) and rattled/banged for england when hot.
Tough luck mate - hope you can fix it
Bob
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hobbsy
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| posted on 18/4/07 at 02:02 PM |
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When big end number 3 went on my Blackbird it seized within <5 miles of suspecting a problem. Oil pressure (or lack thereof) gave it away more
than the noise as these cars are so loud its hard to hear big ends over the exhaust IMO.
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Guinness
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| posted on 18/4/07 at 02:32 PM |
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I know when my no 3 bearing began to go, just as I pulled away from the lights on the coast road, saw a massive cloud of white smoke in my mirrors.
Stopped at a petrol station a mile or so down the road. Checked the oil level, was fine. Drove on about 15 miles. Thought something had changed in
the engine noise. Came out of a 30 zone onto a national speed limit road outside Ponteland, floored it and BANG AD BANG AD BANG AD BANG! No
mistaking it that time, sounded like a lump hammer hitting a oil drum!
Took the sump off and it was full of shiney / sparkly oil.
Hope yours is OK.
Mike
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smart51
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| posted on 18/4/07 at 07:59 PM |
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I've just poured the oil out of the bowl into the original container for disposal. There were no swirls or shiny bits in the top 90% but at the
bottom there were what looked like flakes of copper foil. Mostly about a mm across, some upto 2mm and one about 3mm. The same at the bottom of the
sump.
I also took the rocker cover off and that was just fine. So I've undone all the bolts and hoses holding the engine in ready to lift the lump
out.
How much big end bearing is there to lose before big damage occurs?
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ChrisGamlin
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| posted on 18/4/07 at 08:09 PM |
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Oh dear
If you do have bearing material in the sump then Id say its only a matter of time (and probably not that much time) before it goes bang. Any bearing
wear isn't good at all, its not really a case of x amount of wear before its too bad because in a healthy engine the bearing shouldnt actually
touch the crank journals at all, as it sits on a film of high pressure oil, so once some bearing material is missing, oil pressure drops (because the
gap is bigger so the oil escapes more easily), which then spirals into more wear and then seizing up.
I'd suggest if you can to take the engine out and split the block. Take all the bearing caps off and see what they look like, if its simply a
bearing thats picked up but the crank journals themselves are OK (no scoring etc), then you should get away with just new bearing shells and maybe a
new rod, but to be honest if there are bits like that in the sump, its likely the bearing has started to spin, and its likely to have damaged the
journal as well.
Can you take a pic of the debris in the sump to look at, just in case we're coming to the wrong conclusion?
[Edited on 18/4/07 by ChrisGamlin]
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DIY Si
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| posted on 18/4/07 at 08:15 PM |
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What you describe is precisley what I found when I pulled my sump off after suspected big end failure on my Bird. I could wobble one of the big ends
around with my fingers!  Sounds as if something similar may have happened to yours. Mine sounded like a bag of spanners at all revs, so you may
have gotten away with it, but I wouldn't hold out lots of hope. Sorry it's not what you want to hear.
“Let your plans be dark and as impenetratable as night, and when you move, fall like a thunderbolt.”
Sun Tzu, The Art of War
My new blog: http://spritecave.blogspot.co.uk/
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smart51
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| posted on 18/4/07 at 08:35 PM |
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It just so happens that I have an engine of the same type in my basement with pistons that rock in the bores. It otherwise seems fine. Is it
reasonable to think of swapping any of the rods and/or the crank if they are damaged or is it not that simple?
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DIY Si
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| posted on 18/4/07 at 08:44 PM |
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If they are the same type, then I don't see why not. Should just be a case of changing everything over. I would look at fitting new bearings
whilst it's all apart though, to help prevent it happening again.
Any idea as to why it happened on the engine in the first place? Would be a shame to fit all new stuff just to have it happen again. Low oil prssure
at some point? It only takes a second or two to screw it all up, as happened to me.
“Let your plans be dark and as impenetratable as night, and when you move, fall like a thunderbolt.”
Sun Tzu, The Art of War
My new blog: http://spritecave.blogspot.co.uk/
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ChrisGamlin
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| posted on 18/4/07 at 08:56 PM |
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Yep, as long as knocking out a bearing hasnt scored a bore or bashed the head due to a wayward piston, there's no reason why the crank / rods
from the other engine couldnt be swapped in.
If using the other engine's crank and rods, I'd actually inspect / plastiguage the bearings in that engine and if within tolerence leave
them in rather than go with new ones for the sake of it, because they'll be nicely bedded in and there's less chance of getting something
wrong than fitting new ones.
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