SteveA
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- Dec 20, 2011
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This post is similar toa recent one regarding tracing a noise within the engine, the difference being that this engine has never been run. Built from all new parts with the exception of iron barrels, but including a FullAuto head, Maney cases and 80.4mm crank, Jim Schmitt rods pistons, valve springs, PW3 cam, Maney hollow steel pushrods (do they make more noise than standard Norton ones because they are hollow?). Kibblewhite Black Diamond valves modded for the beehives.
Cam chain is IWIS standard size and a Jim Comstock Hydraulic tensioner is fitted (and primed), but I do notice tight spots in the timing chain that are more than I think it should have (does this set up make noise when turned over slowly?). I did have an IWIS HD chain in there but could not get enough slack in my engine (cases vary). The motor also has a Jim Comstock reed breather that does whine at you even with teh plugs out, so I have also turned it over with this off the cases.
I have tried various things that could/should have been contributing, but this is elusive. I had been working to make sure the pushrods were not touching the tunnel in the head and barrels and the head gasket. Also been making sure the gasket does not foul pistons and that the valves do not touch each other, or the pistons and that the pistons don't touch the squish band. I am using Graphogen as an assembly paste. I have pumped oil into the rockers feeds top and bottom (full sludge trap).
Tappet gap is as recommended by Steve Maney for his pushrods with iron barrels (half the 11thou recommended for the PW3). Valve lift at TDC is close to the 0.145" it is supposed to be, if maybe a couple of thou off (how far off is too far off?). Follower drop under their own weight more than the lift figure of the cam, and the cam tunnel protrusions do not foul the cam (ground back to suit the PW3 anyway), followers also go fully into barrel without fouling at top of follower.
For those who don't know, a FullAuto head rings like a bell if you flick a finger on the fins.....quality stuff....does it amplify noise?
I have addressed the issue of JS spring seats with the FullAuto valve guides (as far as I can see the spring seats don't move on engine rotation. Valves Spring shimming has been set using spring pressure guage to give desired seat pressure, including the fitment of heat washers on exhausts. Springs are not getting coil bound and in any case the noise does not occur when the valves are under load (as far as I can tell).
Without the head on no noise is detectable, just the slide of oiled pistons rings on honing....the pistons only seem to rock when you force them....but of course shorts skirted forged pistons with good clearance will do that. Dropping the pushrods in and holding them with finger pressure whilst rotating reveals nothing untoward.
The engine has been built up and I hear this noise when the tappets open their clearance, if I overtighten the tappet adjusters it goes quiet. I have had the timing cover off and rotated the engine and can see and feel a tittle tension come off the timing chain when I hear the noise. I can hear it forwards and backwards rotation! if I move it over real slow it seems like it may not happen....but then it does....when I tear it down again there are no witness marks that mean much to me.
Sounds like it comes from the cam area and it sounds like the followers are either the source of the noise or instigate it, but it also sounds like the rocker against the valve stem, the sounds you get when moving the rocker around when the valve is closed. Only possible other contributor I can think of is that the woodruff key in the cam slot is not real tight, but it does not seem as if the cam sprocket is moving on the cam!
This has had me scratching my head for months, I have talked to both Jims, Norman White, Steve Maney and Mick Hemmings.....because I have such a combination of parts it is difficult for them to be definitive on the phone, though each have contributed what they can without seeing/hearing and I thank them.
Another fact just to be aware of as you think this through...I am a hearing aid wearing and I think this may amplify the particular metalic noise some! Of course I can take myhearing aids out and not hear it, but I really don't hear much without them!
Then I read the other thread and people report all sorts of noises and I am wondering now, since I cannot see any witness marks, if I should just try firing it up and see what it does it warm?.
Or am I just getting desperate?
Cam chain is IWIS standard size and a Jim Comstock Hydraulic tensioner is fitted (and primed), but I do notice tight spots in the timing chain that are more than I think it should have (does this set up make noise when turned over slowly?). I did have an IWIS HD chain in there but could not get enough slack in my engine (cases vary). The motor also has a Jim Comstock reed breather that does whine at you even with teh plugs out, so I have also turned it over with this off the cases.
I have tried various things that could/should have been contributing, but this is elusive. I had been working to make sure the pushrods were not touching the tunnel in the head and barrels and the head gasket. Also been making sure the gasket does not foul pistons and that the valves do not touch each other, or the pistons and that the pistons don't touch the squish band. I am using Graphogen as an assembly paste. I have pumped oil into the rockers feeds top and bottom (full sludge trap).
Tappet gap is as recommended by Steve Maney for his pushrods with iron barrels (half the 11thou recommended for the PW3). Valve lift at TDC is close to the 0.145" it is supposed to be, if maybe a couple of thou off (how far off is too far off?). Follower drop under their own weight more than the lift figure of the cam, and the cam tunnel protrusions do not foul the cam (ground back to suit the PW3 anyway), followers also go fully into barrel without fouling at top of follower.
For those who don't know, a FullAuto head rings like a bell if you flick a finger on the fins.....quality stuff....does it amplify noise?
I have addressed the issue of JS spring seats with the FullAuto valve guides (as far as I can see the spring seats don't move on engine rotation. Valves Spring shimming has been set using spring pressure guage to give desired seat pressure, including the fitment of heat washers on exhausts. Springs are not getting coil bound and in any case the noise does not occur when the valves are under load (as far as I can tell).
Without the head on no noise is detectable, just the slide of oiled pistons rings on honing....the pistons only seem to rock when you force them....but of course shorts skirted forged pistons with good clearance will do that. Dropping the pushrods in and holding them with finger pressure whilst rotating reveals nothing untoward.
The engine has been built up and I hear this noise when the tappets open their clearance, if I overtighten the tappet adjusters it goes quiet. I have had the timing cover off and rotated the engine and can see and feel a tittle tension come off the timing chain when I hear the noise. I can hear it forwards and backwards rotation! if I move it over real slow it seems like it may not happen....but then it does....when I tear it down again there are no witness marks that mean much to me.
Sounds like it comes from the cam area and it sounds like the followers are either the source of the noise or instigate it, but it also sounds like the rocker against the valve stem, the sounds you get when moving the rocker around when the valve is closed. Only possible other contributor I can think of is that the woodruff key in the cam slot is not real tight, but it does not seem as if the cam sprocket is moving on the cam!
This has had me scratching my head for months, I have talked to both Jims, Norman White, Steve Maney and Mick Hemmings.....because I have such a combination of parts it is difficult for them to be definitive on the phone, though each have contributed what they can without seeing/hearing and I thank them.
Another fact just to be aware of as you think this through...I am a hearing aid wearing and I think this may amplify the particular metalic noise some! Of course I can take myhearing aids out and not hear it, but I really don't hear much without them!
Then I read the other thread and people report all sorts of noises and I am wondering now, since I cannot see any witness marks, if I should just try firing it up and see what it does it warm?.
Or am I just getting desperate?
