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Discussion Starter · #1 ·
As an addition to the other thread, `blessing in disguise`. The paraffin flush was quite clear.
So I filled it with the cheapo oil for an oil flush.
When kicking her over to check for scavenge return, these clicking sounds appear. The balls seem to be engaged with the cups.
I can feel something that seems to be a double click by feeling the exhaust tappets.
My original thought was piston hitting valve/s, but how?

Now some advice please.
This last rebuild needed new barrels, head refurbished...new guides, valves...etc.
I bought standard 650 valves, but I have no idea what what camshaft is fitted. IF someone has put a high lift camshaft in, would this cause the pistons to hit the valves? Are some valve stems shorter?

BTW, no scavenge...new oil pump out for inspection. It never rains...
 

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Caulky,

Easy question comming right back at you here. When you did
these oil changes, did you reprime the sump with a little oil first?


Usually a pint does the trick. It gets the return working right
away, and lube the rocker right away as well. That clicking
noise might have been just a dry top end.

Pookybear
 

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Discussion Starter · #4 ·
pb, I am in the process now of flushing the system out. The reason was unexpected grot in the oil after mistakingly topping-up (less than 1/2 pint) the reservoir with old oil. I expected some thick, black, horrible stuff, but not lumps of metal. As previously mentioned, something nasty has happened to this engine in the past...bits of broken valve collets dont appear normally!
First question is how would I get oil into the sump? Pour it into the rocker boxes?
OK, I should have flushed it out properly the last time.
There seems to be a lot of small sticky lumps of hylomar (gasket cement) in the oil, which is making me suspicious of blockages in the small oil-ways.
 

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First question is how would I get oil into the sump? Pour it into the rocker boxes?
OK, I should have flushed it out properly the last time.
There seems to be a lot of small sticky lumps of hylomar (gasket cement) in the oil, which is making me suspicious of blockages in the small oil-ways.
Caulky,

Yep, right through the rocker box, just take off one of the covers
and use a long funnel to get some oil in there. It really takes too
long for enough oil to build in the sump the other way, so it is
best to prime it up for the sake of your valve train.

Got compressed air at your place? You can always put some air
to it. However, you have to get the oil pump off and go right
to the ports. Just a little burst of air, if the passage is clear you
will hear it.

You can also try just a little transfluid in the oil. Transmission
fluid is full of detergents. Run for only ONE MINUTE and drain.
The transmission oil will break down the oil viscosity, so this would
be a last resort before a rebuild.
Note read little (in the statement above) as a half of a pint.

Pookybear
 

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Discussion Starter · #6 ·
Update, the clicking happens to both exhaust valves, BUT only immediately just past fully open (tappets down).
My triumph mate is stumped...check the pushrods aren`t fouling the tube, cant feel it.
The only places I can feel it is on the tapppet rockers and on the intermediate pinion shaft. All others nil.
Today I removed the exhaust rocker box and refitted it, to check the balls and cups are engaged...OK. Gapped the tappets.
Any comments, ideas?
 

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Valves hitting top of piston? That is about where it would happen. The exhaust is closing and the intake is opening (overlap). Loosen your tappets some and see if it still does it. Cams could be out of time?
 

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I notice in your original post you were not sure of what
cam you got over there. Now might be the time to find out.

Pookybear
 

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Nasty Clicking

Caulky,
To more accurately identify where the clicking is coming from you might try the old schoolboy trick of using a long screwdriver....
With a decent sized screwdriver hold its point against various parts of the rocker boces and the handle part of the screwdriver against you ear. The noise resonates along the length of the screwdriver and where it is loudest is normally where your problem is!! Make a comparison between inlet and exhaust. This might help.
Additionally is there any lateral movement of the tappets on the rocker arm/spindle. When I recently rebuilt an inlet rocker box I managed to mistakenly compress the sprung washer (on either end of the rocker spindle) which allowed the some lateral movement - hell of a clicking noise. Put your fingers in the inspection cap holes and check.

Hope this helps - sorry for insulting your intelligencve if you already knew the screwdriver thing

George F
 

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Discussion Starter · #10 ·
Dont even think about that George...every and all suggestions are welcome.
Cheers, I`ll give it a go.
If I have to take the head off...again, I would give the garage a very wide berth.
 

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Discussion Starter · #11 ·
Right, my triumph expert mate just confirmed pistons `touching` exhaust valves, after listening, touching and looking.
He thinks the reason is because of the head work (new seats, etc) and Hepolite (high compression... standard hasn`t been available for years) pistons.
This combination has just been enough to make the contact. [tick tick]
Remedy: .080" extra think head gasket.
Oh joy! exhausts off, carbs off, rockers off, head off...have a good week...ha ha.
 

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It might be the valves hitting the sides of the relief pockets and not the top of the piston.There seems to be a rash of this happening lately. This could be caused by the pistons being installed in the wrong cylinder or the relief being too small. If the reliefs are too small, you can take a bit off where there is contact with a dremmel and still run the stock head gasket. If the pistons are in the wrong cylinder and they are the same dimensions, you can swap holes with them. To tell if the pistons are in the correct way, look at the stamping on the top of each piston. With the large relief to the rear to accomodate the intake valve size, the numbers should be right side up when read from the out side of the engine as if looking through the spark plug holes.
 

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Discussion Starter · #13 ·
Yes, thankyou Jimmy, I`ll check that when I get the head off.
I fitted the pistons so that the writing on both was the right way up as if sitting on the bike.
My mate said, "ah the pistons are the right way round", after looking through the plug hole, so presumably its OK.
Another thing strikes me...I annealed the gasket myself, because I already had three of them. Maybe not heat treated properly and a bit flat/compressed,...just enough to drop the head a squidgen after torqueing.
Just a thought!
 

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Discussion Starter · #14 ·
As I was very close to hi-jacking B&S`s thread, thought I`d try to redirect my quibbles here.
PB, what do mean by:
"As for skimming the seat, what? I have no idea of what he is
talking about. And if it is what I think, you do not want to go
there anyway."

The job included, nucleus guides, oversize inlet guides, inlet stem seals, diamond hone and:
Leadfree seats...blend cut 3 angles, this job alone cost £160 ($256).
I supplied the valves, and presumably the seats were cut to suit.
Len can be found here:
http://www.cylinderheadshop.co.uk/
 

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As I was very close to hi-jacking B&S`s thread, thought I`d try to redirect my quibbles here.
PB, what do mean by:
"As for skimming the seat, what? I have no idea of what he is
talking about. And if it is what I think, you do not want to go
there anyway."

The job included, nucleus guides, oversize inlet guides, inlet stem seals, diamond hone and:
Leadfree seats...blend cut 3 angles, this job alone cost £160 ($256).
I supplied the valves, and presumably the seats were cut to suit.
Len can be found here:
http://www.cylinderheadshop.co.uk/
Caulky,

Skimming the seat is just another recut of the seat. It will
just mask the real problem! Also recutting the seat will shroud
the valve in the head, furthermore, the stem will stick out of
the head more thus reducing the valve spring pressure a bit.

So, what is the real problem, I do not know. Was either your
head or bores decked down a bit to clean them up?

Pookybear
 

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Discussion Starter · #16 ·
Now you`ve got me worried.
I wont really know what`s going on til the head is taken off.
All In can say is, the barrels are new standard 650, supplied with piston assemblies.
I fitted new small end bushes.
My triumph mate, who used to work on them said "mmm, Hepolite pistons...standard ones have been unavailable for years, must be high compression...different shape tops than standard.!"
But they`re listed as being 9:1.
I supplied standard new valves with my head, when the head job was done.
He also asked if the head had been skimmed...no.
Now I`m in a quandry...do I take it to the head man or fit a .080" head gasket, against his advice?
If high-lift camshafts are in the engine, maybe the old barrel and head assy were `married` to each other.
Any suggestions as to how I can find out...push-rod lift? What is normal?
I`ll try to get the head off today...pissing with rain and gale force wind yesterday.
Cheers.
BTW, the garage is at my brothers place, no facilities apart from lights and power.
In the back of my mind I`m thinking, must split the engine...if the top end is naff, so is the bottom end.
 

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Discussion Starter · #17 · (Edited)
OK, head off.
Thyere`s valve marks on the pistons:

Picture of the head:

This is close to TDC, but probably not exactly:

Anything odd?
These pistons look like 11.1:1 to me!!!
 

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Those do look to be high compression pistons. Going to have to run high test gas for sure. I can't tell from the pics where the valves are hitting. My intakes touched in the bottom radius of the relief cut outs so I used a dremmel and fine stone to remove some aluminum from that area.
 

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Discussion Starter · #19 ·
Just offset from centre, most of upper top left of recess. Bit like a quarter moon, Jimmy.
 

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I don't see how they could be hitting there. The valves have to fit down into the recess (outside edge of valve head close to outside edge of recess). The part of the valve head that would occupy the area you described is recessed upwards, away from the piston. I think what you're seeing is machine marks from the cutting of the reliefs. Look in the bottom radius of the relief and look for a shiny mark. If there is one, that's your contact patch. If it hasn't marked, you might have to reassemble the top to the exhaust rocker box with some non-drying Prussian blue on the valve head to mark the top of the piston where the contact is. Some folks use a thin layer modeling clay on top of the piston and gently turn the engine over so that the valve displaces the clay. Your valves seem to be pretty high in the seats. Did you see where the contact on the seat face was? If it was on the inside edge, you might gain some (enough?) clearance by cutting the seat a bit deeper (skimming?). I just reread where you had new seats installed. My thinking is that the seats might be too high, putting the valve too close too the piston. I would do the clearance check with the clay and find out for sure where it is hitting and how much relief you need. I'm thinking you need .040" but that might be incorrect.
 
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