Top end tappety type noise
Discussion
phazed said:
If the cam timing was out then the valves would open at an incorrect time.
Ignition timing is gauged by TDC which hasn't any relation to the valve/cam timing.
If the valve timing were found to be out after rebuild in conjunction with pulley wheel marks and distributor at no1 could you not rotate the engine to tdc to get correct valve timing although the pulley marks will now be off, Mark pulley and re set distributor back to no1 then set timing,,, see what I’m trying to say? Ignition timing is gauged by TDC which hasn't any relation to the valve/cam timing.
You correct your mechanical install error by re setting everything rather than taking the timing chains off again or am I off on a tangent
You can tell I’ve not done this for a long time, then it was cross flows
To clarify my waffle,
Can the timing marks be 30d off the original timing marks somehow after a Cam and timing gear change. A tooth out kind of thing. And then can you re set it up with the dizzy at no1 tdc etc so ignoring original timing marks on pulley.
Edited by Classic Chim on Tuesday 4th June 11:02
OK back to some basics.....
I have set the engine to TDC No1 cylinder using bodgers method ie long screw driver in No1 spark plug hole rotate engine back and forth till TDC obtained......check timing marks on pulley.
and behold they are miles off.
Whites marks on pulley are at TDC, 6 Degrees adv and 12 Degrees adv
New tdc marked on pulley and will now put plugs back in and reset distributor timing
is 8 degrees at idle and 28 at 3000rpm right ?
I have set the engine to TDC No1 cylinder using bodgers method ie long screw driver in No1 spark plug hole rotate engine back and forth till TDC obtained......check timing marks on pulley.
and behold they are miles off.
Whites marks on pulley are at TDC, 6 Degrees adv and 12 Degrees adv
New tdc marked on pulley and will now put plugs back in and reset distributor timing
is 8 degrees at idle and 28 at 3000rpm right ?
You need to be really sure about true TDC.
I use a dead stop which is a modified spark plug with a length of M8 bolt out the end.
A selection for different engines.
Screw it into No.1 and carefully wind the crank round clockwise until the piston comes up to the stop. Mark the pulley at the timing pointer. Wind counter clock until the piston again come to the stop. Mark pulley. TDC is half way between these two points.
Now to your problem which looks to be a broken pulley. The pulley is actually a vibration damper and consists of the inner section which fits on the crank and the outer ring that has the timing marks. They are joined together with rubber in the same way as a factory fit suspension bush.
The rubber bond has broken down and the outer ring has moved. The problem is that the ring has been drilled as part of balancing the engine so the engine is now out of balance. We had one a few years ago and we sent it over to Powers (I think) who measured the balance drillings and drilled a new one to the same.
Steve
I use a dead stop which is a modified spark plug with a length of M8 bolt out the end.
A selection for different engines.
Screw it into No.1 and carefully wind the crank round clockwise until the piston comes up to the stop. Mark the pulley at the timing pointer. Wind counter clock until the piston again come to the stop. Mark pulley. TDC is half way between these two points.
Now to your problem which looks to be a broken pulley. The pulley is actually a vibration damper and consists of the inner section which fits on the crank and the outer ring that has the timing marks. They are joined together with rubber in the same way as a factory fit suspension bush.
The rubber bond has broken down and the outer ring has moved. The problem is that the ring has been drilled as part of balancing the engine so the engine is now out of balance. We had one a few years ago and we sent it over to Powers (I think) who measured the balance drillings and drilled a new one to the same.
Steve
I have heard about pulleys timing marks not being correct and have read often that people have checked them but pretty much I don’t think I’ve actually read of anyone who has found their own out. Just hearsay from the past.
Maybe yours was the one and only one with the timing marks out!
As far as I’m aware all Rover crankshaft pulleys are are the same and therefore marked at the same. There are none which actually have their timing different from any other one.
Maybe yours was the one and only one with the timing marks out!
As far as I’m aware all Rover crankshaft pulleys are are the same and therefore marked at the same. There are none which actually have their timing different from any other one.
Steve_D said:
You need to be really sure about true TDC.
I use a dead stop which is a modified spark plug with a length of M8 bolt out the end.
A selection for different engines.
Screw it into No.1 and carefully wind the crank round clockwise until the piston comes up to the stop. Mark the pulley at the timing pointer. Wind counter clock until the piston again come to the stop. Mark pulley. TDC is half way between these two points.
Now to your problem which looks to be a broken pulley. The pulley is actually a vibration damper and consists of the inner section which fits on the crank and the outer ring that has the timing marks. They are joined together with rubber in the same way as a factory fit suspension bush.
The rubber bond has broken down and the outer ring has moved. The problem is that the ring has been drilled as part of balancing the engine so the engine is now out of balance. We had one a few years ago and we sent it over to Powers (I think) who measured the balance drillings and drilled a new one to the same.
Steve
WOW.....Now that is interesting.I use a dead stop which is a modified spark plug with a length of M8 bolt out the end.
A selection for different engines.
Screw it into No.1 and carefully wind the crank round clockwise until the piston comes up to the stop. Mark the pulley at the timing pointer. Wind counter clock until the piston again come to the stop. Mark pulley. TDC is half way between these two points.
Now to your problem which looks to be a broken pulley. The pulley is actually a vibration damper and consists of the inner section which fits on the crank and the outer ring that has the timing marks. They are joined together with rubber in the same way as a factory fit suspension bush.
The rubber bond has broken down and the outer ring has moved. The problem is that the ring has been drilled as part of balancing the engine so the engine is now out of balance. We had one a few years ago and we sent it over to Powers (I think) who measured the balance drillings and drilled a new one to the same.
Steve
Rubber based harmonic balancer failure is not unknown on various brands of car (yes even Jap stuff) did a few on Mitsubishi Space-wagons back in the day when this kind of failure was very rare an less vehicles run harmonic style pulleys but more recently BMW diesels the matalastic bond just breaks down eventually , it the only explanation here if your sure that true TDC , bit more extreme but you get the gist 
Edited by Sardonicus on Tuesday 4th June 16:04
Frank,
Don't know if this will help or hinder but the rim in the attached photo on my engine had what I thought was the threaded remains of a sawn off bolt in it. Turns out it was supposed to be trapped there as how the assembly was balanced. So maybe the part peeps suggest is buggered on yours is not individually balanced.
Just a thought.
Don't know if this will help or hinder but the rim in the attached photo on my engine had what I thought was the threaded remains of a sawn off bolt in it. Turns out it was supposed to be trapped there as how the assembly was balanced. So maybe the part peeps suggest is buggered on yours is not individually balanced.
Just a thought.
Maybe this will help you.
Here are a couple of photos of the front of my pre-serpentine 1993 engine. (Before and after restoration)
You can see clearly the drilled holes for balancing, these are difficult to see as they are obscured by the pulley wheel in front.
From your profile, I see that your car is a 1993 (pre-serpentine) but the engine photo you posted above has a serpentine front end??
Anyway, enjoy.
Here are a couple of photos of the front of my pre-serpentine 1993 engine. (Before and after restoration)
You can see clearly the drilled holes for balancing, these are difficult to see as they are obscured by the pulley wheel in front.
From your profile, I see that your car is a 1993 (pre-serpentine) but the engine photo you posted above has a serpentine front end??
Anyway, enjoy.
lancepar said:
Frank,
Don't know if this will help or hinder but the rim in the attached photo on my engine had what I thought was the threaded remains of a sawn off bolt in it. Turns out it was supposed to be trapped there as how the assembly was balanced. So maybe the part peeps suggest is buggered on yours is not individually balanced.
Just a thought.
That broken stud trapped/peened into that mud plate is not uncommon mine had that too Don't know if this will help or hinder but the rim in the attached photo on my engine had what I thought was the threaded remains of a sawn off bolt in it. Turns out it was supposed to be trapped there as how the assembly was balanced. So maybe the part peeps suggest is buggered on yours is not individually balanced.
Just a thought.
Firstly you folks are amazing, always there to help a fellow TVRer in their hour of need. I am indeed in that hour losing the will to carry on at the moment after today. more on that in a moment
Apologies my profile needs updating car is 98 serpentine, the 93 one was my first one.
Will be attacking the bottom pulley as soon as I can find a breaker bar suitable.
Yesterday put it all back together ready for timing set up. All done fine and set at 12 degrees adv on idle. observed it advances more as engine revs increase.
Noticed cylinders 5 & 7 exhausts are completely cold. ie 50 degree when all others are at 250 degrees plus
Checked firing order all good
Swapped ignition leads no change
Checked sparks, same as all other cylinders, not super fat sparks but they are sparking
Swapped plugs no change
listened to injectors with stethoscope all sound the same.
Measured compression on cold engine though both registered 140 psi same as all others
Dismantled top end again to inspect valve lifts all clearly lifting but couldn't measure actual mm of lift as dial gauge was lent out.
Swapped injectors from good cylinders, not that as they performed ok in new locations
reassembled everything and restarted it.
Still not joy, 5 & 7 exhausts still stone cold.
My thoughts.............stumped on this now
Head gasket ?
Apologies my profile needs updating car is 98 serpentine, the 93 one was my first one.
Will be attacking the bottom pulley as soon as I can find a breaker bar suitable.
Yesterday put it all back together ready for timing set up. All done fine and set at 12 degrees adv on idle. observed it advances more as engine revs increase.
Noticed cylinders 5 & 7 exhausts are completely cold. ie 50 degree when all others are at 250 degrees plus
Checked firing order all good
Swapped ignition leads no change
Checked sparks, same as all other cylinders, not super fat sparks but they are sparking
Swapped plugs no change
listened to injectors with stethoscope all sound the same.
Measured compression on cold engine though both registered 140 psi same as all others
Dismantled top end again to inspect valve lifts all clearly lifting but couldn't measure actual mm of lift as dial gauge was lent out.
Swapped injectors from good cylinders, not that as they performed ok in new locations
reassembled everything and restarted it.
Still not joy, 5 & 7 exhausts still stone cold.
My thoughts.............stumped on this now
Head gasket ?
Something to think about or maybe nothing to do with the problem
If cylinders 5 & 7 were the ones where the rockers were replaced, what about the "Preload" setting and shimming under the pedestals, assuming the engine doesn't have adjustable pushrods.
Could this be the issue?
I have to admit that reading about the subject does my head in, never having practical experience of doing it myself.
Just a thought.
If cylinders 5 & 7 were the ones where the rockers were replaced, what about the "Preload" setting and shimming under the pedestals, assuming the engine doesn't have adjustable pushrods.
Could this be the issue?
I have to admit that reading about the subject does my head in, never having practical experience of doing it myself.
Just a thought.
Not got time to scroll right back.
Do you have plug extenders fitted (as factory standard)?
When you tested the sparks, you removed the plugs. Did you reconnect them with the extenders in the circuit to test the spark, or straight to the plug lead with no extenders?
I had a new set of extenders about three years ago......six failed in six months, but I do about 8,000 smiles a year.
Do you have plug extenders fitted (as factory standard)?
When you tested the sparks, you removed the plugs. Did you reconnect them with the extenders in the circuit to test the spark, or straight to the plug lead with no extenders?
I had a new set of extenders about three years ago......six failed in six months, but I do about 8,000 smiles a year.
Gassing Station | Chimaera | Top of Page | What's New | My Stuff