Discussion
Had a slight tappet noise since i got my car, nothing major just alittle noisy, noticed it getting louder the last few times i have used the car but until today thought it was likely just in my head.
Today it has got much louder, performance is still ok, some times its louder than others and appears slightly worse on overrun and is rev dependant.
Fearing the worse i have taken the valve cover off and was amazed at how clean it was. started checking the cams, exhaust all good, inlet was all good till i got to the number 6 cylinder, and the valve closest to the bulk head. The lobe has some light scuffing but i have seen alot worse. I thought i would check the clearance expecting it to be big and its 0.004" so alittle tight if anything. Going to check the remaining valve clearances tomorrow but nothing looks amiss under the valve cover.
Any ideas on what to check next? I Doubt its related but, its had a slight miss for a while, I have ordered new leads, plugs and have a coil pack ready to go on so tha should sort that. When i took the plugs out tonight 3 were black and wet with petrol and the other 3 were nicly brown and dry.
Today it has got much louder, performance is still ok, some times its louder than others and appears slightly worse on overrun and is rev dependant.
Fearing the worse i have taken the valve cover off and was amazed at how clean it was. started checking the cams, exhaust all good, inlet was all good till i got to the number 6 cylinder, and the valve closest to the bulk head. The lobe has some light scuffing but i have seen alot worse. I thought i would check the clearance expecting it to be big and its 0.004" so alittle tight if anything. Going to check the remaining valve clearances tomorrow but nothing looks amiss under the valve cover.
Any ideas on what to check next? I Doubt its related but, its had a slight miss for a while, I have ordered new leads, plugs and have a coil pack ready to go on so tha should sort that. When i took the plugs out tonight 3 were black and wet with petrol and the other 3 were nicly brown and dry.
I have checked the valve cover and it does have some marks caused by the chain but its really not that sort of noise im hearing.
I did notice that the manifold is very close to the chassis, could it be the mani tapping the chassis? i have also had abit of a clunk when getting on the power which i thought might be the diff bushes but could be the engine mount. How much of a gap between the mani and chassis should there be roughly?
I did notice that the manifold is very close to the chassis, could it be the mani tapping the chassis? i have also had abit of a clunk when getting on the power which i thought might be the diff bushes but could be the engine mount. How much of a gap between the mani and chassis should there be roughly?
BGB autosport said:
Had a slight tappet noise since i got my car, nothing major just alittle noisy, noticed it getting louder the last few times i have used the car but until today thought it was likely just in my head.
Today it has got much louder, performance is still ok, some times its louder than others and appears slightly worse on overrun and is rev dependant.
Fearing the worse i have taken the valve cover off and was amazed at how clean it was. started checking the cams, exhaust all good, inlet was all good till i got to the number 6 cylinder, and the valve closest to the bulk head. The lobe has some light scuffing but i have seen alot worse. I thought i would check the clearance expecting it to be big and its 0.004" so alittle tight if anything. Going to check the remaining valve clearances tomorrow but nothing looks amiss under the valve cover.
Any ideas on what to check next? I Doubt its related but, its had a slight miss for a while, I have ordered new leads, plugs and have a coil pack ready to go on so tha should sort that. When i took the plugs out tonight 3 were black and wet with petrol and the other 3 were nicly brown and dry.
Had a few clearances on my spd6 close up due to valve stretching. Resulted in the valve not closing properly which made it feel like it was running on 5 cylinders, dead lumpy. Had to get it re-shimmed. Today it has got much louder, performance is still ok, some times its louder than others and appears slightly worse on overrun and is rev dependant.
Fearing the worse i have taken the valve cover off and was amazed at how clean it was. started checking the cams, exhaust all good, inlet was all good till i got to the number 6 cylinder, and the valve closest to the bulk head. The lobe has some light scuffing but i have seen alot worse. I thought i would check the clearance expecting it to be big and its 0.004" so alittle tight if anything. Going to check the remaining valve clearances tomorrow but nothing looks amiss under the valve cover.
Any ideas on what to check next? I Doubt its related but, its had a slight miss for a while, I have ordered new leads, plugs and have a coil pack ready to go on so tha should sort that. When i took the plugs out tonight 3 were black and wet with petrol and the other 3 were nicly brown and dry.
I have heard that when tappets are too tight they can also tap but have never experianced it.
With it being 0.004 not 0.005-0.007 im unsure as to mess with it, its a back one so may leave it alone. Im just concerned as its the only one with any scoring albeit minor.
With it being 0.004 not 0.005-0.007 im unsure as to mess with it, its a back one so may leave it alone. Im just concerned as its the only one with any scoring albeit minor.
Edited by BGB autosport on Tuesday 24th February 08:21
Hi,
I'd be suprised if the tight valve was causing the tapping, like another post said, if it's 0004, I'd leave well alone. If there is scoring on this follower, it will soon be a bigger gap!
if you are confident that all the shims are still in situ and the gaps are pretty much OK then perhaps the tapping could be a sticky/ bent valve or badbly worn follower bearing/ shaft.
If you haven't already, I'd check all the clearances on every valve and have a feel for play in the followers at the same time. If they are OK, they will feel really solid on the shaft. Any play is easily detecable.
A loose chain is easily adjusted if it's the upper most chain. The chain that drives the water/ oil pump can become loose and this is a timing cover off task. Not sure this would make a tapping noise though. To check if the cam chain is loose, with the cam cover off, see if you can lift the chain off the first tooth . The first is on the drivers side. It should be tight enough (just) to prevent you from pushing the chain away from the tooth.
If there is any movement, it will require tightening, I'm sure this is covered in Graham Varley's Speed 6 manaul.
Good luck!
Richard.
I'd be suprised if the tight valve was causing the tapping, like another post said, if it's 0004, I'd leave well alone. If there is scoring on this follower, it will soon be a bigger gap!
if you are confident that all the shims are still in situ and the gaps are pretty much OK then perhaps the tapping could be a sticky/ bent valve or badbly worn follower bearing/ shaft.
If you haven't already, I'd check all the clearances on every valve and have a feel for play in the followers at the same time. If they are OK, they will feel really solid on the shaft. Any play is easily detecable.
A loose chain is easily adjusted if it's the upper most chain. The chain that drives the water/ oil pump can become loose and this is a timing cover off task. Not sure this would make a tapping noise though. To check if the cam chain is loose, with the cam cover off, see if you can lift the chain off the first tooth . The first is on the drivers side. It should be tight enough (just) to prevent you from pushing the chain away from the tooth.
If there is any movement, it will require tightening, I'm sure this is covered in Graham Varley's Speed 6 manaul.
Good luck!
Richard.
Well, after some messing about last night i found the issue, the follower for the cam lobe wth the scoring has badly worn, clearance is fine but its where the cam touches as it ramps up. (Pic below)
The follower and cams were replaced in december 2003, i have spoken to the company that did it (TVR specialist) and got a pretty crap reply to be honest. Its that long ago they dont really care and cant tell me if it was fitted with the redesigned followers or not.
Im puzzled as to why has it worn in the first place, i thought it was the exhaust side that suffered, not inlet. Started the strip down last night, just got to get the balancer off the crank.
The follower and cams were replaced in december 2003, i have spoken to the company that did it (TVR specialist) and got a pretty crap reply to be honest. Its that long ago they dont really care and cant tell me if it was fitted with the redesigned followers or not.
Im puzzled as to why has it worn in the first place, i thought it was the exhaust side that suffered, not inlet. Started the strip down last night, just got to get the balancer off the crank.
BGB autosport said:
Well, after some messing about last night i found the issue, the follower for the cam lobe wth the scoring has badly worn, clearance is fine but its where the cam touches as it ramps up. (Pic below)
The follower and cams were replaced in december 2003, i have spoken to the company that did it (TVR specialist) and got a pretty crap reply to be honest. Its that long ago they dont really care and cant tell me if it was fitted with the redesigned followers or not.
Im puzzled as to why has it worn in the first place, i thought it was the exhaust side that suffered, not inlet. Started the strip down last night, just got to get the balancer off the crank.
I am glad you found it, and as I said in my previous post this is exactly what happened to mine. It seem that there must have been a batch of followers with softer material on the follower face. As mine was being done by str8 six, they also did the cams, even though the cam was only very slightly scored.The follower and cams were replaced in december 2003, i have spoken to the company that did it (TVR specialist) and got a pretty crap reply to be honest. Its that long ago they dont really care and cant tell me if it was fitted with the redesigned followers or not.
Im puzzled as to why has it worn in the first place, i thought it was the exhaust side that suffered, not inlet. Started the strip down last night, just got to get the balancer off the crank.
I had to replace 5 followers on my engine, I'll get a pic up of the worst bu it's horrific, almost worn all the way through!
The Engine has only done 15k and was rebuilt by a "specialist" at 9k. I didn't own the car then but there are invoices to prove it.
I've replaced all my followers with the DLC version. Hopefully they will last, the cam cover will be off regularly to check!
Cheers,
Richard.
The Engine has only done 15k and was rebuilt by a "specialist" at 9k. I didn't own the car then but there are invoices to prove it.
I've replaced all my followers with the DLC version. Hopefully they will last, the cam cover will be off regularly to check!
Cheers,
Richard.
BGB autosport said:
Well, after some messing about last night i found the issue, the follower for the cam lobe wth the scoring has badly worn, clearance is fine but its where the cam touches as it ramps up. (Pic below)
The follower and cams were replaced in december 2003, i have spoken to the company that did it (TVR specialist) and got a pretty crap reply to be honest. Its that long ago they dont really care and cant tell me if it was fitted with the redesigned followers or not.
Im puzzled as to why has it worn in the first place, i thought it was the exhaust side that suffered, not inlet. Started the strip down last night, just got to get the balancer off the crank.
The follower and cams were replaced in december 2003, i have spoken to the company that did it (TVR specialist) and got a pretty crap reply to be honest. Its that long ago they dont really care and cant tell me if it was fitted with the redesigned followers or not.
Im puzzled as to why has it worn in the first place, i thought it was the exhaust side that suffered, not inlet. Started the strip down last night, just got to get the balancer off the crank.
All of my others look new so im planning on replacing just the one worn one with a DLC coated follower, RG said this was a reasonable route to take as they have already been done in the past and that the other appear fine, provided there is still adjustment left.
I do wonder if the so called specialist that replaced them before and then did the last 12k service set the back cyliner tight presuming it would wear into spec, which has resulted in a smaller clearance, less oil and actually made it wear on the ramp section of the follower.
I do wonder if the so called specialist that replaced them before and then did the last 12k service set the back cyliner tight presuming it would wear into spec, which has resulted in a smaller clearance, less oil and actually made it wear on the ramp section of the follower.
Hope these help, took these when fixing my chocolate Finger followers (Justin on Stephie's PC)
I did have one somewhere where they have been hardness tested. Small indent on the surface. But cant find them.
Incidently - The valve springs were also to high a rating for the speed six, this caused much of the wear in these otherwise excellent engines. De-rating the springs somewhat helps protect these little fella's that work hard. Less HP is used in driving them down too :-)
The original valve springs were "estimated" to bounce @12,000 RPM. I doubt that anyone will get a crank the stretch to that!!
I know I will get shot for this....
I did have one somewhere where they have been hardness tested. Small indent on the surface. But cant find them.
Incidently - The valve springs were also to high a rating for the speed six, this caused much of the wear in these otherwise excellent engines. De-rating the springs somewhat helps protect these little fella's that work hard. Less HP is used in driving them down too :-)
The original valve springs were "estimated" to bounce @12,000 RPM. I doubt that anyone will get a crank the stretch to that!!
I know I will get shot for this....
Edited by Blipi on Saturday 7th March 07:37
I believe that post 04 cars had the redesigned followers.
I have it all back together now but there is a whiring noise coming from the front cover down below.
Started this thread http://www.pistonheads.com/gassing/topic.asp?h=0&a...
I have it all back together now but there is a whiring noise coming from the front cover down below.
Started this thread http://www.pistonheads.com/gassing/topic.asp?h=0&a...
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