If this is your first visit, be sure to
check out the FAQ by clicking the
link above. You may have to register
before you can post: click the register link above to proceed. Registration to this Forum is open to Members of The Stag Owners Club (SOC) and Affiliated Overseas Clubs. Non members with an interest in the Triumph Stag may avail of a 30 day trial membership of the Forum. Details in the FAQ section. Registration is not necessary if you just wish to view the forums. To start viewing messages,
select the forum that you want to visit from the selection below.
engine seems to sound rattely kind of tappet noise , ive checked shimm clearances there all spot on could the timing chains be too tight or possibly jackshaft. also runs a little irratic ,carbs????? tick over is fine and not running ritch any ideas (2 seperate problems )
simon
Noisey buckets over the valves which aren't a problem or as suggested by Tony Hart for someone else with a similar noise a loose valve guide which would need looking at.
actually had this problem just changed the head because valve guides were worn (dont know how)which wore the cylinder head away now refurbished head shimms and valves but stll noisey?? not as bad as before the refurb however still not right
simon
If your head has had new buckets fitted and the rattle appears when over 2000rpm or so, keep below these revs for the first 500 miles and the problem will go away. I replaced the buckets and guides on my engine after it seized the jackshaft, and it sounded horrible when revved at first, even though it was quiet before the rebuild, but 500 miles of running in and it runs fine. One final thought, check the cam sprocket locating bolts for tightness. I have had some come loose even with the locking tab in place, they were made of some sort of monkey metal which stretched.
Neil
Neil
TV8, efi, fast road cams and home built manifolds. 246bhp 220lbft torque
If your head has had new buckets fitted and the rattle appears when over 2000rpm or so, keep below these revs for the first 500 miles and the problem will go away. I replaced the buckets and guides on my engine after it seized the jackshaft, and it sounded horrible when revved at first, even though it was quiet before the rebuild, but 500 miles of running in and it runs fine. One final thought, check the cam sprocket locating bolts for tightness. I have had some come loose even with the locking tab in place, they were made of some sort of monkey metal which stretched.
Neil
thanks neil its possible however its a bit rattley on tick over ????
One further possiblity is that the valve stems have been ground down to allow the fitting of a standard range shim (if the valve seats are recut the valve clearance can get too tight)
The danger of this is that the cam bucket may not be sitting on the shim, and the bucket is actually bearing on the valve spring cap (someone, can't remember who told me about this a while ago), and the result of this is that the valve collets are not held under tension with the result that they wear and fail very quickly with the result that the valve drops into the cylinder. Not good
Another possibility is that the head has been badly warped at some time, the face has been skimmed flat, but the cammshaft bore is left bent. The cam then wears its way up into the camshaft bearing caps so it is running in a straight line, but is free to flap about within its bearings. This can only be checked before the valves are fitted
Neil
Neil
TV8, efi, fast road cams and home built manifolds. 246bhp 220lbft torque
One further possiblity is that the valve stems have been ground down to allow the fitting of a standard range shim (if the valve seats are recut the valve clearance can get too tight)
The danger of this is that the cam bucket may not be sitting on the shim, and the bucket is actually bearing on the valve spring cap (someone, can't remember who told me about this a while ago), and the result of this is that the valve collets are not held under tension with the result that they wear and fail very quickly with the result that the valve drops into the cylinder. Not good
Another possibility is that the head has been badly warped at some time, the face has been skimmed flat, but the cammshaft bore is left bent. The cam then wears its way up into the camshaft bearing caps so it is running in a straight line, but is free to flap about within its bearings. This can only be checked before the valves are fitted
Neil
one thought i had, i was advised that after i had the replacment head skimmed (last week) that a standard head gasket would be fine this was by the guy at machine shop (cleasby crankshaft) maybe should have used thicker gasket as valve possibly catching piston due to using normal size standard gasket????
I am using standard gaskets on engines that have had the heads skimmed to the point where the valves are proud of the head face with no problems, but I have come across the problem you mention caused by a combination of inacurate crank timing marks, and skimmed heads effectively lengthening the timing chain. It left one cylinder bank timed perfectly, and the other one tooth retarded and left a row of inlet valve marks etched in the piston crowns on that bank.
Recheck your cam timing, if it is out the cam sprocket can be redrilled, but that is a new timing chain job. I am assuming the timing chains are not stretched and knackered.
If in doubt the cam timing needs to be set a fraction advanced as it will retard anyway as the timing chain stretches.
Neil
Neil
TV8, efi, fast road cams and home built manifolds. 246bhp 220lbft torque
I am using standard gaskets on engines that have had the heads skimmed to the point where the valves are proud of the head face with no problems, but I have come across the problem you mention caused by a combination of inacurate crank timing marks, and skimmed heads effectively lengthening the timing chain. It left one cylinder bank timed perfectly, and the other one tooth retarded and left a row of inlet valve marks etched in the piston crowns on that bank.
Recheck your cam timing, if it is out the cam sprocket can be redrilled, but that is a new timing chain job. I am assuming the timing chains are not stretched and knackered.
If in doubt the cam timing needs to be set a fraction advanced as it will retard anyway as the timing chain stretches.
Neil
thanks neil going to put mii camera down plugs to see if theres ay marks on the pistons then i will report back
simon
Its a good point Neil, one of my chains had slipped a tooth due to worn chains, but tended to rattle when driving rather than idling. Simon, when you check chains, set it on the crank TDC first then ensure both cams align. I made the mistake of assuming the (bad) cam was positioned right when I replaced them as had crank pulley off.
I am using standard gaskets on engines that have had the heads skimmed to the point where the valves are proud of the head face with no problems, but I have come across the problem you mention caused by a combination of inacurate crank timing marks, and skimmed heads effectively lengthening the timing chain. It left one cylinder bank timed perfectly, and the other one tooth retarded and left a row of inlet valve marks etched in the piston crowns on that bank.
Recheck your cam timing, if it is out the cam sprocket can be redrilled, but that is a new timing chain job. I am assuming the timing chains are not stretched and knackered.
If in doubt the cam timing needs to be set a fraction advanced as it will retard anyway as the timing chain stretches.
Neil
Good point that, about stretched chains. I read somewhere that rather than drilling the cam sprocket, an incremental adjustment can be gained by taking the sprocket off and flipping it round so that it is back to front. Apparently Triumph had a bit of foresight when drilling the holes originally and offset them so that an intermediate position could be gained. If I can find the source of this tip, I'll come back on and mention it, but you could probably test it out by getting a sprocket, tracing its outline (and holes) on to a piece of paper, then flipping the sprocket over, align the holes and see if the teeth line up. If they don't, then there's an adjustment facility already built in. Flipping the sprocket might mean you'd have to think carefully about timing alignment marks.
I've still got what I hope is a tappet noise, had it since the re build 4 years ago, always there on start up and tick over, goes away when hotter or when revved. Have to live with it I was told as quite normal.
Jeff.
I only do what the voices in my wife’s head tell me to do!
Comment