Discussion
I wondered if anyone could help with a particularly annoying engine noise. I recently rebuilt the top end and have replaced my cam, timing chain, followers, pushrods and rocker gear and set up (and stripped and double checked) the preload correctly.
When I start her up from cold she sounds like a dream - no ticking or clacking etc. As she gets progressively warmer there's a ticking/clacking noise coming from the plenum area (not exhaust or rockers). The noise is particularly noticeable on the overrun - i.e. when blipping the throttle but is quite audible up to 3000 rpm and steadily traces the engine speed. Its the same every time I run the car - sounds lovely on the trip out but not the trip back. The car goes like an absolute rocket so I don't think anything can be too wrong.
Could I be unlucky and have a duff follower - is this a possibilty on these engines? If so, why doesn't this manifest itself when the car's cold (when I would expect the followers to be louder?) Alternatively might I need a thicker oil? I have only done a few hundred miles since the rebuild and am running in on 10w 40 magnatec. If the noise doesn't go if I change for a thicker oil would there be any harm in trying some hydraulic lifter additive or could this cause problems elsehwere?
Any thoughts which could help her sound as good as she goes would be much appreciated!!
When I start her up from cold she sounds like a dream - no ticking or clacking etc. As she gets progressively warmer there's a ticking/clacking noise coming from the plenum area (not exhaust or rockers). The noise is particularly noticeable on the overrun - i.e. when blipping the throttle but is quite audible up to 3000 rpm and steadily traces the engine speed. Its the same every time I run the car - sounds lovely on the trip out but not the trip back. The car goes like an absolute rocket so I don't think anything can be too wrong.
Could I be unlucky and have a duff follower - is this a possibilty on these engines? If so, why doesn't this manifest itself when the car's cold (when I would expect the followers to be louder?) Alternatively might I need a thicker oil? I have only done a few hundred miles since the rebuild and am running in on 10w 40 magnatec. If the noise doesn't go if I change for a thicker oil would there be any harm in trying some hydraulic lifter additive or could this cause problems elsehwere?
Any thoughts which could help her sound as good as she goes would be much appreciated!!
There was a thread on here recently which included advice from V8 Racing about running in a new cam/lifters: 2500 rpm for 20 mins. - do not idle otherwise the lifters don't spin properly. Not sure if this is not followed how quickly problems might manifest themselves though. Also, if the noise is coming from the plenum area, possibly a trumpet has become loose or popped out - I've had this a couple of times. Easy enough to check.
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Thanks for the suggestions. I bedded in the cam at 2000 rpm for 20 minutes.
Steve - I did not change them, but this noise has developed since I changed everything. I was quite careful extracting the old cam and fitting the new not to damage anything. Would a bearing give a ticking noise? Also - why the temperature difference? I really can't bear it if it is!
Steve - I did not change them, but this noise has developed since I changed everything. I was quite careful extracting the old cam and fitting the new not to damage anything. Would a bearing give a ticking noise? Also - why the temperature difference? I really can't bear it if it is!
Sorry - I should have mentioned that I also fitted new V8 Developments stage 3 heads with new springs. Its the engine temperature thing that is really curious about this noise - the fact that the engine sounds perfect before it warms up. I can only assume that either the viscosity of the oil, or the expansion of something can be the cause. The trumpets (again new) are all intact.
The other option is a dodgy lifter. As the oil gets thinner as the temp ups, the lifter is no longer able to retain oil pressure. I had this on mine, but only once, with 5-40 oil, I have now changed to a 15-50 and is not happened again. It means the lifters on its way out, but with the thicker oil I can but it off until the finances allow the full rebuild I have in the pipeline.
Just a thought....
Could the noie be a slight leak in the exhaust system? Could be that the engine running and the manifolds heating up exposes a slight leak - they can sound like a clicking or ticking noise.
Like i say just a thought - might be worth checking before stripping the heads down!
Could the noie be a slight leak in the exhaust system? Could be that the engine running and the manifolds heating up exposes a slight leak - they can sound like a clicking or ticking noise.
Like i say just a thought - might be worth checking before stripping the heads down!
Wonder if anyone has any further ideas on the noise described above. Since the last post on this thread I have completely renewed the rocker arms and shafts, and renewed all the lifters again incase I had a duff lifter, but to no avail. Tower View (top chaps) have had a look and double checked the preload, but the noise is still there. Mark thinks that it is a valve guide (lh head), but would obviously have to pull the head to be sure. Has anyone heard of valve guides causing ticking noises? The heads have only got a few hundred miles on them (stage 3 rebuild earlier this year). Is it possible that faulty machining, rather than wear could be to blame?
This is really getting me down as I have renewed the whole top-end now. The car runs like a dream but I just can't live with the noise (much to the annoyance of my lady who thinks this saga will never end).
Any experience or thoughts would be really helpful. I now don't have the time to do the head myself and I'm reluctant to get Tower View to pull off a brand new head without getting some soundings on here first.
Thanks guys.
This is really getting me down as I have renewed the whole top-end now. The car runs like a dream but I just can't live with the noise (much to the annoyance of my lady who thinks this saga will never end).
Any experience or thoughts would be really helpful. I now don't have the time to do the head myself and I'm reluctant to get Tower View to pull off a brand new head without getting some soundings on here first.
Thanks guys.
I dont wish to sound condescending,as i really dont have the first idea about engine building,but i just thought i'd mention this.I had a leaking exhaust manifold gasket on my car which only showed itself once the engine was warm.The ticking sound it made never at any time sounded like it was coming from the manifold particularly,and was much more like it was coming from the rear of the engine,infact i seemed to hear it just as well from the top plenum area,as i could near the offending gasket itself.In the end it was 'found out' by using some tissue paper,with my cooling fans switched off,then you could see the paper blowing from the escaping gasses when it as placed next to the offending gasket.
I just thought i'd mention it thats all,as i found it all too easy to rule out the manifold gaskets at first.Once again,sorry if i'm teaching you to suck eggs here,but i geuss i'd rather you find a duff gasket than something worse
Good luck,and hope you get it sorted soon,Mike
I just thought i'd mention it thats all,as i found it all too easy to rule out the manifold gaskets at first.Once again,sorry if i'm teaching you to suck eggs here,but i geuss i'd rather you find a duff gasket than something worse
Good luck,and hope you get it sorted soon,MikeI have just had a cam and all the necesarry fitted at v8d and the tick is still there. I cant seem to find a pattern i.e when its hot or cold etc.Any way when talking to Ray he said that without a complete strip down he was unable to say what it was and even then he may not find anything.He also said V8d had seen cars like this and they had never turned into anything serious but you are right it does your head in
edit to add he also said it was only on 500's just checked your profile sorry mate
>> Edited by ray_von on Monday 1st May 15:28
edit to add he also said it was only on 500's just checked your profile sorry mate
>> Edited by ray_von on Monday 1st May 15:28
Ditto,mines a 400 but where as before it was a cam tick i now have a top end ticks nice and even hot or cold also i have preloads which strickly aren't needed on a standard cam but this has been checked so unless the orig valve springs are knacked or it needs to bed in who knows? But every other way the car is fine
Paul
Paul
Dunno if it helps much, but, When trying to solve a similar problem some time back [on griff' 500] Myself and a few others on here went round in circles. It was a sort of tick/rattle on overrun when hot from about 2500 revs down to tick-over. On mine couldn't quite get preload correct over all 16 valves, had to strike a medium. Then noticed considerable difference in valve heights set into head. [TVR springs are known to be too strong]I summised that this was the reason for not getting preload bang on. Solutions were either have heads done or fit adjustable push rods. None of above was proven but the symtoms only seemed to be with hydraulic lifters.
>> Edited by macdeb on Monday 1st May 20:05
>> Edited by macdeb on Monday 1st May 20:05
Thanks for the posts guys. Mike - I'm pretty certain its not the exhuast manifolds because I fitted new manifolds and gaskets, I will triple check though!
The really annoying thing is that it did not do this before fitting the new heads. I can't believe that some engines just do this - something mechanical is obviously causing the noise (and by the frequency it sounds like one valve). Its definitely coming from the top-end. Ruling out the cam, followers, pre-load and rockers that only leaves the valves and guides, but I just don't know whether a worn (or loose?) guide would make a tick or not.
The really annoying thing is that it did not do this before fitting the new heads. I can't believe that some engines just do this - something mechanical is obviously causing the noise (and by the frequency it sounds like one valve). Its definitely coming from the top-end. Ruling out the cam, followers, pre-load and rockers that only leaves the valves and guides, but I just don't know whether a worn (or loose?) guide would make a tick or not.
radzoule said:
Thanks for the posts guys. Mike - I'm pretty certain its not the exhuast manifolds because I fitted new manifolds and gaskets, I will triple check though!
That's no reason to assume they are all sealing properly. You need to check for a blow. Mind you I suspect that Tower View would have spotted this if they have listened to the noise.
What a great Tivving day!
Thanks Peter, I spoke to Tower View again, and Mark confirmed its not the manifolds.
I spoke to Ray at V8 Developments and John Eales, and consensus seems to be that a loose valve guide would very rapidly become terminal (unless fitted with a lip) and a worn guide is unlikely to make any noise. However .... I think I am getting a bit closer. Mark confirmed that when he checked the pre-load, he only checked one or two valves on each bank. I had a b*gger of a time setting the preload on the lh bank first time around so that both ends of the spectrum were in tolerance, and was still not completely happy (i.e. some valves would be 20" or a shade under, whilst one would be 60"+). I played around with pushrods a little to try and compensate (the lengths do vary slightly and I have a few sets), and get a best compromise, but wasn't completely happy. John Eales thinks that the problem is therefore likely to actually be a preload issue after all. I really do hope so as the other possibility he suggested was a loose liner
On another, unrelated note, I am planning to install an Omex 150 and wondered whether any other PH'rs who had fitted this unit to the RV8 had any hints or tips, specifically:
(i) where to get a crank wheel and sensor bracket (and rough cost);
(ii) whether a feed can be taken off the existing lucas throttle position sensor (perhaps with a variable resistor to calibrate);
(iii) any suggestions for a basic curve for the RV8.
Hope to see some of you at the Surrey RR on saturday.
Thanks Peter, I spoke to Tower View again, and Mark confirmed its not the manifolds.
I spoke to Ray at V8 Developments and John Eales, and consensus seems to be that a loose valve guide would very rapidly become terminal (unless fitted with a lip) and a worn guide is unlikely to make any noise. However .... I think I am getting a bit closer. Mark confirmed that when he checked the pre-load, he only checked one or two valves on each bank. I had a b*gger of a time setting the preload on the lh bank first time around so that both ends of the spectrum were in tolerance, and was still not completely happy (i.e. some valves would be 20" or a shade under, whilst one would be 60"+). I played around with pushrods a little to try and compensate (the lengths do vary slightly and I have a few sets), and get a best compromise, but wasn't completely happy. John Eales thinks that the problem is therefore likely to actually be a preload issue after all. I really do hope so as the other possibility he suggested was a loose liner
On another, unrelated note, I am planning to install an Omex 150 and wondered whether any other PH'rs who had fitted this unit to the RV8 had any hints or tips, specifically:
(i) where to get a crank wheel and sensor bracket (and rough cost);
(ii) whether a feed can be taken off the existing lucas throttle position sensor (perhaps with a variable resistor to calibrate);
(iii) any suggestions for a basic curve for the RV8.
Hope to see some of you at the Surrey RR on saturday.
John Eales sells 36-1 wheel to go on the back of the front pulley (you have to take the pulley off to fit it though). He can also supply the MVR sensor to go with it. When I dealt with him he didn't have a standard mounting bracket for the sensor to suit a pre-serpentine front end, so I made my own. I think Bill Shirvington supplies these too so if you get stuck go visit the MegaSquirt forum.
For the ignition load I suggest you use a MAP sensor. Sharing sensors between ECUs is just too much of a PITA to contemplate. You don't need any transient sensing for ignition so MAP should work just as well as alpha and is a better load signal (better correlation with torque) so it will probably be easier to set up. As a starting point you could try a conventional ignition curve with about 8 deg static, plus a 'mechanical' advance rising linearly from 0 at idle to about 28 degrees at 3000 rpm (constant from 3000 rpm upwards). You can add 'vacuum' advance if you want to get posh, but it'll run fine without it and probably easier to leave this until you come to map the ignition properly.
For the ignition load I suggest you use a MAP sensor. Sharing sensors between ECUs is just too much of a PITA to contemplate. You don't need any transient sensing for ignition so MAP should work just as well as alpha and is a better load signal (better correlation with torque) so it will probably be easier to set up. As a starting point you could try a conventional ignition curve with about 8 deg static, plus a 'mechanical' advance rising linearly from 0 at idle to about 28 degrees at 3000 rpm (constant from 3000 rpm upwards). You can add 'vacuum' advance if you want to get posh, but it'll run fine without it and probably easier to leave this until you come to map the ignition properly.
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