Noisey engine or am i just picky?

[Rich_s]

Having driven my Spit 1500 for last 2 years the rattly engine is getting a bit too annoying and i want to get it sorted, the tappets are fine and set at about 8 thou which did cure a lot of the rattling, i dont think its the timing chain but not sure, it does sound like a tappet rattle but dont think it is, its not too bad a normal revs but as it approaches 4k it gets very noisey and sounds like any more will result in terminal failure, dont think it will but it does sound that way.

I am thinking the only other things could be the little end bearings, the noise is def coming from near the top of the engine and it looks like i can replace the little end bearing without removing the engine or top end so would like to know if anyone thinks its worthwhile doing the work, or could the problem lie elsewhere ???????????????

any idea's most appreciated as it really is getting annoying driving a rattly car with only 2/3rds of the rev range available.

thanks
rich

[Jaydub]

If you mean small end bearings as in con rod then you wont do that without dropping the sump and removing the head. Sump to undo the big end caps, head off as the pistons and rods come out that way - don't try dropping them out the bottom!
If you think it's top end could it be the rocker shaft/arms etc. as a lot of Triumphs suffer wear due to lack of oil supply.  you can get an external supply to the top end that may help quieten this but I would rather not do that myself - better off rebuilding as Triumph intended it if it is the culprit.

[rotoflex]

Could it be the issue with pitted rocker arms causing incorrect clearance measurement?

[Rich_s]

If the head has to come off then its a no go, last time it came off we found a problem with one of the studs and only just got it to hold half the torque setting so am not talking it off as will have to sort that out :(

i took the rocker apart last year, all seemed ok with not much twist in the arms, i also filed down the faces taking care not to touch the bit that touches the valve, so the clearances are not too bad and by setting them at 8 thou it has got a lot better but the rattle is still there, seem to be near the top at the back near the bulkhead but cant tell if its coming from the cylinder or rocker box, or even if its the same rattle at tickover as it is when it hits 4k ?????????? am just guessing really.

rich

[esxefi]

rattle,.....1500 engine,.....around 4k revs,.......sounds like it could be worn big ends. :(

mind you they wouldn't really be noisy at idle unless severly worn.but i would think it undriveable if that were the case.

sound can travel in funny ways around an engine,the bell housing could be acting as an amplifier as you say it sounds like it's at the rear of the engine.

does the rattle dampen when you snap shut the throttle on over run?

what happens if you press the clutch pedal at idle,does that make a difference?

[Rich_s]

I am not sure if it is the same rattle at tickover as it is at 4k, tickover sounds like tappets but they all seem fine, it has been mentioned it may be the cam followers causing the tickover rattle, if so it will have to wait until i brave sorting the head out before can check and replace them.

Not sure if it dampens if i shut off the throttle, will have a go next time i take it out, pressing the clutch at tickover does not make any difference.

One thing i do notice is it is very reluctant to pull past about 4.5k revs as well, it pulls cleanly up to there but at about 4.5k as well as being noisey it seems to lose any power it had and doesnt want to rev any higher, i tend not to drive quickly anyway but would like the engine to be able to do what it was designed to do.

thanks
rich

[Steve Cureton]

A recent problem on a friends car was caused by worn cam shaft and followers which caused the followers to stick in the tubes, resulting in tapping on every revolution of the cam shaft.

[Velocita Rosso]

So youve set at 8 thou?
So the valves are not closing properly now and you have less power!
The rocker gear needs an overhaul or complete replacement as the rockers and or springs could very well be worn
Even sideways movement on the rocker shaft will cause a rattle

[Rich_s]

it doesnt seem to have less power than it ever has, just less than i think it should, by dropping the valve gap from a measured 10 thou to a measured 8 thou the only difference has been it sounds quieter.

I will the rockers off again and completely strip and look for wear, the noise if def towards the back of the engine so hopefully will see something on the back 4 rockers.

thanks
rich

[Alex]

A helicoil will solve the problem with your head stud.....been there! ;)

[Velocita Rosso]

932 wrote:

it doesnt seem to have less power than it ever has, just less than i think it should, by dropping the valve gap from a measured 10 thou to a measured 8 thou the only difference has been it sounds quieter.

I will the rockers off again and completely strip and look for wear, the noise if def towards the back of the engine so hopefully will see something on the back 4 rockers.

thanks
rich

Your valves will, still not be closing fully
`Look` , with a micrometer and bore gauge for ovality..........and change the springs

[Rich_s]

Finally a good result for my car.

I have taken the rocker shaft off and found the whole thing gummed up with something like black sticky tar, so i cleaned up everything so all nice and smooth, checked and only found slight wear but was equal on all rockers so can live with it. I rebuilt it all using plenty of clean oil and its made q fair bit of difference, the engine is quieter through the rev range and no nasty noise in the higher rev range, so for once the engine sounds almost how it should :D

thanks all
rich

[cook1e]

Make sure you don't leave the tappets set at 8 thou though because if the valves aren't closing properly not only will you lose power but you'll risk burning the seats/valves. The 10 thou setting at cold is to allow for the expansion when the engine gets hot so if you set at at 8 thou cold there will be a 2 thou gap and when hot which will allow hot gassess to escape through the gap which will damage the valve and seats where they should be sealing.

[Rich_s]

tappets are still as they were as have not re-checked yet, i do know that each of the rockers has a slight indent where the valve touches which is visible so if i set to 8 thou i would guess that the gap is still over 10 thou overall, i dont have a click adjust tool only feeler gauges so can't be certain of the exact gap, but there is still a slight tappet rattle so i guess all is still ok.

It still has a leaded head so if it does eventually burn a valve out its a good excuse to get it converted to unleaded :)

ta
rich

[Rich_s]

.....and the saga continues. Just done an oil change today including removing the sump as never done that, little bit of sludge but not much, check the big ends and no play in them so guess thats one good thing.

the rattling is still there though, have put new springs in the rocker shaft but made no difference. i had the dizzy apart today and noticed there is play, if i hold the bit at the bottom i can push the shaft up and down more then i think i should be able to, but couldnt get the end off to put a bigger washer in, also noticed that one of the springs is very loose where one was tight, am guessing this is wrong as well, could either of these little problems cause a rattling, its either these or one of the middle two cylinders cam followers, its driving me nuts :D

i will hopefully be swapping the dizzy for a known perfect one off an MG in a few weeks so can see if it makes any diff at all, if not i guess i either have to put up with it it take the engine apart.

on another plus side today i fitted a new thermostat and engine temp back to normal again :)

rich

[junkuser]

One tight spring and one loose could well be correct.
The MG distributor may be in better condition but what are the chances of it having the correct advance curve for your engine?

[ferny]

cook1e wrote:

Make sure you don't leave the tappets set at 8 thou though because if the valves aren't closing properly not only will you lose power but you'll risk burning the seats/valves. The 10 thou setting at cold is to allow for the expansion when the engine gets hot so if you set at at 8 thou cold there will be a 2 thou gap and when hot which will allow hot gassess to escape through the gap which will damage the valve and seats where they should be sealing.

I set my gaps at 10 thou in Andorra. Engine was very hot, as was the ambient temperature! I checked them later when back in England and it was cold, it was still at 10 thou.

[Rich_s]

The Mg distributor swap will only be for a few moments to see if the rattling stops, if it does i know its that, finger crossed

[Fred101]

Following this thread with great interest, sounds like the exact same problem I have, in terms of noise and engine power.

My head is coming off today to investigate further.

[Rich_s]

Well, bugger.........dizzy swapped over, engine sounded the same, still got the rattling coming from the gap between the dizzy and the engine block, def sounding like a tapping at half engine speed so presume this sort of confirms its a problem with the cam followers being worn.....

guess this means a top end rebuild is required and that 1500cc lump doesnt have the convenient tappet chest covers like on the A series engines, so much easier :) guess i will just have to live with the noisy engine as i'm not rebuilding the bleeding top end just for that - too much of a pain in the arse.

that car really does annoy me a times, will just have to get a louder back box for the exhaust :)

rich

[Rich_s]

there is a glimmer of hope left on the horizon, have read in the Moss catalogue that if the drive gear between the dizzy shaft and the cam does not have the correct float between itself and the dizzy mount body then it causes wear if too tight and a rattle if too big.... might be the cause of the problem if i am lucky, most things that mention the cam followers wearing away say that the tappet gap keeps getting bigger, mine stays as is so there is a slight chance it is this, wont hold my breath though :)

rich

[Freebird]

The best way to set valve clearances if the rockers tips are worn is the use a DTI rather than a feeler gauge. It's a bit of a faff, but you konw what clearances you have got.