Thread: new noise after V8 cam install

Originally Posted by pibby

typing on phone so shall be succinct

with valley gasket off motor turned over on starter for 30 secs and oil visibly being pumped upto rockers. wait 10 min and take measurement of 50 thou preload on lifter.

i assume the lifters would not have bled down?

will this more likely require shims to be added or removed to correct?

apologies if incoherent!

G`day ,

sounds like somethings odd , though i`m impressed you can do that on your phone .

After you got oil at the rockers , shouldn`t matter how long you wait you shouldn`t be able to measure the preload .

If your saying you have 50 thou between the lifter cup and pushrod ballend after you have oil at the rockers then it would certainly rattle .

Edit....

Hi again , after reading that above , if you got the preload after getting oil at the rockers and it has shims fitted , yes remove whatever works .

To suggest how many or much first would need to know how much extra clearence it`s been given .

As said earlier when i did our 4.0 years ago it rattled with what on paper were the right thickness shims , i made some different ones and it has run since 2004 without rattles .

If you have it back at Hobart and it`s still rattling it not likely to stop .

Edit2...

If the 50thou preload is right it should have around 30 thou shims fitted .

IF you change the shims and they are homemade ones make sure the front and rear post shims have the oil holes or cutouts the middle 2 posts don`t have to have them but the 2 ends ones do for oil flow .

If you remove shims you INCREASE the preload. And 50 thou is PLENTY.

Regards Philip A

ok - back on the laptop so can put bit more detail in to make up for my lack of earlier.

i measured 50 thou preload on the lifters AFTER the shims were installed. from memory one side had 25 thou shims and the other 35 thou. again, this was all within minutes of the motor being wound over on the starter and oil visible at rockers. to check lifter preload i did them individually but wound the motor over by hand.

after reading on here the problems people had with non genuine and cheap lifters i enquired as to what lifters were being used and was told eaton. a second set of lifters was put in later which had 'real steel' on the box though i don't know if they have their own lifters or resell someone else's lifters.

the first time the motor was wound over on the starter 2 lifters failed - it was like metal hitting metal. the mechanic moved some lifters around which showed it was two failing and not to do with oil flow.

when the second set of lifters was put in one of them also failed - it appeared unable to hold oil pressure.

so whilst the turning of the motor over on the starter before checking preload was wrong if i was doing this again i would turn it over on the starter after all preloads were checked to ensure that all lifters are working. in this case there were faulty lifters in 2 different sets of new lifters. it's a lot of work to put a motor all back together (with all the injected gas hoo ha in my case) to have to pull it apart twice because of faulty lifters.

aside from faulty lifters there was a lot of tappet type noise when motor was being wound over before i had checked preload. the culprit ended up being some pushrods being of visible difference in length to others and also appearing to insert into the rockers by slightly different lengths. the mechanic ended up putting on some second hand rocker assemblies and pushrods. my guess is this was caused by the wear in the old camshaft allowing everything to bash around. i recall some of the valve stems on the old heads being mushroomed.



so if i come back to my original poorly constructed question which i will try to better phrase -

a preload of 50 thou was measured minutes after the motor was turned over on the starter with the lifters fully primed of oil.

if the motor was left to sit for 2 days without being started would it be more probable for the lifter preload to have :

1/ increased
2/ decreased
3/ stayed the same

(this reminds me of some of the physics/chemistry questions from secondary school)




peter - i had read many times of the holes in the shims as you mention but couldn't visualise. after seeing them in action i now know exactly what you are talking about - doesn't come much simpler than those shims and hows the oil gets up there. the shims being used are pre made with holes in them already. btw - it's just an iphone which like many devices nowadays have the computing power of desktops from a few years ago. problem is the screens are too small and using the touch screens for inputting text is very slow. i am interpreting your answer to mean removing some shims might correct the preload and quiten things down. although i am not 100% sure because of how i didn't word it too well in the first place.


thanks

brett.

Good evening Brett ,

the preload should stay the same , the clearance may enlarge because the lifter looses some pressure but as soon as the engine is turned on the starter and oil pressure is gained the preload should stay static .

Yes , removing the shims is what i`m suggesting if the cause of the rattle is preload or lack of even though you say it has 50 thou but in reality if that is the problem if you remove a rocker cover and rock the arms you will feel the noise and that`s with the lifter holding pressure or run the engine with the cover off and feel the arm and you will feel the noise and if you can`t feel it there it`s something else .

If it has 50 thou preload it should be silent , if the noise is lifters .

If the noise is across the range of all 8 it should be obvious the fault , the noise to a trained ear if lifter rattle should be obvious , can`t help but question your faith in the mechanic .

I prefer to use GM type lifters the ones that some people have trouble with , i`ve used them in a couple of Rover V8s and have never been able to fault the lifter , like i said earlier it`s all to do with how they are put together and the checks along the way .

Peter

This saga is bloody unbelievable!!!
Regards Philip A

Had the POS sitting down the bush property for last 6 or so weeks. Started it a few times over that period. Started it and drove it into the shed during the week – yes, horrendous tappet/lifter noise.

On passenger side found tappet clearances on no 1 cylinder loose. the front rocker assembly nut was finger tight. Tightened it back up.

Turned motor over by hand and found five pushrods which if you grabbed the pushrod you couldn’t move it up and down. However, if push the rocker arm on pushrod side with just a little bit of pressure could generate 1-4mm clearance above valve stem.

Turned the motor over on the starter and had the oil pressure light go out. Did this a few times but there was no change in pushrod play when pushing the rocker arm.

Are these lifters behaving badly ie knackered???

Well the last two times I replaced my cam and lifters, it was EXTREMELY difficult to press them down against the internal spring.

In fact I gave up the idea of priming them by pushing the plungers down in an oil bath and used a syringe to prime them through the hole.

I recall that I had a couple of loose ones after priming with a screwdriver in the first set and I replaced them before fitting.

So yes I think your lifters are cactus.
Regards Philip A

G`day Brett ,

new unprimed lifters require very little pressure to move the top cup ( piece the pushrod rests in ) your little pinky can move it , when primed they require some mechanical help to move the top cup ( as in a lever ) .

I just had a look in the shed and there are used lifters there that have been on shelf for at least 7 years and some not all are still primed .

If after you run the engine and get oil pressure ( which primes the lifters ) you are able to push down with your fingers or even palm and get clearance then it seems the lifters are not as they should be , if however the little bit of pressure is at the end of a lever ?

Seems that you may be able to run the engine with the covers off ?

If the case you could do what we used to do many years ago when there was still a threaded adjustment built into rocker arms ( which was to set preload on a running engine ) and use an old or disposable set of feeler gauges to work out how much running clearance yours has but the noise is telling it has too much running clearance .

To me it doesn`t make sense to have that many faulty lifters but i obviously think differently about things to alot of others here .

I think the lifters are being the tell and not the actual fault .

What would make sense to me would be air in the system in the form of bubbles , this would cause the lifters not to pump up and would give the excessive running clearance and also would agree with your findings of little pressure on the arms to make clearance .

As i`ve said before remote diagnostics leaves alot to be desired , if i could see and feel i may have a different view but if i`d put it together and it still rattled after a couple of minutes ( the way you describe less time ) i`d be looking for things like bubbles .


Peter