3.9V8 Tappet noises and diagnosing

[steve200TDi]

Right,

So I have a 3.9V8 which has now been Megasquirted, originally from a Range Rover Classic with auto box and Broge warner transfer box etc.

It's got what I believe to be a tappetty noise. I'm going to strip the inlet manifold off at the weekend, but I just thought is there any easy diagnostics to do on it to prove its tappets or other wise.

So far I've taken one rocker cover off and barred it over to see if there was a loose rocker, but none are loose.

I've also had it running with a rocker off to try and see of hear anything, but nothing has become obvious. One thing I thought I saw was that one push rod was spinning round like the other 7.

Any thought greatly appreciated.

Thanks

Steve

[Tanuki]

Job One for me would be checking that you've got full oil-pressure feed to all the cam-followers and associated valve-gear.

--

"Do not despize the snake for having no horns, for who is to say he will not become a Dragon?

[Hybrid_From_Hell]

What oil is in it make and grade ?

[rocksteady]

Stage left, exaust gaskit?

[steve200TDi]

OK,

Tanuki - Not easy without taking it all apart, how would you go about doing this?

Nige - I've done an oil change as I thought it could cure it, I used 10w40 of the Castrol variety.

Rock steady - People did suggest this, but there definitely no exhaust blowing!

Steve

So the tapping could be a hydraulic lifter failing or failed, but the valve train has no slack in it, at least on one side!

[smallfry]

Assume you mean pushrod is NOT turning like the other 7 ?

The cam peak has a slight slope on it to make the lifters turn. If it is not turning either the cam lobe is wiped out or the lifter has collapsed or the face worn off. take the lifter out (if you can) and look at the face. If you cannot get the lifter out because the cam end is belled out, it will have to come out downwards when the camshaft is out. Which will mean the camshaft has had it.

I have found the cam lobes most likely to fail first are the 6th and 7th one back on the LH bank (looking from behind)

[Bowie69]

Check for an exhaust port gasket leak....

[steve200TDi]

Small fry - Indeed I do mean that one push rod appeared not to be spinning unlike the other 7 which were!

And interestingly enough its the third push rod from the back of the engine on the drivers side.

Bowie - I'll check again, but I'm pretty sure its not!

Thanks

Steve

[need4speed]

As above, look in the direction of the non-spinning pushrod. Its telling you its not happy about something.

[Hybrid_From_Hell]

Change oil for Valvoline 20/50 vr1

What you have is too thin ......can cause all sorts of issues ....

[FridgeFreezer]

10W40 is a bit thin but not going to be a deal breaker.

Also check the exhaust manifolds for hairline cracks, they do it for a hobby.

[iomlt]

I cannot rate VR1 highly enough... you can treat the V8 Soooo rough on this stuff and it protects....

[steve200TDi]

Right, so the rockers, push rods and hydraulic lifters have been removed and neatly placed on the bench.

They all look pretty good with minimal wear apart from one!

This one lifter, situated at the back of the engine on cylinder 8 exhaust has a nice concaved dish on the cam lobe end, so I suspect this is the culprit!

My plan of action, as I guess the camshaft will be have been damaged (will inspect closer tomorrow) is to replace camshaft and lifters, push rods and I might as well replace the timing chain.

Questions:

- Camshaft bearing - If they look ok I guess I can leave them, what's the normal routine for this?

- Push rods - there cheap enough so I might as well stick a new set in, I will visually inspect the rockers for wear too. I've heard about setting tappet preload, is this only set on new engine builds or do I need to at least check it?

- Timing chain, I might as well replace the gears as well. Recommendations, I see you can get duplex and silent chain.

I had thought about a fancy cam, but its only going to minimal mileage a year, so I think standard components will suffice.

Thanks

Steve

[Bowie69]

May as well go aftermarket on the cam, DON'T buy a cheap 'OEM' one.... it will be nasty.

New, genuine, lifters only.

Yes, change the chain, and if you can stump the cash, definitely go for the duplex setup.

As long as the push rods are straight and still round on the end I wouldn't change them, they don't really wear much.

Inspect rockers and shafts, definitely disassemble and clean as well as you can, but they often wear the shaft on the underside.

Camshaft bearings you don't normally touch unless you are going mad on the rebuild or very obviously dead, the load on them is minimal and is half engine speed anyways.

If you change lifters you MUST change cam, if you change cam you MUST change lifters

[Team Idris]

I guess 3.5 is like 3.9? If so check the steel cap inside the rocker arm where the push rod runs. On mine they were nearly worn through.

I got a Piper Max Torque cam as it sounded like good middle ground. But I can't tell you how much better it is, as my OE cam was stuffed

Duplex chain while I was rummaging around in there

Tappit pre-load is about making sure you are in-between 'tappit gap' and 'bottoming out' as far as I could make out? It looked to fall into the same category as push rods catching the holes in the heads, in that it would only be a problem if you had done a heavy head skim or other serious mods. But its worth observing the amount the tappits are pushed in when on the back of the cam, just so you know.

Running in the cam; I had some right ticks and noises. So much so I pulled the manifold and pulled the tappits, but all looked good? I had used the zinc Greece stuff supplied. They say run at 1500rpm for a bit in some threads? But I was having carb trouble

I see Gas Monkey Garage totally ate the cam and tappit last week while running in a small block. Can anyone shed any light on how to do this properly and the risks? I'm a diesel fitter by trade, and the cams easily did one engine rebuild, so it's an area that was new to me? It'd be nice to arm steve200tdi right

[steve200TDi]

Thanks Bowie, that leads me onto my next question of how do you identify what cam has come out. I'm guessing or would have thought that a fancy Piper cam or similar has 'Piper cam' stamped on it!? I also can measure the camshaft too.

This is what it says on my camshaft, there are a few numbers, but this was the only text:

I read that as C3 CWC, but what it means I havent a clue!

Also this is the affending cam lobe, notice the curvature!

I've also found an all steel timing chain set here which I thought was good for reasonable money.

http://www.v8tuner.co.uk/product.php?id=98

Has anyone got any recommendations for an aftermarket cam which can be used with all standard components?

Thanks

Steve

[FridgeFreezer]

Yep that cam's bu&&ered!!!

It's painful but I would second the comment about not fitting unbranded cams, either gen parts or Piper / Kent. V8Tuner should steer you right on cam choice, my preference is always for the low-down grunt, I fitted a Piper to the 4.6, this is the label:



Don't order the identical part for your 3.9 as the 4.6 has a shorter nose but the same profile should be fine. I'm on standard rods, lifters, etc.

Likewise, either genuine or known quality lifters, rods, etc. and a duplex timing chain seems rude not to bother for the few quid extra it costs.

Tappet preload, I've never bothered with it, I believe it's more a "nice-to-do" if you're using standard or near-standard bits, and only really becomes an issue if you fit a wild cam & solid lifters.

[Bowie69]

Tappet preload, I've never bothered with it, I believe it's more a "nice-to-do" if you're using standard or near-standard bits, and only really becomes an issue if you fit a wild cam & solid lifters.

Or skim a good amount off the heads to up the compression ratio.

Any one of the aftermarket cams will be fine, Kent, Crower, Piper etc all know how to make em for the Rover V8, just don't whatever you do skimp on the lifters, or you'll be buying a new cam and doing the job again in 10K.

If you ring or email V8Tuner, he will be able to talk you through the options.

Oh, and go for the duplex option!

[smallfry]

Using shims to "correct" lifter preload is completely and utterly the incorrect way of doing it in any case, It bu&&ers up the valve geometry, assuming Rover got it right in the first place....................

It will only be necessary if the head/s have been skimmed, seats recut and valve stem length not corrected, or an aftermarket regrind go faster cam has been fitted which has a smaller base circle.

Assuming the valve geometry was correct in the first place, the only correct way to do it, is to alter the pushrod length. In the US, engine manufacturers, (Ford GM etc) would offer a range of different length pushrods for this very purpose. Unfortunately, the only option for the Rover V8 is adjustable pushrods.

Personally, I wouldnt bother with either. Just avoid reground cams

Another thing.........I would not recommend fitting a Britpart camshaft and followers because "THEY" say that they are no good, although I have, and it still seems to be OK after 15k

[Bull Bar Cowboy]

Using shims to "correct" lifter preload is completely and utterly the incorrect way of doing it in any case, It bu&&ers up the valve geometry, assuming Rover got it right in the first place....................

Another thing.........I would not recommend fitting a Britpart camshaft and followers because "THEY" say that they are no good, although I have, and it still seems to be OK after 15k

I don’t understand this, please explain how lifting the pedestal rocker shaft centre line affects the valve geometry …………. how incorrect valve geometry affects the engine performance ? ………………… remember we are not talking inclined valves here ……….. we are talking 1.6:1 ratio rockers that are of an elderly and simple design.

Generally preload is only an issue when the heads have been 'worked' and / or the block faced (sometimes done to get the piston height correct) ............ but with an unknown history engine its always best to check the preload after any top end work as previous owners might have had the head skimmed a couple of times ! Preload is important ......... too much load preload will cause premature valve train wear ......... in extreme cases it will hold a valve slight open.

With rover V8 race engines adjustable rods are used so that the preload can be set exactly on each valve, whereas shimming the pedestals is a compromise on some of the valves between the min and max preload requirement, however, it is entirely satisfactory for most applications.

Also 15k is not sufficient mileage to comment upon a cam and follows without removing the cam and measuring the lobes.

[smallfry]

I didnt say anything about it affecting performance. It most certainly affects longevity reliability and wear though. It all about wrong geometry pushing the valve sideways excessively and wearing the valve stems and guides, and if you move the rocker pivot point in relation to the valve stem (which is what shims do) this will be the result. Dont get me wrong here, it will work fine............for a while, but in the long term it will be causing premature wear.

We ARE in fact talking about inclined valves, athough that has nothing to do with it as such.

A race engine will be using solid lifters so preload is not even an issue, in this case the adjustable pushrods are adjusting valve clearance. Yes, I know some "perfomance" engines use hydraulic cams, but they are not really "race" engines, which operate at much higher RPM, and the higher RPM and the oil pressure it creates is what causes lifters to "pump up" and hold valves open, as they are operating beyond their design limits. Even more so if the builder has "uprated" the oil pump or relief valve.

While I agree that 15k is not enough milage to comment on a camshaft without actually measuring it, a good guide it to remove the rocker covers with the engine running (as the OP has done) and see if the pushrods are spinning, as indeed they still are. If there is any significant wear some (or one) will be spinning at a different rate or not at all.

However, my point is that for the money spent, its fine. You can easily spend £400 - £500 on a genuine or perfomance cam and lifters plus the chain and sprockets, but how long do they last ? A genuine one will be starting to show signs of wear after 40 to 50k, if you are lucky, and a perfomance item ? Who knows ? But I would put money on it that you couldnt find anyone who can HONESTLY say, and be able to prove it, that they have had 100k out of one with no wear showing.

And another thing, nowhere in any genuine Rover/ Land Rover workshop manual will you find ANY reference to shimming . Not that I have ever seen anyway...............although I am always happy to eat a large slice of humble pie !

[steve200TDi]

Thank you all for your help.

I had a chat with Paul from V8 tuners last week and have a box of bit coming next week.

Oh and Fridge and Bowie, I put the extra money in

I'll now move over to here: http://forums.lr4x4.com/index.php?showtopic=87607

Steve

[Hybrid_From_Hell]

And use vr1 oil !!