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Tapping 3.5 Engine

Posted: Sun Aug 30, 2009 4:31 pm
by smoker
Hi all, I have a Rover 3500 SD1 that has quite a heavy top end rattle when it gets hot.

It's had a reground crank, new P6 pistons and oil pump gears. All the bores were professionally checked and honed. Head skimmed and valves seats cut and ground in

It was quiet after the rebuild but after 2000 miles the rattle has started.

The cam is a Piper Torque max. The cam followers are new from Real Steel.

Oil pressure goes off the gauge when cruising along with a cold engine (60psi) then settles down to about 35 psi at 2000rpm and 15 psi cold.
I use 10w 40 mineral oil with a zinc additive.

I have taken out the tappets and they have lost there bright finish and now have a smooth matt finish which i guess is normal. They all seem quite flat with just a trace of very very light pitting.
It seems like when the oil thins and the pressure drops the tappet are becoming noisy. Should I replace these as i don't know what else I can do ?

many thanks for any thoughts you might have

Posted: Sun Aug 30, 2009 5:03 pm
by topcatcustom
What followers do you have, and have you checked the pre-load? Are the bases of them convex, flat, or concave? Check with a straight edge if you can get them out easy.

TC

Posted: Sun Aug 30, 2009 5:04 pm
by ian.stewart
1st wrong weight oil, must be 20/50, and is the oil you are using all mineral oil or semi syn, tapping could be down to the oil, or could be more sinister cam lobe or lifter breaking up, did you run the cam in with plenty of assy lube at 2k for 20 mins??

Posted: Sun Aug 30, 2009 6:41 pm
by smoker
Thanks for those ideas I will change to 20w-50.

The followers are std. Rover I believe from Real Steel.
I coated the cam in piper pre assembly lube and ran it in gently.

The followers aren't dished and the cam lobes are unmarked.
I set the gao between the plunger and snap ring as close as I could to 40 thou using the shim kit and a piece of wire.

I'm baffed why it's so noisy so please keep suggestions coming :)

Posted: Tue Sep 01, 2009 4:46 am
by ChrisJC
Double check lifter preload.

Did you check _all_ of them?

Note you can't do it when the engine has been run without removing and draining the lifters.

Chris.

Posted: Tue Sep 01, 2009 12:52 pm
by CastleMGBV8
Lifters MUST go back in to the same cam lobe they were on before.

Kevin.

Posted: Wed Sep 02, 2009 11:58 am
by bigaldart
You cannot break a cam in gently, run it to 2 or 3000 rpm on fire up and hold for at least 10mins preferably 20 before subjecting it to road usage. For road use there is no point trying to finesse the pre load, 60 thou to 100 is good enough, unless you intend seeing more than 5000 rpm on a regular basis. Could also have been pinking rather than valve train noise, check everything on ignition and fuelling and make sure valve stem seals in place and in good order, check guides for any play. Any build up on back of valves is a give away for oil getting down the guides.

Alan

Posted: Wed Sep 02, 2009 7:37 pm
by mgbv8
The only thing you have not mentioned is the rockers and rocker shafts?
Are these new / in good nick??

I agree with Ian. I use 20/50 Halfords classic in all my RV8's with great results.

60psi oil pressure is a bit high to be honest. Hot or cold! If it stays this high it will cause excess wear on the dissy drive gear.

Tappng noise

Posted: Sat Sep 19, 2009 6:13 pm
by smoker
Hi all,

I replaced the cam followers today (new genuine Land Rover parts) and changed the oil to Halfords classic 20w-50. Started up and i can still hear a tap tap tap noise when the engine gets hot :cry: . I'm sure it should be quiter

When the engine is cold or the revs are above 1200 rpm the noise is much less. All the rocker gear and cam seem to be in good condition and oil pressure is as per the book

Has anyone used the Piper Torque Max cam and found it to be noisier than the origonal ??. Any other ideas appreciated, thanks all

Re: Tappng noise

Posted: Sat Sep 19, 2009 7:18 pm
by ChrisJC
smoker wrote:
Has anyone used the Piper Torque Max cam and found it to be noisier than the origonal ??. Any other ideas appreciated, thanks all
I used one and found it to be as quiet as any other...

Did you check preload whilst you had it all apart?

Chris.

Re: Tappng noise

Posted: Sat Sep 19, 2009 7:43 pm
by smoker
ChrisJC wrote:
smoker wrote:
Has anyone used the Piper Torque Max cam and found it to be noisier than the origonal ??. Any other ideas appreciated, thanks all
I used one and found it to be as quiet as any other...

Did you check preload whilst you had it all apart?

Chris.
Thanks Chris. I checked the preload there is between 40 and 60 thou gap (measured with a bent welding rod) gap between the plunger and snap ring.
I think I put a 1mm shim under all the rocker pedestals to get this.

Posted: Sat Sep 19, 2009 8:16 pm
by Ian Anderson
Check for telltale leaks around the exhaust manifolds

a small leak can sometimes sound like a tick

Ian

Posted: Sat Sep 19, 2009 10:55 pm
by smoker
Thanks Ian, All the manifold gaskets are only a few thousand miles old and I check the bolt tightness regularly but I will check again. It does sound more 'mechanical' than anything. It's so strange I started it up from cold again tonight and the noise had almost gone away. i get a loud 'ticking' when it gets hot.
I was wondering if taking the shim out of the rocker pedestal might be worth a try ?. Otherwise I'm completely out of ideas bar taking the engine out and rebuilding it again :cry: .The bearings, pistons, cam,oil pump rotors etc. are all new

Ian Anderson wrote:Check for telltale leaks around the exhaust manifolds

a small leak can sometimes sound like a tick

Ian

Posted: Sun Sep 20, 2009 4:37 am
by kiwicar
I see you are using 10/40 oil in a 3.5, the engine is designed to use 20/50, change the oil the to 20/50 the tapping will go, stay with it and live with the tapping. there are quite a few posts on 20/50 oil and early oil pumps and bearing tollerances, and asociated tapping tappets.
Mike

Posted: Sun Sep 20, 2009 10:43 am
by CastleMGBV8
Smoker,

I would suggest checking that you have a good oil supply to the valve gear, as you have had the heads off it is quite possible that when they were re-fitted that they were switched from one bank of cylinders to the other, this is perfectly ok as oil ways are drilled in the heads so that they can be fitted either way.

Only one pair of oilways feed the rocker gear that being the front pair and what happens is the redundant oilways tend to get blocked so if you switch heads from one bank to the other you have no oil to the rocker gear causing extreme wear.

If you cant see oil ousing out from the rockers it would suggest a blockage, take the valve gear off and check the cups that the pushrods fit into, they are prone to wear in high mileage engines anyway and the steel inserts can wear away completely in extreme cases.

If no oil supply the oilways will have to be cleaned/drilled out and then turn the engine over to push out any residue,

Also check that if you have fitted shims that you have not accidently blocked the oilways from the front oil feeds.

Blocked oilways to the rocker gear may also explain the very high oil pressure but it also may be a sticking releaf valve in the oil pump.

Kevin.