Tapping on Start-up.

[stoutgoose]

Rover V8, 3.9 litre. Standard lifters, rockers, head gear, etc. Manual choke/Weber 500 carb. Engine has covered around 18,000 miles since rebuild by JE Engineering. Using 20/50 semi-synth oil.

I started the engine this morning (last started 4 days previously), and after the brief tapping before full pressure was achieved, the engine ran quietly.

I moved the car out of the garage and shut it down.

Upon restarting 40 minutes later, a distinct tapping was apparent from the L/H (drivers-side) rocker cover/top of engine, rear cylinder (number 8, I think). It sounded as if one of the lifters hadn't primed properly and was tapping empty.

It quietend partially, but was still noisy in comparison to the others, before slowly (over a period of around 3 minutes) quietening back to a normal level.

This is the first time it has continued to make such a noise after the initial, brief, start rattle.

Is this a common situation, what causes it and does it spell the end? I haven't started it since then, so don't know if it will do the same again.

Capilliary pressure gauge shows rapid pressure gain on start to around 40psi.
Hot pressures are good. Tadpole oil pressure relief valve fitted.

Any opinions?

[neil still building it]

hi when you say :started 4 days prviously .
did it run for long ie long enough to warm up...and all the oil to flow
sounds like a little air in a tappet+ how olds the oil.....
neil

[craggle]

My Range Rover has just had a new cam, lifters, timing chain, Pushrods, rocker shafts and rockers. This was all fitted my myself so I know everything is new.

On initial startup after a few days standing, you still get the rattle from the lifters but it goes as soon as the oil pressure rises.

On my old Range Rover there was always one lifter that rattled longer than the others. This started once about 10 - 15K miles were on the engine.
Sometimes it would wait until the temperature was up to normal before quieting down. This didn't happen all the time though but it seemed more common in the cold frosty mornings.

I found using an engine flush during each oil change would help to reduce the time taken for the lifters to shut up and a good quality non synthetic 20/50 oil helped.

Craig.

[stoutgoose]

Thanks for the info Craig.

Neil thanks for your reply. The car was given a good run on the previous occasion. The oil is less than 500 miles old, I tend to change it every 1500 to 2000 miles. The engine is in a Stag so only gets about 3-4000 miles a year, with a reasonable amount of hard driving.

I'm currently using Coopers filters but after reading some of the other threads am thinking of changing to Moroso/K&N.

Out of interest, do you know what a comfortable rev limit is for the Rover V8?

I have my rev limiter currently set to 6000 with a soft cut starting at 5800. On 1st and 2nd it's regularly cutting in on fast starts. The engine was built by JE Engineering, putting out 250bhp with a hot cam and raised compression ratio, but pretty much standard rods pistons, etc.

Thanks, Steve.

[wilf]

6000 may be a little too much for standard cast pistons - 5500 is reckoned to be totally safe, 6000 is pushing it a little.

[Sidecarbod]

Originally Posted by stoutgoose

Thanks for the info Craig.

Neil thanks for your reply. The car was given a good run on the previous occasion. The oil is less than 500 miles old, I tend to change it every 1500 to 2000 miles. The engine is in a Stag so only gets about 3-4000 miles a year, with a reasonable amount of hard driving.

I'm currently using Coopers filters but after reading some of the other threads am thinking of changing to Moroso/K&N.

Out of interest, do you know what a comfortable rev limit is for the Rover V8?

I have my rev limiter currently set to 6000 with a soft cut starting at 5800. On 1st and 2nd it's regularly cutting in on fast starts. The engine was built by JE Engineering, putting out 250bhp with a hot cam and raised compression ratio, but pretty much standard rods pistons, etc.

Thanks, Steve.

Hi Steve,

JE should be able to tell you what it's safe to rev the lump to but I reckon 6K should be fine. I rev my 3.5 to that and its got a standard bottom end. You pistons are going to be slightly heavier but not by much. (I have taken mine to 6.5 a few times but I reckon that there less power up there than at 6).

At the end of the day unless your engine can breath at 6k, i.e the cam, inlet, and heads can provide the fresh gas then it is pointless to rev it that high.

The odd person may get a bit "funny" that your on a Cobra forum when you've got a Stag! I'm not one of them! (Probably no one will mind as at least your car is a bit special, not just a Astra or something "tin toppish")

Did you know that there is a V8 forum that is quite good, not as good as this place but as long as you've got a V8 you can ask stuff on there.

HTH,

Pete