crank bearings, knocking on start up

[daverclasper]

Hi folks

 

Since getting my choke working a lot better (cheers again Pete Lewis for top tip) and the Vitesse starting quicker, I'm now getting, what sounds like the crank mains rumbling for a second or so at times on start up.

 

This can be daily, for the first start of the day, even though a spin on adapter is fitted and a Man filter, though in the horizontal position.

 

I'm wondering how much harm this can cause and therefore if I should give it longer time cranking off choke to build oil pressure.

 

Also the car has oil pressure within factory spec, though the oil pressure gauge needle wavers slightly when at my uneven idle. Therefore, wondering if the pump is keeping general pressure, though the bearings may be worn and are losing the pressure a bit.

 

Any advice as always much appreciated.

 

Cheers. Dave

 

 

[dougbgt6]

The one way valve in the filter is quite crude, it's just a rubber flap and some are more effective than others. There was a guy on the old site built a blow and suck tool to test new filters. He would go through half a dozen of a shop's stock till he found one he liked.

 

Horizontal sounds, intuitively, not helpful. Can you not get it tilted a bit? The chassis on my GT6 doesn't allow vertical fitting the best I can get is 45 degrees but that seems to work.

 

Having said that these engines were designed to have drain back filters and the death rattle was acceptable.

[Pete Lewis]

yes they have  given a couple of knocks on start up for 40 or more years and still running  ,,,,,its a real problem !!!!      not.

 

just let the pressure build  a few seconds before you rev it.

 

dougs spot on the spin on and its position is not utopia but generally an improvement on the orig.  cartridge element

 

dont loose  sleep over this ,  only if shes knocking when youre pulling

 

Pete

[daverclasper]

Cheers Guys.

 

Thanks for putting my mind at rest. It just the noise sounds kind of drastic and hard to know what it's doing.

 

Cheers, Dave 

[Guest]

Dave.

 

If you can position the filter housing so that it is as vertical as possible - which is likely to be 45 degrees, as I have on my Vitesse, you will improve the lubrication supply on start-up (i.e. reduces oil starvation to an absolute minimum). 

 

As Pete says, keep off the gas until the oil light has extinguished and the pressure has built up; all of about a second or so on a healthy engine.

 

Good luck.

 

Richard.

[Ben Caswell]

Try spinning the engine over a few turns before pulling out the choke

[DerekS]

And the other thing of course,keep your foot off the clutch pedal. Keeps the weight off the engine thrust washers.

[Pete Lewis]

You wont notice this on more modern engines where tolerances and clearances are much tighter

than the days of old, so whilst its less likely on a modern with better filter positions and high spec oil pumps if it has no pressure on crank up you wont hear it , but its there , just less noticable

Pete

[david lewis]

i have always used stp oil additive for donkeys years,it seems to make the oil stick to the engine parts and protects the bearings for the first few seconds after starting,I  used to have a bedford van whose engines were  notorious for knocking from the bearings on  startup due to the slanted engine draining the oil from the filter and the stp stopped the knocking.

cheers

[GT6M]

2 reasons for this

1  filters dring back

2, the oil gallerys totally empty

 

need a M MK1 tank,!!

 

M