Rover V8 Cam follower pump up

phewitt · Post by **phewitt** » Thu Feb 19, 2015 8:12 pm

Please can someone familiar with the Rover V8 or Buick 425 engine advise me on the amount of time it should take for the cam followers to pump up after having been completely emptied of oil?

I have just replaced the valley gasket and took the opportunity of checking the cam and the followers. I have stripped the followers and cleaned them out. I soaked them in oil overnight and refitted.

I have just got the car together and started it this evening. The noise from the followers is quite loud. I ran the car for a short time (about a minute) as I do not have any coolant installed at the moment and whilst I can convince myself they have got a little quieter, they are still a lot noisier than I would have expected.

I read elsewhere on the web that it could take as long as running up to temperature and even going for a short drive before the followers pump up to full pressure.

I can only assume that soaking them in oil does not allow sufficient oil to seep into the follower.

Any thoughts gratefully received.

ChrisJC · Post by **ChrisJC** » Thu Feb 19, 2015 9:45 pm

In my experience, seconds.

Chris.

Baracus · Post by **Baracus** » Thu Feb 19, 2015 11:17 pm

When i bled mine out completely to sort the preload it took a fair while for them to fully pump up, in the order of a few minutes, which feels like a lifetime when all that clattering is going on!

phewitt · Post by **phewitt** » Fri Feb 20, 2015 8:44 am

Baracus wrote:When i bled mine out completely to sort the preload it took a fair while for them to fully pump up, in the order of a few minutes, which feels like a lifetime when all that clattering is going on!

This is what I have done. Stripped and cleaned and the pre-load setup. OK I will drop in some coolant this weekend and run it for a bit longer.

Many thanks.

DaveEFI · Post by **DaveEFI** » Fri Feb 20, 2015 9:38 am

Was where they were stored overnight while soaking in the oil cold?

phewitt · Post by **phewitt** » Fri Feb 20, 2015 9:49 am

DaveEFI wrote:Was where they were stored overnight while soaking in the oil cold?

Yes it was; I suspect the high viscosity has prevented the followers from absorbing the oil.

kiwicar · Post by **kiwicar** » Fri Feb 20, 2015 10:46 am

Hi
the oil has to go in through a very small hole with probably only about 40 psi behind it and if it is 20/50 it is pretty viscous at ambient temperature, I would not expect them to fill properly until you have got it up to temperature and to at least 4500 revs where you may get 65Psi behind it.
best regards
Mike

phewitt · Post by **phewitt** » Fri Feb 20, 2015 1:01 pm

kiwicar wrote:Hi
the oil has to go in through a very small hole with probably only about 40 psi behind it and if it is 20/50 it is pretty viscous at ambient temperature, I would not expect them to fill properly until you have got it up to temperature and to at least 4500 revs where you may get 65Psi behind it.
best regards
Mike

Thanks Mike; I guess I'll just have to close my ears to the sound for a bit. In one way I am glad, after all the work I have done I would be a bit concerned if everyone came on and said they had never experienced the long pump up time.

mgbv8 · Post by **mgbv8** » Fri Feb 20, 2015 7:56 pm

Buy a priming tool (or make one) and prime the oil system with the dissy out while someone is cranking the engine once you feel resistnce to the priming tool.

Or run the priming tool until you see pressure and get someone to turn the engine over with a socket for a few revs.

That will fill the lifters and save you some frown lines I think

Perry

DEVONMAN · Post by **DEVONMAN** » Fri Feb 20, 2015 8:30 pm

If you feel inclined to soak the lifters overnight you should check before installation that the plunger in the lifter will still compress at least 60 thou.
If it feels solid then on start up the valves will lift more than the designed amount and may result in some undesired consequences.

In the case of the OP this seems not to apply.

I have read that some engine builders submerge the lifters in oil and pump the plunger till it goes solid..... not good, but probably get away with it on a standard engine rebuild with a stock camshaft.

Regards Denis

sidecar · Post by **sidecar** » Fri Feb 20, 2015 8:35 pm

DEVONMAN wrote:If you feel inclined to soak the lifters overnight you should check before installation that the plunger in the lifter will still compress at least 60 thou.
If it feels solid then on start up the valves will lift more than the designed amount and may result in some undesired consequences.

In the case of the OP this seems not to apply.

I have read that some engine builders submerge the lifters in oil and pump the plunger till it goes solid..... not good, but probably get away with it on a standard engine rebuild with a stock camshaft.

Regards Denis

What you are describing is also how Rover limit the revs on these engines, basically when the engine is revved so hard that the valves float the lifters pump up which causes the valves to be held off their seats, this causes a misfire and kills the power which hopefully tells the 'nut behind the wheel' to change up a gear. Like you say this has to be taken into account when building a non-standard engine.

phewitt · Post by **phewitt** » Sun Feb 22, 2015 10:03 pm

All

Thanks for the replies, the car is now running a lot quieter after the initial clatter the other evening.

Cheers,
Paul

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Rover V8 Cam follower pump up

Rover V8 Cam follower pump up

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