The V8 Owners Forum -

Hey guys,

I’m about to do a couple of fiddles on my RV8 and wanted to get some advice up front before I commenced.

Firstly I am running with the uprated oil pressure relief spring, but I’m getting quite high oil pressures even when warm so I’m thinking of refitting the original spring.
When I fitted the uprated one there wasn’t any oil in the engine, whereas now it’s been ran. So…. the questions are:
1) When I unscrew the retaining bolt and remove the spring, how much oil am I likely to have come out of here?! Should I prepare for a down pour?
2) Will the pump need priming again afterwards?

Secondly, I’m replacing the rocker shafts and rockers for new items (keeping the pedestals) because mine are quite worn and when the engine gets hot I can here a tapping noise from the RH bank which I ‘think’ could be the excessive play in the rockers – The symptoms sound very similar to ones described in a thread a found on another website. I have adjustable pushrods which were set with the min 20 thou lifter preload when built up. So again the questions are…..
3) After fitting the new rocker shafts and rockers will I need to reset the lifter pre-load (I am guessing so).
4) Is there a way to set pre-load without removing the intake manifold and valley gasket? I have access to the adjustment nuts on the pushrods by just removing the rocker covers, but of course can’t access the lifters. I’d like to avoid having to remove the intake manifold and valley gasket to save time but also to avoid the risk of getting a new water leak somewhere.

Any thoughts/advice would be much appreciated, thanks!

Gary.

mk1storm wrote:Hey guys,

I’m about to do a couple of fiddles on my RV8 and wanted to get some advice up front before I commenced.

Firstly I am running with the uprated oil pressure relief spring, but I’m getting quite high oil pressures even when warm so I’m thinking of refitting the original spring.
When I fitted the uprated one there wasn’t any oil in the engine, whereas now it’s been ran. So…. the questions are:
1) When I unscrew the retaining bolt and remove the spring, how much oil am I likely to have come out of here?! Should I prepare for a down pour?
2) Will the pump need priming again afterwards?

Secondly, I’m replacing the rocker shafts and rockers for new items (keeping the pedestals) because mine are quite worn and when the engine gets hot I can here a tapping noise from the RH bank which I ‘think’ could be the excessive play in the rockers – The symptoms sound very similar to ones described in a thread a found on another website. I have adjustable pushrods which were set with the min 20 thou lifter preload when built up. So again the questions are…..
3) After fitting the new rocker shafts and rockers will I need to reset the lifter pre-load (I am guessing so).
4) Is there a way to set pre-load without removing the intake manifold and valley gasket? I have access to the adjustment nuts on the pushrods by just removing the rocker covers, but of course can’t access the lifters. I’d like to avoid having to remove the intake manifold and valley gasket to save time but also to avoid the risk of getting a new water leak somewhere.

Any thoughts/advice would be much appreciated, thanks!

Gary.

Hi Gary,

Not much oil will come out of the pump when you remove the bolt and spring, maybe an egg cup full. I did not have to prime my engine when I messed about with my spring. (I drill and tapped the bolt so that I can adjust the oil pressure via an allen bolt)

If you have adjustable pushrods then you should be able to work out how many 'flats' the adjusters need to be turned over and above the point where all of the free play has been removed. You need to be sure that the lifter is on the base circle. From memory I went for 4 flats which is about 20-23 thou preload. (I don't want to run the 40 thou that some people run).

Watch out, there are some really dodgy rockers and rocker shafts for sale these days, they have more play than a 100k miles Rover set!

Regards,

Pete.

Hi Pete,

Great stuff, just the info I needed!

Good news that I shouldn’t need to prime (will watch the oil pressure light and pressure gauge of course), also good that I should be able to adjust/check the pre-loads without removing the valley gasket/intake manifold etc…

What I might do is calculate the number of flats to give the right preload as per your suggestion, but also check a couple of my currently set-up pushrods before I disassemble any of the valve gear to see if they’re as I would expect them to be from the calculation, that way I can do a sanity check of the calc and hopefully not knacker anything!

Yeah I’d read about the dodgy rockers and shafts that are about. My rocker shafts are definitely worn (remember seeing that when I bolted them into the engine, but at the time I just wanted to get the thing running) so will be new shafts and then I have a set of new rockers, good condition old rockers and my original rockers to sort through and select the best combination. Hopefully with some careful measurement etc I can find a good set.

Thanks again.

Cheers,
Gary.

Gary you might find this thread interesting regarding rockers/shafts:
http://www.v8forum.co.uk/forum/viewtopi ... c&start=15

The only way i'm aware of to measure lifter preload is directly at the lifter, using various bits of welding wire. I'm sure if there is some other way someone will shout up?
edit: just read the post above and seems there is away
Tom.

Hi Tom,

Yeah I'd read that thread a few weeks back thanks (your info was really useful) and based on that I bought the rocker shafts from island4x4 to try.
Just waiting on some rockers to arrive (new) and then when I have those I'm going to sort through all of the rockers I have, two sets of 2nd hand ones and the new set and see if I can get a decent set out of them. Ideally the new ones will have a decent tolerance (although I'm not counting on that) and I can use them as a complete set.

Cheers!

mk1storm wrote:Hi Pete,

Great stuff, just the info I needed!

Good news that I shouldn’t need to prime (will watch the oil pressure light and pressure gauge of course), also good that I should be able to adjust/check the pre-loads without removing the valley gasket/intake manifold etc…

What I might do is calculate the number of flats to give the right preload as per your suggestion, but also check a couple of my currently set-up pushrods before I disassemble any of the valve gear to see if they’re as I would expect them to be from the calculation, that way I can do a sanity check of the calc and hopefully not knacker anything!

Yeah I’d read about the dodgy rockers and shafts that are about. My rocker shafts are definitely worn (remember seeing that when I bolted them into the engine, but at the time I just wanted to get the thing running) so will be new shafts and then I have a set of new rockers, good condition old rockers and my original rockers to sort through and select the best combination. Hopefully with some careful measurement etc I can find a good set.

Thanks again.

Cheers,
Gary.

The number of flats to preload figure will depend on the thread used.

I use the Real Steal AZ545 pushrods (ends are AZ75) (3/8 whitworth) where 1 flat is approx 5 thou.

Just a fyi, high preload can also affect the hyrdocarbon readings.