The V8 Owners Forum -

ok just been reading a post from PWD95 about preload and draing his lifters, so i thought id try and help him and everyone else out with this one

well heres my little step by step guide to lifter preload.... (use this for your site if you want tony )

well by now if your worrying about lifter pre-load you should already have your engine in bits, so i wont go that far....

well if in anyway your lifters look nackered, or worn then dont be scared to throw them away and get some new ones, there arent that much!!!!!!
but if your like me and have only done a few miles on the new lifters then you will need to know this.........


well first off take out every lifter from the engine and either mark or put into a place where you can easyily know which lifter goes into which hole!!!!!, and clean off all the oil from the out side with a clean rag

then pop off the retainer clip.... i used a small precision screwdriver so i could just get from behind it and pop it off.... very easy



then pop off the top cap... you can see the oil that fills it up now... i tipped most of the oil out, then put a kitchen towel inside to soke up the rest... clean all the oil off



now to remove the plundger..... this doesnt seem to fall out on its own so through the oil making a air type seal, so i got a small (none sharp) screwdriver with a bit of clean rag rapped around and pushed inside, so i had something to grip the plundger.... no force needed and out it comes....... BE VERY CAREFULL NOT TO LOSE THE SPRING UNDERNEITH!!!!!!! same again, clean all the oil off



well here is the lifter fully disasembled and cleaned thoroughly......



the lifter is now empty of all oil and now can be ready to be preloaded... well thats after you put it all back together.. its not hard just put it all back together the reverse of how i told you to undo it!!!!!


well you should have a fully assembled EMPTY lifter.... place back into the origanal holes they came from (i hope you marked them up).. make sure the head and rocker pedastalls/shaft are all tightened up to there correct torque, and the push rods are all fitted!!!!!!



now the lifter internal plundger has no oil pressure behind it, it can now easyily be pushed down into the lifter and can be checked for its preload......... start off checking the lifter closest to you and work your way around making sure you dont miss any of them out........

as your number 1 lifter make sure the cam is 180 degrees off its lobe so you know there is no upward force upon it, you only have to turn the crank (if the timing chain is still attached) or the camshaft (if it isnt) to do this..... as the valve sping pushes onto the rocker, and the rocker pushes onto the push rod, you can get an indication of what your pre-load is by looking at the cap between the plundger and the retainer clip......

these are fully emptyed and ready to be checked.... as you can see before any messurment is checked, that this is WAY!!!!! too much pre-load (the closest one only)



HOW TO TEST IT.......

well ive read alot of books and internet sites about what the prelaod should be, and it all veries from 20- 60 tho (0.020-0.060 inch) but MY referance is 20tho (0.020inch)... if you intend setting it at 20th then i used a piece of 0.6mm welding wire(this is a nats cock over 20tho) and bend a tiny peice of the end over so it can be placed under the retainer clip........

as you can see may pre-load was know where near the 20tho i recomend,as i can fit a bent pop rivet under which messured at 3mm/0.118inch .... just abit more than my recommended 0.020inch

yours should be no where near this.........



HOW TO ADJUST PRE-LOAD

well if your pre-load is over the recommended 20-60 tho then its time to adjust it......

there are shimms avalible that go under the rocker pedistall, to inclease the rocker height from the pushrod, but there are a few problems with this, and some people class it as a cheap fix....... well basicaly if some of your lifters are pre-loaded at 30tho, and another lot on the same bank are set to 60tho, it is immpossible to get all them set to the same with shimms, so you have to compimise and set the hole rocker shafter so that all the lifter produce 45tho......

another problem is, as the rocker shaft is pushed upwards with shimms the rocker to valve angle will have changed, and can cause damage to the rocker/valve, as it was never intended to rock in this manner!!!!!



dont get me wrong alot of people have used this way, as a fix and most proberly have had no problems with it... i would say this should be ok for a normal road car BUT!!! i wouldnt do it my self!!!!

the best way to adjust preload in my opion is to buy adjustable pushrods.... fare enough these cost alot more than shimms but atleast every lifter can be adjusted to the correct pre-load, and the rocker and valve angles wont have been changed!!!!!!



I HOPE THIS HELPS SOMEONE!!!!!!

adam

Thanks Disco95

I've suspected for some time that I may not of got the pre-loads on my lifters correct and asked Real Steel what was the easiest way of checking them. They suggested removing one lifter at a time and using a socket that will fit into the top of the lifter placing it into a vice and just squeezing out the oil which seemed logical as with no oil pressure from the engine there is nothing holding them in the pumped up position apart from the residual oil inside.

I'm not suggesting your wrong, as your method is very thorough but do you see anything wrong with just squeezing the oil out?

Another question, if you measured the pre load without draining would this give an incorrect figure providing the cam is on the base of it's circle and the valves are closed?

Thanks,

Kevin.

CastleMGBV8 wrote: I'm not suggesting your wrong, as your method is very thorough but do you see anything wrong with just squeezing the oil out?

Another question, if you measured the pre load without draining would this give an incorrect figure providing the cam is on the base of it's circle and the valves are closed?

Thanks,

Kevin.

well personaly i would say your method would work in theory, but i wouldnt do it.... first off you need alot of force to push the oil out of a lifter, and if anythinging slipped you could seriously damage the lifter, plus if they are old lifters something could be jammed are the holes blocked, and putting force on them could seriously damage them, dont forget oil doesnt compress!!!!!!

but thats just my 10 pence worth, you never know this may work out to be a very good method of draining them...... just i recon my way at least you get rid of the crappy oil from inside which can make the lifter tappety.... every body knows if you get tappety lifter the first thing you should do is change the oil.....


as for the pre-load check while they are full, this is a deffinat NO!!!!!!

the lifters are an early form of varible valve timing, and need to drain off to give less valve over lap, and valve lift. and to pump up to increase valve over lap and lift at higher revvs......if you try and set the pre-load when they are full and the plunger is at its end where the retainer stops it, then you will have no extra play for in the pludger, so all the cam timing will be messed up and can seriously stump performance!!!!!!!


im glad my first post helped and i just hope this helps too!!!!

Great info chaps, thank you very much. What's the best way to prime them all up after?

I use Rhoades bleed down lifters, but that just how I do mine.
I open them up and drain them.
Kev
You cant just squeeze the oil out mate. Try it yourself. If you dont empty the lifter, you need a lot more force to get the pre load gap right. The result will be that the running pre load is completey different from one that is set on a dry lifter to one that still has oil in it.

PWD
To prime the lifters just crank the engine over with the plugs out and the HT disconnected. I dont normally bother with that though. I know my engine makes oil pressure quickly so I start it and the lifters rattle for about 3 seconds at idle then they fill up and all goes quiet. Well, as quiet as you can expect from Rhoades lifters at idle eh?

Does this mean the preload adjustment?

http://www.v-8.org.uk/forum/viewtopic.php?t=1150

YEP!!!!!


basicaly what its telling you is that every half a turn some of the lifters will be 180degrees off its lobe, so instead of turning the crank 360+ degrees to see if 1 of the lifters is off the lobe, you can just do it his method......

very time saving method!!!!

Marvellous. Wish me luck.

Thought that would be too easy. I think I have too much pre load ie. the plungers/pistons in the lifters were too far down in the the body of the lifter.

My heads were skimmed 20thou so i just fitted 16 thou shims to compensate, I have a Hurricane cam and of course the base circle dimension of the cam could be different to the original SD1 cam so that would throw the situation out. Looks like I may have to do it the hard way and probably fit adjustable push rods to do the job properly.


Kevin.

Thing is the adjustable push-rods I've seen are all heavy items, which look like they are about ready to snap is half at any point.
When I've set preload on mine I used the shims and swapped push-rods around to get a good reading.

Ideally roller rockers with adjusting screws would be the way to go but mucho dinero

Matt

Matt
The chrome moly rods and separate tips that you fit weigh about the same as the standard heavy RV8 pushrods from RS.
I was a bit disappointed when I assembled the new adjustable rods and felt the weight. I wonder why they dont do a heavy rod with the smaller tip for the rhoades lifters?