Both sets of valves will look closed.

If cyl 1 is at the end of it's compression stroke, both valves will have been fully closed as the piston rises and the back of the cam lobes will be near the rocker arm leaving a clearance.

At the same time, cyl 4 is at the top of it's exhaust stroke and will be starting it's inlet phase.
So the exhaust valve will be almost closed and inlet will be just starting to open.

If you turn the crank and watch for this point, you should see the arms rock on cyl 4. At this tdc rocking point there will be NO clearance between cam and rocker arm so you can't adjust them.

There are other methods but I use this table.

Cyl 4 valves rocking- set cyl 1
cyl 2 valves rocking- set cyl 3
cyl 1 valves rocking- set cyl 4
cyl 3 valves rocking- set cyl 2

Don't panic if you miss tdc by a few degrees. It's not critical.

 

So then....

Does the car have the T/B on the r/h end of the plastic inlet manifold?

I ask cos no one has told how the inlet manifold comes off and goes back on - I'm interested in what sealant might be required on the bolts as [I suspect] some may go into the oily parts of the head... not blind holes.
After removing the manifold, you might want to consider replacing the 'sealing rings' - in the rocker cover - which keep the 4 steel sparkplug tubes oiltight.

Any piccies of you putting it all back together would be much appreciated, M8.

knownClone

 

thanks for that response,it has helped my understanding of what cylinder 4 is doing while cyl 1 is at tdc,so if i have understood this correctly are you saying that when cylinder 1 (gearbox end on renaults?) is in its rocking stage is it in TDC (compression)position?
the reason i ask is when you say rocking it doesnt appear to be an accurate description.What point in the compression cycle is "rocking",its just that when cylinder 1 is at TDC and the arms are rocking,cylinder 4 is very tight with no movement and i cannot get the feeler gauge in.

 

Rocking isn't in the compression cycle.

Which ever cylider has valves rocking- it's the opposite cylinder that is on compression.

If you get the valves rocking on cyl 1 (gearbox end in this case) lift up and down on the rocker arm on cyl 4.

Can you feel any play at all ?
What size feeler are you using ?

 

TDC firing stroke - valves totally shut, feeler setting.

TDC exh/intake stroke - one closing/one opening [well 2x as its a 16V, but the one rocker arm!].

knownClone

 

my engine is slightly different to yours as my cam cover contains the TB underneath inside the housing.interesting thought about the spark plug gaskets.they probably will leak as the engines covered 139,000 miles.i bet they are main dealer only though.

 

The spark plug gasket are on ebay 17.50 or a set. dealers want 80 quid a set

 

cor! the more i read it the more i'm getting confused.
i was understood to believe that just after cylinder 1's inlet valve has dropped and risen and the piston comes to the top that was compression and also tdc,or is that not the case.what if i get cylinder no.1 to tdc and the cam sprocket is aligned,is this a position to set no.4?
i have been using .10 on inlet and .20 on exhaust

 

Yes, you're right.

That is compression and tdc on cyl 1.
As cyl 1 rises to tdc look carefully at the rockers on cyl 4.
What are they doing as the piston rises to the top.
The exhaust should be closing and the inlet opening.
That is 'rocking'

So- cyl 4 rocking, set clearance on cyl 1

Haynes has clearance as
inlet 0.05-0.12
exhaust 0.15-0.22
cold engine.

They may never have been set before and the gaps have a tendancy to close up rather than get bigger.

 

this is whats confusing me,by setting the cyl 1. to TDC causes cyl.4. to "rock" this means i can set the gaps on cyl.1.

so in theory if i get each individual cylinder to a TDC compression state i can set the gaps for that cylinder?

the reason i say this is because i reckon its easy and accurate to get each cylinder to compression TDC by putting a tube down the spark plug hole and watching it rise with the piston and watching the inlet valve drop and rise.whether the others are actually rocking then will not matter because i know that each cylinder i adjust will be in the "perfect state".surely the rockers will be at their "loosest position" ready for gapping.

 

Works both ways.
Like I said. There are other methods.

Rocking on cyl 4 just is just another way of determining that cyl 1 is at tdc on compression and that gaps are loosest.

 

by jove i think i finally have it.i adjusted all the gaps to .10 on the inlet and .20 on the exhaust and i can only say that whilst the car did run ok before, the gaps were easily twice that of the setting they are now.only thing of note was when i got each cylinder to top dead centre the other corresponding cylinder was only just on exhaust stroke, hardly any movement at all,it was only when i continued cranking the engine round a bit more that the exhaust valves had a bit more play in them.

 

This link will explain the reason for what you are seeing.
http://www.compcams.com/Pages/416/valve-timing-tutorial.aspx

 

Can you help me with a H4B three cylinder valve clearance specs?

Thanks Lenn

 

Hi, I've done the valve clearance adjustment on my mk3 d4f 740. Im not a mechanic but im mechanically minded, and i have done lots of things including clearance settings with my father years ago, so it's not alien to me, however i wasn't sure how much of a drag should i feel. I aimed for a decent drag at the middle of the spec (0.25-0.32 for intake and 0.35-0.42 for exhaust as my camshaft has a groove) so 0.33 didn't fit in, 0.28 had a drag. Same on the exhaust, but 0.38 had a drag and 0.43 didn't go through. Long story short, car sounds way better, no more rattling when the engine is cold. Sometimes it takes a little bit more cranking when starting up. I'd say 3 rotations more by the sound. When I press the accelerator from idle (in neutral) first it goes down for a second to 500ish rpm, then it goes up fine. Idle is about at 600, I'd say it's like before but still feels a bit low. Idle is stable otherwise. Do you guys think I messed up the clearance setting by setting it too tight? Or is it the throttle body if I accidentally knocked it when handling it, maybe the fuel system? Should I re check settings just to make sure valves are set correctly?
There is no smoke in the exhaust, no petol smell. I can't hear any misfires, no lights on dash. When i remove the oil filler cap when the engine is running, rhythmic puffs come out but nothing too excessive or pressurized. I need to mention I had 99 octane fuel and an injector cleaner additive into the tank right after the job.

Thanks for anyone's help.