V6 timing - here we go again!!

[kaiser]

There are no good reasons for timing tools at all, as the indication on the rear sprockets is very clear and very accurate, provided the marks are made correctly by the factory!.
As I have said, there are different ways to time a car, and not only one holy grail. The timing marks are the factory's best shot at the optimum, in their book.

Even that will be a toss up between performance, consumption, power and torque.

Once that "optimum" is found/determined/established/agreed upon!!, you would be ill advised not to mark that position, and even Rover would not make an exception here, is my firm belief.

Now, as some say, there are three different tools available. How do you know your tool is right? and also right for this application?
And where are the pictures? I don't believe for a moment that anyone could go through this and not document what transpired after all this arguing! I certainly would not!

I will always go with the marks on any modern engine, they are made in the manufacturing process, and not inscribed, punched, filed by the engine builder like in days of old. Failing that, I would measure lift, TDC and time according to established rules and sound practice, and then tune for whatever was my primary desire.
But failing that, I will go with the marks. They should be very accurate unless somebody has lost a screw somewhere in the process!

[SD1too]

Originally Posted by ballymenaman

... on my car the rear marks don't align when the front tools are fitted.

Are both rear marks off the horizontal Andy or just one? If just one, inlet or exhaust?

Simon

[minimutly]

sd1Too, it should be obvious by now that the rear marks cannot line up at safe for all engines. Why is this so? Well at least speaking for the 2.5 180 and 190 engines, the cams are the same, as are the pulleys, but the timing for both is 4 degrees retarded. You imagine setting the engine in lock, then moving the inlet cam 4 degrees, the rear marks will move away from each other, bound to.
So, some versions might line up, but they can't all. Hence people making sweeping statements based on their engine may be correct, but not universally so.
As far as correct timing is concerned, I believe the 2.5 180 is the setting to use, unless youre after that magic 190 that mgr were chasing.

[SD1too]

Originally Posted by minimutly

Well at least speaking for the 2.5 180 and 190 engines, the cams are the same, as are the pulleys, but the timing for both is 4 degrees retarded.

Where do you get your valve timing data Huw for the 180 Ps engine?

Simon

[Bolin]

When I sorted my cambelt tensioner pulley I used the front tools with the locking pin, then removed the pin and rotated the engine very slightly to get the rear tool to fit on the LH (front bank) secondary sprockets, and then rotated the engine very slightly the other way to get the tool to fit on the RH (rear bank) secondary sprockets. This was in accordance with the famous video (watch for the engine being rotated slightly to do the rear belts, it is not in the commentary).

With the pin inserted, the marks on the secondary sprockets are aligned - but not precisely. When I looked at them, they looked aligned. But running a straight edge across showed that they were not totally aligned.

My experience matched up with the famous video, with what 1955diesel said on .org (and Mike Noc repeated on the other thread) and with the advice also given to me by Jon (JN12).

It does sound like Kaiser hasn't timed his engine in accordance with RAVE and the famous video or even the 'diplomatic cars' instruction that 1955diesel mentioned - and I am also sure that I have read of Kaiser complaining about the engine's lack of performance. If would be interesting to see what his car does on a rolling road, to then have the belts replaced using the tools as per RAVE and the famous video, and then see how the rolling road performance differs. That would be the only way to end the debate I think!

[zefrench]

As a point of reference, after I put the pin to lock the crankcase, both sets of rear sprockets did not line up.

Instead of having the exhaust sprocket at 3'o clock and the inlet sprocket at 9'o clock, I had the notches of exhaust at 4'o clock and the inlet at 10'o clock.

Since I wanted to have the best possible timing (or so I thought) I removed the front (large belt side) inlet sprockets, and that is where I noticed that the notch on the front of the inlet camshaft allows for a greater play (at least 3 to 4 teeth in my estimation).

Thus I was able to time both sets of rear belts and then use the special tools to hold the front inlet sprockets with their associated bolts hand tighten alloying "play"

The final result was the rear sprockets were then at 3 and 9 o clock, the large belt was on, AND THE SAFETY PIN FOR THE CRANKCASE STILL ENGAGED.

I hope this information is of use to others.

[Phil-T4]

I think some of you may be missing an important factor, the cut outs in each end of the camshaft for the pulleys are machined in different places so that the rear pulleys are in line when the correct tool for that cam is used on the front pulley.

Yes i have changed belts on many customers cars, 2.0L, 2.5L, ZT 180, ZT 190 so i'm not talking about experiences with just my own car i have seen and done them all many times!

So basically, if you have the correct cams in the heads, lock the front pulleys with the correct associated tool, the rear marks will be in line, maybe not perfectly but very close, if the deviation on the rears is 1 or 2 teeth, I would remove cam covers and check the paint colour or part number on the cam to make sure they match the engine.


Simon, TB0052 for the ZT180 launch says "2.5 KV6 (177 PS) with 190 specification cam timing"

[SD1too]

Originally Posted by Phil-T4

... the cut outs in each end of the camshaft for the pulleys are machined in different places so that the rear pulleys are in line when the correct tool for that cam is used on the front pulley.

Thank you for that vital piece of information Phil. It has to be the case doesn't it, when there is only one inlet camshaft rearsprocket across the engine range.

Simon, TB0052 for the ZT180 launch says "2.5 KV6 (177 PS) with 190 specification cam timing"

Now that has puzzled me! Rimmer Bros. says that the 180 & 190 engines share the same camshafts.
However, the 180 develops the same power and torque as the 177 Ps Rover engine.
Sealey says that their Rover 2.5 litre 177 Ps front tools are used additionally on the 160 & 180 engines, i.e. the same valve timing! But your TB0052 says the opposite.

So Phil, when you worked on a 180 engine, which front tools did you use: standard Rover 2.5 177 Ps or 190? And did the rear marks line up?

Simon

[BigRuss]

The ZT 190 and 180 do use the same cams and the 190 adapter plate needs to be used for both

The sealy instructions are a bit confusing as they are referring to the 180 engine as fitted to the MG ZS which is the same engine as the ZT160 and the 75 2.5
The power output of the ZS is actually 177PS they just rounded it up

Russ

[minimutly]

Originally Posted by Phil-T4

Just looked on the Rimmers site but cant see what your referring too?

Rear pulley LHB101380 and damper pulley LHB101730 both the same for 2.0L and 2.5L

Front pulleys LHB101710 both the same for 2.0L and 2.5L

Also, the timing figures were on one of the earlier posts here -was it you Phil?
And yes rimmers list the same cam for the 180 and 190 engine.
Same cams, same pulleys, different timing, marks will be out. Makes sense to me - but i don't have personal experience, just quoting others here.
Also,


Simon, TB0052 for the ZT180 launch says "2.5 KV6 (177 PS) with 190 specification cam timing"
This could easily mean (and I believe it does), 190 cams, but not timed the same.
As for the difference in power, the raised rpm limit on the 190 might account for some of it, but the different timing will bump up the top end, at the loss of the bottom end.