Few Issues

tim leech · Post by **tim leech** » Sun Oct 01, 2006 8:41 pm

She looks nice tim!

I have a 16v which im not using but runs very well so if you wanted to look at that togive you any ideas then your welcome and im only in burton.

jeremy · Post by **jeremy** » Sun Oct 01, 2006 9:26 pm

I think the ignition is triggered by a flywheel sensor - and then 'processed' by the ECU. I don't suppose finding or making really accurate timing marks would be easy - and it won't form a check on the valve timing.

Tim2cv · Post by **Tim2cv** » Mon Oct 02, 2006 4:55 pm

I am starting to think the clutch isnt that great... or just very badly adjusted...
Loosened the cover off the cambelt to have a look and feel inside and its rock hard (very tight) this cant be right? it smells too!
looks like i may change the cambelt again to be sure....

Tim Leech I may pop down one night for a look see and feel of the cambelt on your car etc just so i can gauge mine... be in touch.

TIM

Kitch · Post by **Kitch** » Mon Oct 02, 2006 5:26 pm

The cambelt will probably feel mega-tight between the two cam pulleys....this is normal. Any looser and the belt will probably rattle against the belt cover lower down on the block. It shouldn't smell though, if it was too tight I guess it could make a burning smell?
If the clutch is making it slow, it can only slip. You'd notice that straight away, failing that the clutch will have no effect.

You can't really use a timing strobe on the engine. Well you can, but you can't adjust it so its pointless! The ignition system doesn't have a distributor so you can't alter the timing...the ECU does this via the TDC sensor on the bell housing.
If that sensor or the ECU is a bit duff, that could affect the timing, but it highly unlikely.

As I've said already though, you need to get more air into it. That long nose bonnet won't be helping and these engines thrive on air. Just by putting a cone filter on the AFM rather than that big old air box, the difference is unreal for such a simple and crude modification.

Toddman · Post by **Toddman** » Tue Oct 03, 2006 4:59 pm

Jeremy is spot on about cam timing on these cars please don't bodge it use the correctluy fitting pins when checking it - I will happily post you mine Tim.
They do have a distributor but the advance and retard is all done from a map in the ecu and triggering is taken via the flywheel sensor as Kitch said so you cannot alter the ign timing without reprogramming the ecu.

Cheers
Luke

Kitch · Post by **Kitch** » Tue Oct 03, 2006 6:01 pm

Thing is though, I've done two without the pins and both run fine.

Jezzie 16v · Post by **Jezzie 16v** » Tue Oct 03, 2006 8:37 pm

Kitch wrote:Thing is though, I've done two without the pins and both run fine.

Not wishing to upset the apple cart but what about the one that did'nt run fine ?

I'm no mechanic but surely with something as critical as cambelt timing the correct tools should be used.

Jez

Kitch · Post by **Kitch** » Tue Oct 03, 2006 9:09 pm

Jezzie 16v wrote:
Kitch wrote:Thing is though, I've done two without the pins and both run fine.
Not wishing to upset the apple cart but what about the one that did'nt run fine ?

I'm no mechanic but surely with something as critical as cambelt timing the correct tools should be used.

Jez

They do run fine?

The timing pins are stepped to sit in certain places. So I used something else which also holds the cambelt in a certain place.

jeremy · Post by **jeremy** » Tue Oct 03, 2006 9:26 pm

Most XU series engines only have a tensioner on the trailing side of the cam drive and apoart from the possibility of the belt flying off its easy to see that the pull side is the important side and that variations in the position of the tensioner will have no effect on the valve timing.

However if you put a tensioner on the pull side as well and connect the 2 tensioners together with a suitable mechanism to move them from side to side - you have variable valve timing - the holy grail of motor engineers for at least 70 years!

16 valve has this - except it is set on initial assembly and bolted tight (shame!) but the point is that the valve timing is fine tuned on the 'pull' tensioner.

Engine tuners will tell you that valve timing is critical - which is no doubt why people like Triumph and Jaguar used symetrical timing for inlets and exhaust which was obviously the results of months of painstaking research (or liquid lunches which I suspect decided the fate of British car rear suspension for decades - front before lunch - rear after - Ah yes - we'll use leaf springs zzzzzz)

Kitch · Post by **Kitch** » Tue Oct 03, 2006 9:33 pm

Yeah thats right. On the engine I've done, I fitted the belt and tightened the tensioners in sequence. As you tighten them up the cams try to move....hence the pins.

Jezzie 16v · Post by **Jezzie 16v** » Wed Oct 04, 2006 5:43 pm

Oh well i stand corrected on my previous post, It seems i got my wires crossed

i was under the impression that Rich (Kitch) had problems with his red 16v when he rebuilt that a while back, i must of got him mixed up with someone else.

So i'm sure the 2 bx's he has done cambelts on are both fine.

Jez

Kitch · Post by **Kitch** » Wed Oct 04, 2006 6:25 pm

I did have issues with the red one, but it was the tappets which were (and still are) very noisy. Also the cambelt occasionally knocked against the belt cover, so had to sort that. I wasn't brave enough with the belt tension. Managed to sort it though.

tim leech · Post by **tim leech** » Thu Oct 05, 2006 11:54 am

OK tm no problems let me know as its in winter hibernation and that batterys flat!