Technical Questions on timing and head gaskets!

[Welsh Jon]

Hello there,

I have today bought myself a Cinq Sporting with the same problems as another member here and have wwasted no time in starting the cylinder head as soon as I got the car back to my house.

The first of what will probably be a few questions I have to ask on doing this job is, how accuratly do the timing marks line up?

As my fingers will not fit in where the spark plugs are kept I have used a pencil to find TDC and lined up the timing marks as best as I can see. Though when the top mark on the cam sprocket is lined up damn near perfect the crank sprocket is out by what I estimate 20-30 degrees to the mark (behind/anti-clockwise to the timing mark).

Now I drove the car home around 70 miles, and compared to a 889cc Seicento I used to own seemed a little sluggish, though I put this down to the progressive problem with the head gasket.

Am I being to fussy here or did the guys who done the timing belt last year (as documents show) put the belt on a tooth out on the crank sprocket?

Any help is greatly appreciated,

Jon

 

[rallycinq]

They should line up exactly. You can check TDC by popping the plug out the bellhousing.

Cheers

D

 

[Welsh Jon]

I thought they should line up exactly! They must have put it in a tooth out then maybe?

I forgot to mention that it's a 1997 Cinq Sporting ... if that makes any difference.

Well I'm going to have a go in the morning now, I'm calling it a night.

What I think would be the way to go about it now (please, please, please correct me if you think I'm wrong!) is to align it as best I can to TDC, set the cam sprocket exactly to the mark and then when the belt is off put the crank exactly on the TDC mark using the mark on the flywheel (looking through the bell housing).

Would this be accurate?
If I did this and I was wrong what would be the consequences and how could I go about correcting it?

Jon

 

[fingers99]

Get it wrong and it just won't run properly: the 8v is a "safe" engine. so no chance of valve to piston contact.

 

[rallycinq]

I would be setting the crank first, then aligning the cam to it.

Cheers

D

 

[Welsh Jon]

Right! The head is off! Now for more questions ...


If you look at the picture of the inlet and outlet valves (all are the same) you will see that there is a glazed (maybe not so obvious here) uneven build-up on the exhaust valve and that both are white. Is this normal? If not what can be done to correct this? (I thought they should be brownish and build-ups even)

Also any recommendations for cleaning the valves and head? I was looking to clean up the oily stuff with white spirits or petrol, and the valves (not going near the stems) with the blunt end of a knife and then some fine sand paper.

Then putting the valves in I was going to use a compound to grind them in (I think that's the term I'm after, turning them in with paste). Would I need to do this?

If I have left anything out please let me know!

Many thanks, Jon

 

[randomizered]

A dremel or similar with a brass brush will clean it all up nice, and do no damage as the valve metal is so much harder. DO NOT do the valve seats like this though if they are alu as this will screw them up. If they are inserts though (which i think the are), then if your very careful, you can remove deposits from them as well.

Grind them in the head once you've done this, and replace the stem seals as well.

For cleaning i used petrol, adn isopropynol (works better and smells less) ... compressor helps a lot as well

Can't remember what colour mine were, but i think white is ok?! They are very hot as they are the exhaust side.

Kristian

 

[rallycinq]

Put masking tape round the valve stem and then put it in a drill, then use a scotchbrite pad to remove the build up.

Use the pad in the head too to get any build up out of there, or the above dremmel with brass brush.

Yes, lap the valves in and replace the seals.

Cheers

D