Technical Timing Belt Replacement

[QTD]

I have a 1979 Fiat Spider 2000 and would like to replace the timing belt. Bought a 124 Spider Shop Manual for $42 from VickAuto but it is useless.
I have been searching for online but there are conflicting information. Thank you in advance for your guidance.
QTD

 

[beatyourtruck]

I use the Haynes manual and a BIG shop manual I bought from International Auto many years ago....between the two of them, I could almost always find what I needed. I would recommend the Haynes manual. It is still available for $28 on Amazon....worth every penny. Not perfect, but for basic stuff like timing etc, it is easy to follow and accurate.

 

[varesecrazy]

remember the Classic 124 spider section is NOT HERE in "Mazda - land"

 

[124spiderman]

If your not confident I wouldn't attempt it. Get it wrong and goodbye engine.

 

[F123C]

I have a 1979 Fiat Spider 2000 and would like to replace the timing belt. Bought a 124 Spider Shop Manual for $42 from VickAuto but it is useless.
I have been searching for online but there are conflicting information. Thank you in advance for your guidance.
QTD

I'm curious as to why you say this Shop Manual is useless, VickAuto's website says it's a reprint of the factory manual. Should be comprehensive?

Replacing the timing belt on a Fiat twin cam is fairly straightforward. Apart from the usual requirements to get the crankshaft and camshafts correctly aligned and the belt tension correct, the only other important point is to ensure that the auxiliary shaft pulley is also correctly positioned,(Iirc it's timing mark should be set at 23 degrees clockwise from the 12 o'clock position = 3 teeth on the periphery) otherwise the lobe or eccentric on the auxiliary shaft can collide with the crank. no. 2 big end.

Make sure the tensioner bearing is fit for re-use or replace it. Check the belt pulleys carefully if they're the plastic type as they can crack around the centre metal bush and if so, need to be renewed.

Tension the belt, not too tight, not too loose. I used to adjust the tensioner until I could just about twist the long run of the belt through 90 degrees. Rotate the engine by 2 complete turns by hand and recheck everything is still correct (you might have to re-tension the belt) before attempting to start the engine.

The timing marks should be in the manual you have, the rest is pretty straightforward.

If you haven't replaced any timing belts before, perhaps you could find someone to 'walk you through it' just to be on the safe side.

But as 124 Spiderman has said, if you get it wrong, you can wreck your engine (big time!). So be careful.

Any other questions, just ask.

Al.

 

[SJ9spider]

Good advice. I need to replace the timing belt on my recently-acquired 1981 spider 2000. What is the best way to prevent the crankshaft from moving when removing the big nut holding on the crankshaft pulley? Or do you need to even worry about that if you leave the belt on while just loosening the nut? (that way if there is movement at least the cams, etc all move in unison).
I too have the International Auto Parts manual - it has a pretty good description on timing belt replacement (but does not mention how to lock the crank to remove pulley).
Thanks

 

[Mr Ken]

Yes, I understand what you say/mean however WHICH one of the (3) is the ZERO mark on the Crank pulley The BIGGEST mark ?
PLEASE someone help me out. I'm going NUTS...

 

[124BC1]

Yes, I understand what you say/mean however WHICH one of the (3) is the ZERO mark on the Crank pulley The BIGGEST mark ?
PLEASE someone help me out. I'm going NUTS...

All of the 124 Twin Cam engines I've seen have only one timing mark on the crank pulley (there's a raised line on the casting pointing to a small notch on the pulley rim, it looks like a saw cut, (see green arrow in the pic) and 3 timing marks (10, 5, 0 degrees) on the timing belt cover. So in the following pic, the ZERO mark (top dead centre) is the BIGGEST (longest) mark on the timing belt cover (indicated by the red arrow)

 

[Mr Ken]

Yes, I understand what you say/mean however WHICH one of the (3) is the ZERO mark on the Crank pulley The BIGGEST mark ?
PLEASE someone help me out. I'm going NUTS...

OMG THANK YOU Soooo Much. First Thank all of you who welcomed me as A comer. I finally figged my password thingy. Does anyone have any recommendations for sealants or gasket compound to install cambox gaskets ? ? ? Thx. Mr Ken

 

[s130]

Which gaskets are you asking about. The cam box is actually a carrier that bolts onto the head. This means there is a gasket between the carrier and the head and of course the gasket for the top cover plate.

For the top gaskets:

Many years ago a went to a local rubber supplier and sifted through there off cuts box and got some nitrile rubber sheet about 2mm thick. I then used the old top gasket to cut a new one from the nitrile sheet. That was over 30 years ago, quite a few valve shim checks/adjustments and the nitrile gaskets are still good. They don't stick, leave no residue etc. Well worth the 30 to 60 mins I spent with a stanley knife and scissors making them.

For the lower ones than they are more problematic and don't need to be disturbed unless they leak, or you are removing the whole carrier.