you can't leave your head on

[Tappy]

Hey guys

Got my head off this weekend

few questions do ;

- how do i know theres anything wrong with it ? cant see anything thats wrong on plain sight (but then i'm a novice in this so pls point out where to look )
-the second exhoust valve only opens up to 6mm all the other exhoust valves open up to 10 mm ? can this be correct ? seems much a difference
-if you set the cams on the points designed for replacing the timing belt how should the valves be ? can it be some previous owner realigned the cams ?

probably some more questions later but i'll start with these

[ventura ace]

[quote="Tappy"]
-the second exhoust valve only opens up to 6mm all the other exhoust valves open up to 10 mm ? can this be correct ? seems much a difference
quote]

Is there a shim missing for the valve that only opens 6mm (look under the valve cover)? Or, is that valve not closing all the way? Maybe it is fully opening, but only partially closing. 6mm is way off!

[So Cal Mark]

look at the cam lobes, you probably have a flat one. Do a search about oil, you'll find a long discussion about using oil with zinc additives to prevent cam failure

[Tappy]

Is there a shim missing for the valve that only opens 6mm (look under the valve cover)? Or, is that valve not closing all the way? Maybe it is fully opening, but only partially closing. 6mm is way off!

The shim is present, valve closes all the way , but see that camshaft lobe Theres about 3.16 mm missing.I wonder if this has to do with the knocking sound or the exhoust "ploffing"

Dont know what cause 't it ,there seems to be not a visual problem with the valve itself , maybey this was a po problem ? this cams are both of different cars as far i know. @ least i'm sure there's a problem , so i better solve this first



but since i only have the haynes manual and no prior skills i think i just go in search of another complete cam
if any one has a spare , pls contact me
http://www.fiatspider.com:16080/f08/vie ... =19&t=3859

[Tappy]

right on mark , your the man that posts faster then its shadow

[pope]

Tappy,
What is the grade of oil that you normally use in the Spider?

[Tappy]

10w 40 syntetic ?

[pope]

Tappy,
This forum has had a lengthly discussion about the oil used in the Spider. In america, the formula for auto oil has changed significantly since the time the fiat spider was built. One thing that has changed is the removal of Zinc (ZDDP) from oil. The oil that still has significant amounts is the 15W-40 (this is also the oil that Fiat suggests you use in the owners manual) which is a diesel oil. The Zinc is a sacrificial soft metal that takes the abuse and helps leave the cam lobes and tappets in good shape. In America, 0w5 throught 10w-40 contain almost no zinc.

My personal opinion is that anyone that doesnt use 15W-40 is gambling with their engine.

[Tappy]

ok like to gamble , but not with the spider

so i'll change it right away , or even better take alook @ that discussion first

thx for pointing this out , however cant really imagine that one of the lobes getting 3 mm shorter just bye using the wrong oil ?

[racydave]

I would suspect that if it was a oil problem that it would show up in more than one cam lobe. Either there is to much resistance in that valve set-up,( check for bent valve ) or its possible that lobe was not hardened properly. I saw a TV show last week that showed the modifier they added to base oil to obtain the variance in viscosities, it was interesting.

[So Cal Mark]

I've never seen a Fiat cam with two flat lobes, but I have a shelf full of cams with one flat lobe. I've yet to see one with a binding cam bucket.