Cam Shaft Pulleys

[AlfaJack]

The current pulleys that are fitted are solid but I have some others from another head which have holes in them...they are Lancia/Fiat parts too.

Any advantage in swapping them?

[Steve Webb]

Seriously doubt it. If you are going to go to the trouble of swapping cam pulleys, you may as well buy and fit some vernier ones.

[AlfaJack]

Seriously doubt it. If you are going to go to the trouble of swapping cam pulleys, you may as well buy and fit some vernier ones.

I didnt think so either. I am always curious as to why they give little things design changes. Always think they must of had good reason:rolleyes:

Vernier pulleys, very nice but not for now.

[Juan AR155Q4]

I have the ones with holes fitted in my camshafts but I just think its an inertia issue. Although I don't think that this will make any noticeable performance change.

[AlfaJack]

Thanks. Best I do not touch them then :)

[Brul(tm)]

Vernier pulleys, very nice but not for now.

They are also on my to do or whis list ;)

Greetings,
Marc

[cuore_sportivo_155]

lafa, and maybe lancia has well, have the habit of doing things properly at first (like crossdrilling pulleys), and then give up on those things to save a few ?? on manufacturing.... this has been like that since WW2 at least...

[Evodelta]

The current pulleys that are fitted are solid but I have some others from another head which have holes in them...they are Lancia/Fiat parts too.

Any advantage in swapping them?

If they are lighter (which they must be) and you have them on the shelf then yes fit them, it's only a very mild mod, but if you have them already then it is worth doing. Just make sure they are not from an N/A engine or check the timing marks on them incase they are any different (I don't know whether they will be or not). Also check the tooth profile as there was a very early type used on the 'grale which was weak, recalled and discontinued.

Solid ones are early type, with holes in are later type so things did improve....

[AlfaJack]

Thank you. I will post a photo of them and do a comparison. But given that I will not know if these are the early weak type I may give it a miss.

[Evodelta]

Sorry - I meant that the belt that used this type of tooth form was weak, not the pulleys themselves. If your (trapezoidal type) belt fits these pulleys (and the difference is huge) and they have the same locating marks (both timing and dowel hole) then you will be ok. The weak belt type which is a square tooth was recalled and binned from only the early 16v 'grales which was probably around what, G or H plate?

As we are talking about different tooth types, if you look closely at your belt it has a very small groove or channel on each tooth, this is so the air can escape from each one as it hits it's opposite number on the pulley, if it didn't it would have a tendency to float slightly at high RPM.

[AlfaJack]

Interesting stuff. I would never had considered that a belt could float like that. More design work than you would think.

Cheers!