131mirafiori forum

Hello, it wanted to know if the pulleys of the camshaft,crankshaft, and secondary tree(oil pump) of the fiat 131 abarth 16v,have the same number of teeth that the models 8v, Are pulleys compatible 16v with them 8v?Are the belt transmission and the tensile one the same?Excuse for my English. thank you.

Hello Joan,

Yes, they are the same. But cambelt is different. Cams from Abarth engines are closer together and the cilinder head is higher.

Hello, thank you very much, mirafiori76, the cambelt of an engine 2.0 8v has 148 teeth, you know when it has it of 16v? Or does someone index / brand / manufacturer that has it to buy it?
I have a great doubt.Nowadays I have a cylinder block of 1 fiat 131 racing, with a headcylinder 16v of an abarth stradale, the pulleys that I mount are of 8v, my problem is if the pulleys put of 16v, that you have said to me that they are the same of 8v, or to leave them 8v valves and to mount beltcam of 8v of 148 teeth or to mount the beltcam of 16v.
Sorry for my English.
Thank you again.

Ow, i don't know how much teeth the 16V belt has. I should count mine. Problem is i don't have it nearby. The belt is also a bit wider then the 8V belt. It's stronger. The one from group 4 (which i have) is even wider.
You can't use the belt from 8V because it's shorter. I must admit that i really don't know if the campullyes are the same. Problem is that the 16V differs with the 8V head in all ways. Because the cams are closer together and the head is higher i think the marks don't fit. You could use them but i think the marks won't align. If you know how to put the cams in the right position you might forget the marks. just be carefull.

Hello, does nobody know that they take beltcam them 16v? I believe that they can be 143 teeth, someone has a photo where one sees well the whole distribution of 131 abarth 16v? Thank you.

Hi Joan,

Could you share some photo's with us from your set up?
Regards,

Mike

Hello, I tell the history of this engine and the problems that I am with. I buy the head block 16v with the instructions of fret and montage of the distribution, the pulleys are  of 8v, except that of the auxiliary tree (bomb of oil) that is small, with this small pulley I mount a tensile big more that the normal 8v ,and belt cam of 144 teeth, the engine work well, but max does not overcome them more 6.000rpm, not if have to be through the fault of of this pulley  small and of the belt  long, it can be that it alters the distribution timing and can be that this makes open and close the valves out of time and lose something of rpm's?  ? Am I trying to mount the original equipment of belt, tensile and pulleys, haver if it can be the problem? These engines which are the rpm that to achieve to come?

Like i said, pullyes are the same, but marks are out of place. You could turn one of the cams to the left or right and try again. If this doesn't help, do the same with the other one. If the belt fits then it's ok. I mean, that won't be the problem.
Also check lift of all valves. If they are not lifted enough the engine willnot deliver it's bhp.

Thanks for your reply, I'll do you talk

Cosworth can supply a shorter belt that will work.
Tom