Do 308's with plastic pulleys use same timing belts?

I have been told that the only difference is between the QV motors vs. the non-QV motors. So all the 2V motors should use the same belt regardless of the material of the cam pulley.

 

101R254 is the correct part for the plastic pulleys.

 

Are you sure the "S" can't be used in the plastic pulley carb cars? I have a set I'm about to install on my 1977 308 GTB USA carb car:

The belt has two names/numbers on it: DAYCO 101 S 254 -- and -- ISORAN 101 R 254 94095

The belt also has this number on it: 4164060

So, it lists BOTH numbers! Furthermore, on the Dayco box, it lists compatible models: 208 GTB-GTS, 'BB 512L (?), Dino 208/308, Mondial.
It also lists engine sizes: 2.0, 3.0, 3.2, 5.0

These were purchased as compatible for a 2V 308..

Are they OK to use on my plastic-pulleyed 308 carb?

Thanks,
Greg

 

Anybody? Bueller? Bueller?



Greg

 

The BB is indeed a 5L (liter)..

No idea on the belts..I'd be more worried about cracks in the plastic gears at this point.. and go with solid replacements???

 

I just had new belts installed on my 1981 2V and the invoice lists 101R254, but I never saw the belts before they were installed, so I don't know what other numbers were on the box or belts. I do have the "plastic" pulleys. I remember at a previous belt change when I ordered the belts I was sent belts for the 4V and they were not interchangable with the 2V belts.

 

Please dude, don't tell me that my 77 has the dreaded plastic pulleys, (sn 22207).

help!
chris

 

Yep, I knew the BB512 is a 5 liter flat 12, but the graphic on the box has that "L" on the end, "512BBL"....

Just puzzled by the "L" at the end....??


Chris,
My 1977 GTB #23227 (Dec. 77 build date) has 'em.. pretty sure. Don't all the early 308's have 'em? What's the official "cut-off" date or serial # from plastic cam gears on the 308 line? (Like Ferrari ever had an "official cut-off" of anything back in the '70s!!)

Greg

 

101S254 is probably OK. If you have the "wrong" belt (the later belt), it won't even reach over the pulleys.

 

My May 77 GTB has steel gears and my Nov 77 GTB has plastic.

Dave

 

^^^^ wow, that's weird....

Has anybody experienced failure of these much-maligned plastic cam gears? Maybe they switched to them for weight savings. Ferrari hopefully knew what they were doing..

??


Greg

 

My '82 Euro GTS QV has plastic gears. No sign of deterioration.

In 7 years on fchat, the only plastic gear failures I've read of were people reporting scrapping plastic gears because one of the flanges broke off during a major. IMHO, scrapping was dumb.

The plastic gears are molded w/o the flanges, then the flange was glued onto either the gear's inner or outer edge depending on the final part # being made. Usually the failure is that the glue lets go & the flange partially or completely separates. All that's needed is to thoroughly clean the two edges & re-glue the flange on with high strength (slow setting) epoxy. Re-glued 2 of my gears back in '01 (search old Fchat) & they're holding fine.

BTW, I've seen steel gears that were pretty badly rusted when the belt was removed. The rust damage was bad enough that the outer edges of the teeth were pretty square & SHARP. You could see where the teeth were cutting into the base of the belt's teeth. No wonder stripped teeth are a common belt failure!

 

Verell,
Very interesting, thanks. Maybe plastic is the way to go on these gears....

Mine seem fine, after 30 years..


Greg