Dayco timing belt - universal - will fit both old and new engines?
 

This may be a question for Roger. The Dayco 219SP254H timing belt is said to be universal and fit all engines 1977 to 1995. Is that correct? I have no square timing gears of the early design to check on. The teeth of the the Dayco belt are different compared to other belts.
Åke

Looks interesting.

Will not work on early square tooth gears.. well not for very long, anyway. Square tooth gears are NLA, anyway, aren't they?

Interesting - looking into it further.

I found some information about different tooth profiles used for Dayco belts. It says quote: It is important to underline that ‘SP’ belts, because of their parabolic profile and tooth indent, can function on a wide variety of pulley designs.
Does that mean the 219SP254H belt will work on early square tooth gears?
I have asked Dayco but no reply so far.
http://m.dayco.com.au/databank/docum...othprofile.pdf
Quote:
Tooth Pitch 9.525 mm (3/8")
These tooth profiles were developed to respond to the unification needs of the automotive
market for deep tooth profiles. They offer optimum performance levels for
both petrol and diesel engines. It is important to underline that ‘SP’ belts, because of
their parabolic profile and tooth indent, can function on a wide variety of pulley
designs. These belts also feature a double fabric covering the teeth.
‘SP+’ belts belong to second generation of ‘SP’ belts. They are designed to operate
with pulleys manufactured by us and on other pulleys. The tooth size is greater than
on ‘SP’ belts which allows the ‘SP+’ belts to be used on engines with very high peak
loads. These profiles, with double fabric covering are available in polychloroprene,
or HSN. However, in recent years the trend has been towards using HSN.
Åke

I would put a round tooth belt tooth on a round tooth pulley,
and a square tooth belt on a square tooth pulley,
I would not use that hybrid belt.
From the looks of things this will cause extra wear on all of the parts
kinda like banging a square peg into a round hole

Tough to tell from a picture, but it doesn't even look like it fits well on a round tooth sprocket.

The Dayco belt fit as well on the round tooth sprocket as any other timing belt I have tried. Do not mind the picture it is me holding the belt in place when taking a photo.
Think I will be able to try the Dayco belt on an early design square tooth sprocket in the next few days.
Åke

Finally I have able to obtain an early design square teeth timing gear for testing. The Dayco timing belt do not fit very well on the gear, the "valley" between the teeth is not deep enough. The belt is riding on the edge of the belt teeth. However I have heard of someone using the Dayco belt on an early car having early design timing gears with no issue. The conclusion is that the Dayco timing belt should be used with late design rounded teeth timing gears.
Åke
PS The groove at the top of the belt tooth is said to reduce noise.