jheis

I just picked up a set of '86.5 cam sprockets figuring to convert to the high torque (round tooth) timing belt the next time I do my '82. However, I now see that the part numbers for the 16v and 32v sprockets are different.

I know that the 32v sprockets are different to accommodate the distributor rotors, but is that the only difference? In other words, can the 32v sprockets be used on the early cars?

James

PorKen

The 32V cam gears (sprockets) bolt to a star shaped hub. The hub fits tightly over the cam woodruff key, as opposed to the 32V gear, which is slotted.

The hub and gear combination fit on the 16V camshaft, but the hub is too thick, so the gear sticks out too far.
...

I make a kit to convert to the 32V gear, which also lets you advance or retard the cam timing for more torque or horsepower. The kit includes machined hubs, and 'pointers' which correlate to the setup notch on the 16V gear.



Here's the manual, it might give you a better picture of the parts involved: (16V32VGearSetup2_0.pdf 513KB)

If you only want the HTD belt, then 83-84 gears are the ticket. The flat tooth belt is actually fine for the early cars, and not really worth the expense of changing all the gears - unless you want adjustability!

GlenL

And don't forget that you've got to replace the crank gear and the one on the oil pump, too.

Hmmm... Maybe a daring person could get away without doing that.

Anyways, the "High Torque Design" is not entirely accurate as the belt itself is the same material. It's the teeth that were changed to be rounded instead of square. With my engineers hat on, (well, it's around here somewhere) I'm not sure that it is really any better.

Garth S

Glen is correct in that all four cogs are required - you cannot get away with less ( so don't take the dare ): the HTD belt will not mesh with the 'square' gears, even though the tooth spacing is identical. I've done a fairly complete conversion on an '80: full HTD with an '85 tensioner - so I can finish wiring in a "low belt tension" alarm.
You do need the '83-4 cam gears as Ken mentioned - unless you progress to his well designed system above.
Why HTD? - likely preference: there are more choices available and they seem to run quieter - I use an aftermarket HTD that has a further modified 'dimpled' tooth design that has yet to exhibit stretch/tension loss in either car.

Dave H.

less noise with the rounded belt/gears...

PorKen

HTD belt and gears are significantly quieter, especially if you don't have the covers on.

Standing over the engine and revving up to 5 grand was deafening with flat teeth. After converting, it was much, much quieter at high engine speeds, and at idle, I was scared to hear clicking - which was the fuel injectors!

jheis

Thanks Guys:

Yes, I know you need all four gears, but the cam sprockets were the ones I had a question about and PorKen answered it pretty well.

Anyone need a pair of 32 valve cam sprockets cheap? PM me.

James

FlyingDog

If you've already got the sprockets, get Ken's kit. You'll be able to adjust the timing of the two cams to match, so your engine will run smoother. You can also try to advance and retard them to adjust performance.

jheis

I'll bite, how much for the kit?

James

FlyingDog

The price went up since I bought mine, but it's still worth it in my opinion.
https://rennlist.com/forums/928-forum/181816-32v-cam-timing-tool-and-16v-32v-conv-group-buy-2-a.html