scottpeterd

Checking over the engine before we start it up, I noticed that my timing belt tensioner (1979) is not the original. There are no fill or drain holes. Only a tension bolt at the end. As I understand it, this is from a later model.

I had the TB/WP service done 5 years ago in Seattle. Could they have replaced the original with a later model one? Are they interchangeable?

TIA

Geza

Deleted

gbgastowers

I think the older ones are a sealed system and oil has to be added by taking it apart. No fill or drain holes. My 82 is that way

rjtw

Scott,
A photo would be nice so we all know what you're talking about, but I think PET is enough. Download a copy of PET for your car. PET usually has the answers for almost any part-related question!

GBGT above is right. Is the part for -82 what you're seeing? If not then post a picture.

Here's '83 up:



And here's the tensioner for up to 82:

PorKen

'83 introduced the HTD round-tooth belt and an updated tensioner.

The tensioner body is drilled so that oil also fills the engine block cavities requiring the oil fill and bleed ports.

The tensioner piston had some bi-metal washers removed to make room for a one-way valve assembly for 'damping' (when cold).

FredR

Whereas it has been ingrained into me not to turn the engine anticlockwise it is the first time I have spotted the comment about how doing so might "destroy" the tensioner. Any thoughts as to how that might conceivably happen?

PorKen

Normally, the tensioner spring washers act on the belt on the 'loose' side of the crank gear. The 'tight' side is pulled between the crank gear and the cam gears.

Turning the crank CCW would make the 'loose' side 'tight' and could crush/crack the washers (especially when cold)?


Further than this, the unregulated loose belt now on the other side of the crank gear might be able to jump teeth if the belt were not initially tensioned (pre-stretched) properly.

scottpeterd

This is what I have

linderpat

You have the correct tensioner for a 79. No fill holes. Same as my 78.

Petza914

Interesting info on the tensioner difference and the CCW engine rotation.

However, why anyone would run the stock tensioner vs a zero maintenance, oilless Porken version, I don't really understand.

belgiumbarry

because we are purists ? ......

Petza914

Ha ha​​​​​​... says the guy that was going to fit carbs with custom manifolds to his 928.

belgiumbarry

was ? ....is ! ....just a matter of time .
More, my white '82 ( visual copy of Carl's car ) already has carbs IDA48 ... must finish that car and dyno tune/test it ! at least it already runs perfect at idle and moving.... pity it is no more "street legal" , only for rallies, ( or track ) ... so i cannot test it on the street ..or risk a big fine.

scottpeterd

Obviously, our engines are not worthy...