Lizard928

I wouldn't be worried about it at all Paul.

fraggle

Since I was just looking inside a 32V head ('88) with the covers off and the tensioners out for replacing the plastic ramps/pads.

I agree, bad idea, but looking at the design I really can't see how they could be damaged be someone rotating the motor by hand. I'd be really surprised. I'd be more worried about goofing up the tension and skipping a tooth or two. I'd re-check the timing (by hand!!) after a few revolutions in the right direction.

Jim bailey - 928 International

I thought the concern was that the cup shaped washers MIGHT flatten out some which MIGHT cause the tension to be high on a hot engine......In the past people have been sold 911 starters for the 928....they spin "backwards" after eventually figuring out that the engine was spinning backwards and putting on a correct starter motor the cars all ran O K a least initially and I never heard from tham again about any problems ... I would suggest checking tension cold and hot but I really do not think you hurt anything.

Bill Ball

A large light yellow multi-langauge card comes with the belt from Porsche, at least for the later models. It is used to record the mileage and includes a reminder:

The new toothed belt must be checked or tightened after 3.200 to 4.000 km (2,000 to 2,500 miles).
If this is neglected, damage could occur on teh toothed belt and in turn even lead to engine damnage.
Please make sure of conformance to this point.

The Warranty & Manitenance book for my 89 includes a check of the tensioner oil level every 30 000 miles, and belt change every 60 000 miles. The belt change includes a notation to "Check condition and tension after 20000-2500 miles (3200-4000 km).

Odd, there is no indication of a belt tension check at 2000-2500 miles after purchase in the maintenance book.

Perhaps what you found in the WSM 15-14 pertains to the early design belt.

rahulsingh

If the cams has been removed I believe crank can be rotated in any direction but if cam & tensioner is installed i don't think it is a good idea to rotate it in anticlockwise direction. Correct me if I am wrong.

dr bob

Holy decades-old thread revival!

The issues around counterclockwise crank rotation are related to pulling directly on the tensioner, potentially allowing the belt to walk up on a pulley. That ends with a cam snout broken and/or a belt that's out of time with the crank. Both are easily checked, one is easily remedied.

In my limited experience, it's generally easy to avoid turning the engine backwards. While working on the clutch you might be looking forwards in the car and forget that clockwise on the crank is not the same as righty-tighty on the flywheel. Pay attention!

UKKid35

I can confirm that no damage was done

Or at least if it has been done then its effects have remained hidden for about 50k miles

Bill Ball

Please report back again in 10 years so we can remain assured there was no detectable long term damage.