Boxer Flywheel Timing Cover (Rational)

Referring to the small cover with drilled holes (approx. 1.5" x 3") on the Boxer bell housing held on with 2 6mm nuts.

It is adjacent to a large opening. Why is it drilled? Is there some thought of looking through the holes to conduct timing checks? It would be harder to do this way. I wouldn't consider it. Why is it there at all (as a cover)? If the concern is dropping something in the bell housing, it is just next to a much larger unprotected opening.

It's just some perplexing feature to ponder Image Unavailable, Please Login or appreciate. (?) Image Unavailable, Please Login

 

Why are tires black? The rubber they are made from isn't black?

 

To reduce weight?

My serious answer would be that on a 365BB that drilled cover is the only way to have a quicky look inside at the clutch area without removing it, and, with the opening being at 12 o'clock, stuff could drop in without having some sort of cover:

https://www.ferrariparts.co.uk/diagram/ferrari/365-gt4-bb/016-clutch-and-controls

so the holes just sort of carried over to the other flat 12s (and it still gives a quick way to look in without removing the cover). That side opening on the 512BB/BBi looks to me like an inspection port that they added to be able to look in at the clutch slave cylinder mechanism and fork (and would not be easy to use for timing measurements), and the other "improvement" was to add an opening at the bottom so a rear main seal leak would be more obvious. That 365BB bell housing design is just way too "sealed up", and it doesn't need to be, plus no reason to have that cover at the 12 o'clock position -- Ferrari just kept improving the design (and kept the holes).

 

Thanks!

I was just wondering if there's something more to it. And I agree that the 365 cover is fairly closed off.

 

I recall once watching two retired ex-Lamborghini factory gentlemen get my Countach running for the first time after a lengthy restoration. When it didn’t fire up correctly, they lifted it in the air to check timing by looking through a few small holes drilled in the bellhousing. The holes were created at the factory as a ‘cheat’, to permit something to be checked quickly that perhaps only an insider would be aware of. The check instantly passed, the car was running sweetly minutes later.

 

For the work to set up and make the bell housing casting and the cover with (I think) a dozen holes drilled in it), there could have been some reason...or not.

Like Ferrari made the 308-oil fill cap placement expose the cam timing alignment.?

 

Not all V8s had an oil filler cap on the engine and when they did it only exposed 1 of 4 cam marks. In any event most had external cam marks. Safe to say its placement was pure coincidence.

Ventilation of the clutch has had a pretty high priority on many models. That and possibly Guidos sense of aesthetics. Reading anymore into it than that and debris protection is just reading into it that which is not there.

I have timed hundreds. Nothing can be seen through the holes.

 

Thanks Brian,

I realized that when doing a 308 major with T belts, the crank rotating procedure to settle the belts before locking the tensioner at least for me can lose track of where the engine is in the cycle - meaning, I can find TDC w the flywheel ez enough, but not enough info. That's where the "oil cap viewport" is a quick help.

 

Using an existing design feature is a very long way from it being engineered for that purpose.