Porker928

I like your theory as it's similar to what I heard. But the only problem with it is the original 928 engines up to the S2 engine did not have distributors mounted on the ends of the Cams but they still had the vent holes?

Mrmerlin's idea is interesting but the engine already has a cam belt failure warning system. All that hot air drawn into the cold air intake is a high price to pay for warning about something that is already been warned about?

Landseer

It can't possibly make much difference, really. I run the cars with the vents connected, not connected, tubes on the car, tubes off the car. No difference.

RKD in OKC

I'm sticking to cooling the timing belt. To keep it from stretching.

jon928se

It's the cause of the 2-6 bearing failure problem.

The air drawn in through the TB covers cools the TB pulley region of the crankshaft causing the front of the crank to run at a cooler temperature. This causes a thermally induced relative vacuum in the crank oil passageways at the front which draws in more aerated oil to the 2-6 bearing area

Simples

innit

Porker928

Thanks for your answers.

I think I agree with the whole removing of oil vapor, ozone and generally bad things for the belt idea with negligible effect on cold air intake.

tedward515

I thought that was for spraying WD40 in there to keep the tb lubricated

GregBBRD

That's a valid point. That was not my theory, BTW. That is what I was told by the guys at Porsche.

mark kibort

thats why amzoil is used to reduce cam timing belt stretch and wear. the 10buck a quart oil has vapors that coat the timing belt, making it impervious to ozone, oxygen and also fights issues when running dry tensioner housings.

Stromius

Intake on the passenger side induces a coriolis effect similar to the Atlantic (CW) while the driver’s side has a Pacific coriolis (CCW) effect thus creating geostrophic forces (aka Eötvös effect) in the middle of the engine. The ribbed belt forces oxygen molecules closer together and super saturate the inbound air for high combustion.

PorKen

Timing belt cooling.

The intake is next to the crankshaft, behind the oil level sensor.

jon928se

Thats why it keeps the front of the crank cool - misguidedly

svpmx83

and here I was, thinking that the posts were there to stop the tubes flopping around

tlsmith1999

I thought they were there as an air pressure relief. When the car is driven at 928 speed, the intake tubes can scoop up too much air, throwing off A/F mixture.

Jim Chambers

Everyone knows that they are there to allow escape of the carbon dioxide released from the panting gerbils who are running on the timing belt powering the car.

kccampro

You guys are so dumb... clearly the holes at the top of the TB covers are the access point for water to be poured into the covers so that the volume of the interior area can be measured. The more the TB wares the greater the interior volume of the TB cover system... you then measure the volumetric difference over time and tells you that you need to change the belt. Your welcome, next time I'm going to charge for that knowledge.