DobermanDad

Hmmmm....I was just more curious than anything.

I just powder coated my fan last summer, no need to replace it, especially after all that time put in.

LPMM

^^^ THIS and I have yet to see a proper curved 12-blade aluminum fan for our 964s.

cobalt

So long as there are no cracks or extensive corrosion you should be good to go for years to come. Magnesium gets a bad rap but it is a fantastic alloy. I spent the past 6 months helping a local foundry that pours aluminum, elemental copper, brass and bronze to pour aluminum based magnesium alloys. We essentially tried an entirely new sand and process and so far the results are better than expected. I have been considering redesigning and manufacturing valve covers in mag alloy so they should not warp like the factory ones and see how that goes. I might consider other projects as well but honestly for what it takes to cast a mag fan housing it would still be cheaper to buy a factory unit at $327.71 from suncoast than i can manufacture them for. The valve covers at $229.62 each I can easily better that price after a redesign but it will be a while before I get to it.

DobermanDad

I think I got lucky. My mag. valve covers are still in good shape and no leaks. I have a spare set of Aluminum lowers, but don't even really need them.

I may just sand blast and PC my covers and call it done.

HiWind

Who's the best source in UK or Europe for windscreens for 964?
Want to order 3-5 - thanks!

John McM

Anthony, any thoughts you can share on our effort at CNC valve covers? With material and CNC machining time costs they are not an overly commercial proposition.

cobalt

I just posted on the other thread. He made some nice pieces but the time to hog that much material is costly. I am just in the throws of starting. I am not looking to machine but cast them out of AZ91T6 Magnesium alloy. The cost to cast is far less and they would need minimal machining. I also have to work out the coating costs to prevent corrosion.

It will be a few months since the holidays are here before I have exact figures but preliminary numbers to manufacture a set is less than the cost of one new cover from Porsche. I would not post anything here without discussing it with IB first. But the possibilities are good that this will happen by the summer. If it works out I might consider attacking some other aluminum parts in magnesium for weight savings if there is interest.

luckyJ

while cleaning/painting my cooling fan, I noticed two small hairline cracks on the face of my fan....is this safe to use and is it possible to glue/weld together? is there someway to salvage it? thank you

John McM

I had the same crack. My mechanic said it wasn't in urgent need of replacement but when the bearing needed replacement as well I just bought a new assembly. In my aviation days we drilled the end of cracks to stop them spreading. Not sure it's wise to do the same with magnesium.

Goughary

Your mechanic is wrong. "Non Urgent" in this case, means, "it's not likely to blow apart right this second, but at any moment it could, and I hope no one is standing near it with the lid open. And by the way, I know it's coming here for the 5k in repairs your engine bay will need once it goes...so have at it"

Ever seen what happens? It's not pretty, especially if it happens when you are spinning the motor fast...

Just sayin. If there is a crack, you just replace it immediately. It's one of those things...

luckyJ

I'm about to take the AC bracket off to gain access to the passenger side timing chain cover/gaskets...but this crank pulley bolt is tricky....if I try to turn it CCW, then the crank pulley moves in sync and I read somewhere that this could cause internal damage...

what is the proper procedure to unbolt this please? thank you

Goughary

You have to use a special tool that grips the heads of the cap nuts to loosen that bolt.

The tool is expensive but there are plans for one on rennlist somewhere

Goughary

Here you go...

https://rennlist.com/forums/964-foru...oval-tool.html

John McM

This is the tool. If you use this it is a no brainer. I borrowed mine from the local OPC , but have a plan to make up some heads with CNC milling at some stage.

cobalt

Based on the location it is less of a concern than if it was a blade or other cross section. Does the crack go through? If I were you while you have it apart spend the $300 and buy a replacement although you could probably get away with this for a while if you don't push the car hard all the time.

That is a strange place for it to crack and no doubt was the result of some mechanic screwing up at some point.