Stock 0.8 bar wastegate - annular spacers inside

[Speedy Squirrel]

I took apart my Porsche wastegate to measure the valve to guide clearance, and I found 2 spacers inside. Is this the stock arrangement? Do you leave them in when you put in a 1 bar spring?

[OSI930]

Not stock. The spacers you have are usually added to increase boost. You should have a thin steel washer above and below the spring.

[Speedy Squirrel]

Thanks for your help. I figured they were aftermarket. I did/do have the thin steel shims. For those who have not seen it before, here are pictures of Porsche wastegate guts. I measured my valve guide clearance at around 0.3mm.

WASTEGATE BODY & LATER STYLE MUFFLER (note bronze guide)



INTERIOR OF EXHAUST GAS PASSAGE



TOP SIDE & VALVE GUIDE



INVERTED STYLE WASTEGATE VALVE



WASTEGATE VALVE SEAT (This plate fits with a light press to the main body)



CANISTER BOTTOM (note port for boost pressure)



The canister top, diaphragm, and valve retainer are shown above.

[911nut]

So what pressure was your wastegate opening up at with those spacers? Are you getting any blow by through the valve guide?
My stock w/g was shot at 70k miles. I replaced it with a Tial and never looked back.

[Speedy Squirrel]

The boost pressure was around 0.8 bar with spacers. That is puzzling, isn't it? I wonder if the spring took a set with that much preload (each spacer was 10mm thick). The rest of it seems to be in good shape, no evidence of blowby. I wonder if they are born with a pretty big valve guide clearance.

[911nut]

Originally Posted by Speedy Squirrel

The boost pressure was around 0.8 bar with spacers. That is puzzling, isn't it? I wonder if the spring took a set with that much preload (each spacer was 10mm thick). The rest of it seems to be in good shape, no evidence of blowby. I wonder if they are born with a pretty big valve guide clearance.

Interesting that it was only .8, unless the spring on it's own is only good for .7. The clearance isn't that big (.006 inch per side). Since you don't have blow by, I'd sandblast the body and keep using it. How's the condition of the fiber washer on the top of the steel body? I never figured out what a good replacement for it would be.

[Speedy Squirrel]

Fiber gasket tore apart during dis-assembly. I used some graphite gasket material to make a new one. I don't know how well that will work. It can take the temperature, but it seems pretty soft. If it doesn't hold up I will try grafoil. Mr. Gasket sells that as part number 5960.

[T77911S]

mine was leaking too.
i put enough pressure in to open it. i could hear and feel the air coming out of the exhaust pipe.
put a tial on there.