Jastx

Will be mounting new tires soon and am considering changing valve stems to the metal ones like on the hollow spoke wheels -- I like the more serious look.

Are there any reasons not to do this? Are there any problems with the metal valve stems -- more prone to leaking or anything?

Thanks!

John D.

Hey John..!

Actually - if you don't like the metal after you get them, you can pull off the "metal" outer body, and underneath - it's just a black rubber stem....

ceboyd

some race clubs/groups require the metal valve stems and metal caps

..the idea being that the metal is less prone to failure.. etc.

metal ones tend to be more pricey..

...I have metal on the fikse's but rubber on the boxtser... both work just fine..

What I DONT like about the metal ones is that kids like to steal the metal caps for their bicycle wheels

mike cap

John,

I replaced the metal valve stems this winter on my 18" hollow spokes during the course of sending them out for refinishing. The metal valve stems are pretty well made, with 'O' rings for sealing. I would make sure of the torque for the nuts on install. As far as fitting your wheels, you need to verify this. I don't recall any squawks about these style of valve stems being leak prone.

The part number is # 993-361-073-00. I think they were something like $10.00 each.

STLPCA

John
AFAIK the metal stems for the Technology (hollow) wheels are not rubber. They are metal stems that mount from the inside & seal w/a gasket & nut. There are aftermarket "metal stems" that are just rubber stems w/a chrome sleeve.

There are pros & cons to metal v rubber. Among them are that the metal are not maintenance free although almost nobody properly maintains them. The nut should be torqued, the gasket replaced, & the valve replaced when tires are replaced. The rubber ones are routinely replaced w/the tires. Although rare, I recently had a rubber stem failure (not the valve) on a track tire. Fortunately, it was a slow leak. Many years ago I totalled a car aftter a catastrophic valve stem failure on a wire wheel.

One of several prior valve stem threads.

garychios

I dont know about the porsche metal valve stems, but real metal valve stems are required for high horsepower cars drag racing. They are less like to fail or rip. I run metal valve stems along with elongated hardened wheel studs on my race cars.

Bill Verburg

Dan 96C2 St.Louis summed it up nicely. here is a pic of a true metal stem and a sleeve type that just slips over a rubber stem.


The rubber seals of the metal stems need to be replaced as often as rubber stems, but they metal are superior for track use because they don't bend and they come w/ gasketed caps(just visible in the cap here) which are an additional safety feature

They also look great!

SkipSauls

I've been told that if you mix the type of metals/alloys between the wheels and stems then you may get some ugly results, as in a rust-like corrosion or other discoloration. I have metal valve stems on 6 sets of wheels for my race cars and have never seen anything like this, but then again these stems came with the wheels and may have been "matched". I'd certainly check into this on a street car where discoloration may be a factor, but on a track car I wouldn't care much as long as the wheel and stem function correctly.

Bill Verburg

Steel and aluminum actually have Anodic Indexs that are fairly close to each other, Meaning that in a harsh environment(sea water and road salt qualify) they will corrode but fairly slowly, in a controlled environment(inside a mounted tire where Nitrogen is used for inflation)) they won't corrode at all. Magnesium and Zinc have idexes that are far from steel or aluminum , hence their use for sacrificial purposes around props and aluminum hulls.

Martin S.

I am looking for steel valve stems that fit the standard 17" X 7 and 17" by 9 993 Cup wheels. I have them on one set of Cup wheels but cannot recall remember where I got them. I wonder if the 18" hollow turbo valve stems will fit? Any advice and or part numbers or source appreciated!!

garychios

I run those exact stems on my race car

dave morris

Earlier, Skip mentioned rust. I have metal valve stems on my '84 911 which is pretty much exclusively a track car. When the wheels come off the car, I like to get the brake dust off, and generally hit them with a hose. They lay around for awhile and bingo ... rust is forming at the base of the stem. No big deal, but a small downside.