no-go valve guide tool

[Tom F2]

Has anyone tried on of these? I tried one from Baum Tools recently, and I am not sure of whether the tool they sell is the real deal - I suspect that it is an SIR manufactured item.

The tool from Baum has a single machined shaft that starts with a 9.000 mm diameter, and narrows to 8.970 as you get to a handle. The tool looks a lot like the P206 pictured in the shop manual, but I expected to find two machined shafts, end-to-end, one at 9.000 mm diameter, the other at 9.150 or thereabouts. So, the tool should "go" at 9.000, but "no go" at the wear limit of 9.150, I think.

Thanks in advance.

Tom

[Tom F2]

Here's the picture showing what I am trying to describe in my first post.

[cgarr]

Are these used for checking new guides when reamed or old guides? I dont now how you can check an old guide since I have never seen one wear round, they always seem to be elliptical.

[Tom F2]

As I understand it, this tool is to decide whether a used guide is fit to go back in service, or to double check whether a new guide is within spec.

[euro911sc]

Looks like this tool only checks the 9.0 spec. The inner taper is to prevent the tool from getting stuck. This tool seems to be rather useless, or not as useful as it could be.

It appears that this tool might only be for measuring the NEW guide after reaming it to size. NOT for determining if a current guide is still usable. To do that, you would need a big end, and if it goes in the guide then its bad, obviously

Best regards,

Michael

[Jim Williams]

Here is my equivalent of that tool.

The longer end measures 8.997 mm all the way up and down the shaft. There is no measureable taper.

The short end measures 9.017 mm. It is made so that it can be used to help determine the the ellipticity of a worn guide by rotating the tool inside the guide.





I've had the tool for some time, it could have been bought from Baum. I bought a number of Porsche tools from them several years back.

[Tom F2]

Thanks, I'd say that this is the same tool, but it doesn't seem very useful.

[Jim Williams]

Depends on your point of view, I guess. If the small end won't fit, the internal guide diameter is too small and will have to be honed. If the large end does fit, it's too large (according to the spec book) for a freshly installed guide. Potentially useful for the builder who is installing new guides.

[anh911]

My guess is that the tool is not a go, no go, but simply meant to be used in conjunction with an indicator to measure side to side play when testing guides.