manifold / port thickness gauge tool

[Balidey]

I have an alloy manifold that needs its ports opening up to match my head, but the manifold itself needs opening quite a lot and I would guess quite far back into the manifold, otherwise I will have a divergance. My father will be helping me with my build and he used to use a tool like a pair of long thin scissors and you could pass one part into a port and the other into the waterway (my manifold has a waterway below the floor) and whatever the thickness of material is in between the manifold end of the tool was visible on the outside. This way you can remove material without breaking through or getting too thin.
I have tried to explain it as best as I can, but maybe the attached sketch helps.
What I would like to know is are these tools used by engine builders still? What are they called and where can I get them from? If they are not generally available then using my sketch I think I could make them myself.



I will be taking photos of my manifold later this evening which will help explain why I need to use a tool similar to this.

Regards,
Steve

[Guy Croft]

For most heads I do I have to rely on cutting up old ones to assess cast and few permit direct measurement of thickness in situ. But - if you consider producing such a tool, I suggest you give it some add ons:

1. Markings (cm) along its length - like a depth gauge) so you can see how far in the port you are.
2. Reversible set up so you can measure internal & external
3. A 'protractor style' gauge (mm) that you can directly read the port dia from. Gauging the port width against a vernier is always a nuisance.
4. The tool wants plastic coated jaws so it doesn't scratch the port!

I'd buy one!

GC