Topic: piston notch tool

[cbr954]

Anyone know where I can find a piston notching tool for the valve reliefs?  Standard stem diameter but 33.5 mm and 28mm valve heads.

[simon#42]

its called a milling cutter , not specific to pistons . check any machine tool supplier for sizes .

[cbr954]

well i dont have a milling machine or a fixture to hold pistons so I was looking for tooling like what is available for larger engines using valve guide in head to cut the notches deeper.  Didnt know if they are available this small or not.

[Dresda500]

In your case it's likely much cheaper to just braze a piece of tool steel to an old valve with enough overhang to give extra clearance radially. Simple and cheap. Even if you have oversize valves, the tool steel can overhang a few millimeters needed without concern.

[simon#42]

well i dont have a milling machine or a fixture to hold pistons so I was looking for tooling like what is available for larger engines using valve guide in head to cut the notches deeper.  Didnt know if they are available this small or not.

have never seen a tool like that , you dont need a milling machine though just a drill , you will need to make a simple fixture to hold the piston though .

[Dresda500]

I think he's talking this type. Back in the day, we would just have the shortblock assembled with all the pistons in the bores and use a dummy head and set on there with these type cutters. Before economical versions could be bought off the shelf we basically just made exactly the same thing, just with an old valve and some brazed on tool steel. You set your depth of cut by having a collar on the stem above the valve guide with the amount of clearance from collar to guide equal to the amount you wanted to shave off. Pretty elementary, but works a treat . Of course this meant disassembling a cleaning the crap out of your parts afterwards.

https://www.lindytools.com/ihpc

[simon#42]

that looks quite a good idea . not the way i would prefer to do it though . thanks for educating me !

[cbr954]

Yes those are the type I was looking for but doesnt look like anyone makes them very small so I will have to figure out another way.  Probably hours on a dermal tool is my only option now.  Thanks for the responses.

[bear]

This is what we used. We would dummy up an engine and use the head for a guide to get angle and position spot on. It works a treat.

[Tracksnblades1]

This is what we used. We would dummy up an engine and use the head for a guide to get angle and position spot on. It works a treat.

^^^^^^

That’s all we have ever used..
The more accurate you braze and sharpen
the HSS cutters on, the easier it is on the
guides…😁

[scottly]

Before economical versions could be bought off the shelf we basically just made exactly the same thing, just with an old valve and some brazed on tool steel. You set your depth of cut by having a collar on the stem above the valve guide with the amount of clearance from collar to guide equal to the amount you wanted to shave off. Pretty elementary, but works a treat . Of course this meant disassembling a cleaning the crap out of your parts afterwards.

On an already assembled engine, the trick was to smear axle grease around the top of the piston at the outside edge to prevent the aluminum chips from getting between the piston and the bore.

[Dresda500]

Before economical versions could be bought off the shelf we basically just made exactly the same thing, just with an old valve and some brazed on tool steel. You set your depth of cut by having a collar on the stem above the valve guide with the amount of clearance from collar to guide equal to the amount you wanted to shave off. Pretty elementary, but works a treat . Of course this meant disassembling a cleaning the crap out of your parts afterwards.

On an already assembled engine, the trick was to smear axle grease around the top of the piston at the outside edge to prevent the aluminum chips from getting between the piston and the bore.

Yes, good tip, then shop vac it out and be done with it!  If the OP doesn't have brazing capabilities but have an old valve, your local machine shop can surely help