Can you Lap new valves to old seats?

Can you Lap new valves to old seats?

Short answer is no – you will now get load of people telling you it’s fine. New valves should go into new/reground seats then be lapped in. If you want to grab some emmery paper and attack the seats then go for it…

How do you seat a new valve?

1. PREPARATION AND WATER SHUTOFF. Take the original valve seat to the store to get the right replacement part.
2. REMOVE THE HANDLE. Remove the handle by removing the screw holding the faucet in place.
3. REMOVE THE VALVE.
4. REMOVE THE OLD VALVE SEAT.
5. INSTALL THE NEW SEAT.
6. REASSEMBLE THE FAUCET.

Should I lap brand new valves?

New seats, with new valves should require no lapping to get a good seal – my machinist refuses to lap in the first place, considering it to be a half-baked solution.

How much does it cost to install new valve seats?

The average cost for a valve adjustment is between $246 and $336. Labor costs are estimated between $220 and $278 while parts are priced between $26 and $58. Estimate does not include taxes and fees.

How long should you lap a valve?

The lapping process for each valve should take less than a minute if the valve seat and face were ground correctly.

Can you lap valves too much?

Although some seats may need two or three times of lapping, it is not necessary or good to over-lap the valves. It is unlikely, but possible, to remove too much, and doing so will ruin the valve seat. If you are unable to achieve a consistent grey ring, the seats are probably worn out and will require cutting.

How long do you lap valves?

Are valve seats replaceable?

For that reason, replacing valve seats is often necessary when reconditioning aluminum or cast iron cylinder heads. Another reason to replace a seat is if a valve has broken because the seat is not concentric with the guide.

When should you lap valves?

Lapping works good, just more work, and prolly unnecessary if the valves aren’t leaking already. If the valves are leaking, it’s usually due to mis-alignment caused by worn guides.

How do I know if my valves are seating?

So to test the seat, take a new valve–or one that you are certain is good–install it in the guide, give it a good push and see if it bounces back off the seat. A bad seat tends to damp the action, so the valve will feel like it sticks in the seat.

Why is lapping a valve seat so important?

The contact area between the two, especially on exhaust valves, is important for heat transfer and engine longevity. Lapping of used, pitted valves and seats will likely not do anything except use up some time, effort, and lapping compound.

What’s the best way to lap a valve?

You would use ‘lapping compound’ (strangely enough) available at most parts stores. Stick the valve in with just a little dab of compund on the face and use a ‘lapping tool’ (a small round wood handle with a suction cup) to attach to the valve. Lapping or grinding of new valves is NOT recommended anymore. Check with your supplier to be sure.

Is it OK to cut new valve seats?

Cutting New Valve Seats. Most often you can get away with just lapping new valves into existing seats. When the seat itself gets burned, you will never get good, long-lasting compression unless you repair the burned area before putting the head back into service.

Is it necessary for new valves and valves?

If any of the kerosene leaks past any of the valves, then that leaking valve seal is not good enough. Lapping might be enough to fix it, or the valve and/or valve seat may need to be trued up. There are measuring tools for checking the concentricity of the valve seat to the valve guide, and of the valve face to the valve stem.