Valve seat condition

[pett3227b]

Should I have the valve seats on my block cleaned up by a machinist? I have tried to upload pics of the valve seats themselves but am having some problems with the computer so I have decided to just describe them for now. I took a wire wheel on my angle grinder after removing all the old carbon there are a lot of pits. most are the size of a pin head. There are lots of them. they are many in the area that makes the actual contact with the valve face. I figured this may be enough for someone to tell me if I need them cleaned up by a machinist or not. Let me know and Thank-you

[tst]

seats to be clean and smooth, no pits so they need to be reground to make them that way and if the pitting is to deep seats need replacing, check valve guides and guides for wear also, pull the valve up about and inch out of the guide and see how much "sideways" play it has

[Eugene]

You are asking a question that cannot be answered without a hands on visual inspection.

You may be able to rent a valve seat grinder.

My guess is that if the valve seats are pitted, you will need additional engine work. So, perhaps take the disassembled engine to a machine shop.

[SamsFarm]

Get a quote for repair with someone doing the work.......

Then price a valve seat cutter for your application, plus the few items listed below.

Plus you'll need one of those suction cup valve lap gizzy, and some clover valve lapping compound!

Then dicide if you want to pay to have it done or buy some tools and do it yourself

[inairam]

Here is a post I made when I did my top end. It lists some tools I used. viewtopic.php?f=1&t=93111&hilit=valve+keeps+valve+keeps.

It is not hard to clean the block top and valve area to at least see what you have. Just use soft material light scotch bright or other nonsteel abrasives. I had the valves ground and the head ground flat at an engine machine shop and did the reassemble myself after cutting the valve seats with a Newway cutter hand tool.

[Stevetractor]

Lapping used valves and seats a bandaid at best. Have the valves and seats ground. If there is much wear in the guides and valve stems, replace with new. Lap new or ground valves to seats upon assembly.

[pett3227b]

I did the test with each valve at a 1 inch height above the seats to see how much play they have. They feel pretty tight. There is a little bit of wiggle I am wondering how to know what is marginal, good or bad. I also learned that i should look at each stem and the insides of the guides for scoring I will do that and see what I got. Thankyou

[SamsFarm]

I did the test with each valve at a 1 inch height above the seats to see how much play they have. They feel pretty tight. There is a little bit of wiggle I am wondering how to know what is marginal, good or bad.

The service manual probably has the minimum / maximum specifications for the valve stem and the valve guide diameters.

I dont have mine handy and am too lazy at the moment to enably cookies, log in again and go look at the one in the manual section here!

[SamsFarm]

Lapping used valves and seats a bandaid at best. Have the valves and seats ground. If there is much wear in the guides and valve stems, replace with new. Lap new or ground valves to seats upon assembly.

If the valve stems and guides are within spec, I would not replace them just because the seats need work!

[Bill V in Md]

Below is the specification page for the engine valves from the Blue Ribbon Service Manual GSS-1007 ENGINE. This manual is available under Service Manuals in Quick Links (upper left of this page).

GSS-1007 Engine 4-22-55 pg15.pdf

(360.46 KiB) Downloaded 206 times

[Stevetractor]

A machinist once told me if you gently slide your finger nail along the stem and it catches an edge, chuck them. Your nail is pretty sensitive. Also with labour nowadays, new valves vs grinding, probably not a big difference.