Valve seats. How to remove?
 

Hi guys. how do you remove a valve seat assuming it can't be set up in a milling machine?

Can it be shrunk by welding on it? Can you weld on it? (I have MIG).

I do have a hand powered valve seat cutter but don't fancy trying to cut them out with that.

Any advice or pointers offered appreciated.

Mart.

Re: Valve seats. How to remove?
 

Lots of info. here.
https://www.google.com/search?q=how+...hrome&ie=UTF-8

Re: Valve seats. How to remove?
 

There are pullers more or less advanced.
The std bruteforce version https://goodson.com/products/valve-seat-pullers
Weld a washer and pull may or may not work depending on what material in seat...some stellites will weld some not...they get brittle and crack easy...
I have seats in oversize for replacing if you need...putting a std size back sometimes ends up loose.

Re: Valve seats. How to remove?
 

Yes, a quick weld on the seat about as fast as possible. Ring will simply fall out. One word of caution---I once knew a guy to whom I explained my technique. Only too late he realized his block did not have seat rings. Ugly.

Re: Valve seats. How to remove?
 

John's correct above here, that's exactly how we get them out also!

If we happen to have the block mounted on the Bridgeport for any other machining at that point we have the option of simply cutting the seats out with an end mill also.

Thanks, Gary in N.Y.

P.S. I'll also give you this, we generally find a +.005" will go right back in without any add'l machining, in other words once the original is removed it is simply a matter of pressing in the O/S replacement! This method has always worked for us here!

Re: Valve seats. How to remove?
 

Thanks for the tips guys.

This will be another hoop for me to jump through.

Re: Valve seats. How to remove?
 

Mart what I do is use the tig torch and just weld on the seat without adding any filler rod at all the seats shrink a lot doing it this way. Very easy to do. Once the seats are out if you have an accurate way of measuring the bores for the seats in the block i think you will find there not round anymore. Now the next hoop in the project will need attention.
Ronnieroadster

Re: Valve seats. How to remove?
 

Tigs are like precise acetylene torches really. You can heat an area pretty quick without welding on low temps.


Guess that's why they say if you can gas weld you can tig. I can tig like the average bear but haven't learned gas welding. A skill I wish I had.

Re: Valve seats. How to remove?
 

Tig works the best . Heat with 1/16th tungsten , quench , they fall out.

Re: Valve seats. How to remove?
 

Thanks fellas. Unfortunately I'm limited to mig.

I do have arc and oxy acetylene, but for this job, of the options I do have, it will need to be mig.

Mart.

Re: Valve seats. How to remove?
 

Mart the mig will also work. Heck when i need to remove cylinder sleeves i run the mig up and down the sleeves and that works the sleeves shrink nicely so there easy to remove. Simple back yard Hot Rodding
Ronnieroadster

Re: Valve seats. How to remove?
 

What am I missing here? Doesn't heating a ring shaped object make it bigger around, not smaller? I'd like to change out an exhaust valve seat in an 8ba block. The seat in question has a bunch of punch marks around it to make it tighter fitting in the block. It is quite apparent that it was done and then run that way with no ill effects, but??? I have mig and oxy/aceteylene. I think I will get a photo of what I'm dealing with. Somewhere I have an envelope with 4 slightly oversized seats.

Re: Valve seats. How to remove?
 

What is going on is that you are "heat shrinking" the seat . . . once it gets cold (you can quench it), it will fall out.

Re: Valve seats. How to remove?
 

Could you also heat it up with a propane torch and then quench the seat?

Re: Valve seats. How to remove?
 

Maybe...Maybe not....
The idea is to get the ring as hot as possible WITHOUT getting the block hot so when the heat is removed the ring will cool as fast as possible. The ring will shrink the most this way and fall out.
If after heating or welding and cooling and the ring has been staked, a few taps with a punch on the inside all the way around will usually relieve the punch marks and loosen the ring.

Re: Valve seats. How to remove?
 

Now that the ring is off, you can use a 1.72 intake valve.

Re: Valve seats. How to remove?
 

At our shop we remove the old seats with our big machine used to install new seats. You didn't mention the year of the engine. Early engines don't use separate seats. Before you use a welder or torch, consider having a good machine shop advise you. The area around the valve pocket in the block can be easily damaged.

Re: Valve seats. How to remove?
 

It's an 8ba and has hardened seats on all valves.

Re: Valve seats. How to remove?
 

The 48 and some 50\s 8ba blocks had seats in both similar to the 59series blocks. This lasted untill mid 51 when the harden seats were removed form both. Some of the early 8ba blocks also had the 59 fuel pump push rod. "The mo you know"
Gramps

Re: Valve seats. How to remove?
 

With original seats, do you advise adding synthetic lead to fuel ? Thank you