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Discussion Starter #1
when you have new valve seats put in how do they take out the old seats?are they bored out?i have a set of iron bowtie heads that are only a couple of yrs. old but have not spent much time on hte street.with this rebuild that i'm doing i'm putting in a little larger cam and springs to help with both the larger cam and 1.6 rockers and while having them apart i notice that the seats look bad.like they were installed poorly.when i bought them a had the 2.02's replaced with 2.05's and since they were complete and i couldn't see the seats at the time.for my plans now i need to know about the seats though.as always i appreciate your help.
 

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seats

If i understand your question the heads already had seats installed in them??? if so then they can be removed by putting a a small bead of weld across them and they will all but fall out. If the heads have not had seat installed before then they will need bored out......

Keith
 

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valve seats

IF your heads didnt come from the factory with hardened valve seats, they have to be cut for them. The heads that come from the factory with them are removeable and can be replaced.
I would consult my favorite machine shop on the valve seats. It may be that you just need a good valve job.
 

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There a few ways to take them out some shops have a puller but i have never seen them work wright some will cut them and then remove the parts thats left with a pick or screw driver and some shops will weld on them to shrink the seats or you could heat the head and they will come out.So for your question there is no easy way.Tom or narb how are you removing seats.





mike
 

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By the sound of the post. Someone put 2.05 intakes in and did not do the seats properly. I have seen other shops do this. (Just move the seat up, and not open up the bowl). I usually just take a profile cutter and open the bowl/seat area to the proper dimension. Then re-touch the seat.

As with the other answers. Most factory small block exhaust seats have to be bored out and an insert installed. If you have this done on a used set of heads, the machinist will probably want new guides installed at the same time. As most equipment depends on a good tight valve guide for a proper seat cut.

I usually cut out old inserts with a cutter one size smaller than the existing seat. When the cutter hits bottom of the old installed seat, it usually pops the old outer ring up and out. Quick and easy. No weld splatter, minimal cleanup.
 

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Discussion Starter #6
bobcrman
i have a set of iron bowtie heads with only a few miles on them.when i ordered them from aerohead ind./div.indy cylinder a couple of yrs ago a got a pretty good price for them and they were willing to put the 2.05's in for the right price and i had no reason to look at themunder the valve til now,since i was forced to rebuild my rebuild i was going to take the time to do some porting which is why i got them,all the extra matearial for porting.anyway ahfter i get them apart it looks like maybe the cast was funky some how.the metal looks bad everywhere.under the seat there are gaps in the metal that looks like it needs a few spots of weld then clean it up with a rotary grinder.thats why i asked about the seats.if that weld tuches the seat will it still be able to be bored out with no problem or should i stay away from that.they also did the worst job of grinding those seats for the 2.05 that i've ever seen.i didn't expect that from indy cylinder.
thanks for your help everyone.
 

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I weld my seats out. I have seat pullers but I hate the things, I always wind up gouging the head. There are a few seats that are made of some pretty tough material and they don't weld too well. I had to remove the seats out of a Dart Iron Eagle Head, and they were exceptionally tough to remove, even after I had welded them.

I use a small 110 volt wire feed welder to put a small beed on the seat, use dummy valves to cover the intake seat and I'm very careful. They either fall out or you just gently peck them out of place. Most hard seat inserts don't need replacing most of the time unless it's a well engine on natural gas or something like that, so it's not something I do everyday anyway. I don't like to cut them out because I hate to place wear and tear on my machine and cutters when I can use a welder instead.
 

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Another way i have done it is you take and old valve chuck it up in the lathe cut the od down so it just fits in side the seat ring and weld it in then you have the stem hanging out the other side to hammmer on and the seat pops out.




mike
 

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Discussion Starter #9
according to the GM cataloque these heads come bare.when i got them they were completeincluding the guides.they must put them together then.now to put the 2.05 in place of the 2.02 all they do is open the seat up a little more right.they don't change the hole seat do they?i am trying to figure outhow these irregularitie got ther.did they do it putting the seats in?anyway since this small cavity is there what i need to know is can i put a few welds in there to fill the cavity and grind it flush?but in doing so i will be tacking the seat to the head.when it comes time to change the seats can it be done by boring the seat out,in which case it will bore thru the weld.if that can't be done i'll have to leave the cavity unless someone knows about some 2000* apoxy or cold weld i can use.i hope i'm saying this clear enough.
 

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Discussion Starter #10
ok i've found an old petersen's book from 1979 on cams,valves and exaust systems and it has some good info in it.i found a picture of a seat boring machine that looks like it will bore the seat after i put a few tack welds in the cavityunder the seat.i'll tack it.as i fill the cavity i'll actually weld the seat to the port wall but it looks like when the time comes the boring machine will be able to bore it out.
one more question.does anyone know about how much it would cost to have my valve seats but not the valves retouched?they really did a crappy job on these heads.i didn't expect this kind of shoddy work from a sister comp.of indy cylinder heads inc.
 

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Be careful of the material that you weld with. I prefer to braze, if it is an accessible area. Many of the welding alloys are harder than the hinges of HeII. A seat cutter will not touch the stuff. As a matter of fact the weld material can ruin the cutter. Then you have some real problems!!

Devcon markets some repair epoxies that will hold up.. GM uses them on porosity problems.
 

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Discussion Starter #12
i saw someone taking about devcon a while back and did a quick search to find out just a little bit about it and kept it in my favorites and was just about to look them up.as long as you touched on brazing though,is there any special rod to use on that.i don't have a mig ,my brother in law would have to do that for me.i do have a set of tanks and can braze pretty well.i'm still looking up devcon.do you know if that epoxy can e gotten thru GM?
 
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