Best way to remove an exhaust seat

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cgarb
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Best way to remove an exhaust seat

Post by cgarb » Sat Oct 07, 2017 6:46 pm

I have a set of heads at fresh from the machine shop, they are E7 heads that I ported. I started grinding the seats and noticed that 2 exhaust seats were cracking across towards the intake seat. I had my machine shop bore those 2 and install seats. The seat he used has a much larger ID than what the heads are ported to and there is about a .06" step that would need blended in. I found some seats that are the same 1.687 OD but have a smaller 1.31 ID that would match up closer. What would be the best way to remove the seats and install the new ones without damaging the counterbore?

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Re: Best way to remove an exhaust seat

Post by resurrectionjoe » Sat Oct 07, 2017 7:00 pm

TIG welder .

Weld a bead around the seat and it will fall right out.

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Re: Best way to remove an exhaust seat

Post by jcisworthy » Sat Oct 07, 2017 7:11 pm

Use a cutter to set the venturi. The seats are in just cut them to size?
There is no place like this place, so this must be the place
Freedom Village
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http://www.rbjracing.tk

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Re: Best way to remove an exhaust seat

Post by PRH » Sat Oct 07, 2017 7:55 pm

It probably depends on what you have for tooling as to which method you use.

For myself, cutting them out is easiest.

I would set up the cutter to about .015" smaller than the OD of the seat, bore it out, then that .007" thick piece remaining can easily be popped out.
Somewhat handy with a die grinder.

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Re: Best way to remove an exhaust seat

Post by peejay » Sat Oct 07, 2017 8:07 pm

resurrectionjoe wrote:
Sat Oct 07, 2017 7:00 pm
TIG welder .

Weld a bead around the seat and it will fall right out.
I've done this carefully with an oxyacetylene torch, too. Very small flame and stop adding heat before it starts to show color, and hit it with water to cool it off before it has a chance to transfer heat away.

It's like magic.

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Re: Best way to remove an exhaust seat

Post by DaveMcLain » Sat Oct 07, 2017 8:49 pm

As stated in an earlier post just use a welder to weld a bead around the seat, let it cool and it will fall right out.

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Re: Best way to remove an exhaust seat

Post by Brian W » Sat Oct 07, 2017 9:13 pm

I take an old valve and chuck it up in lathe. Cut the OD to the size of the throat of seat. Then TIG weld it to the seat and drive seat out by hitting stem with hammer. Works great.

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Re: Best way to remove an exhaust seat

Post by cgarb » Sat Oct 07, 2017 10:30 pm

The guy who installed them said he put fluid weld on them, will that make it worse to get out?

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Re: Best way to remove an exhaust seat

Post by Jagdpanzer » Sat Oct 07, 2017 10:31 pm


resurrectionjoe
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Re: Best way to remove an exhaust seat

Post by resurrectionjoe » Sat Oct 07, 2017 10:45 pm

cgarb wrote:
Sat Oct 07, 2017 10:30 pm
The guy who installed them said he put fluid weld on them, will that make it worse to get out?
Not if you TIG weld them

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Re: Best way to remove an exhaust seat

Post by cgarb » Sun Oct 08, 2017 1:33 am

Ahhh...now to go buy the Tig welder...lol. I have a mig, with creative shielding and some antispatter spray I'll make something happen.

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Re: Best way to remove an exhaust seat

Post by modok » Sun Oct 08, 2017 2:13 am

MIG can work. yes depending on what the seat is made of it might get ugly. OLD SCHOOL they'd say put a freeze plug in the there to weld to the seat, but I've never done that. They are galvanized, no thanks :lol:
But I will use a washer, or some scrap from punch or hole saw, even an old valve maybe, can be a nice round thing to weld in there and that will keep the spatter out of the port and give something to drive against. Probably can drive out though the port this case. If you do weld a round thing in there don't make it a tight fit, at least .050 gap, so get lots of shrinkage as the weld cools :D
Glen Urban

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Re: Best way to remove an exhaust seat

Post by mag2555 » Sun Oct 08, 2017 7:05 am

As posted why the Hell do we want to pull out new seats just for the sake of having to get the Throat in them machined or ground?!!!!

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Re: Best way to remove an exhaust seat

Post by peejay » Sun Oct 08, 2017 7:24 am

If you heat it right you won't need to drive them out hardly. It will shrink when it cools off and lose press fit and literally fall out of the head. Running a bead of weld around the inside helps because the hot bead will shrink it even more when it cools off. I would think that welding something into the seat would keep it from shrinking as much.

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Re: Best way to remove an exhaust seat

Post by Carnut1 » Sun Oct 08, 2017 7:31 am

For an e7 that has cracking issue already I would not touch it with heat or splash water on it hot. I would finesse the curve with a grinder and run it. The flow difference will be negligible. Thanks, Charlie
Servedio Cylinder Head Development
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