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Best way to remove an exhaust seat
Posted: Sat Oct 07, 2017 6:46 pm
by cgarb
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?
Re: Best way to remove an exhaust seat
Posted: Sat Oct 07, 2017 7:00 pm
by resurrectionjoe
TIG welder .
Weld a bead around the seat and it will fall right out.
Re: Best way to remove an exhaust seat
Posted: Sat Oct 07, 2017 7:11 pm
by jcisworthy
Use a cutter to set the venturi. The seats are in just cut them to size?
Re: Best way to remove an exhaust seat
Posted: Sat Oct 07, 2017 7:55 pm
by PRH
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.
Re: Best way to remove an exhaust seat
Posted: Sat Oct 07, 2017 8:07 pm
by peejay
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.
Re: Best way to remove an exhaust seat
Posted: Sat Oct 07, 2017 8:49 pm
by DaveMcLain
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.
Re: Best way to remove an exhaust seat
Posted: Sat Oct 07, 2017 9:13 pm
by Brian W
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.
Re: Best way to remove an exhaust seat
Posted: Sat Oct 07, 2017 10:30 pm
by cgarb
The guy who installed them said he put fluid weld on them, will that make it worse to get out?
Re: Best way to remove an exhaust seat
Posted: Sat Oct 07, 2017 10:31 pm
by Jagdpanzer
Re: Best way to remove an exhaust seat
Posted: Sat Oct 07, 2017 10:45 pm
by resurrectionjoe
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
Re: Best way to remove an exhaust seat
Posted: Sun Oct 08, 2017 1:33 am
by cgarb
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.
Re: Best way to remove an exhaust seat
Posted: Sun Oct 08, 2017 2:13 am
by modok
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
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
Re: Best way to remove an exhaust seat
Posted: Sun Oct 08, 2017 7:05 am
by mag2555
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?!!!!
Re: Best way to remove an exhaust seat
Posted: Sun Oct 08, 2017 7:24 am
by peejay
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.
Re: Best way to remove an exhaust seat
Posted: Sun Oct 08, 2017 7:31 am
by Carnut1
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