dallas_

I'm working on a new crate motor and will be using the rear steam vents. It looks like they have factory plugs in them. Any suggestions on how to remove the plugs without removing the heads?

Also, are those holes threaded? If not, and I have to tap them, I guess I'll be pulling the heads anyway.
Thanks

imma_stocker

iTrader: (19)

The ports are not threaded. Plugs are actually a plate with bolt hole right next to ports. Factory plugs are simple unbolt deal.

Several vendors make very nice bolt on vent tubes that will run under various intake manifold styles up to the front vent tubes. Nitrous Outlet has a few options I've seen in person, each looked high quality (on road course vettes).

DIY option if you have thick enough block off plates already, drill and tap the plate for whatever fitting type then bolt them back on. More DIY and kits here https://ls1tech.com/forums/generatio...-ls-motor.html

dallas_

Thanks for the tips. It looks like this one is some type of plug insert, not a plate.

Nathaninwa

I drilled mine out. My motor came apart anyways so I tapped all of them for 1/8 pipe

imma_stocker

iTrader: (19)

That looks annoying.

dallas_

You read my mind.
Looks like I'm pulling the heads. Just not comfortable drilling that out and getting shavings in the coolant passage.

Eredin

iTrader: (1)

This.

It's unfortunate you do not have the blocks there, as they simply bolt down via the threaded hole that is pictured.

dallas_

ok, to follow up, here's what I did:
Used a 1/8" drill bit dipped in grease and very slowly drilled into the plug, stopping frequently to remove the chips and vacuum the hole. When I got the hole deep enough, used an EZ out to work the plug out. I also plugged the other cooling passages and pressurized it a bit with compressed air to blow out any small chips that got in during the process. Probably overkill but didn't want any little chips in there.

I expect you could easily tap them out from the other side if the heads were off (assuming you can get to that cooling passage from the other side).

Posted this just in case someone else has the same issue.

themealonwheels

iTrader: (20)

Man, I saw the same thing on my ls3 crate motor. I understand why gm did that instead of a block bolted on, but what a pain. Not even sure I'd like to drill it, though the minimal shavings content shouldn't be a problem for the head coolant passages.

JRcamaroZ28

iTrader: (41)

They are press fit in use a drift punch and just knock them out with a few solid taps and it will fall right out.

themealonwheels

iTrader: (20)

You mean by punching them out from the block side of the head. Problem is, the head is installed on a crate motor. When ordering a crate motor, people don't want to disassemble the whole thing just to get those plugs out.

JRcamaroZ28

iTrader: (41)

I missed you have a crate motor just saw the guy above had his heads off.

KENS80V

iTrader: (16)

They are actually riveted in placed. You can buy the rivets from GM. (#12602048)

Here is pdf on how to install them. Removing them would involve drilling out the center of the rivet to weaken it then carefully pull it out.

https://www.google.ca/url?sa=t&rct=j...1_rSPk-0BlS6Jw

aceez71

I know it’s an old thread. I just had same problem with a set of heads I bought from Texas speed. Fortunately I had installed the head (Only 1 had a rivet plug ) on the driver side and the plug ended up in the front. I say fortunately because when I drilled the rivet the head of the rivet fell into the water passage. Just so happens that is the water port to the water pump, rivet head was laying there I blew air through the now open port small shavings and rivet head out of engine. Moral of the story is any other plug would’ve been drilled out would’ve it ended up in the cooling system and that piece is big enough to create Major problems.

140K_GXP

Reviving this thread again. I am wanting to remove the rivets from the rear of the heads on my 2011 Grand Sport. Was thinking about using a bit sized for an M3 bolt, tapping the rivet and then using an M3 bolt and a spacer to pull the plugs out. But I would be doing this on the car.

I am running an E-force supercharger and would like to have max flow through the heads.

RB04Av

Dent puller?

Can't comment on whether that would work in that chassis.

Maybe just a sheet metal screw and some sort of prybar.

01CamaroSSTx

iTrader: (3)

GM engineers didn't see a need for the rear crossover steam ports anymore since the highest point of the cylinder head is at the front of the block and this is where any air bubbles will find their way anyway This is the reason they've been plugging the rears off since the 2000 LS1 and it wasn't until the Gen IV's that they started permanently filling those ports in. Engine coolant makes its way around the cylinders and through the heads already so all I can see from adding a rear crossover steam line is that you're adding another place for coolant and trapped air to go. I must have an older set of 823's on my 370 build because they have the provisions for the steam port plugs.

hpfiend

iTrader: (4)

Tried to center punch to drill and the centers of the rivets fell in. In retrospect I would prob try to left hand drill bit these centers out



Tapped the remaining hole with a 6-32 tap coated in grease.

Used a socket head stainless 6-32 bolt and a 3D printed bushing and fender washer and they pulled right out!


There it is! Now if I compress the ports from the other side, I wonder if I can’t blow out the aluminum rivet centers?

Royce Cochran

I have a similar situation with a new supercharged LS3 crate motor in a "57 Chevy. I bought one of those rivet plugs just to see what I dealing with. The plug part is some kind of al alloy but the center pin is some kind of steel, maybe stainless but magnetic.... not good. Whoever installed the motor in the car (long story) left the plugs in and then installed the Eaton supercharger leaving minimum room to work. I have a plan but it's going to be risky.
I have another observation that I don't understand. GM sold these LS3 crate motors without steam vent tubes installed but with the rivet plugs. Surely they didn't expect people to remove the heads to remove the plugs. So I guess it's ok to drill out the plugs and don't worry about the chips. Any thoughts?