Do you know what this is??

bmxmon · 01-26-2005, 09:03 AM

Hey everybody, I am having trouble trying to figure out what exactly this is. I will put some pics of it up so you can see it. I brought these pictures to Napa, and they couldnt tell me what it was for! This hole seems to connect all the exhaust ports through, from what i believe is those EGR ports. Any help would be awesome, i need to know where i can get a new one. Pic one is of the side of the head where the block off thing is missing, the other pic is of the one that is still there. Thanks.

USMC302 · 01-26-2005, 01:07 PM

Could it possibly be a cylinder head coolant passage? Maybe a freeze plug could fix that.

Dark_5.0 · 01-26-2005, 01:20 PM

Hmmm...... What kind of heads are those?

I have never seen anything like that.

bmxmon · 01-26-2005, 01:44 PM

79 ford 302, what I was told anywho, out of a Ford truck. It has theads in it, the machine shop didnt think that a freeze plug would hold.

Ieatcamaros · 01-26-2005, 09:42 PM

I have never seen that before either. I don't see the threads that you are talking about. Obviously there are inside the hole a little deeper than we can see in the pic. Does it have threaded hole in it for a bolt the same size as the bolt in the other head? You can get a slug made to look like the other one and just bolt it on if that's the case. I think that it is most likely egr/smog related. Are there any "ports" on the back of the heads?

NitroNixon · 01-27-2005, 09:08 AM

I agree with Ieatcamaros.

bmxmon · 01-27-2005, 09:32 AM

yeah, sorry about the pics not showing the threads. There are no other holes on the outside of the block, other than the one I am trying to figure out. Getting a slug made sounds good, but where do i go to do that?? I'm pretty sure that they are smog related also, because of those humps in the exhaust ports, the holes connect (the ones that go through those humps) to this odd thing on the outside of my heads, without a plug I would have a major exhaust leak. Thanks for the help.

Ieatcamaros · 01-27-2005, 09:56 PM

An auto machine is probably not going to do that. It depends on the shop's capabilities and/or whether or not they want to do it. That is just not part of what they do. If you go to a regular machine shop that does this type of stuff, they can do it for you. I am a machinist and I do this stuff all the time. Just look under machine shops in your yellow pages and look for one that says general machine work. Your probably looking at $25-45 depending on the shop's rates. Just a thought: Down here where I live, you can take something like that to the high school's trade/vocational school and get it done for nothing. PM me if you don't have any luck.

tarmon8r · 01-28-2005, 01:38 AM

Id try hitting up a junk yard... or even upgrading the heads to be honest.. Maybe something a little bit more modern like a pair of E7 from a stock mustang. I swear they would have to flow better than those 79 smog heads. Or get a pair of 69 heads..Just something relatively cheap, or go with a pair of gt-40, i think i saw those for $640 a pair.

nastyn8 · 01-28-2005, 02:06 AM

There is nothing like that on my 79 302. it really blows my mind. Ill have to really look into it

~The Jester~ · 01-28-2005, 05:58 PM

All it does is let the smog pump put some fresh air in those EGR holes in your exhaust ports. Plug that sucker up, and you'll be just fine. Find a bolt that fits in the threads in the middle, and a big azz flat washer to cover the rest of the hole. Little ultra copper on the back of the washer and you're good to go.

Later heads had those on the back of the head, on both side. Then they had a tube connecting the 2 together. We used to leave the tube on, crimp the end going to the smog pump, and then mig weld it shut.

Capri306 · 01-29-2005, 02:46 AM

The ports at that point have NOTHING to do with EGR. They are air injection reactor (better known as A.I.R.) pump passages, designed to add fresh air to the exhaust stream in hopes of completing oxidation, and to aid the catalysts. Air is only pumped into these "upstream" ports when the engine is cold, up to a predetermined temperature and time. This is what those "bumps" in the exhaust ports are for, and that longitudinal passage going the entire length of the head is simply a common manifold for all of them. If you've ever had the joy of replacing air tubes on a small block Chevy, now you know why Ford did it better.

Okay, enough of the education on emission controls. You're gonna hafta plug that hole with something if you're not running an air pump. I'd suggest doing something like most guys are saying on here, and create something that's going to thread in there and plug it as well.

By the two pictures, it appears that this is a 90 degree elbow with a bolt through the center attached, correct? If this is the case, a large fender washer may do the trick, otherwise mebbe you can fill the end of the tube with welding. DO NOT be tempted to use something cheap and easy like Liquid Steel or JB Weld, as they WILL NOT work for long. Find a friend with a MIG or even a flux-core wire welder and fill up the center on the end of that piece.

FWIW, this is pretty unique looking, even for a 1979 piece.
BTW, find some different heads. Experience with 1978 heads speaking here.

01-26-2005, 01:07 PM	#2
USMC302 Registered Member Join Date: Apr 2001 Location: Gallatin, Tn Posts: 1,326	Re: Do you know what this is?? Could it possibly be a cylinder head coolant passage? Maybe a freeze plug could fix that. __________________ Last edited by USMC302; 01-26-2005 at 01:27 PM..

01-26-2005, 01:20 PM	#3
Dark_5.0 Registered Member Join Date: Apr 2001 Location: Staging lane Posts: 4,337	Re: Do you know what this is?? Hmmm...... What kind of heads are those? I have never seen anything like that. __________________ 92' LX-Big brakes, Lots and lots of suspension, GT40X heads, Ported cobra intake, stock cam, Vortech SC trim. 00' Lightning-Stock 88'CRX-13 second ego killer

01-26-2005, 01:44 PM	#4
bmxmon Registered Member Join Date: Mar 2004 Location: Minnesota Posts: 950	Re: Do you know what this is?? 79 ford 302, what I was told anywho, out of a Ford truck. It has theads in it, the machine shop didnt think that a freeze plug would hold.

01-26-2005, 09:42 PM	#5
Ieatcamaros Domestic Rice really sucks! Join Date: Apr 2002 Location: KY Posts: 973	Re: Do you know what this is?? I have never seen that before either. I don't see the threads that you are talking about. Obviously there are inside the hole a little deeper than we can see in the pic. Does it have threaded hole in it for a bolt the same size as the bolt in the other head? You can get a slug made to look like the other one and just bolt it on if that's the case. I think that it is most likely egr/smog related. Are there any "ports" on the back of the heads? __________________ The sig says it all.

01-27-2005, 09:08 AM	#6
NitroNixon Registered Member Join Date: Mar 2002 Location: DC Posts: 129	Re: Do you know what this is?? I agree with Ieatcamaros. __________________ 87 GT As of 2/1/06 650 DP Carb Crosswind Intake Edelbrock Performer Heads 97 Explorer Bottomend w/ B-303 Cam 1.7 Roller Rockers Flowtech Longtube Headers Flowtech H-Pipe MSD Black Wires MSD ignition MSD Distributor Blaster 3 Coil Electric Fan Underdrive Pullies T5 Trans Hurst Shifter Lowered 1.5" 373 Gears

01-27-2005, 09:32 AM	#7
bmxmon Registered Member Join Date: Mar 2004 Location: Minnesota Posts: 950	Re: Do you know what this is?? yeah, sorry about the pics not showing the threads. There are no other holes on the outside of the block, other than the one I am trying to figure out. Getting a slug made sounds good, but where do i go to do that?? I'm pretty sure that they are smog related also, because of those humps in the exhaust ports, the holes connect (the ones that go through those humps) to this odd thing on the outside of my heads, without a plug I would have a major exhaust leak. Thanks for the help.

01-27-2005, 09:56 PM	#8
Ieatcamaros Domestic Rice really sucks! Join Date: Apr 2002 Location: KY Posts: 973	Re: Do you know what this is?? An auto machine is probably not going to do that. It depends on the shop's capabilities and/or whether or not they want to do it. That is just not part of what they do. If you go to a regular machine shop that does this type of stuff, they can do it for you. I am a machinist and I do this stuff all the time. Just look under machine shops in your yellow pages and look for one that says general machine work. Your probably looking at $25-45 depending on the shop's rates. Just a thought: Down here where I live, you can take something like that to the high school's trade/vocational school and get it done for nothing. PM me if you don't have any luck. __________________ The sig says it all.

01-28-2005, 01:38 AM	#9
tarmon8r Registered Member Join Date: Jun 2002 Location: manassas, va Posts: 186	Re: Do you know what this is?? Id try hitting up a junk yard... or even upgrading the heads to be honest.. Maybe something a little bit more modern like a pair of E7 from a stock mustang. I swear they would have to flow better than those 79 smog heads. Or get a pair of 69 heads..Just something relatively cheap, or go with a pair of gt-40, i think i saw those for $640 a pair. __________________ 1983 mustang, 393 cubic inch stroker small block, victor jr heads and intake, gold race 1.6 roller rockers. comp cam 304, 244@ .050. .576" hydralic retro roller cam,lunati rods. block was o-ringed,10:1 forged pistons, speed pro fit fit rings, clevite bearings,msd distributor and igniton,be cool huge radiator, black lite electric fan, march underdrive pulleys, mildon deep sump oil pan, mac 1 3.4" long tube headers, 3" dr gas x-pipe and mac exhaust,ARP bolts. car weighs 2900 lbs w/out driver, sub frames, weld wheels, mickey thompson sportsman pro 26 x 10.5 x 15's,#8 fuel line steel braided

01-28-2005, 02:06 AM	#10
nastyn8 Smokes The Dope Join Date: Aug 2004 Location: Eldorado, Illinois Posts: 144	Re: Do you know what this is?? There is nothing like that on my 79 302. it really blows my mind. Ill have to really look into it __________________ 88' coupe with a 2.3, displacement replacement in near future. 46' f1 My page

01-28-2005, 05:58 PM	#11
~The Jester~ Rat Killer Join Date: Aug 2002 Location: Cold ass Ohio Posts: 1,143	Re: Do you know what this is?? All it does is let the smog pump put some fresh air in those EGR holes in your exhaust ports. Plug that sucker up, and you'll be just fine. Find a bolt that fits in the threads in the middle, and a big azz flat washer to cover the rest of the hole. Little ultra copper on the back of the washer and you're good to go. Later heads had those on the back of the head, on both side. Then they had a tube connecting the 2 together. We used to leave the tube on, crimp the end going to the smog pump, and then mig weld it shut. __________________ d-Con Racing "Nothing fancy, just 347 inches of RAT POISON!" MICE need not apply.....

01-29-2005, 02:46 AM	#12
Capri306 Moderator Join Date: Sep 1998 Location: Grand Rapids, Michigan, USA Posts: 1,001	Re: Do you know what this is?? The ports at that point have NOTHING to do with EGR. They are air injection reactor (better known as A.I.R.) pump passages, designed to add fresh air to the exhaust stream in hopes of completing oxidation, and to aid the catalysts. Air is only pumped into these "upstream" ports when the engine is cold, up to a predetermined temperature and time. This is what those "bumps" in the exhaust ports are for, and that longitudinal passage going the entire length of the head is simply a common manifold for all of them. If you've ever had the joy of replacing air tubes on a small block Chevy, now you know why Ford did it better. Okay, enough of the education on emission controls. You're gonna hafta plug that hole with something if you're not running an air pump. I'd suggest doing something like most guys are saying on here, and create something that's going to thread in there and plug it as well. By the two pictures, it appears that this is a 90 degree elbow with a bolt through the center attached, correct? If this is the case, a large fender washer may do the trick, otherwise mebbe you can fill the end of the tube with welding. DO NOT be tempted to use something cheap and easy like Liquid Steel or JB Weld, as they WILL NOT work for long. Find a friend with a MIG or even a flux-core wire welder and fill up the center on the end of that piece. FWIW, this is pretty unique looking, even for a 1979 piece. BTW, find some different heads. Experience with 1978 heads speaking here. __________________ Capri306, Moderator The Mustang Works Online 1979 Mercury Capri 1987 5.0L Mustang LX Notchback 1993 5.8L Eddie Bauer Bronco