318 cylinder head

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George Jets said:
Rockauto.com
they are in stock again now. Need to type in 11 zeros when they ask for your VIN when ordering so your order will go through.

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Nice heads and even better price. Sad that any local shop around here couldn't recondition them for a couple hundred a piece. $225 doesn't get you much now days when labor is $75-100 per hour.
 
David Eldridge said:
Ok I know there are a ton of posts like this, but all seem to go off topic. I'm sure this will like all others but worth a shot. I have a 1970 Dodge Dart with its original bone stock 318 with a 4 barrel. Heads finally need redone. Question is will 340/360 heads or an aftermarket head drop the compression ratio too much? Once again I know this has already been asked but it seems it's with all the super low compression 318's from the mid 70's. I'm not in that boat. And no no engine swap or pistons or anything. This is the original engine to the car and the bottom end is great! Might do a mild cam too.
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The 340/360 head can really use a .050 milling of the deck.
The 318 head can use upgraded valves.
Ether is pricey for a very modest return.
Camshaft dependent, I’d just run the 318 head as is.

What is the end goal?
 
David Eldridge said:
Neat that they have those and great price!!! However no way am I putting a set of heads with EGR ports on that car!!! LOL
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Not to get too excited. Tap 1/4" 20 allen headed set screws into the 3/16" holes below the exhaust ports, simple thats it.

318 6.jpg


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Edit: Assembled on to a 1969 stock spec 318 short block, the good 9.2:1 cr factory engine.

318 3.jpg
 
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David Eldridge said:
However no way am I putting a set of heads with EGR ports on that car!!! LOL
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Obviously, you have no idea the way the head or the egr system works. Let me clue you in a tad bit and say, if your engine build has no egr equipment, then the heads egr system will it work.
 
David Eldridge said:
Neat that they have those and great price!!! However no way am I putting a set of heads with EGR ports on that car!!! LOL
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Those are AIR ports and not EGR ports. (Air Injection Reaction)

Development[edit]
The mechanism by which exhaust emissions are controlled depends on the method of injection and the point at which air enters the exhaust system, and has varied during the course of the development of the technology.

The first systems injected air very close to the engine, either in the cylinder head's exhaust ports or in the exhaust manifold. These systems provided oxygen to oxidize (burn) unburned and partially burned fuel in the exhaust before its ejection from the tailpipe. There was significant unburned and partially burned fuel in the exhaust of 1960s and early 1970s vehicles, and so secondary air injection significantly reduced tailpipe emissions. However, the extra heat of recombustion, particularly with an excessively rich exhaust caused by misfiring or a maladjusted carburetor, tended to damage exhaust valves and could even be seen to cause the exhaust manifold to incandesce.

As emission control strategies grew more sophisticated and effective, the amount of unburned and partially burned fuel in the exhaust stream shrank, and particularly when the catalytic converter was introduced, the function of secondary air injection shifted. Rather than being a primary emission control device, the secondary air injection system was adapted to support the efficient function of the catalytic converter. The original air injection point became known as the upstream injection point. When the catalytic converter is cold, air injected at the upstream point burns with the deliberately rich exhaust so as to bring the catalyst up to operating temperature quickly. Once the catalyst is warm, air is injected to the downstream location — the catalytic converter itself — to assist with catalysis of unburned hydrocarbons.
 
toolmanmike said:
The AIR system always said the injected air burned the hydrocarbons. I think it just diluted the exhaust so it would pass emissions testing. LOL
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It actually burned them...in the lack of oxygen environment of an exhaust manifold the unburned fuel never had a chance to light off although 2 of the 3 parts for combustion were there (fuel and temperature) add oxygen and voom! They got burned. Dilution would not help it pass as it would still register. The BS was the open ports in the bottom of some intakes, that was just crazy if the egr valve got crud in the pintle and stayed open ....photo courtesy iceman_krebs
FullSizeRender.jpg
 
rumblefish360 said:
Obviously, you have no idea the way the head or the egr system works. Let me clue you in a tad bit and say, if your engine build has no egr equipment, then the heads egr system will it work.[/QUOT
rumblefish360 said:
Obviously, you have no idea the way the head or the egr system works. Let me clue you in a tad bit and say, if your engine build has no egr equipment, then the heads egr system will it work.
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My bad first thought of a smogger motor was egr. And yes I do know how egr and AIR systems work. Didn't read the post close enough. And apparently you don't know that having egr heads heat up the manifold, thus increasing intake temps, even if the port is blocked, heat is still getting to the manifold. Bottom line is emissions add ons are designed to burn gases, therefore generating heat
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Allow me to show you something about quoting...
Type outside the quote tags!
Above is just hitting the reply button and then how your quote appears.

apparently you don't know that having egr heads heat up the manifold, thus increasing intake temps, even if the port is blocked, heat is still getting to the manifold. Bottom line is emissions add ons are designed to burn gases, therefore generating heat
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Apparently, you assume to much. And think you know something, but please continue....
 
David Eldridge said:
My bad first thought of a smogger motor was egr. And yes I do know how egr and AIR systems work. Didn't read the post close enough. And apparently you don't know that having egr heads heat up the manifold, thus increasing intake temps, even if the port is blocked, heat is still getting to the manifold. Bottom line is emissions add ons are designed to burn gases, therefore generating heat
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Actually, no. The EGR brings no more heat to the intake manifold than a standard exhaust cross over. Also, on stock or mild engines, an EGR system has some benefits. It can increase MPG by helping to reburn unburned hydrocarbons and it also reduces combustion temperatures. That's why I actually like using the 73 340 intake on small block street builds. It has the EGR build into the plenum floor of the intake and requires no outside mounted valve.
 
RustyRatRod said:
Actually, no. The EGR brings no more heat to the intake manifold than a standard exhaust cross over. Also, on stock or mild engines, an EGR system has some benefits. It can increase MPG by helping to reburn unburned hydrocarbons and it also reduces combustion temperatures. That's why I actually like using the 73 340 intake on small block street builds. It has the EGR build into the plenum floor of the intake and requires no outside mounted valve.
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I'm still trying to figure out what he means by EGR heads. The heads don't have anything to do with EGR. A.I.R. yes, EGR, no.
 
cudamark said:
I'm still trying to figure out what he means by EGR heads. The heads don't have anything to do with EGR. A.I.R. yes, EGR, no.
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I believe he has his terms kornfrooshed.
 
David Eldridge said:
Later heads have a port that goes back through the intake. The exhaust doesn't just magically get back into the intake.
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If you're talking about the exhaust crossover, almost all have that. That was designed into the head and intake to keep the carburetor from icing up. It was an easy place to tap into later on when EGR was implemented.
 
toolmanmike said:
Nice heads and even better price. Sad that any local shop around here couldn't recondition them for a couple hundred a piece. $225 doesn't get you much now days when labor is $75-100 per hour.
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That is sad.
Around here ..one shop will do the basic reman for 350..nothing fancy.., the other...all 350 gets you is guides,valve job and stem height cut, maybe a light surface if they are out more than a .0015. and you put them together, setup spring heights.

The cheap does just the 45 and 30 cuts, the other does a 3 and 4 angle.
I like the put it together deal so far... cause i check it all anyhow.
 
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