Are these swirl ports?

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swirl ports and quench chambers are 2 differnt things! are the push rod hole larger and round? probably same as 308 head just another number on it...
 
And for all intents and purposes 302 and 308 casting heads were always considered "swirl port" heads and the others not.
 
dirty white boy said:
larry shepard book in heads section says all LA heads are swirl port heads, RRR done posted this in this thread.
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Get the book. It's true. It's in there. The 302 and 308 castings are swirl port heads too.......and the 302 head is technically not a closed chamber head. Quench, yes, but open chamber. The area around the plug is wide open. Look at the 273 heads. They were closed chamber. Look at the 516 and 915 big block heads. Closed chamber.
 
RustyRatRod said:
Get the book. It's true. It's in there. The 302 and 308 castings are swirl port heads too.......and the 302 head is technically not a closed chamber head. Quench, yes, but open chamber. The area around the plug is wide open. Look at the 273 heads. They were closed chamber. Look at the 516 and 915 big block heads. Closed chamber.
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I have the Larry shepherd how to hotrod a small block mopar book I will most definitely check that out I guess I looked over that part or just didnt retain that part?
 
dartfreak75 said:
I have the Larry shepherd how to hotrod a small block mopar book I will most definitely check that out I guess I looked over that part or just didnt retain that part?
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I see Shepard groups the 308/576 heads together but no mention of the 923 head we are talking about. I read the head chapter in Shepard's book and saw no mention of "all LA heads are swirl port heads" as quoted in post #29 above. In fact Shepard mentioned the #302 as being the first with a swirl port design. He also said it's the only head with a "true heart shaped chamber". He must not have paid attention to the 273 heads. In fact the #080 head on the 64 273's was a heart shaped closed chamber head. I have a pair of 302's and a pair of 920's and both have a "heart shaped chamber" The only thing the early heads don't have is that little brow in between the valves like the 302's have. I guess it's just a difference in what your definition of heart shaped is.

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All this worry about swirl, when in fact porting for power requires the reduction and control of swirl. Swirl for power is a power loser. Swirl is great if you want to get the cats to light off quick.

Personally, I'm not out to "save the planet" when the planet doesn't need to be saved.

Horsepower is more important than emissions any day. I make my carbon foot print as big as I can, every day. The green trees love me for it.
 
dartfreak75 said:
That is interesting. I did not know that. So all small block open chambered heads are swirl ports???
What about closed chambers heads are they swirl ports also??
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RustyRatRod said:
I don't think they did testing on closed chamber stuff. They had no need for 273 stuff. All of the testing I am aware of was done on the 318/340 and 360 open chamber heads. It wouldn't surprise me if the closed chambers were too, because Chrysler was ahead of the times like that.
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I was waiting for somebody to say something.
"Swirl port", that means port, not chamber.
That's a chrysler sb thing, others did it too...but I never heard any echos as loud as the mopar one.
There is no difference between a 915 and 308 'intake port' other than the push rod pinch.

Thanks for the revist, it was fun.
 
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toolmanmike said:
I see Shepard groups the 308/576 heads together but no mention of the 923 head we are talking about. I read the head chapter in Shepard's book and saw no mention of "all LA heads are swirl port heads" as quoted in post #29 above. In fact Shepard mentioned the #302 as being the first with a swirl port design. He also said it's the only head with a "true heart shaped chamber". He must not have paid attention to the 273 heads. In fact the #080 head on the 64 273's was a heart shaped closed chamber head. I have a pair of 302's and a pair of 920's and both have a "heart shaped chamber" The only thing the early heads don't have is that little brow in between the valves like the 302's have. I guess it's just a difference in what your definition of heart shaped is.

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Lol I have opinions and no actual facts so I'm keeping my mouth shut because......

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toolmanmike said:
:rofl:
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Here is my overall assessment of this topic. They are factory cast iron heads. Putting a label on them changes nothing. If you are using them chances are you are not building a race car and top performance is not the goal anyways so why worry about a label ? Imo there are about 4 or 5 different sbm heads you have the early 273 heads them the early open chamber small port 318 heads then there is the early 340 heads with 202 valves then there is the later 340/360 heads with 1.88 valves then you have the later 80s 302 and 308 closed chambered heads that pretty much sums it up. Imo for a street car eith a little work they all are good usable heads and can make decent enough power to have fun with. Obviously they are not going to make the same amount of power as a fully ported race w2 head or a fully ported aftermarket aluminum head but they are good enough for a fun street car.
 
yellow rose said:
All this worry about swirl, when in fact porting for power requires the reduction and control of swirl. Swirl for power is a power loser. Swirl is great if you want to get the cats to light off quick.

Personally, I'm not out to "save the planet" when the planet doesn't need to be saved.

Horsepower is more important than emissions any day. I make my carbon foot print as big as I can, every day. The green trees love me for it.
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Swirl is good for torque. That's why "the worst" heads for the Chevy small block are those things with the finger ramp in the intake port.......but guess what? All they came on were trucks and they work great for that. Everything has a place.

The book I am talking about is the Mopar Performance engine book. Not Larry Shepard's small block book, or any other book. The big thick MP book. It's in there where he says it. ........and the testing he was speaking of took place about 1973. Now, what heads was Chrysler making for the small block then?
 
RustyRatRod said:
Swirl is good for torque. That's why "the worst" heads for the Chevy small block are those things with the finger ramp in the intake port.......but guess what? All they came on were trucks and they work great for that. Everything has a place.

The book I am talking about is the Mopar Performance engine book. Not Larry Shepard's small block book, or any other book. The big thick MP book. It's in there where he says it. ........and the testing he was speaking of took place about 1973. Now, what heads was Chrysler making for the small block then?
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True, if the RPM and the air speed is very slow. It takes an awful lot of energy to make the charge swirl. I'm talking about power improvements from idle to maybe 2200 RPM. After that, they are pretty much a loser. The biggest "trick" was the trick flow ports. I made a mint fixing those.
 
yellow rose said:
True, if the RPM and the air speed is very slow. It takes an awful lot of energy to make the charge swirl. I'm talking about power improvements from idle to maybe 2200 RPM. After that, they are pretty much a loser. The biggest "trick" was the trick flow ports. I made a mint fixing those.
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I agree 100%. Swirl and quench are two attributes that get people all worked up and actually mean very little.
 
I remember those swirl spacers that used to set down under the throttle body or carb base back when I was in high school I remember all the v6 Camaro and 4banger mustang guys would brag about how fast it made their cars while I was blowing their doors off with my 78 dodge aspen lol
 
dartfreak75 said:
I remember those swirl spacers that used to set down under the throttle body or carb base back when I was in high school I remember all the v6 Camaro and 4banger mustang guys would brag about how fast it made their cars while I was blowing their doors off with my 78 dodge aspen lol
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LOL...now we have a pretty good idea how old you are!
 
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