Late 80's swirl port heads 302/714's

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moparlee

moparlee

64 Valiant
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How much can you do to them before the swirl port stuff is gone?

Once you port them isn't that history?

I'd like to know if port matching or upping to to 360 valves enders the swirl port side of it.....if that makes since.
 
yellow rose said:
Swirl is for emissions.
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If we were in a head porting forum, That could be a vary long discussion!!!!!!!
But, the simple answer, YR is on the mark. They were designed to try and get better emissions.
 
Splittin hairs with swirl. Port hell outta um and be done.
 
My first head porting(360 with the air port bump in the exhaust.

As RRR said i ported the **** out of the intake and exh port. would run 7200 rpm with my 340........but would not pass the old sniffer test.
Stock set of X heads with a port clean up, and the old I/M tester was happy...........same cam, same compression, same intake,............ran out of breath at 5800 RPM. but they past the emission test so i could licence my car.
 
Cudafever said:
My first head porting(360 with the air port bump in the exhaust.

As RRR said i ported the **** out of the intake and exh port. would run 7200 rpm with my 340........but would not pass the old sniffer test.
Stock set of X heads with a port clean up, and the old I/M tester was happy...........same cam, same compression, same intake,............ran out of breath at 5800 RPM. but they past the emission test so i could licence my car.
Click to expand...

So you did a head swap to pass emissions? That's hot roddin right there. LOL
 
It wouldn't pass at idle, but past in flying colors at 2500 rpm side of the I/M test.
The way i ported the exhaust it cause a Bad reversion at low rpm (The inside of my intake was black ) I also feel that's why it rev so high as well. once that exhaust port started pulling it started pulling fuel from the intake during overlap
stock x head acted like the .474/280 cam i had in it
The "ported" head acted like it had .550+ lift cam and 300+ degree of duration cam.
 
We'll I was reading a post on RCC where one guy was saying that him and a buddy did a dyno test on a 318....took some pre 85 318 heads and a pair of 302 heads....I'm taking it they had the same guy just do a valve job on both sets of heads. Just a head change was 20 to 25 HP gain with the 302's.

But I have read also over the years that once ported they are so close to the same it isn't funny other than the 302's having closed chambers.

So if that their dyno thing is true or accurate then maybe their only better if not ported.....so reading all that just curious if ya down a gasket match on intake and exhaust would it hurt it?

I've also read that they (302,714 heads) are more of a velocity head.

I wish I was rich to do a bunch flow testing and dyno testing.

I was hoping some guys have been able to play with stuff here is why I was asking....LOL

So yes opinions are welcome....it's all for food for thought anyways.

Thanks everybody.
 
As with virtually everything hot rod related...... whether or not fooling with 714/302 heads makes sense for you really depends on what you’re building and what you’re trying to do with the motor/car.

Shortly after MP was hyping up the use of those heads I was commissioned to build/revamp a couple of oval track motors.
318’s with 2bbl carbs, stock intakes, solid cams, headers, 10:1cr.
You could use pretty much any stock heads, valve size rule for mopars was 1.88/1.50.

They were mid-pack guys when I got the motors.
One already had the closed chamber heads, the other had regular open chamber 318 heads. They had 1.78/1.50 valves in both.
The front runner cars would turn close to 7k on the faster tracks.
I felt 360 heads would make more power, but knew a test was needed to be sure.
I recut the intake seats on the closed chamber heads to accept 1.88 valves and did a bowl cut.
On the 360 heads I installed ex seats to fit the 1.50 valves.
Both heads milled to achieve 10:1.

Swapped heads on the dyno...... 596 360 heads were over 30hp more peak hp for that application.
At the very top of the power band the power difference was even more.

They won a series championship that year....... and got teched/inspected waaay more than any other team.

If you’re trying to make decent power, and will be running fairly healthy cam and are willing to turn some rpm..... use 360 heads.

If it’s a mild street 318 based build, in the 1hp/ci or less range..... use whatever is cheaper.
 
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moparlee said:
We'll I was reading a post on RCC where one guy was saying that him and a buddy did a dyno test on a 318....took some pre 85 318 heads and a pair of 302 heads....I'm taking it they had the same guy just do a valve job on both sets of heads. Just a head change was 20 to 25 HP gain with the 302's.

But I have read also over the years that once ported they are so close to the same it isn't funny other than the 302's having closed chambers.

So if that their dyno thing is true or accurate then maybe their only better if not ported.....so reading all that just curious if ya down a gasket match on intake and exhaust would it hurt it?

I've also read that they (302,714 heads) are more of a velocity head.

I wish I was rich to do a bunch flow testing and dyno testing.

I was hoping some guys have been able to play with stuff here is why I was asking....LOL

So yes opinions are welcome....it's all for food for thought anyways.

Thanks everybody.
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I would say with a mild 318, a set of port matched 302's would work well. If you're building a 400 horse engine, you could port the Hell out of a set and use bigger valves or just buy a set of aluminum's instead.
 
I've either heard PRH story before or similar
I've found the open chambers make more power on a race motor, unshoruded valves and all that. Good to see back to back test with same valves and valve job procedure
I still like closed chamber on the street, truck, motorhome
they seem to take less timing and are less picky on the fuel
perhaps it's that the 360 heads are being run above the torque (BMEP) peak
I can't guarantee good gas
 
I agree on the big port being better....back in the in 90's my brother in law at the time help me biuld a 318 with late 60's pistons in a 73 block with an RV cam that came real close to a 340 cam. We put 360 915 heads with stock 188 intakes, and 80's cast iron four barrel intake.

All in a light 64 2 door Valiant with a wide ratio 4 speed with an 8 1/4 with 2.76 gears....man what fun. Now it has a 340 with Ryan ported E-brock with a 6 barrel intake. Close ratio 4 speed and 8 3/4 with 4.10's.

But....the older I get I dream of low dollar motors for mileage and also builds for 1 HP per cubes with cheapest stockish stuff as possible.

Back to topic here my curiosity would like to see what a 302/714 head would do with some 360 valves....but if you loose the swirl/velocity then I think your wasting the heads and run them with just gasket matched if that doesn't hurt them. Cause if you do port work and it doesn't make them any different that doing to any other 318 then....I think the 302/714 heads should just left alone and use the for a good little gas motors....

Not sure if any of that makes any sense at all....LOL
 
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Well I hope to find out what the 302s will do shortly. I've got a pair going on a 318 I'm building now that have been gasket matched up to 340/360 ports, and has 1.88/1.60s.
 
There is no swirl in 302/"714"heads, never heard of those heads included in the bs swirl gimmick.
The 360 heads, those are all swirl, the wall hump ...that was swirl enhancer. 308 is a swirl head there is no difference between that int port and any other '360' production head beside maybe port volume, which varies 5 cc or so.. The 894 x is not a swirl head. The shape isn't there. No one has to agree with what I'm saying, it is what it is.

OP the only hp gain was from the fast burn chamber that also raised the compression..being that they came 64cc and the 675 head was right at 68cc....they flow the same with the 302 head a hair, literally, less... like 3 or 4 cfm LESS than a cherry stock 675 head.
 
I think I built the oval track 318’s for 3 years, then the rules changed and allowed 360’s.
I don’t remember exactly where we ended up power wise with the 318’s before we went to the 360’s, but it was solidly over 350hp.
That’s running unported 596 heads, and a stock 360-2bbl intake manifold and a Holley 500 2bbl carb.

When I did that first dyno test between the 596’s and the 302’s with the 1.88 intake valves....... the motor never broke 300hp with the 302’s.
 
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PRH said:
I think I built the oval track 318’s for 3 years, then the rules changes and allowed 360’s.
I don’t remember exactly where we ended up power wise with the 318’s before we went to the 360’s, but it was solidly over 350hp.
That’s running unported 596 heads, and a stock 360-2bbl intake manifold and a Holley 500 2bbl carb.

When I did that first dyno test between the 596’s and the 302’s with the 1.88 intake valves....... the motor never broke 300hp with the 302’s.
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With an engine like that big ports win every time.
 
Were the "swirl port" differences in the chamber or in the bowl. I can clearly see the chamber difference but not any big difference in the bowls or ports. And, intake only or both?
 
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302Castings019_zpse479835b.jpg
 
toolmanmike said:
...

View attachment 1715417414
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That is my least favorite chamber. Ever. I know guys drool over that thing but I detest it. Reverse flow it once and you'd hate it too.

That's the same basic chamber the W5 had. That was mistake number 1 on that head. I had $150.00 a month phone bills to Chrysler calling them about the crap that was wrong with that head. Like why are the valve pockets so F'ing deep? Why are the seats A) **** materiel and B) why are they so thin? And C) why are you using and oddball O.D. on the guides???

That's a few of many complaints I had. And it starts with that horrendous chamber.
 
yellow rose said:
That is my least favorite chamber. Ever. I know guys drool over that thing but I detest it. Reverse flow it once and you'd hate it too.

That's the same basic chamber the W5 had. That was mistake number 1 on that head. I had $150.00 a month phone bills to Chrysler calling them about the crap that was wrong with that head. Like why are the valve pockets so F'ing deep? Why are the seats A) **** materiel and B) why are they so thin? And C) why are you using and oddball O.D. on the guides???

That's a few of many complaints I had. And it starts with that horrendous chamber.
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Interesting.
 
toolmanmike said:
Were the "swirl port" differences in the chamber or in the bowl. I can clearly see the chamber difference but not any big difference in the bowls or ports. And, intake only or both?
Click to expand...

See I'm not sure....the one person above says that they are not even swirl ports at all....but I do not know for sure.
But those who've got 20-25 horse power gain from older heads....makes you wonder what about the head did that?
 
yellow rose said:
That is my least favorite chamber. Ever. I know guys drool over that thing but I detest it. Reverse flow it once and you'd hate it too.

That's the same basic chamber the W5 had. That was mistake number 1 on that head. I had $150.00 a month phone bills to Chrysler calling them about the crap that was wrong with that head. Like why are the valve pockets so F'ing deep? Why are the seats A) **** materiel and B) why are they so thin? And C) why are you using and oddball O.D. on the guides???

That's a few of many complaints I had. And it starts with that horrendous chamber.
Click to expand...

I know you hate the "Heart Shape Chambers, But with a flat top piston, it gave you some compression without rebuilding the motor.
It also gave you quench that the open chamber will not without some kind of dome piston. aka rebuild again. or shave the **** out of a 360/340 head for compression...........and then you end up with a Heart Shaped combustion chamber any ways.....
 
My 273 heads are very similar except the drop between the valves isn't as pronounced.

11_14_0.JPEG
 
I have some 67 water small port heads with phord spark plus that have chambers that look like those 273 heads.
 
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