David Vizard, Uncle Tony's garage, Unity motorsport. Mission impossible Dodge 302 Head porting

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Here's a dyno test of a 367 hp engine test at 50% throttle and made 94% of the power 344 hp, the intake might be less of a problem than we think.

 
67autocross said:
A buddy of mine who flys over to Australia from Canada about 6 times a year just took 2 heads and an intake in his suitcase for me that I sold…the Australian who bought them said it was like a half price sale!
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I brought a motorcycle drag slick, packed with transmission parts and a side exhaust for a KZ1000 back once as luggage . Customs guy had a laugh.
 
George Jets said:
Here is an interesting video of an experimental transparent intake manifold to show the fuel/air mixture moving through it.

Shows what is going on inside like where Charles is doing his intake manifold internal runner cleanups.

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From memory, they also did this with the Hemi cross rams to try and solve the fuel puddling issues.
 
I find it interesting to see how different people go about porting.

For example....... if I’m bringing a port opening out to a scribed line......... I generally get the opening to size first.

I also don’t change burrs as often.
Not that there’s really any right or wrong way to go about it........ the final shape being right is what matters.
 
273 said:
Here's a dyno test of a 367 hp engine test at 50% throttle and made 94% of the power 344 hp, the intake might be less of a problem than we think.

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It depends upon what part is biggest restriction to air flow. That intake they used definitely was not the restriction. As far as 50% throttle blade angle goes, I wonder how that translates to what percentage the restriction of max airflow is. That was pretty big throttle body in the video.
 
273 said:
Here's a dyno test of a 367 hp engine test at 50% throttle and made 94% of the power 344 hp, the intake might be less of a problem than we think.

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So a 50% decrease in the available airflow didn't correspond to a 50% decrease in power generated......Guess an engine will only use what it can not what you give it.
 
mgoblue9798 said:
It depends upon what part is biggest restriction to air flow. That intake they used definitely was not the restriction. As far as 50% throttle blade angle goes, I wonder how that translates to what percentage the restriction of max airflow is. That was pretty big throttle body in the video.
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It might not translate to well to intake runner size the length of the restriction might come into play, it's probably more comparable to the carb. I guess the importance of restriction is head than intake then carb.
 
Reminds me of this test where they swapped out a tiny Streetmaster for an Air gap and gained a whopping 16 Hp at peak airflow demand:

Mopar Performance Parts - '71 Satellite 340 Small-Block Bolt-Ons - Hot Rod Magazine

-1971_plymouth_satellite-performance_parts_install.jpg


Compare the size of those ports and plenum and realize it was only a 16 HP difference @ 5000 RPM
 
Charles Servedio
Single Plane port work.



Charles is happy with the flow numbers that are evolving with the single plane intake manifold.
 
Hysteric said:
Reminds me of this test where they swapped out a tiny Streetmaster for an Air gap and gained a whopping 16 Hp at peak airflow demand:

Mopar Performance Parts - '71 Satellite 340 Small-Block Bolt-Ons - Hot Rod Magazine

View attachment 1716038796

Compare the size of those ports and plenum and realize it was only a 16 HP difference @ 5000 RPM
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The rest of the story is the engine was basically a stock rebuilt high compression 340 with stock spec cam and 1.88 360 heads. And it had 318 exhaust manifolds on it. And made more than 20hp difference at 3000 rpm- AT THE WHEELS.

Under those conditions the manifold swap made a huge difference, and did not have the benefit or cam or headers to do so.

Point is swap the cam to anything bigger and put headers and good exhaust on that engine, and THEN swap the intake and watch the power numbers go up substantially because the old intake then becomes the restriction.

As always it is using the right combination of parts to get the biggest change in output.

That is $400 well spent for an intake swap, especially considering you could likely sell the old intake for 150 to 200.
 
If they did the intake last it would of worth more, only real way to do it swap everything then go back and forth with each part to see what it subtracts from final power, but your point still valid by itself didn't do much.
 
mgoblue9798 said:
The rest of the story is the engine was basically a stock rebuilt high compression 340 with stock spec cam and 1.88 360 heads. And it had 318 exhaust manifolds on it. And made more than 20hp difference at 3000 rpm- AT THE WHEELS.

Under those conditions the manifold swap made a huge difference, and did not have the benefit or cam or headers to do so.

Point is swap the cam to anything bigger and put headers and good exhaust on that engine, and THEN swap the intake and watch the power numbers go up substantially because the old intake then becomes the restriction.

As always it is using the right combination of parts to get the biggest change in output.

That is $400 well spent for an intake swap, especially considering you could likely sell the old intake for 150 to 200.
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Big difference in port size not a big difference in outcome. Peak airflow demand isn't @ 3000 RPM.

Seems people need to move the goal posts so as not to have to deal with the reality.
 
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Hysteric said:
Big difference in port size not a big difference in outcome. Peak airflow demand isn't @ 3000 RPM.

Seems people need to move the goal posts so as not to have to deal with the reality.
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The airgap was better at all rpms according to the article.

Your downplaying the difference of 16hp at the rear wheel to try to further your agenda is either disingenuous or ignorant. 16hp at the wheel is about 19 to 20 on the dyno.

That 20 hp at peak, with even bigger differences along the rpm curve is some of the easiest hp in terms of dollars spent that there is. What were you expecting with an intake swap on a less than optimal stockish 340?
 
Dont try to confuse a guy who spends all of his time on here pushing small ports, **** intakes, and 318 engines as some kind of hidden power secret. Hes a idiot
 
replicaracer43 said:
Hes a idiot
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Oh the irony....
mgoblue9798 said:
Your downplaying the difference of 16hp at the rear wheel to try to further your agenda is either disingenuous or ignorant.
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I'm just highlighting how a tiny port half the size of the air gap didn't kill performance as most would suspect. Why didn't that 302 lose a whole lot of power by halving the the throttle opening? Didn't it lose a lot of flow? Maybe you can't comprehend that an engine can only use so much air and giving it more wont changer that ability.
 
Hysteric said:
Oh the irony....

I'm just highlighting how a tiny port half the size of the air gap didn't kill performance as most would suspect. Why didn't that 302 lose a whole lot of power by halving the the throttle opening? Didn't it lose a lot of flow? Maybe you can't comprehend that an engine can only use so much air and giving it more wont changer that ability.
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damn,...i like 302 heads to but ...damn!! take your 302s have them dipped in 24 ct gold and set them on your mantle,..then thay be worth something!!
 
Concerning the Aussie 265 Pentroof design inline six.
A complete car was shipped to Italy along with Aussie engineers to fit the Weber carbs. The car was driven in up a hill, starting at 20 mph, in top gear with three people in the back & crested the hill doing 60 mph..

British racing car driver Sterling Moss was employed by Chrys to to TV ads for the new design.
 
Bewy said:
Concerning the Aussie 265 Pentroof design inline six.
A complete car was shipped to Italy along with Aussie engineers to fit the Weber carbs. The car was driven in up a hill, starting at 20 mph, in top gear with three people in the back & crested the hill doing 60 mph..

British racing car driver Sterling Moss was employed by Chrys to to TV ads for the new design.
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As I understand it, they had to get the Italians to sort it out, because they couldn't.
 
Hysteric said:
Oh the irony....

I'm just highlighting how a tiny port half the size of the air gap didn't kill performance as most would suspect. Why didn't that 302 lose a whole lot of power by halving the the throttle opening? Didn't it lose a lot of flow? Maybe you can't comprehend that an engine can only use so much air and giving it more wont changer that ability.
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I can comprehend fine thanks. There is a place for smaller ports depending upon the build. You cherry picked one data point to try to make your point, but chose poorly.

For the record I am using some tiny port 413 RV heads on a 440 RV engine I am building. Been told by many that they are junk and wont make any power. Fact is they are the best heads for my application as the engine will never see north of 4500 rpm. It is all about low speed torque and keeping part throttle velocity high trying to get more efficiency.
 
Since this thread is off the rails anyhow...
In 1994 I helped a good friend build a low$$ 360, stock stroke, speed pro h405p pistons .060, MP 284/484cam, 850 DP, generic a body headers, 904 with 4000 stall GER(, yeah, a GER) converter. He had a Streetmaster intake and I told him to get a real one. The Dart went 8.5s in the 1/8th. Mid summer he picked up a single plane M1. That change dropped it to 8.10 in the 1/8th. No other changes. By the end of the summer it ran 7.8s.

I was young and had a lot to learn, still do. I just feel that the 360 needed more than what the Streetmaster could give it.
That is my real world experience.

Form your own opinions.
Maybe we were too dumb to extract the power from the Streetmaster..
Maybe the 360 needed more flow, that the M1 provided.

Whatever you think, it is fine , if you think I'm dumb, it won't bother me.

Edit: Maybe the power of the S-master was blowing through the GER converter, hence the slower times... Maybe I need to rethink this....
 
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Mopar Sam said:
Since this thread is off the rails anyhow...
In 1994 I helped a good friend build a low$$ 360, stock stroke, speed pro h405p pistons .060, MP 284/484cam, 850 DP, generic a body headers, 904 with 4000 stall GER(, yeah, a GER) converter. He had a Streetmaster intake and I told him to get a real one. The Dart went 8.5s in the 1/8th. Mid summer he picked up a single plane M1. That change dropped it to 8.10 in the 1/8th. No other changes. By the end of the summer it ran 7.8s.

I was young and had a lot to learn, still do. I just feel that the 360 needed more than what the Streetmaster could give it.
That is my real world experience.

Form your own opinions.
Maybe we were too dumb to extract the power from the Streetmaster..
Maybe the 360 needed more flow, that the M1 provided.

Whatever you think, it is fine , if you think I'm dumb, it won't bother me.

Edit: Maybe the power of the S-master was blowing through the GER converter, hence the slower times... Maybe I need to rethink this....
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I only came back to this thread because I saw YOU posted, I knew right then, there would be something worth reading... and there was !!!

:lol:
 
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