Don't read if you're close minded

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And what about distribution? Of air & fuel? Many production engines had snivvies riveted to the side of the booster to re-direct airflow. Obviously the factories found variations in cyl-to-cyl air flow & this was a fix that was used.
Aftermarket carbs.........Well who knows. Some of the variations in HP might be from how a particular carb directs airflow...& not in it's cfm rating.
 
Here's Larry Widmers take:

There’s a lot that leads up to this, but here’s a quick and dirty of my first experience with dynomometers (other than for kart engines). Our BOSS 429 Mustang had run 10.0’s locally at two tracks, before we were heading up to our first really big drag racing event in Pennsylvania. Bunkie Knudsen (president of Ford Motor Company) had taken a liking to our project, as had VP of Special Vehicles Jacque Passino. We left several weeks before the race and stopped at Holman & Moody in Charlotte. H&M built every Ford factory race car, including NASCAR stock cars, the GT40MkII’s, etc, etc. There was nothing on the planet that rivaled their operation, as that’s where all Ford Racing parts were developed and produced. It was like racing heaven.
While our car was more than competitive, we still spend weeks on one of the H&M dynos, where their experts changed cams, carburetors, etc, etc….ultimately finding an additional 125HP more than we had on arrival. We couldn’t wait to get to the races, as the quickest car in the country had just run a 9.95 second ET, and with all the new-found HP, there was no doubt in our minds that we’d have him covered.
First run and the car bogged and then accelerated slowly up to 7000 rpm where it became a rocket….In an effort to fix the bog, we began increasing flywheel mass, which helped the leave, but slowed the engine more through the gears. Bottom line was that we were still damned near a second slower than when we left Fort Worth. Our ET’s were so poor that we couldn’t have qualified for the 32 car field, so we hastily took all of the H&M pieces off, rebuilt our old combination, and promptly qualified 7th. We did very well in the 3-days or round-robin racing, and knocked off a number of quicker cars in the process (due to our staggered wheelbase and early leaves).
The Ford Drag Racing office now loved us, and life was good, but the most important lesson was that engines that make big power on a dyno, do not necessarily get you down the track efficiently. Everything I did from that point forward was geared toward acceleration and nothing else.
I built a number of intake manifolds to help produce ball-busting power at the bottom of the gear and each improved ET’s. The manifolds included the first cast aluminum tunnel ram (Engineering project in school) which use d a Wieand BBC plenum, “the hairy one” which I made of fiberglass (NHRA refused to let me run it), and then once I was moving and shrinking the intake ports, my aluminum manifolds which were the first with a V plenum and semi-side-exit runners. This was all done to increase intake velocity.
The car responded to each of these combinations favorably, but I got to thinking about piston speed and its effect on the intake velocity. We were running the Ford Nascar rods, which with the engines short 3.59” stroke, netted a rod ratio of 1.93-1. I figured that if the piston speed (acceleration rate to and from TDC) was higher, it would increase acceleration. I had rods made that netted a 1.78-1 rod ratio, and finally found a manufactured who had piston blanks large enough to make the huge-bore 4.40”, pistons with the pin relocated. First run out of the box netted an ET that was .5 (yes .5) seconds quicker than ever.
A couple years later when Roger Penske had me do a pair of 351C heads for his NASCAR program, I left the cross-sections of those huge ports pretty much stock, but picked up a lot of flow with my unique asymmetric valve seat arrangement. On Penske’s dyno, the heads were deemed good, but not that much better than what they were running. I brought the heads back to Cowtown, and set about shrinking the ports. I made aluminum castings that displaced 30% of the intake port cross-section, another that went behind the valve guide so lessen the bowl volume, and finally cast iron castings that I brazed into the exhaust ports to increase their velocities. Next I went to Edelbrock where Vic and Jim McFarland allowed me to scrape some cores to reduce the Torker maniifolds’ runner cross-sections to match my little intake ports. Murray Jensen at Edelbrock built an 830cfm square bore Holley, and I was set for more testing. I should mention that these “crazy little” heads weren’t well received at Penske’s. All of the Fords were currently running the Bod Moore box manifolds with the huge 4500 Holley carbs.
After several pulls on the dyno, the head of R&D said once again….there’re about the same on power as what we have right now. They paid me for the heads, etc, and I returned to Ft Worth with the knowledge that I’d blown my chance at the big time.
Two months later, I received a call from Roger Penske. He asked me to do several more sets of heads. My response was “do you mean the heads that don’t work?” Roger went on to tell me that they were at Daytona, and the best their engine combinations could do was 182mph….middle of the pack at best. In desperation, he had those crazy little heads flown down, with which they went 188mph, picking up 2 mpg in the process.
When I went to work for Roger, I found that almost every time we found more power on the dyno, it did not transfer to better on-track performance. Re-thinking the situation, I concluded that we needed to use dyno for acceleration runs from the lowest rpm we anticipated seeing to the highest, and whatever gave us the quickest ET on the dyno, always translated to quicker lap times.
There’s a lot more to all of this, but this is what led me to using the phrase “transient response”, and to this day, every head and manifold I do is engineered to net the quickest acceleration from the bottom of the gear to the top…..and making big dyno numbers isn’t involved, nor is huge airflow in many instances.

Maybe Larry knows something......He's running 21 to 1 compression ratios in his Honda race engines.
 
Here's Larry Widmers take:

There’s a lot that leads up to this, but here’s a quick and dirty of my first experience with dynomometers (other than for kart engines). Our BOSS 429 Mustang had run 10.0’s locally at two tracks, before we were heading up to our first really big drag racing event in Pennsylvania. Bunkie Knudsen (president of Ford Motor Company) had taken a liking to our project, as had VP of Special Vehicles Jacque Passino. We left several weeks before the race and stopped at Holman & Moody in Charlotte. H&M built every Ford factory race car, including NASCAR stock cars, the GT40MkII’s, etc, etc. There was nothing on the planet that rivaled their operation, as that’s where all Ford Racing parts were developed and produced. It was like racing heaven.
While our car was more than competitive, we still spend weeks on one of the H&M dynos, where their experts changed cams, carburetors, etc, etc….ultimately finding an additional 125HP more than we had on arrival. We couldn’t wait to get to the races, as the quickest car in the country had just run a 9.95 second ET, and with all the new-found HP, there was no doubt in our minds that we’d have him covered.
First run and the car bogged and then accelerated slowly up to 7000 rpm where it became a rocket….In an effort to fix the bog, we began increasing flywheel mass, which helped the leave, but slowed the engine more through the gears. Bottom line was that we were still damned near a second slower than when we left Fort Worth. Our ET’s were so poor that we couldn’t have qualified for the 32 car field, so we hastily took all of the H&M pieces off, rebuilt our old combination, and promptly qualified 7th. We did very well in the 3-days or round-robin racing, and knocked off a number of quicker cars in the process (due to our staggered wheelbase and early leaves).
The Ford Drag Racing office now loved us, and life was good, but the most important lesson was that engines that make big power on a dyno, do not necessarily get you down the track efficiently. Everything I did from that point forward was geared toward acceleration and nothing else.
I built a number of intake manifolds to help produce ball-busting power at the bottom of the gear and each improved ET’s. The manifolds included the first cast aluminum tunnel ram (Engineering project in school) which use d a Wieand BBC plenum, “the hairy one” which I made of fiberglass (NHRA refused to let me run it), and then once I was moving and shrinking the intake ports, my aluminum manifolds which were the first with a V plenum and semi-side-exit runners. This was all done to increase intake velocity.
The car responded to each of these combinations favorably, but I got to thinking about piston speed and its effect on the intake velocity. We were running the Ford Nascar rods, which with the engines short 3.59” stroke, netted a rod ratio of 1.93-1. I figured that if the piston speed (acceleration rate to and from TDC) was higher, it would increase acceleration. I had rods made that netted a 1.78-1 rod ratio, and finally found a manufactured who had piston blanks large enough to make the huge-bore 4.40”, pistons with the pin relocated. First run out of the box netted an ET that was .5 (yes .5) seconds quicker than ever.
A couple years later when Roger Penske had me do a pair of 351C heads for his NASCAR program, I left the cross-sections of those huge ports pretty much stock, but picked up a lot of flow with my unique asymmetric valve seat arrangement. On Penske’s dyno, the heads were deemed good, but not that much better than what they were running. I brought the heads back to Cowtown, and set about shrinking the ports. I made aluminum castings that displaced 30% of the intake port cross-section, another that went behind the valve guide so lessen the bowl volume, and finally cast iron castings that I brazed into the exhaust ports to increase their velocities. Next I went to Edelbrock where Vic and Jim McFarland allowed me to scrape some cores to reduce the Torker maniifolds’ runner cross-sections to match my little intake ports. Murray Jensen at Edelbrock built an 830cfm square bore Holley, and I was set for more testing. I should mention that these “crazy little” heads weren’t well received at Penske’s. All of the Fords were currently running the Bod Moore box manifolds with the huge 4500 Holley carbs.
After several pulls on the dyno, the head of R&D said once again….there’re about the same on power as what we have right now. They paid me for the heads, etc, and I returned to Ft Worth with the knowledge that I’d blown my chance at the big time.
Two months later, I received a call from Roger Penske. He asked me to do several more sets of heads. My response was “do you mean the heads that don’t work?” Roger went on to tell me that they were at Daytona, and the best their engine combinations could do was 182mph….middle of the pack at best. In desperation, he had those crazy little heads flown down, with which they went 188mph, picking up 2 mpg in the process.
When I went to work for Roger, I found that almost every time we found more power on the dyno, it did not transfer to better on-track performance. Re-thinking the situation, I concluded that we needed to use dyno for acceleration runs from the lowest rpm we anticipated seeing to the highest, and whatever gave us the quickest ET on the dyno, always translated to quicker lap times.
There’s a lot more to all of this, but this is what led me to using the phrase “transient response”, and to this day, every head and manifold I do is engineered to net the quickest acceleration from the bottom of the gear to the top…..and making big dyno numbers isn’t involved, nor is huge airflow in many instances.

Maybe Larry knows something......He's running 21 to 1 compression ratios in his Honda race engines.
Interesting piece of history. Not to take anything away from Larry's accomplishment, what he did was very impressive but one take away from this story is that Ford's 351 Cleveland heads have ports that were too big for this NASCAR application. I think the head experts of today would be in universal agreement with that. They have a better understanding of how port size and shape effect an engine. Pioneer's like Larry played a big part in contributing to the knowledge base that experts have at there disposal today. My guess is that if ports can be too big for an application that they can also be too small. But that is a less sexy story to tell.
 
Probably the only thing surprising to them was, after the BOSS 302 debacle, where the Cleveland heads were grossly oversized...especially for road racing....was that they were too big even for larger circle track engines..
 
Interesting piece of history. Not to take anything away from Larry's accomplishment, what he did was very impressive but one take away from this story is that Ford's 351 Cleveland heads have ports that were too big for this NASCAR application. I think the head experts of today would be in universal agreement with that. They have a better understanding of how port size and shape effect an engine. Pioneer's like Larry played a big part in contributing to the knowledge base that experts have at there disposal today. My guess is that if ports can be too big for an application that they can also be too small. But that is a less sexy story to tell.
"I built a number of intake manifolds to help produce ball-busting power at the bottom of the gear and each improved ET’s. The manifolds included the first cast aluminum tunnel ram (Engineering project in school) which use d a Wieand BBC plenum, “the hairy one” which I made of fiberglass (NHRA refused to let me run it), and then once I was moving and shrinking the intake ports, my aluminum manifolds which were the first with a V plenum and semi-side-exit runners. This was all done to increase intake velocity."

Not only shrinking ports but intake manifolds as well to increase ET.

He also said this:

We’ve worked many a program where we used a record holding engine as a base line. In every instance, when the "soft" counterpart was tested, we’d gain perhaps only 8-10% more usable power, but the recovery time and acceleration rates were in a league all their own. As one would expect, the specific fuel consumption was always lower, but in every case the specific airflow requirement for the engine dropped considerably as well. So, now we’re making more power with the same displacement at the same or hopefully lower rpm ranges, and the engine’s consuming both less air and fuel. This not only verifies the fact that we’re achieving greater combustion efficiency, but the airflow relative to power notions that most believe in are no longer applicable.
 
Probably the only thing surprising to them was, after the BOSS 302 debacle, where the Cleveland heads were grossly oversized...especially for road racing....was that they were too big even for larger circle track engines..
Current dyno testing done by Richard holdener doesn't support this at all.

Boss351s and 302s made more power everywhere than their lower performance counterparts. Lower RPM included.
 
Current dyno testing done by Richard holdener doesn't support this at all.

Boss351s and 302s made more power everywhere than their lower performance counterparts. Lower RPM included.

post #102
larry w said:
....I found that almost every time we found more power on the dyno, it did not transfer to better on-track performance.
 
Current dyno testing done by Richard holdener doesn't support this at all.

Boss351s and 302s made more power everywhere than their lower performance counterparts. Lower RPM included.
The real world proved otherwise, in real time, at the time, by the best drivers, tuners & builders, with lots of money & reputation at stake, on the track, with real asphalt, real tires, real throttle transitions,....this isn't a theoretical.
 
Warren Johnson; (paraphrased)"it's too bad We can't just bolt wheels & tires to the dyno & go racing!". That's all You need to know right there..
 
"I built a number of intake manifolds to help produce ball-busting power at the bottom of the gear and each improved ET’s. The manifolds included the first cast aluminum tunnel ram (Engineering project in school) which use d a Wieand BBC plenum, “the hairy one” which I made of fiberglass (NHRA refused to let me run it), and then once I was moving and shrinking the intake ports, my aluminum manifolds which were the first with a V plenum and semi-side-exit runners. This was all done to increase intake velocity."

Not only shrinking ports but intake manifolds as well to increase ET.

He also said this:

We’ve worked many a program where we used a record holding engine as a base line. In every instance, when the "soft" counterpart was tested, we’d gain perhaps only 8-10% more usable power, but the recovery time and acceleration rates were in a league all their own. As one would expect, the specific fuel consumption was always lower, but in every case the specific airflow requirement for the engine dropped considerably as well. So, now we’re making more power with the same displacement at the same or hopefully lower rpm ranges, and the engine’s consuming both less air and fuel. This not only verifies the fact that we’re achieving greater combustion efficiency, but the airflow relative to power notions that most believe in are no longer applicable.
In 2024 I think most high end head porters are aware that bigger isn't always better.
 
Most of us aren't building high effort, highly competitive racing engines, and most of us aren't even close to running port sizes with those cross sections and volumes. I've never heard anyone say the X head was too much for a 340 or that the 1.88 J head was an improvement to a 340 or porting a 340 head turned it into a slug. A 340 has about a 2.1 cid to port volume same a 273, 318 would need a 151 cc port, 360 171 cc, 408 195 cc to be in similar ratio as a stock 273/340.
 
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In 2024 I think most high end head porters are aware that bigger isn't always better.
Most head porters have no idea what combustion is and how it takes place. When your only objective is to increase airflow why would they?
 
Most head porters have no idea what combustion is and how it takes place. When your only objective is to increase airflow why would they?
out of all your stupid comments, this statement is the most ridiculous i have ever heard. where does your pea sized brain get this **** from?
oh ya asking for a friend
 
out of all your stupid comments, this statement is the most ridiculous i have ever heard. where does your pea sized brain get this **** from?
oh ya asking for a friend
That was my exact thought when I read it too. It is utterly ridiculous lol.
 
I've only come across 2 guys who could run compression ratios into the 20s and one of them was doing it with pump fuel.

Can you point out all these head porters who know enough about this stuff who are doing that?
 
Again your ridiculous, without context it means nothing.
 
1720059298041.png
That runs 20:1 cr.
 
All these HIGHLY ANECDOTAL and THIRD PERSON...three times removed....accounts of guys talking about how dyno results don't translate to real performance. Lolz.

Couple points....

1. Dyno tech has definitely progressed since freaking 1970. Am I saying that the tests done back in the day were all garbage? No. But if you pick up over 100 HP and go slower... something is off in the combination. Or something was flawed.

2. All...ALL of the major racing teams today rely heavily on the engine dyno to test and evaluate changes. Serious efforts will have race courses programmed into the dyno to simulate real world dynamics.

3. Yeah that Boss 302 couldn't be made to work for road racing lolz
1720065116789.png
 
All these HIGHLY ANECDOTAL and THIRD PERSON...three times removed....accounts of guys talking about how dyno results don't translate to real performance. Lolz.

Couple points....

1. Dyno tech has definitely progressed since freaking 1970. Am I saying that the tests done back in the day were all garbage? No. But if you pick up over 100 HP and go slower... something is off in the combination. Or something was flawed.

2. All...ALL of the major racing teams today rely heavily on the engine dyno to test and evaluate changes. Serious efforts will have race courses programmed into the dyno to simulate real world dynamics.

3. Yeah that Boss 302 couldn't be made to work for road racing lolz View attachment 1716271401
Uhmmmm, the Z28 302, the BOSS 302, and the T/A block 340 destroked to 305 were all for one purpose....the TransAm racing series. If You had even the slightest clue of what You are talking about, You'd know that the TransAm teams running the BOSS 302s ended up filling about the whole bottom 1/3 of the 4V Cleveland Heads Intake ports because they were F*(king dogs getting back in the throttle & apexing/track outs on slower turns...fact...no amount of postumus dyno voodoo is going to change the reality..have a nice day.

EDIT: Hilariously, I just tagged on 273's Vizard Flow vs Velocity Thread, see posts #35 & #36, lololol.
 
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Uhmmmm, the Z28 302, the BOSS 302, and the T/A block 340 destroked to 305 were all for one purpose....the TransAm racing series. If You had even the slightest clue of what You are talking about, You'd know that the TransAm teams running the BOSS 302s ended up filling about the whole bottom 1/3 of the 4V Cleveland Heads Intake ports because they were F*(king dogs getting back in the throttle & apexing/track outs on slower turns...fact...no amount of postumus dyno voodoo is going to change the reality..have a nice day.
A Dog in a highly competitive race class, I imagine the vast majority of people on this site aren't running in super highly competitive racing where being a 10th of a second off can make a huge deal but for the average guy probably not so much.

Most here have a weekend throttle blip burnout machine that might see the track now and then context matters.
 
A Dog in a highly competitive race class, I imagine the vast majority of people on this site aren't running in super highly competitive racing where being a 10th of a second off can make a huge deal but for the average guy probably not so much.

Most here have a weekend throttle blip burnout machine that might see the track now and then context matters.
So You believe if a port is too large for competitive racing, it'll be just okey dokey on the street, is that the context that matters??? I can guarantee that's worth more than "a 10th".
 
So You believe if a port is too large for competitive racing, it'll be just okey dokey on the street,
There's people running around with built old school Cleveland's, would they be better off with a modern heads, probably but doesn't mean their not enjoying their cars.
is that the context that matters??? I can guarantee that's worth more than "a 10th".
Wasn't given exact figures, point is what's important in highly competitive racing not necessarily important to the average dude.
 
Roger Huntington made a very good point in his American Supercars book. Ferd built the 429 Shotgun engine with huge intake ports to beat the 426 Hemi. Only 'half' worked.....
Ferds were quicker on long tracks, Hemi was quicker on short tracks...
 
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