gnicholson wrote:I'm sure the heated intake would help but this thing is mostly driven in warmer weather and a manifold is plenty heat soaked. I realize I could tune this thing a little better but I've worked on it a great deal and it's pretty close to as good as I can make it. I think just as you have already said that a dual-plane would make it better and is an easy option to try. I just don't want to cut the top end Power more than I need to so I was wondering about the flow capacity of that manifold. I thought maybe the AFR dual-plane would move a little more aiir . I will definitely need to put a larger carburetor on it the 750 on it now coupled with a dual-plane will definitely hurt top in power thanks for the replies
See if you can get info on the runner size, my guess is the AFR will be better for you cubic inches...the Air Gap was designed more for 350/383 CI engines.
If you go with a cast Air Gap the Dart version (if it is still in production) is said to be a touch larger than the Edelbrock but that is based on a several year old test???
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The Dart dual plane air gap is smaller, I have both n it has smaller plenums and runners, Jegs shows the Dart as 0-6000rpm. I read awhile back the Dart was suppose to be larger but it's not. Not long ago I compared two rpm air gaps, a dart and the EPS, the airp gaps were largest and EPS smallest.
BOOT wrote:The Dart dual plane air gap is smaller, I have both n it has smaller plenums and runners, Jegs shows the Dart as 0-6000rpm. I read awhile back the Dart was suppose to be larger but it's not. Not long ago I compared two rpm air gaps, a dart and the EPS, the airp gaps were largest and EPS smallest.
Thanks for the correction.
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THE ABOVE POST IN NO WAY REFLECTS THE VIEWS OF SPEED TALK OR IT'S MEMBERS AND SHOULD BE VIEWED AS ENTERTAINMENT ONLY...Thanks, The Management!
mag2555 wrote:That shop with there 210 cfm claim are blowing smoke up your Butt!
The stock bottom of the heap Edelbrock Perfromer flows way more then 210 cfm@28"!
If that Manifolds port area at the flange says basically constant up to the Plenum then there is no way it could not flow atleast 250 cfm@28", and 250 cfm can make you a tad over 500 hp!
Dr J's test a OOTB 351W Air Gap vs one they ported. They saw as high as 256 cfm in their test. The low end was down at 229 cfm on runners 1&4. That's quite a swing. Almost 30 cfm difference between the highest and lowest.
bigjoe1 wrote:By the way, I had a long talk with Harold(Brookshire) last year at the PRI show. We met at the airport and he told me everything he knew about everything.It was a nice visit. JOE SHERMAN RACING
The rpm air gaps I measure the runners were inconsistent CSA and poor castings, both had core shift and even the same bolt holes were off on both intakes.
BOOT wrote:The Dart dual plane air gap is smaller, I have both n it has smaller plenums and runners, Jegs shows the Dart as 0-6000rpm. I read awhile back the Dart was suppose to be larger but it's not. Not long ago I compared two rpm air gaps, a dart and the EPS, the airp gaps were largest and EPS smallest.
I have a welded and ported AirGap on my 410" sbc. I just bought a Weiand 8016 to port and try against it. The Weiand has bigger runners and more volume. I know I may not feel or notice a significant change but I wanted to do it because my heads (Speier 210 ported Pro-files) were huge compared to the AirGap.
I will port the Weiand this winter and post pics of both. Then "street seat of pants" test in spring.
BOOT wrote:The Dart dual plane air gap is smaller, I have both n it has smaller plenums and runners, Jegs shows the Dart as 0-6000rpm. I read awhile back the Dart was suppose to be larger but it's not. Not long ago I compared two rpm air gaps, a dart and the EPS, the airp gaps were largest and EPS smallest.
I have a welded and ported AirGap on my 410" sbc. I just bought a Weiand 8016 to port and try against it. The Weiand has bigger runners and more volume. I know I may not feel or notice a significant change but I wanted to do it because my heads (Speier 210 ported Pro-files) were huge compared to the AirGap.
I will port the Weiand this winter and post pics of both. Then "street seat of pants" test in spring.
The weiand 8016 is the old stealth design, it has a full plenum divider so even if the runner size is larger you might not loose any lower and midrange response and power
BOOT wrote:The Dart dual plane air gap is smaller, I have both n it has smaller plenums and runners, Jegs shows the Dart as 0-6000rpm. I read awhile back the Dart was suppose to be larger but it's not. Not long ago I compared two rpm air gaps, a dart and the EPS, the airp gaps were largest and EPS smallest.
Hey BOOT, do you happen to have the avg. runner entry area and runner lengths of the Performer RPM Air-Gap handy?
550 is probably possible with a performer rpm type intake, but it'll still be down on a good single plane.
Just seen a performer rpm against a Motown and victor JR, all with some porting, on a 355 cube SBC.
The performer rpm was better up to 4500 ish rpm and close till 5000, after 5000 the 2 single planes walked away from it.
It was down 30 HP or so up top vs the Motown and Victor JR.
The dual plane manifold will need a camshaft that is optimum for it.
If the cam is not optimized for the dual plane intake
its full potential power will not be realized.
It's a different cam than whats optimum for the single plane.
If a small block chev dual plane manifold was cast with appropriate larger and taller
runners sizes and the carb pad was also as high as the single plane carb pad is
(5.5" to 6" high) to allow larger volume and height dual plane runners
it will make a lot more power.
The current SBC dual plane intakes are just too small and too low.
Imagine the runners spider from a BBC rpm intake cut off, sectioned thru the plenum length and width
and corrected for the SBC port flange layout. Welded back together, onto a SBC manifold base.
Now it has generous appropriate larger, higher flowing runners and more carb height.
Starting with a 5.5 to 6" carb pad height allows room for larger/taller dual plane runners
on a sbc. Yup it won't fit under a stock hood.
Unfortunately the right left side cylinder bank offset of a BBC is opposite that of a SBC
So it's runner spider cannot be a donor.
F-BIRD'88 wrote:The dual plane manifold will need a camshaft that is optimum for it.
If the cam is not optimized for the dual plane intake
its full potential power will not be realized.
It's a different cam than whats optimum for the single plane.
So what's different, and how close to the single up top will it be without loosing down low after you optimize the cam ?
How many times have you optimized the cam differences to know this ?
randy331 wrote:550 is probably possible with a performer rpm type intake, but it'll still be down on a good single plane.
Just seen a performer rpm against a Motown and victor JR, all with some porting, on a 355 cube SBC.
The performer rpm was better up to 4500 ish rpm and close till 5000, after 5000 the 2 single planes walked away from it.
It was down 30 HP or so up top vs the Motown and Victor JR.
Randy
That seems to be a pretty consistent cross over point the test I have seen.
Please Note!
THE ABOVE POST IN NO WAY REFLECTS THE VIEWS OF SPEED TALK OR IT'S MEMBERS AND SHOULD BE VIEWED AS ENTERTAINMENT ONLY...Thanks, The Management!
BOOT wrote:The Dart dual plane air gap is smaller, I have both n it has smaller plenums and runners, Jegs shows the Dart as 0-6000rpm. I read awhile back the Dart was suppose to be larger but it's not. Not long ago I compared two rpm air gaps, a dart and the EPS, the airp gaps were largest and EPS smallest.
Hey BOOT, do you happen to have the avg. runner entry area and runner lengths of the Performer RPM Air-Gap handy?
