American 4 BBL knowhow
is enough to make the dog turd head of the cattle herd.
If you'd aked me, for years I'd have sworn, based on the evidence, that Port on Port Independent Runner induction beats all.
In 90% of the cases, it does. But Shelby dual quad 4-bbl FE 427's and certain 240 Z's can beat a handfull of direct mount Webers or Motorbike carbs with good execution and design.
Port on port, Independent Runner carburation requires the biggest waste of space to get the intake venturis up to size of any carb system, and on a tight engine bay like a X shell Falcon, Mustang/Maverick/Granada body or any Fox platform, there just aint the space to fit one of those systems on without a lot of really hard, elite engineering work. American smarts alters the outcome of the carb crap shoot, though.
See
http://bringatrailer.com/2012/09/29/bat ... -race-car/
Induction is an unconventional but highly effective 390 cfm Holley 4150HP carb on a Bob Sharp style custom intake manifold. These manifolds were sold by Bob Sharp back in the early 70’s, and this is an improved reproduction.
The Holley carb outperformed the 45 DCOE Webers on the car originally, and the seller says he was as astonished as anyone by this.
See
https://www.youtube.com/watch?time_cont ... mUAw6CD1yU
And the answer is to keep the log, and do something like that 1971 Datsun 240Z SCCA Race Car. It has 45 DCOE beating 4bbl Holley carburation...
I studied
real hard Ak Millers Horseing around with the Mustang Six. And then looked at what actually happened with the outcome of all that talk from Hot Rods 1967 articles. Ak continued to share the in line six gospel to all who would listen, with Jay Storer and many others catching the gist of it. What most weren't awre of was that the 1969 Mustang 200 and 250 was supposed to get an optional Aussie 2V head with a Fuel Injection unit that Ford Dearborn had been testing for years, which is why Ak could say some of his 1967 carb swaps made a 200 six fell like it was fuel injected.
http://www.classicinlines.com/HA7.asp
I was also very interested to find out what the small carburetors would do for horsepower in the lower rpm ranges, so we took a reading at 2800 rpm and netted 75 hp at the rear wheels. At 3800 rpm we had l05 hp, and we reached the top of the ladder at 4800 rpm, with 125 hp. This proved to us that our idea on the soundness of this type carburetion was right. When you jump on the throttle with the little bears, it is just like having fuel injection. It feels like all the horsepower unloads at once.
The gains in accleration were from a 120 hp gross rated Califonia spec 85 flywheel 0- 60 mph 12.5 sec, 19 seond 1/4 mile drag time car to a 125 flwheel hp 10.2 and 17.2 sec 1/4 mile car with just the head, exhaust, carb and cam change. Then an extra 25 rear wheel hp from the carb made it a true 158 hp car, able to do 8.5sec 0-60's and 16.6 second 1/4 miles, still with a 3 speed. The Jag carbs made it only sligtly slower, at 16.9 seconds for the 1320 dash.
At the 145 to 158 hp level with just 260 degrees of low lift cam and the open C7 DE closed chamber 52 to 54 nominal emissions head (it was planed down to 44 cc), Ak was right to where Nissan/Datsun was in the development 240Z engine...
The development from 1960 was little 156 cube engines Hilborn Fuel injection and the first Stropp Bros and Holman Moody tripower 1-bbls that have set in motion 55 years of Offenhauser bolt on adaptors which can make 180 bhp on a 200 and up to 220 or so on a 250. Hydrofoil racers like Clay Smith had looked into port on port injection with Stu Hilborn Hydofoils develped by Johnson Prop and Paul Sawyer. It was nothing to have those little four bearing pip-squeeks turn to 8600 rpm, and make 240 bhp. These days, a triple carbed 170 like Paul Knotts 1962 XK Falcon with saw off log can make 280 hp with 45 DCOE's.
But Ak Miller style, it went in public steps like this
Bigger 1-bbl 240 carb-->125 flywheel bhp
Twin HS6's-->145 flywheel bhp
Twin S&C carbs-->150 flywheel bhp
Four Keheins-->158 flywheel bhp
The MAVI GT Offenhauser 200 and 250 with a bewildering array of carb options--->125 to 220 flywheel hp depending on cam and pistons
Then Impco LPG and Turbo 250--->A Bye Bye little Buddy/Crosely Beater at---> 205 flywheel bhp
Triple Weber 45DCOE's on sawn off Argie style 200--->well over the 205 flywheel hp level
Bosch K Jetronic on sawn off Argie style 200--->well over the 205 flywheel hp level
When forced with California Air Resources Board Clean Air Rules, unlike others, Ak saw the 50000 mile durability requirments on the wall, and automatically ended up with making 2 and 4-bbl carb Holley or Autolite/ Motorcraft adaptors and draw through turbos if his customers didn't want his Impco or OHG propane carbs. The Pangra was first, then a whole bunch of AME kitset 200 and 250 turbo 4-bbl engines which produced better results.
So effectively, Ak Miller side shifted one step back
from the Aussie heads that used Six GSX 600 carbs,
the triple 45DCOE Weber and single throttle body Mercededs Benz Bosch Fuel injection set ups he also testing between 1967 and 1970,
and instead went back to 4-bbl Holley and turbo set ups that didn't have the space limitations of the 158 bhp four Kehien small log 3.3, or the 145 bhp twin HS6 1-3/4" set up.
The Offy tripower and 2-bbl Holley or Autolite/Motorcraft direct mount made some real power from every dollar. The probelm was fitting it all in.
In Australia and Argentina, the advent of the tall deck 250 and 221 in line sixes made all sorts of problems, they slanted the engine to fit it into 4 X 4's and early VA3000 Tri Power Falcons.
But it was the Datsun guys who copied those methods the Aussies and Argies used to sort that out.