[Boston71T37]

Curious if there was ever a 326-455 manifold with the carb cocked 15 degrees? Ran one on a BBC rectangle port 454 in high school and that thing would scream all the way to 6700 RPMs, also recieived numerous compliments on the angled carb pad mounting!

[b-man]

Nope, just a BBC thing.

[Boston71T37]

OK, thanks! I've definitely seen 302 Ford's with them too though.

[72projectbird]

I've seen these before, but never stopped to figure out why they did it? So whats the scoop?

[Boston71T37]

They were designed for 3000-7000 RPM. No vacuum at idle (no power brakes) unless cam had 10-12 inches of vacuum at idle

[Boston71T37]

"Another feature of the single-plane concept related to how carburetor size played a role in cylinder-to-cylinder mixture distribution.* As it turned out, the smaller the total flow capacity (cfm rating), the greater the air/fuel charge plowed into the plenum floor, especially at higher rpm where the manifold really liked to work.*"

[screamingchief]

Originally Posted by 72projectbird

I've seen these before, but never stopped to figure out why they did it? So whats the scoop?

Well,it's a known fact that OE MarkIV BBC heads typically had long & short ports as SOP,and as such with a typical/traditional open plenum intake that engine would often require "stagger jetting" the given carb to account for that uneven port length situation,and my guess would be that particular intake design was an attempt to equalize the port lengths for more even cylinder filling and better charge distribution traits,and as such allow one to jet the carb in a more traditional manner.

Same deal with BBC mechanical port fuel injection and the different length injector "stacks" they would use.

HTH

Bret P.

[72projectbird]

That's cool, I learned something today!

They do look wild, just never knew the reason.

[Craig Hendrickson]

Originally Posted by Boston71T37

Curious if there was ever a 326-455 manifold with the carb cocked 15 degrees?

Yes! Not for street and not production, but here's the "canted carb" tunnel ram custom made by H-O Racing Specialties in 1973 for our NHRA 326 E/MP Tempest. This manifold still exists today with different (bigger) carbs and linkage on a SD-455 in Selden Ruwwe's 1963 Tempest drag car.

[67GTO4SPEED]

Originally Posted by Craig Hendrickson

Yes! Not for street and not production, but here's the "canted carb" tunnel ram custom made by H-O Racing Specialties in 1973 for our NHRA 326 E/MP Tempest. This manifold still exists today with different (bigger) carbs and linkage on a SD-455 in Selden Ruwwe's 1963 Tempest drag car.

That is all the way awesome! Thanks for sharing! You guys were truly trailblazers for the Pontiac cause. I was reading your book when I built my first Pontiac engine back in the late 90's.

[Boston71T37]

I'm in love

[HWYSTR455]

Craig - What kind of valve covers are those? M/Ts with the logos stripped off or somthing?

.

[Craig Hendrickson]

Craig - What kind of valve covers are those? M/Ts with the logos stripped off or somthing?

Yes. Kern milled the "M/T" off flat. He also painted the crackle black.

May he RIP.