2 4's on 65

[cc walker]

were 2 4's a option on a65 327/350?

[William C.]

Re: 2 4's on 65

No!

[Donald T.]

Re: 2 4's on 65

It should have a single holley 2818. Dual quads were only used on C1's.

[cc walker]

Re: 2 4's on 65

when to a local show & shine,a car and owner new to us,had a 65 327/350
so equipped.i also have a327/350 65,ilooked at a options list for a
65 some time ago did not see that.he was postive it was original,i was
just checking,you never know about "double secret" stuff.
cc

[mike cobine]

Re: 2 4's on 65

I remember a '63 coupe that had a dual quad setup. I think the word was it was original. however, as we all know, it wasn't to '63, just made with original Corvette parts as opposed to being Edelbrock or Offenhauser or such.

They have a great visual impact and so people often tell those looking they "are original" because there are so many that as soon as you say "I modified it", they act like you did something horrible. Easier to say "it's original" and let them think "wow, those original Corvettes were so neat!"

[cc walker]

Re: 2 4's on 65

it did look cool,why made a big deal out of it,i could'nt care less what
he does with his car.you are right about it driving some over the edge.mine
is original,but it just what i like.

[cc walker]

Re: 2 4's on 65

it did look cool,why made a big deal out of it,i could'nt care less what
he does with his car.you are right about it driving some over the edge.mine
is original,but it is just what i like.

[William C.]

Re: 2 4's on 65

Yours is not only originaly, but very likely faster as well. The old wcfb 2X4 setups were not really great for airflow compared to the Holley and later intake manifold.

[Donald M.]

Re: 2 4's on 65

I installed "Tri-Quads" on my 327. Three four barrels!Of course, it flooded a lot and I had to kinda glue on the end carb and.....

[Duke W.]

Re: 2 4's on 65

The 2x4 inlet manifold was designed to mate with the old medium port 1.72/1.50" heads and it would be restictive with big port 461s or later big port heads unless it was ported out about as far as you could go.

The runners are too short to achieve good inlet inertia tuning on a street engines, and eventhough the ports are short, their small cross section makes them restictive.

There are sound engineering reasons why Chevrolet abandoned the 2x4 manifold and installed single four-barrel inlet systems on carbureted Corvette engines after 1961.

The 3x2 BB setup was strictly a marketing ploy to achieve more "sex appeal". The fact that L-88 used a single four-barrel carubetor tells you what really works best.

Then there was the "cross-fire injection" system with two throttle bodies that even Dave McClellan said was a mistake in his book, and that system was designed on his watch as Chief Engineer.

Duke

[mike cobine]

Re: 2 4's on 65

But they look cool.


The 3x2 BB setup was strictly a marketing ploy to achieve more "sex appeal". The fact that L-88 used a single four-barrel carubetor tells you what really works best.


After driving some set up poorly and some set up very well, I think that there was an entirely different target they were shooting for, a fuel-injection-type throttle without the expense of fuel injection. Remember that Duntov was a road racer, not a drag racer.

When set up right, there are no bogs or hesitations or jumps or anything. It is like running a big electric slot car, it just goes.

So many messed up the vacuum system to where you feel the other carbs come in or you get those surges of "power" and that traditionally means you were off the power in order to get a surge of power.

However, it was the wrong timing and the wrong market. People knew about the surge when the back two barrels of a four barrel kick in and wanted (needed) the same with the tripower. Thus a lot of vacuum systems went in the trash to have progressive mechanical linkage.

It was also just terrible from a maintenance stand point.


Then there was the "cross-fire injection" system with two throttle bodies that even Dave McClellan said was a mistake in his book, and that system was designed on his watch as Chief Engineer.


I think this one was an answer to a problem using existing materials because no one will budget the money. The wonderful TBI used on so many Chevy engines is great for economy, but basically a large two-barrel and you know it on any vehicle that you attempt to tow a heavy load with. You just can't open the throttle enough under load as it is too small. What is the silly thing, about 400 cfm? 350?

The one on my 7.4L is about what was needed on my 5.7L, which couldn't climb a hill towing a trailer with its TBI. I need the one from the 5.7L on my 7.4L in addition to the one there now.

So the obvious solution if you can't build a bigger one (and have no money) is to install two.

Did it work? Better than the single existing TBI.

Was it a mistake? Maybe, but probably not given the options and circumstances.

Was it any good? Looked better than those Q-Jets on the '75-'81 Vettes.

Looking back, a lot of Corvette history can be viewed as "mistakes". But a lot of those "mistakes" are the results of items not available, no money to create the item, and not enough experience to know that item is insufficient.

[Mike McKown]

Re: 2 4's on 65

Looking back, a lot of Corvette history can be viewed as "mistakes". But a lot of those "mistakes" are the results of items not available, no money to create the item, and not enough experience to know that item is insufficient.

For "lack of money", I ran a 2X4 270 set up on a '62 340 engine. It ran very well. When I finally changed it over to an AFB and aluminum intake, I couldn't confirm any performance advantage.

[Duke W.]

Re: 2 4's on 65

TBI was GM's lower cost alternative to electronic port injection, when they finally threw in the towel on trying to make carbuetors meet emissions and CAFE.

Did it work?

The answer to that is how long it lasted!

Duke

[Clem Z.]

i could never under stand why GM went to those

very expensive computor controlled carbs and then went the TBI. the TBI are pretty bullet proof as my silverado has 120,000+ miles with never any work done to the TBI. the TBI are also cheaper to rebuild or replace as some of those computer controlled carbs cost over $600 rebuilt at the auto parts. i did a lot of business rebuilding those carbs.