by kookykrispy Tue Dec 09, 2014 6:19 pm
Ah yes, the holley 3 barrel list #3916. I've always thought these were pretty cool and have a neat history. There is one for sale on my local craigslist, I was actually considering picking it up and modifying it for my blower engine.
http://seattle.craigslist.org/skc/pts/4787115642.html I decided against it when I discovered that the rebuild kit is no longer available from holley? Bummer. The real problem is the vacuum secondary was larger than a standard holley and you cannot get the replacement diaphragm anymore. The story is the 3916 was designed for the nascar racers in the 60's, running big blocks that needed a carb capable of moving alot of CFM. 950 is alot of CFM, so this is more of a race carb, you probably wouldn't want to use this on a small street engine that didn't need all that airflow. I also read these were used on some of the Baldwin-motion supercars, and were also favorites of many old school drag racers prior to the advent of the holley Dominator.
Interesting that the 3 barrel design is now being used in the new street demon carbs. I'd like to try one of these carbs out. They look very impressive, and are based somewhat on the carter thermoquad design, but with many improvements.
http://www.hotrod.com/how-to/engine/ccrp-1209-01-street-demon-carburetor-the-new-625-cfm/ Twinpilot001 wrote:edelbrock also made a chev intake for that carb - model c3b- i believe some of us here still run that manifold too!
Interesting. Both the c4b and c3b are early intakes so they have the provision for a front oil filler to work with early 283 and 327 style valve covers, like the original corvette covers pictured here. The center oil filler tube is particularly convenient in a early chevy van because its much easier to fill the oil at the center of the engine since the valve covers are under the sides of the 2nd gen doghouse. I run this vintage c4b intake on the 350 engine in my '68 camaro and I love it. Works really well on my 350. It has 4 separate holes in the intake, unlike the c3b.
The c3b is similar but has a cut in the center plenum divider to allow for that rear butterfly of the 3 barrel holley.
You can find these cool early intakes on eBay or at swap meets. Remember though: HEI distributor won't work because it is too large and will not clear the rear plenum of the intake. I am using a pro-comp electronic distributor with external coil, which does clear.
I noticed a modern performer RPM air-gap intake also has a cut down center plenum divider. I am pretty sure this is done more for an airflow engineering reason than for anything else. I have read that notching the center plenum divider in a dual plane intake can help increase the signal to the base of the carb at higher rpms.
