mods to 2 bbl intake manifold


http://209.208.111.198/Topic21958.aspx 		Print Topic | Close Window

By texasmark1 - 16 Years Ago
while I have my heads off, are there any mods I can do to my 2 bbl intake manifold to make it for efficient?  have read the stuff about clean up, etc on 4 bbls, but wonder if I can do much of anything to a 2 bbl version?

thanks,Mark

By bird55 - 16 Years Ago
If you have the time and inclination you could always do a little smoothing up of the passages but it's going to be marginal at best. Just don't make anything shiny, but try getting rid of sharp edges.

Also check out a Barry grant 2 barrel. Could be really sweet and simple, just might be cost prohibitive. But I sure would like to know if it would work.
By bird55 - 16 Years Ago
you could probably get rid of the choke crossover too, since (if) you live in a warmer climate.
By MoonShadow - 16 Years Ago
The later two barrel manifolds fit larger carbs. I had a 500CFM Holley two barrel on mine some years ago and It worked great. I'm sure a little port matching and smoothing would always help. Chuck in NH
By Ted - 16 Years Ago
You didn’t say which two barrel intake you’re dealing with.  Here’s a pic of a modified late model two barrel intake off a circle track engine where the rules required a two barrel carburetor.  In this case a 500 cfm two barrel Holley was being used but this type of modification is not recommended for the daily driven street car due to the lack of air velocity under the carb at low rpms.  For a street car, just insure that the carb bore openings match those of the carb being used, transition the curves under the bores to allow a smoother transition of air to the cylinders, and port match the intake openings so they match the heads.
By texasmark1 - 16 Years Ago
once again, thanks for all the responses...

now if I can just find a suitable grinding bit for my drill...

this is a home project, after all!

thanks,Mark

By 46yblock - 16 Years Ago
Has anyone noticed some intake gaskets fit better than others? 

Concerning 2 barrel carbs:  I've been planning on using a 300 cfm Autolite.  Would a 350 cfm Holley do better?  The objectives are throttle response, low rpm driveability, and mileage.

Texasmark.  Do yourself a favor and buy a right angle dye grinder, $15-20.  Then a set of double cut burrs, $40 at Easton.  You'll be happy.

By Unibodyguy - 16 Years Ago
Mark,

       one thing I did on a friends 60 Ford pickup with a 292, 2bll. and stick.  He and I did some reaserch and put a carb. spacer from TD Products ( Trans Dapt I think) It had what they called a "Swirl Port"  spacer that created a Tornado or swirling affect on the air/fuel mixture as it went into the intake. I know we also port matched up the carb openings to the intake as well, and had to put in some longer carb studs.  It made quite a difference especially when he put on a 500 Holley. The stock carb, we noticed quite a bit better mid-range accelleration, and bit better off the line. And after we did all of that, it got about the same gas milage in town and slightly better on the highway, about a mile to the gallon better in fact.