logo
12 Port News - Features
12 Port History
Casting Numbers
Online Store
Tech Tips
Become a Member
Previous Thread
Next Thread
Print Thread
Rate Thread
#21828 03/31/02 07:19 PM
Joined: Jul 2000
Posts: 41
5
54chevy Offline OP
Active BB Member
OP Offline
Active BB Member
5
Joined: Jul 2000
Posts: 41
I was curious what leo had to say about spliting the siamessed intake ports. I would think that this would need to be done with an injected motor. that way one cylinder wouldn't be stealing mixture from the other. what do you think?

Joined: Jun 2000
Posts: 272
5
Contributor
*****
Offline
Contributor
*****
5
Joined: Jun 2000
Posts: 272
A common thought of high performance builders is that the larger runner volume of the siamesed intakes actually helps boost performance and that separating the runners is the wrong thing to do. Since adjacent cylinders pull on the siamesed port at different times, some racers run only 3 larger injectors instead of 6 smaller ones. The Sissel racing head design makes significant efforts to blend the two ports as well and combine intake runners to increase volume and shape for better flow to the valve seat area.

Joined: Jul 2000
Posts: 4,588
Likes: 20
1000 Post Club
**
Online Content
1000 Post Club
**
Joined: Jul 2000
Posts: 4,588
Likes: 20
some say that spliting the port worked at one time and is good for low end But not good for High Rpms. It is best not to split the port to the best that i know of. Unless you plan on low rpms and plan on doing the same to the intake right up to the carb. Which has been done many yrs ago. I don't know of anyone doing that any more. Again to best that I know it is Better to blend the ports Because they do Not draw at the same time and the port Vol is Much Better. I only Know of One person still doing test On the split port and adding the Lump port at the same time to what has the best Flow But so far it is With the lump ports and Nt being split. hope this Helps }[oooooo]



------------------
NovaMan/Twisted6/Larry


Larry/Twisted6
[oooooo] smile
Adding CFM adds boost smile
shocked God doesn't like ugly.
Joined: Mar 2002
Posts: 195
P
Contributor
Offline
Contributor
P
Joined: Mar 2002
Posts: 195
 Quote:
Originally posted by Twisted6:
some say that spliting the port worked at one time and is good for low end But not good for High Rpms. It is best not to split the port to the best that i know of. Unless you plan on low rpms and plan on doing the same to the intake right up to the carb. Which has been done many yrs ago. I don't know of anyone doing that any more. Again to best that I know it is Better to blend the ports Because they do Not draw at the same time and the port Vol is Much Better. I only Know of One person still doing test On the split port and adding the Lump port at the same time to what has the best Flow But so far it is With the lump ports and Nt being split. hope this Helps }[oooooo]

I have being doing some thinking on this myself as I am current switching my v8 camaro to hot hot 292. several years back I built a 250 for my 35 chevy --202's , split the ports , the whole nine yards --impressive but when you look at the late throttle body injection it is one pulsing injector feeding a common chamber.I've seen some guys with progromable computers get some surprising performance from these systems. I am inclined to believe that spliting the ports may not be worth the effort--Paulweldit


BAN LOW PERFORFMANCE DRIVERS.....
NOT HIGH PERFORMANCE CARS!!

Moderated by  stock49, Twisted6, will6er 

Link Copied to Clipboard
Who's Online Now
0 members (), 125 guests, and 27 robots.
Key: Admin, Global Mod, Mod
Newest Members
Hairyclive, THarper, crash, ocean1907, Jabez House
6,816 Registered Users
Sponsored Advertisement
Sponsored Advertisement
This Space is Available
Powered by UBB.threads™ PHP Forum Software 7.7.5