Small Block & Big Block Chevy Specific Mouse & Rat Motor Discussion & Conversions

Oval or Rectangle Ports?

Thread Tools
 
Search this Thread
 
Old 07-31-2005, 12:08 PM
  #1  
On The Tree
Thread Starter
iTrader: (1)
 
Frizzle Fry's Avatar
 
Join Date: May 2005
Location: Oregon
Posts: 177
Likes: 0
Received 0 Likes on 0 Posts
Default Oval or Rectangle Ports?

I'm in the market for a new intake for my 396 and I'm not sure if it has oval or rectangle port heads. Any way to find out? It's a 1969 Suburban with stock heads. Also, as far as intake manifolds are concerned, can one be used with another oval/rec or rec/oval?

Right now it has a Torker II which doesn't give me the low end I need with such a heavy rig. I'm looking for a good dual plane. Wanna swap?
Old 07-31-2005, 01:59 PM
  #2  
TECH Addict
 
Racehead's Avatar
 
Join Date: Nov 2001
Location: LaConner WA
Posts: 2,662
Likes: 0
Received 1 Like on 1 Post

Default

If the engine is all OEM then it's gonna have oval ports. Whether or not is has large or small oval ports I couldn't tell you in that year. You also need to use oval port intakes with oval port heads etc.
Old 07-31-2005, 10:29 PM
  #3  
Teching In
 
FastRedChevy's Avatar
 
Join Date: Mar 2005
Location: Roseville, Michigan
Posts: 41
Likes: 0
Received 0 Likes on 0 Posts
Default

Look on your intake it might say torqer O meanig oval ports if there is an R its has rectangle port. If you dont see that yank off a valve cover and get the casting number.

More than likely they are oval ports unless someone has changed it.

I seen many people use oval port intakes on rectangle port heads its supposed to help somehow with tq. but ive never herd how it works, i guess its an old school trick.
Old 07-31-2005, 11:09 PM
  #4  
On The Tree
Thread Starter
iTrader: (1)
 
Frizzle Fry's Avatar
 
Join Date: May 2005
Location: Oregon
Posts: 177
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by FastRedChevy
Look on your intake it might say torqer O meanig oval ports if there is an R its has rectangle port. If you dont see that yank off a valve cover and get the casting number.

More than likely they are oval ports unless someone has changed it.

I seen many people use oval port intakes on rectangle port heads its supposed to help somehow with tq. but ive never herd how it works, i guess its an old school trick.
Yeah, just wanted to find out without removing anything. My guess on the oval intake with rec heads would be that it may induce some turbulance, thus better torque. Of course at the expense of high RPM flow.

Why would they call a single plane manifold a torker anyway... You guys agree I should go with a dual plane like performer air gap?
Old 08-01-2005, 11:22 AM
  #5  
Teching In
 
FastRedChevy's Avatar
 
Join Date: Mar 2005
Location: Roseville, Michigan
Posts: 41
Likes: 0
Received 0 Likes on 0 Posts
Default

Well we dont know the rest of your parts but a RPM air gap is a nice manifold.
Old 08-01-2005, 11:22 AM
  #6  
TECH Addict
 
Racehead's Avatar
 
Join Date: Nov 2001
Location: LaConner WA
Posts: 2,662
Likes: 0
Received 1 Like on 1 Post

Default

A Performer or Performer RPM are both excellent choices. On a 396 I'd say the Performer would more than likely the better choice, depending on intended rpm range of the engine. I've got the Performer RPM on my 2nd gen and love it. I usually shift ( when racing ) at 6200 rpms and go thru the traps at 6400 rpms. I makes absolutely GREAT torque. Hard to hook up, but fun to try
Old 08-01-2005, 12:19 PM
  #7  
On The Tree
Thread Starter
iTrader: (1)
 
Frizzle Fry's Avatar
 
Join Date: May 2005
Location: Oregon
Posts: 177
Likes: 0
Received 0 Likes on 0 Posts
Default

Thanks Racehead

Originally Posted by FastRedChevy
Well we dont know the rest of your parts but a RPM air gap is a nice manifold.
Sorry, hate to be that guy... The motor has the stock heads and cam (as far as I know), the torker II I mentioned, a Holley 650 (kinda small for a 396, I know, but better for low end), HEI dist w/50,000 volt coil (red cap), and full length headers waiting to be installed with 3 chamber flows. You agree the torker is all wrong for this combo?

I'd love to throw a new cam in it. I have been looking at the comp 268H-270H.
Old 08-01-2005, 05:01 PM
  #8  
TECH Fanatic
iTrader: (1)
 
Sandmann120's Avatar
 
Join Date: Dec 2004
Location: SW Iowa
Posts: 1,015
Likes: 0
Received 0 Likes on 0 Posts

Default

Throw the Torker in the garbage. Go for the Performer RPM, and a cam around that range should work just fine.
Old 08-02-2005, 06:13 PM
  #9  
On The Tree
Thread Starter
iTrader: (1)
 
Frizzle Fry's Avatar
 
Join Date: May 2005
Location: Oregon
Posts: 177
Likes: 0
Received 0 Likes on 0 Posts
Default

What about the performer 2-0? Any opinions on it vs. performer rpm for a heavy suburban?
Old 08-04-2005, 01:19 PM
  #10  
TECH Regular
iTrader: (9)
 
mikes98z's Avatar
 
Join Date: Jul 2004
Location: Brandon, FL
Posts: 419
Likes: 0
Received 0 Likes on 0 Posts

Default

I had a 402 (punched 396) in my 71 Elky and the single plane intake is garbage for street driving or a heavy car. I would go with the performer RPM. As for a carb, the 750 or 780 would be my choice.

Oval port heads vs. square ports. The square ports are just that, square, the ovals will be curved at the corner and ususally smaller. Stay away from the peanut port oval heads. No power potential. Also, check the casting numbers at mortec.com. This will help you out. The big ovals will a good size valve would be great for the street. The big square ports are for alot of flow in a racing application.

Dual pattern cam around a .500 lift will work great.

Good luck!



Quick Reply: Oval or Rectangle Ports?



All times are GMT -5. The time now is 05:24 PM.