Go Back  Offshoreonly.com > Technical > Do It Yourself, Boating on a Budget
Why is a Chevy head still like this? >

Why is a Chevy head still like this?

Notices

Why is a Chevy head still like this?

Old 12-22-2011, 07:21 PM
  #1  
Registered
Thread Starter
 
Join Date: Jan 2005
Location: Pasadena, MD
Posts: 3,569
Received 121 Likes on 39 Posts
Default Why is a Chevy head still like this?

Every BBC Chevy head I mess with I always have to fill in these holes in the head for the manifold choke. These are off a Gen v motor. When was the last time Chevy used a manifold mounted choke to even need them?

f_inscreenname is offline  
Old 12-22-2011, 08:22 PM
  #2  
Registered
 
Join Date: Oct 2005
Location: Waldorf, Md
Posts: 926
Received 166 Likes on 105 Posts
Default

Those holes are not for the "manifold choke" they are an exhaust crossover passage that is used to heat the underside of the maniold to help fuel atomization in very cold weather. It allows for decent driveability when the engine is cold. They probably have not been needed since GM stopped using carburetors but they are not going to change the head castings now. Also, most heads are used on cars and trucks, which still need the passage on older vehicles. By the way, filling them the way you are doing would not be my first choice. I would be real worried about the epoxy getting burned out by the exhaust gasses. Racers actually use melted aluminum to fill the passages, but for a street or marine engine all you need to do is cut a small piece of sheet metal to put over the passage and let the intake manifold gasket hold it in place.

Bill Koustenis
Advanced Automotive Machine
Waldorf Md
BillK is offline  
Old 12-22-2011, 08:35 PM
  #3  
Registered
Thread Starter
 
Join Date: Jan 2005
Location: Pasadena, MD
Posts: 3,569
Received 121 Likes on 39 Posts
Default

Thanks Bill.
I've been doing it that way (fill with tinfoil and the last 3/8th filled with JB Weld) for the last decade. Never had an issue with it.
f_inscreenname is offline  
Old 12-22-2011, 08:40 PM
  #4  
Registered
 
Join Date: Mar 2009
Location: OFallon,Mo.
Posts: 1,758
Likes: 0
Received 3 Likes on 2 Posts
Default

Seems to me I bought intake gaskets before which included metal plates which fit into the gaskets to cover those holes.
picklenjim is offline  
Old 12-22-2011, 10:05 PM
  #5  
Registered
iTrader: (28)
 
Join Date: Mar 2003
Location: PA/MD
Posts: 2,497
Received 4 Likes on 4 Posts
Default

Originally Posted by picklenjim
Seems to me I bought intake gaskets before which included metal plates which fit into the gaskets to cover those holes.
Yes, I have bought intake sets that come with a couple different metal inserts. You can not use them and leave it open, use one which has a small hole that only lets a small amount of exhaust through or use the solid insert that totally blocks it. I think most Fel-pro intake sets come with these....I could be wrong
Baja226sport is offline  
Old 12-22-2011, 10:31 PM
  #6  
Registered
 
Join Date: Mar 2009
Location: OFallon,Mo.
Posts: 1,758
Likes: 0
Received 3 Likes on 2 Posts
Default

Originally Posted by Baja226sport
Yes, I have bought intake sets that come with a couple different metal inserts. You can not use them and leave it open, use one which has a small hole that only lets a small amount of exhaust through or use the solid insert that totally blocks it. I think most Fel-pro intake sets come with these....I could be wrong
No, your right. Their Felpro. Just looked in my box of extra gaskets. Got a bunch with the small holes. Used all the solid ones.

Last edited by picklenjim; 12-22-2011 at 10:33 PM.
picklenjim is offline  
Old 12-23-2011, 09:27 AM
  #7  
Registered
Thread Starter
 
Join Date: Jan 2005
Location: Pasadena, MD
Posts: 3,569
Received 121 Likes on 39 Posts
Default

I guess i need to check my gaskets. Seems like in the past this area was left open. I've been using Endelbrock gaskets for aluminum intakes.
f_inscreenname is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.