Water passage in SBC intake - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans Advertise
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 07-13-2019, 09:48 AM
Registered User
 
Join Date: Feb 2018
Location: Oklahoma City Oklahoma
Posts: 30
Wiki Edits: 0

Thanks: 17
Thanked 5 Times in 5 Posts
Water passage in SBC intake

Is it wise or even feasible to drill & tap for water passages in rear of SBC intake to connect the rear water passages?

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 07-13-2019, 10:01 AM
Registered User
 
Join Date: Jun 2010
Location: TX
Posts: 3,844
Wiki Edits: 0

Thanks: 37
Thanked 445 Times in 415 Posts
You should not drill and tap a intake manifold anywhere unless there is a casting boss in the intake manifold that is thick enough for coarse threads. I hope I am getting that is what you mean.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 07-13-2019, 10:12 AM
Registered User
 
Join Date: Feb 2018
Location: Oklahoma City Oklahoma
Posts: 30
Wiki Edits: 0

Thanks: 17
Thanked 5 Times in 5 Posts
Yes sir! there is sort of a boss but not for the complete area it would take. Just wondering about increasing coolant flow to cyls 5,6,7, & 8 and stoppin the little bit of rust on a long term engine.
Reply With Quote Quick reply to this message
 
  #4 (permalink)  
Old 07-13-2019, 10:31 AM
ericnova72's Avatar
More for Less Racer
 
Join Date: Jan 2007
Location: S.W. Lower Michigan
Age: 52
Posts: 17,446
Wiki Edits: 0

Thanks: 262
Thanked 3,134 Times in 2,629 Posts
I've done it. Grind the little boss that is there, usually just a rib like protrusion, flat to be parallel with the rest of the intake flange. Then drill and tap, I think I went 1/4" or 3/8" NPT pipe thread but don't remember which one it was that I used.
Make sure you drill and tap on an angle close to the same as the intake bolts, in order to have enough thread contact.
You don't have enough material to drill them to be vertical like the bosses on the front water crossover passage.

Then connect those rear ports to a adapter flange under the thermostat housing. Hooking them to the front water crossover bosses kind of defeats the smooth unrestricted flow path from the rear to the front.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 07-13-2019, 10:36 AM
Registered User
 
Join Date: Feb 2018
Location: Oklahoma City Oklahoma
Posts: 30
Wiki Edits: 0

Thanks: 17
Thanked 5 Times in 5 Posts
I was thinkin just connect the rear head water passages together with a steel braided hose.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 07-13-2019, 11:01 AM
Registered User
 
Join Date: Apr 2007
Posts: 12,287
Wiki Edits: 0

Thanks: 166
Thanked 1,096 Times in 875 Posts
Yes, if there is sufficient casting thickness and its surface features permit access to allow modification for access to drill, tap and fitting clearance.

For my GenI SBC builds I always want 4 corner coolant return for street and looped track engines so I make it a point to look for that feature on or adaptable to the intakes used in those ways. I'm less concerned about coolant flow balancing for exclusively used drag race engines since they just don't operate for a long enough period of time so cooling them in this tegard is a lesser concern than the manifolds induction capabilities.

Engines with exhaust valves adjacently mounted in the center of the head can benefit from taking most of the head coolant at that point and returning it from each end. Serious racers even tap the head at this mid point to directly inject coolant from an externally plumbed line from the pump outlet. On the street the SBC uses a bypass system that supplies an amount of hot coolant to the pump hub. This does several things in maintaining a circulation when the thermostat is closed and feeds the cabin heater; but one of it's little appriciated functions is to buffer the temperature of the incomming coolant so as not to chill the forward cylinders so much. A lot of guys like to delete this on the theory that it forces more hot coolant through the radiator thus allowing the engine to operate cooler. There is some truth to this in outcome but given the overcooling of the forward cylinders that this results in a far better solution if space permits is to use a larger or better radiator with a functional bypass. The SBC II, the so called LT1 and 4 of the 1990's, went to great lengths to use a complicated mixer system, not unlike that of heavy duty working engines gas and diesel, to achieve this end of moderating the incoming coolant temp.

Other engines, such as many of Fords without adjacently mounted exhaust valves use a different coolant routing scheme of returning block coolant to the head at the rear to be removed at the front. The idea here is the the cooler running forward cylinders end up with the hottest running combustion chambers thus some degree of power balance is achieved between the front and rear cylinders. Using 4 corner return on a such configured Ford would short circuit this process. So its important to keep in mind that the cooling systems of differently configured engines is solving different problems unique to that design. So runnng 4 corner return on a Ford is likely to be of little benefit in terms of cooling and may actually result in increasing the power disparities between cylinders to a larger extent than they typically are.

Bogie

Last edited by BogiesAnnex1; 07-13-2019 at 11:06 AM.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 07-13-2019, 11:03 AM
ericnova72's Avatar
More for Less Racer
 
Join Date: Jan 2007
Location: S.W. Lower Michigan
Age: 52
Posts: 17,446
Wiki Edits: 0

Thanks: 262
Thanked 3,134 Times in 2,629 Posts
Quote:
Originally Posted by 65panhed View Post
I was thinkin just connect the rear head water passages together with a steel braided hose.
I suppose you could....I have no idea if this helps or not.

I've always done it the way the circle track guys do, hoses from the rear corners to the front to get the hottest water out of the back of the block and heads.

I don't see the point of having a crossover in the rear, with no movement to the front....what would be the point?? Flow needs to go from the back to the front, not across.

https://www.summitracing.com/parts/k...5000/overview/
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 07-13-2019, 12:00 PM
Registered User
 
Join Date: Feb 2018
Location: Oklahoma City Oklahoma
Posts: 30
Wiki Edits: 0

Thanks: 17
Thanked 5 Times in 5 Posts
Thanx gentlemen for sharing your wisdom and expertise with the things I don't understand!!!
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 07-13-2019, 02:55 PM
ericnova72's Avatar
More for Less Racer
 
Join Date: Jan 2007
Location: S.W. Lower Michigan
Age: 52
Posts: 17,446
Wiki Edits: 0

Thanks: 262
Thanked 3,134 Times in 2,629 Posts
Quote:
Originally Posted by 65panhed View Post
Thanx gentlemen for sharing your wisdom and expertise with the things I don't understand!!!
Just to give you a quick flow path on the water...it is pumped into the front of the block on both sides by the pump to flow around the cylinders, and is restricted from immediately flowing up into the head by the small size water holes in the head gasket. Once the water is through the head gasket restriction and into the heads, it flows forward and out to the thermostat leg of the intake.

Back cylinders and back section of the heads naturally ends up hotter then the front half, so that is the reason behind connecting the rear water port from the head to the front under the thermostat. Helps balance out the front to back cooling.

To take this farther, some guys will drill and tap the legs of the water pump for a hose connection, then run a hose from the pump legs under the spark plugs along the side of the block, and drill and tap the block for a hose connection below the two center exhaust ports and below the rearmost exhaust port so that cold water is fed into the block more evenly than just at the front like it is stock. They use a piece of shim stock with a smaller 1/2"-5/8" hole through it to partially block the front ports of the block where the waterpump bolts up, in order to force more to those new side feed hoses they just installed.
Reply With Quote Quick reply to this message
The Following User Says Thank You to ericnova72 For This Useful Post:
65panhed (07-13-2019)

Recent Engine posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Insurance
Please select your insurance company (Optional)

Log-in



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may 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



All times are GMT -6. The time now is 05:12 AM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.