TheAMCForum.com Homepage
Forum Home Forum Home > The Garage > AMC V8 Engine Repair and Modifications
  New Posts New Posts RSS Feed - Engine Block Cooling Jacket Flush
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Click for TheAMCForum Rules / Click for PDF version of Forum Rules
Your donations help keep this valuable resource free and growing. Thank you.

Engine Block Cooling Jacket Flush

 Post Reply Post Reply Page  12>
Author
Message
wight4031 View Drop Down
AMC Apprentice
AMC Apprentice
Avatar

Joined: Dec/13/2021
Location: Houston, Tx
Status: Offline
Points: 139
Post Options Post Options   Thanks (0) Thanks(0)   Quote wight4031 Quote  Post ReplyReply Direct Link To This Post Topic: Engine Block Cooling Jacket Flush
    Posted: Apr/24/2022 at 11:29am
So, I'm replacing my intake manifold on my 304, going with an Edelbrock Performer, which requires draining the coolant.  The block drain was fouled when I removed the plugs, had to punch through with a screwdriver.  

Could use some advice:
  1. Is there something I can soak the water jacket in that will dissolve the solids, something like vinegar or CLR, without attacking the water jacket?  I'm going to flush the system out with a water hose, but I would like to soak the jacket when done with the flush.
  2. If this soak is ok, is it best to do the soak shortly after draining, or when ready to refill the water jacket?  
  3. Will vinegar or CLR damage the seals on the water pump?

Thanks.

Robert

Robert
Houston, Tx
73 Commando Bullnose Truck Cab
304V8, T176, D300
Back to Top
wight4031 View Drop Down
AMC Apprentice
AMC Apprentice
Avatar

Joined: Dec/13/2021
Location: Houston, Tx
Status: Offline
Points: 139
Post Options Post Options   Thanks (0) Thanks(0)   Quote wight4031 Quote  Post ReplyReply Direct Link To This Post Posted: Apr/24/2022 at 3:58pm
So, an additional question.  

What is this thing?  It looks like some type of pressure relief valve/vacuum breaker.  It came off the AMC 304 Intake Manifold, water side.  There was nothing connected to it when I started disassembly, so I want to know if I need to reuse it, purchase a new one, or just install a pipe plug on the new intake manifold.


Robert
Houston, Tx
73 Commando Bullnose Truck Cab
304V8, T176, D300
Back to Top
Trader View Drop Down
AMC Addicted
AMC Addicted


Joined: May/15/2018
Location: Ontario
Status: Offline
Points: 6751
Post Options Post Options   Thanks (1) Thanks(1)   Quote Trader Quote  Post ReplyReply Direct Link To This Post Posted: Apr/24/2022 at 4:23pm
That is a ported vacuum switch and was used to control EGR, fuel recovery canister ... depending on year. Doesn't seem that you are keeping things stock, so likely don't use it.
Cleaning the block in the vehicle with anything but a coolant flush can loosen some pretty big pieces of crud. If you take a frost plug out each side, I'd say use the vinegar soak and flush several times until clear. Likely needs more then on soaking if coolant has not had regular changes.
Back to Top
6PakBee View Drop Down
Supporter of TheAMCForum
Supporter of TheAMCForum
Avatar
Charter Member

Joined: Jul/01/2007
Location: North Dakota
Status: Offline
Points: 5454
Post Options Post Options   Thanks (0) Thanks(0)   Quote 6PakBee Quote  Post ReplyReply Direct Link To This Post Posted: Apr/24/2022 at 4:32pm
Use a commercial flush.  Any of the other methods work great with a bare block but I'd be hesitant to try them on a fully assembled engine.
Roger Gazur
1969 'B' Scheme SC/Rambler
1970 RWB 4-spd Machine
1970 Sonic Silver auto AMX

All project cars.

Forum Cockroach
Back to Top
wight4031 View Drop Down
AMC Apprentice
AMC Apprentice
Avatar

Joined: Dec/13/2021
Location: Houston, Tx
Status: Offline
Points: 139
Post Options Post Options   Thanks (0) Thanks(0)   Quote wight4031 Quote  Post ReplyReply Direct Link To This Post Posted: Apr/24/2022 at 6:05pm
The PO had already converted a bunch...

Air Pump missing
Stock exhaust manifolds gone, replaced with custom short pipes that come out just in front of the rear tires.
4-barrel Holley Carb on the 2-barrel intake manifold
Dana 300 xfer case instead of the stock Dana 20
Tremec T176 4-speed trans instead of the T15 3-speed
AMC model 20 rear axle instead of the stock Dana 44
The factory wagon cab is missing, but it has a truck cab instead
and the factory seats are missing, it has bucket seats from a Wrangler...

I've reverted back to only a 4-in lift, since the PO tried to do an axle over spring conversion....

I think I overpaid for this project vehicle, but it has kept me busy for the past 18 months. 




Robert
Houston, Tx
73 Commando Bullnose Truck Cab
304V8, T176, D300
Back to Top
wight4031 View Drop Down
AMC Apprentice
AMC Apprentice
Avatar

Joined: Dec/13/2021
Location: Houston, Tx
Status: Offline
Points: 139
Post Options Post Options   Thanks (0) Thanks(0)   Quote wight4031 Quote  Post ReplyReply Direct Link To This Post Posted: Apr/24/2022 at 6:10pm
The PO must also have not known what that ported vacuum switch did, it was connected to the water side of the intake manifold, not the vacuum source.


Robert
Houston, Tx
73 Commando Bullnose Truck Cab
304V8, T176, D300
Back to Top
6PakBee View Drop Down
Supporter of TheAMCForum
Supporter of TheAMCForum
Avatar
Charter Member

Joined: Jul/01/2007
Location: North Dakota
Status: Offline
Points: 5454
Post Options Post Options   Thanks (0) Thanks(0)   Quote 6PakBee Quote  Post ReplyReply Direct Link To This Post Posted: Apr/24/2022 at 6:55pm
Wow, could you post a picture of that?  I have all kinds of visions dancing in my head!
Roger Gazur
1969 'B' Scheme SC/Rambler
1970 RWB 4-spd Machine
1970 Sonic Silver auto AMX

All project cars.

Forum Cockroach
Back to Top
Buzzman72 View Drop Down
AMC Addicted
AMC Addicted
Avatar

Joined: Sep/15/2009
Location: Southern IN
Status: Offline
Points: 2713
Post Options Post Options   Thanks (1) Thanks(1)   Quote Buzzman72 Quote  Post ReplyReply Direct Link To This Post Posted: Apr/24/2022 at 7:09pm
Originally posted by wight4031 wight4031 wrote:

The PO must also have not known what that ported vacuum switch did, it was connected to the water side of the intake manifold, not the vacuum source.

I think you are misunderstanding how the ported vacuum switch works. It DOES screw into the coolant side of the intake manifold. As the temperature of the coolant rises, the vacuum source is switched. Vacuum is sourced from the intake [full vacuum] AND from the carburetor [ported], and at operating temp the ported switch changes the source of the vacuum.





Edited by Buzzman72 - Apr/24/2022 at 7:19pm
Buzzman72...void where prohibited, your mileage may vary, objects in mirror may be closer than they appear, and alcohol may intensify any side effects.
Back to Top
wight4031 View Drop Down
AMC Apprentice
AMC Apprentice
Avatar

Joined: Dec/13/2021
Location: Houston, Tx
Status: Offline
Points: 139
Post Options Post Options   Thanks (0) Thanks(0)   Quote wight4031 Quote  Post ReplyReply Direct Link To This Post Posted: Apr/24/2022 at 7:52pm
thank you, that helps.

Given the ERG and all was deleted by the PO, that vacuum port switch will be replaced by a brass plug.

Robert
Houston, Tx
73 Commando Bullnose Truck Cab
304V8, T176, D300
Back to Top
Skwishy View Drop Down
AMC Apprentice
AMC Apprentice
Avatar

Joined: Feb/01/2018
Location: Wisconsin
Status: Offline
Points: 208
Post Options Post Options   Thanks (0) Thanks(0)   Quote Skwishy Quote  Post ReplyReply Direct Link To This Post Posted: Apr/24/2022 at 10:09pm
just a thought, hang on to it for some of the aussie or cali folks who still want emission compliance or keeping things original. im sure someone could make good use of that part
HFD Helmet #33
'68 AMC Ambassador SST. always looking for parts and cool stories. In dire need of a manual trans.
Back to Top
 Post Reply Post Reply Page  12>
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.03
Copyright ©2001-2019 Web Wiz Ltd.

This page was generated in 0.172 seconds.
All content of this site Copyright © 2018 TheAMCForum unless otherwise noted, all rights reserved.
PROBLEMS LOGGING IN or REGISTERING:
If you have problems logging in or registering, then please contact a Moderator or