Jump to content

Pressurizing The Cooling System.........


Recommended Posts

Posted

Will this have any adverse effects such as freeze plugs popping out if I run a 7 psi cap?  I'm installing an aluminium radiator.  It came with this cap.  Has anyone gone down this road before?  Or should I just stick with the stock cap?

Posted

I've got a new alum. radiator in my 50 4 dr. running 7lb. cap for over a year with no problems, tried to get a 4lb. cap for it but napa didn't have a 4 lb. to fit the filler neck of the new radiator.

Radiator like that will handle a 16 lb. cap but the motor? I didn't want to try it! -_-

 

Doug

Posted

Depends on the radiator design, If the expansion / overflow outlet is below the cap, or on the expansion tank, you could put a 100 lb cap on it and it wouldn't change a thing.  To much pressure on a designed to be pressurized system will strain the soldered joints in the radiator before the welsh plugs, assuming they are installed correctly.

Posted (edited)

Your freeze plugs won't pop out unless they are weak . I am running a radiator from a car that had a slant 6 engine . I use a 13 pound cap and leave lots of air in the top tank for expansion . It has been good for several years now . I also had the radiator modified from 3 rows to 4 rows .  Edit ; I also run a 160 degree thermostat and 160 is usually what it runs at . 

Edited by Jerry Roberts
Posted

Your on thin ice due to the type of welsh plug used. I wouldn't go over 4-5 lbs. I have seen them fail.  

Posted

Your on thin ice due to the type of welsh plug used. I wouldn't go over 4-5 lbs. I have seen them fail.  

This is my main concern too.  Although it seems at least some others on this board are running pressurized systems with success.   Have convex plugs been installed from the factory on any vehicles utilizing pressures of 5psi or more?  I'm not aware of any, but then, I'm not aware of a lot of stuff!

Posted

Will this have any adverse effects such as freeze plugs popping out if I run a 7 psi cap?  I'm installing an aluminium radiator.  It came with this cap.  Has anyone gone down this road before?  Or should I just stick with the stock cap?

Don't forget your heater core, I don't know if it will take much more than 4 to 7 pounds. I'm going to try a 4 pound cap on my aluminum radiator.

:D

  • Like 1
Posted

After reading this thread, I checked my radiator cap by placing it on a scale and pushing down to see

 

how much pressure it took to open up, 5 lb....

 

I took a 15lb cap from the shop and did the same, it took about 20lb of pressure to open.....

Posted

After installing an aluminum aftermarket radiator with a 7 pound cap, I bypassed the heater core altogether, uncertain as I was about whether the heater core was going to fail under pressure or not. I figure I'll address that problem later since the car is still not roadworthy yet.

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.

Terms of Use