Missing my old hole!

[StreetWedge65]

I was having some strange temperature spikes. The electric dash gauge really never fluctuated, but the Auto Meter manual gauge would jump from 180° to 230°. Then back to 180° then to near 260°. Whenever it happened there was some loud knocks. Didn't matter if I was on the highway or sitting in the shop. The fluctuating was really quick. I checked everything from a bad gauge to a head gasket problem. When I pulled the T-Stat, I just drained enough water to not make a mess. Never saw anything that jumped out at me until I took a small screwdriver to check the bypass hole in the housing. I couldn't find it. So I drained more water and low and behold, no HOLE.
Check and recheck, then check again what you're buying.
Shame on you, PROFLO

 

[PurpleBeeper]

I was having some strange temperature spikes. The electric dash gauge really never fluctuated, but the Auto Meter manual gauge would jump from 180° to 230°. Then back to 180° then to near 260°. Didn't matter if I was on the highway or sitting in the shop. The fluctuating was really quick. I checked everything from a bad gauge to a head gasket problem. When I pulled the T-Stat, I just drained enough water to not make a mess. Never saw anything that jumped out at me until I took a small screwdriver to check the bypass hole in the housing. I couldn't find it. So I drained more water and low and behold, no HOLE.
Check and recheck, then check again what you're buying.
Shame on you, PROFLO

View attachment 693356

OK, please school me on this one.... What is the bypass hole?

 

[StreetWedge65]

It allows a certain amount of coolant to mix/flow before t-stat operates. It's like a "dead-head" without the bypass hole. Water pump is trying to pump but it can't move any water until the thermostat opens. When it does open it causes a thermal shock.

 

[moparwacko]

Was afraid to look here, thought it may be a "blue room" thread.
Carry on.....

 

[StreetWedge65]

Yeah, kinda miss-leading. Sorry.
I got my hole figured out though!
Years ago I worked on a 500hp and 600hp steam boilers. The auto flow controller was acting up and not keeping the water level where it needed to be. When the young(new)employee noticed it he grabbed the make up water valve and gave it a good spin. You could hear pipes banging from blocks away. After he got his pants changed, they sent him home.

 

[StreetWedge65]

When I built this engine I had several aluminum pump housings laying around. I just grabbed the cleanest one. Maybe that's why it looked so good. Because PO found out it was bad and changed it. How many of y'all ever knew there was a hole there or checked it before installing? I knew housing had them, but it's not something I normally check. I will from now on. I really don't want to remove it, so lots of grease on the drill bits. And a good shop vacuum should work.

 

[StreetWedge65]

Well finally got back to the '65 after Christmas, grandkids and a funeral. Got the hole drilled. Lots and lots of grease on the bits and a good shop vacuum.
Amazing what a ½" hole does for cooling. No fluctuations, no noises and never got over 185°.

 

[moobster]

Yes, it can't be stressed enough, to use an ample amount of grease when getting your hole drilled...lol

 

[oldbee]

I remember & then totally forgot about that hole thru all the coolant thread questions. Thanks much!

 

[WileERobby]

What, your new hole isn't any good ?

 

[StreetWedge65]

What, your new hole isn't any good ?

New hole is great. Any hole is better than no hole!