water by-pass
Instructor
Joined: Jan 2002
Posts: 161
Likes: 0
From: Wichita Falls TX
Re: water by-pass (66c60)
Gonna tack on to your post...
Is the water by-pass needed? I have a bad overheat problem right now and mine is plugged off (external). It's the only thing other than changing the radiator that I got left to try and fix the problem.... EZ sends
Is the water by-pass needed? I have a bad overheat problem right now and mine is plugged off (external). It's the only thing other than changing the radiator that I got left to try and fix the problem.... EZ sends
Melting Slicks
Joined: Aug 1999
Posts: 2,848
Likes: 3
From: Atlanta, Ga, Fulton
Re: water by-pass (EZG63Conv)
No internal changes were made on engines that did not have the external bypass. I doubt that the external bypass has anything to do with a heating problem. I have run both big blocks and small blocks with the bypass plugged and had not trouble. As a matter of fact in one or two cases I ran engines with the bypass plugged and later with the bypass open. There was no difference in cooling. The only time the bypass is gonna hwlp is when the thermostat is stuck closed.
Race Director
Joined: May 2000
Posts: 12,712
Likes: 2,271
Re: water by-pass (TheOman)
All C2 SBs have an internal bypass. It's the third hole in the water pump. In addition, the heater cores circuit functions as a bypass, so a SHP engine without heater delete has three bypass circuits.
Duke
Duke
Instructor
Joined: Jan 2002
Posts: 161
Likes: 0
From: Wichita Falls TX
Re: water by-pass (SWCDuke)
Well,
Just went ahead an bought a DeWitt's Radiator for it....Hopefully I can enjoy the rest of the summer instead of shutting down/watching the car quit after the fuel boils.....EZ sends
Just went ahead an bought a DeWitt's Radiator for it....Hopefully I can enjoy the rest of the summer instead of shutting down/watching the car quit after the fuel boils.....EZ sends
Race Director
Joined: May 2000
Posts: 12,712
Likes: 2,271
Re: water by-pass (SWCDuke)
I was never clear to me why early C2 SHP/FI engines had what amounted to a third bypass circuit between the top of the pump and inlet manifold - the other two being the heater circuit and the internal bypass built into the water pump.
Maybe it was to create sufficience bypass flow area in the event the heater delete option was added, but then the lower HP engines didn't have the external bypass and they could be ordered with heater delete, too.
I suspect that it was eventualy eliminated because it really wasn't necessary.
Anyone have any ideas on this subject?
Duke
Maybe it was to create sufficience bypass flow area in the event the heater delete option was added, but then the lower HP engines didn't have the external bypass and they could be ordered with heater delete, too.
I suspect that it was eventualy eliminated because it really wasn't necessary.
Anyone have any ideas on this subject?
Duke
Race Director
Joined: Nov 2000
Posts: 10,347
Likes: 673
From: Beverly Hills (Pine Ridge) Florida
Re: water by-pass (SWCDuke)
Just an added note: My 70 Vette (350/350 4 speed) of course did not have the bypass, but it did have a vacumm valve that shut off the water flow through the heater when the A/C was on. I changed the water pump due to a shaft leak, went for a test drive and the water temp went though the roof (with the A/C on). When I turned off the A/C, the water temp returned to normal. After several trial & error tests, I found the the water temp would rise substantially (and I mean this happened almost immediately) would only occur when the heater water flow was blocked by the vacumm valve. In other words, something was happening with the new pump (actually a rebuild) that demanded flow through the heater. I replaced this pump with another rebuild from the same outfit, and everything returned to normal (good cooling with or without the vacumm valve closed). Note that all 3 pumps (original, 1st & 2nd rebuilds were all the same casting number (back then I was a stickler for being # correct - boy time has a way of changing your perspective, now I just drive and enjoy them!).
Plasticman
[Modified by Plasticman, 8:27 PM 6/24/2002]
Plasticman
[Modified by Plasticman, 8:27 PM 6/24/2002]
Le Mans Master
Joined: Apr 2000
Posts: 5,106
Likes: 1,364
From: New York New York
2024 C1 of the Year Finalist - Unmodified
2024 C2 of the Year Finalist - Unmodified
2023 C2 of the Year Finalist - Unmodified
2023 C1 of the Year Finalist - Unmodified
Re: water by-pass (66c60)
I just finished a rebuild on a 283 that I purchased used. When going over the engine I noticed that the third hole below the bolt had a freeze plug in it. I inquired about it and was told that when there was an external by- pass, this hole was plugged, because it was not needed.
Since my early 61 uses a copper radiator without an expansion tank, I removed the plug.
Since my early 61 uses a copper radiator without an expansion tank, I removed the plug.
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