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Plumbed Intake Manifold

Space Cowboy

Well-known member
Joined
Oct 8, 2003
Messages
408
Location
Houston Texas
Corvette
1968 Convertible - Candy Apple - 427/475+
Has anyone ever plumbed their big block manifold up to the thermostat housing. I'm having some continuous overheating problems and Be Cool thinks that air is getting trapped on the back side of the intake. They claim the only way to take care of it is to plumb it. If any of you folks have done this, I would appreciate some photos and description of what you did. FYI... I have an Edelbrock Torker II intake.

Thanks!
 
Joined
Jan 1, 2002
Messages
7,246
Location
Washington, Michigan
Corvette
'67 Marina Blue Convertible
I doubt if that has anything to do with your overheating issues; have never seen that to be necessary or advantageous except on all-out race cars that run at WOT all the time. 99% of cooling problems relate either to a radiator with inadequate heat rejection capability (cooling capacity) or inadequate airflow through it (assuming the rest of the cooling system is in good shape).

:beer
 

Space Cowboy

Well-known member
Joined
Oct 8, 2003
Messages
408
Location
Houston Texas
Corvette
1968 Convertible - Candy Apple - 427/475+
I'm trying one last thing. I'm replacing my 180 deg. thermostat with a 160 deg. My fan switch is a 195/175 deg. I hope that letting the water flow sooner out of the block will aid in keeping the temp down.
 
Joined
Jan 1, 2002
Messages
7,246
Location
Washington, Michigan
Corvette
'67 Marina Blue Convertible
I'm trying one last thing. I'm replacing my 180 deg. thermostat with a 160 deg. My fan switch is a 195/175 deg. I hope that letting the water flow sooner out of the block will aid in keeping the temp down.

Don't bother - that won't change anything; the 160* 'stat will be wide open, just like the one that's in there now. No such thing as "water flowing sooner out of the block" - when the 'stat is wide open, the coolant flow is continuous. What do you have for a radiator, shroud, fan and clutch? Stock? Modified? Old? New? Is your chin spoiler all there?

:beer
 
Joined
Apr 29, 2001
Messages
2,141
Location
Rio Rancho, NM
Corvette
1981 HD Suspension; ZN1 Option
Has anyone ever plumbed their big block manifold up to the thermostat housing. I'm having some continuous overheating problems and Be Cool thinks that air is getting trapped on the back side of the intake. They claim the only way to take care of it is to plumb it. If any of you folks have done this, I would appreciate some photos and description of what you did. FYI... I have an Edelbrock Torker II intake.

Thanks!

Space,

Does your engine back-fires often or regularly?
 

Space Cowboy

Well-known member
Joined
Oct 8, 2003
Messages
408
Location
Houston Texas
Corvette
1968 Convertible - Candy Apple - 427/475+
JohnZ,

I have the BeCool 60227 radiator which is rated at 700hp... BeCool 75007 Dual 11" elect. fans whick pull 2700+ cfm (combined). One fan stays on all the time, the other is controlled by a therm. switch which turns on at 195* and off at 175*. Yes, the spoiler is still there. If I currently have a 180* thermostat in it right now, and replacing with a 160*, the switch will open 20* sooner.... therefore making the water flow out of the block sooner.

I'll be running fine down the road at 180* or so, then it will spike to 210*+. The secondary fan does kick in, and the temp very slowly drops, but those spikes are causing it to boil over. I'm simply trying to prevent the temp from spiking the way its been. Be Cool thinks that air is in the system, but I'm having a hard time believing that is the problem. They are the ones that actually suggested to switch the thermostat to 160* btw.

GerryLP... the egine never back-fires at all.

Thanks
 
Joined
Jan 1, 2002
Messages
7,246
Location
Washington, Michigan
Corvette
'67 Marina Blue Convertible
JohnZ,

I have the BeCool 60227 radiator which is rated at 700hp... BeCool 75007 Dual 11" elect. fans whick pull 2700+ cfm (combined). One fan stays on all the time, the other is controlled by a therm. switch which turns on at 195* and off at 175*. Yes, the spoiler is still there. If I currently have a 180* thermostat in it right now, and replacing with a 160*, the switch will open 20* sooner.... therefore making the water flow out of the block sooner.

I'll be running fine down the road at 180* or so, then it will spike to 210*+. The secondary fan does kick in, and the temp very slowly drops, but those spikes are causing it to boil over. I'm simply trying to prevent the temp from spiking the way its been. Be Cool thinks that air is in the system, but I'm having a hard time believing that is the problem. They are the ones that actually suggested to switch the thermostat to 160* btw.

GerryLP... the egine never back-fires at all.

Thanks

1. The temp at which the fan(s) come on has nothing to do with "making the water flow out of the block sooner"; the cooling system is continuous-flow, with the thermostat modulating flow. The temp "spike" you describe is indicative of a defective thermostat; under constant load, it should maintain a constant temperature - "spikes" say it's sticking instead of operating smoothly.

2. It won't boil over at an indicated 210*F unless the radiator cap is shot; if the cap seals and is working, a 50/50 mix of water and anti-freeze won't boil until 265*F at 15 psi. Have someone with an I.R. gun shoot your upper radiator hose just above the thermostat housing and compare that against what the gauge says at the same time so you know what the gauge is really telling you.

I'm continually amazed by radiator manufacturers (except DeWitts) who still don't understand how cooling systems work, and what thermostats do (and don't do).

:beer
 

Space Cowboy

Well-known member
Joined
Oct 8, 2003
Messages
408
Location
Houston Texas
Corvette
1968 Convertible - Candy Apple - 427/475+
JohnZ... you have misunderstood what I said in a previous reply. The fans are not controlled by the thermostat... they are controlled by a separate thermally controlled switch which is mounted into the intake behind the thermostat housing. I know the thermostat has nothing to do with controlling the fans... the switch does.

The thermostat itself is brand new. However, that doesn't mean it could be defective.

Let me guess... you have a DeWitts system. No sense in slinging names around.... gets you no where.
 
Joined
Jan 1, 2002
Messages
7,246
Location
Washington, Michigan
Corvette
'67 Marina Blue Convertible
Let me guess... you have a DeWitts system. No sense in slinging names around.... gets you no where.

Yes, I do, because it's an exact reproduction of my original radiator, but that's not important; I mention DeWitts because Tom knows cooling systems and understands how they work, unlike many of the other vendors.

You might want to go to BarryK's site:

http://lbfun.com/Corvette/Tech/vettetech.html

And scroll down to "Cooling", and either left-click to read, or right-click to download, "Cooling.pdf", which is the "Corvette Cooling Basics" article I wrote in the September, 2003 issue of "Corvette Enthusiast" magazine; it's factual information (from my 30 years of solving cooling problems), and debunks most of the Internet misinformation that's out there. It's also available for download from the DeWitts site (www.dewitts.com).

:beer
 

Space Cowboy

Well-known member
Joined
Oct 8, 2003
Messages
408
Location
Houston Texas
Corvette
1968 Convertible - Candy Apple - 427/475+
Interesting read. Thansk for forwarding it. I'm going to replace my 180* thermostat with another... just in case its defective. I do agree with that the spikes could be caused by a sticking thermostat.
 

minifridge1138

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Joined
Feb 2, 2007
Messages
908
Location
USA
Corvette
1982 Black Fastback
Never argue with JohnZ.... he is always right.

I have found that out the hard way...
 

Space Cowboy

Well-known member
Joined
Oct 8, 2003
Messages
408
Location
Houston Texas
Corvette
1968 Convertible - Candy Apple - 427/475+
Never argue with JohnZ.... he is always right.

I have found that out the hard way...

Who was arguing??? I was simply stating what I was being told to me by the mfg. Although JohnZ has a lot of info, he misunderstood one of my replies (no big deal though). JohnZ is a VERY valuable member of the forum and I appreciate all of the information he provides to us as well as others.

Everyone raise your beer mugs to JohnZ:beer
 

minifridge1138

Well-known member
Joined
Feb 2, 2007
Messages
908
Location
USA
Corvette
1982 Black Fastback
Sorry. I wasn't accusing you of arguing. I was just making a joke. Sometimes humor is lost when it is typed.

I agree that JohnZ is an amazing source of information.

Good luck!
 

AKRAY4PLAY

Well-known member
Joined
Oct 14, 2001
Messages
584
Location
Wasilla, Alaska, U.S.A.
Corvette
'77 L-82, black on black. Full mod 406 small block
does your thermostat have a small by-pass hole?? i have run into problems with friends' cars that over cool and shut the thermostat highway speeds. this leads to cold (140-150* ish) water sitting around the t-stat and heat to build in the heads where most guage sensors are. what you end up seeing is 220 on the gauge and only 150 ish on the t-stat housing. a small 1/8" hole allows some limited circulation to heat up the t-stat in conjuction with the heads. basically your t-stat sees what your dash gauge reads and makes your diagnosis a little easier. just a thought and very easy to try since you are pulling the t-stat anyway.
 

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