Boosted LT1 runs hot
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From: Southwest Michigan
Boosted LT1 runs hot Hey Guys,
Relatively new to the site, First post. I have a 95 Camaro with a LT1 base 383 built for boost. This is my first boosted engine and I need some advice. Running a Vortech at 10 lbs boost. As the title implies I am having cooling trouble. I replaced the radiator with an aluminum 3 core, am running a 160 degree stat (replaced twice), electric WP and yes the system is bled but the car constantly wants to run at 220+ when the outside temp hits 80 or more degrees. I know that temp isn't dangerous but I would be way more comfortable at 180/190. Now to my real question. I have no intercooler. Could this be the major cause of my problem? Do I need one? Chime in you guys with knowledge and let me know what you think,
Thanks
P.S. forgot to mention that 220 deg is with both fans running constantly and it runs hotter highway then city. Yes I have an air dam.
Relatively new to the site, First post. I have a 95 Camaro with a LT1 base 383 built for boost. This is my first boosted engine and I need some advice. Running a Vortech at 10 lbs boost. As the title implies I am having cooling trouble. I replaced the radiator with an aluminum 3 core, am running a 160 degree stat (replaced twice), electric WP and yes the system is bled but the car constantly wants to run at 220+ when the outside temp hits 80 or more degrees. I know that temp isn't dangerous but I would be way more comfortable at 180/190. Now to my real question. I have no intercooler. Could this be the major cause of my problem? Do I need one? Chime in you guys with knowledge and let me know what you think,
Thanks
P.S. forgot to mention that 220 deg is with both fans running constantly and it runs hotter highway then city. Yes I have an air dam.
Is the rad still standing on an angle or has it been modified and straight up? Have you tried bleeding the system with the two shrader valves? Could be a bad radiator cap not keeping pressure?
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Teching In
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From: Southwest Michigan
Radiator is in its stock location. Have bled the system. Cooling system holds pressure, not losing any coolant. Radiator, cap are new. Have tried different cap.
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From: Kernersville, NC
Seems to me that something is not right if you are running that hot with the fans on constantly. As some side info, when the car gets to around 70mph, the fans become a restriction if they are on.
Are you sure the EWP isn't failing or wired incorrectly? What brand is it? GPM rating? Is shroud in front of the radiator undamaged and fully intact?
Are you sure the EWP isn't failing or wired incorrectly? What brand is it? GPM rating? Is shroud in front of the radiator undamaged and fully intact?
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From: Maricopa, AZ
Sounds like a coolant flow issue. Usually when a vehicle runs hotter at highway speeds than in stop and go traffic or idling the coolant flow is the issue. Clogged Radiators, Stuck Thermostats, etc. What EWP are you running? You could put a mechanical one back on and see if that helps.
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From: Southwest Michigan
Sounds like a coolant flow issue. Usually when a vehicle runs hotter at highway speeds than in stop and go traffic or idling the coolant flow is the issue. Clogged Radiators, Stuck Thermostats, etc. What EWP are you running? You could put a mechanical one back on and see if that helps.
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From: Maricopa, AZ
I've thought about that a bit, and used to always think the same thing. But it can't be true. If it were, when a clutch fan kicked in at highway speed (think 65mph in a C1500 while towing in the Phoenix heat) the coolant temps wouldn't drop. But it does, every single time. I've personally experienced this.
On top of that, the electric motors that are spinning the fan blades are slowed down my the movement of the air they create. If the air in front of the blades are already at a higher speed (or lower pressure) then the blades will speed up even more than if the air was being drawn through them. Obviously there would be a point that the air flow through the fan blades exceeds the speed of which the fan blades can spin, but through a radiator with at best 40% of the air in front of it actually getting through, I doubt it's at any speed our cars (or any car for that matter) could do safely.
The fans being on above ~40mph in our cars is pretty pointless as the ram air flow through the radiator is sufficient to cool the coolant down to the thermostat (usually), but I don't see how they would become more of a restriction to the air flow if they were on vs off. You'd think the restriction would be less on than off.
Just a thought.
Last edited by hrcslam; Oct 4, 2018 at 09:51 AM.
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Teching In
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From: Southwest Michigan
EWP is Meziere, not sure of the GPH rating. Aluminum 3 core radiator is new as was the stock one I bought first. Have had 2 new stats
But the fan shroud? I bought the car this summer, first 4th gen I've owned. There is an air dam under the front but there is suppose to be a shroud in front of the radiator? I don't have one.
But the fan shroud? I bought the car this summer, first 4th gen I've owned. There is an air dam under the front but there is suppose to be a shroud in front of the radiator? I don't have one.
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What brand is the radiator. Meziere is a good quality brand that makes very long lasting pumps. But, no company that manufactures parts with moving components is immune to issues. Possibly it's a bad pump?
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From: Maricopa, AZ
EWP is Meziere, not sure of the GPH rating. Aluminum 3 core radiator is new as was the stock one I bought first. Have had 2 new stats
But the fan shroud? I bought the car this summer, first 4th gen I've owned. There is an air dam under the front but there is suppose to be a shroud in front of the radiator? I don't have one.
But the fan shroud? I bought the car this summer, first 4th gen I've owned. There is an air dam under the front but there is suppose to be a shroud in front of the radiator? I don't have one.
Yes, you should have a shroud in front of the radiator. It directs the air from the lower air dam through the radiator. This is only important for highway speeds, the fans only need the shroud they are mounted on if the fans are mounted directly to the radiator (like stock).
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From: Southwest Michigan
Well, that missing shroud sounds like it is at least part of my problem. Not sure of the radiator brand. Bought it off CL but you could see it had never been installed. As far as the WP I can see the coolant circulate and if you shut the car off hot and then turn on key only to start the WP and turn on the fans (I have toggles) you can watch the temp drop on the gauge.
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From: Kernersville, NC
Different cars have different fan configs/flow characteristics. What may happen on one, may not happen on another. I'm fairly certain that truck flows air through and around the nose much different than an F-body. Which may account for what you observed. I haven't run any kind of testing so I don't know how my '96 would react.
I can't find for the life of me where I read the 70mph thing....it may have in GMHTP. I've seen it several times. I thought it was in the factory service manual, but I have not been able to find it.
Here is another spot it is mentioned. Looks like the B/D bodies turn off the fans sooner than the F bodies at highway speeds.
http://www.corvetteactioncenter.com/...ystem-526.html
Edit: Going back to my DC theory, it looks like for a constant voltage, load vs speed are inversely proportional. So I may be wrong on the speed trying to self correct. However, there is something in the back of my head telling me that as the motor slows, the cemf decreases, which increases current, which then increases emf, then it causes an increase in speed to counteract the increased load. I've got to dig more.
Edit2:....and after more digging, the increased current stops the deceleration, but does not recover the speed.....at least not without some voltage increase, winding tricks, or a DC drive. So, I've got my "wires" crossed.
Last edited by ACE1252; Oct 4, 2018 at 11:49 PM.
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From: Kernersville, NC
OP, are you absolutely sure you are using the right thermostat? An LT1 Gen II specific thermostat. If I'm not mistake, using a conventional SBC thermostat will cause the car to run very hot....if not overheat.
Did you have your car tuned for the supercharger, what size injectors, what fuel pump,is the airdam still installed?
Your air fuel ratios are extremely lean and yes an intercooler will help with hp/tq but not cooling
Your air fuel ratios are extremely lean and yes an intercooler will help with hp/tq but not cooling
Thread Starter
Teching In
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From: Southwest Michigan
Absolutely sure of the stat. Have replaced it twice and they are for LT1's.
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From: Southwest Michigan
The A/F ratios that I quoted are at cruising speeds in closed loop operation. This is when the engine seems to be heating up. The A/F is richer under boost. The car has been tuned but it's been a couple years. 48# injectors. I'm drawing a blank at the moment on the fuel pump but I have 60 psi at the rails. and yes, the air dam is installed. I am not finding info on the shroud that hrcslam mentioned.
P.S. I bought this car earlier this summer with blown head gaskets and a bad radiator. I took a chance and got a good deal. I bought the car out of Texas through a friend down there but did not know the person I bought it from. So I know some of the cars history, etc
P.S. I bought this car earlier this summer with blown head gaskets and a bad radiator. I took a chance and got a good deal. I bought the car out of Texas through a friend down there but did not know the person I bought it from. So I know some of the cars history, etc
Last edited by Pointless; Oct 4, 2018 at 11:17 PM. Reason: Additional info
Thread Starter
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From: Southwest Michigan
