454 cooling issues

[prairiehotrodder]

DSC01448.JPG

this is what it looks like right now and how i've been testing it. No bumper. Hard to see how an air dam will help with the rad sticking down like that.

[Tom68]

No bumper might mean you have high pressure behind the radiator (depends on inner guards) needs a big fan then to get air to flow if that's the case.

[Tuner]

Might need a chin spoiler under the radiator core support, like the mid 80's Camaro, to cause the air to go through the radiator instead of under the car. I think the G body cars had a plastic dam below the radiator and will overheat without it.

The little 1-1/2" lip under the radiator on C3 Corvettes is just the right height to get broke off when rolling up to the concrete parking bumper berm at the Dairy Queen and without that little lip they overheat like a pig. In the late 70's we bought so many of those from the local Chev dealer we accused them of being in cahoots with the Dairy Queen to break them off the cars.

You can't road race a mid-80's Camaro without that 4" vertical air dam they have on all production cars. Without that air dam below the radiator it will not cool even at 100+ MPH.

[Geoff2]

It is going to want 45-50* [ sometimes more ] at cruise if you want to keep it cool.

[Tuner]

DSC01448.JPG

this is what it looks like right now and how i've been testing it. No bumper. Hard to see how an air dam will help with the rad sticking down like that.

https://www.ebay.com/itm/144285613741?c ... =426106891

I think your car had this on it when it was new. This is a molded plastic piece that attaches under the core support and hangs straight down several inches. It prevents the air from going under the car. Air follows the path of least resistance and if it can go under the car easier than it can go through the radiator, that is exactly what it does.

https://www.opgi.com/sheet-metal-body-p ... 40973.html




Paintable ABS plastic deflector
Complete with mounting holes

Reproduced to factory specifications, this lower deflector is primarily for use on Monte Carlo models, but can also be mounted to any El Camino and Malibu. Molded to factory specifications, the ABS deflector is available in black only, but easily paintable to match your vehicle. Correctly located mounting holes are pre-drilled to aid installation.

[rgalajda]

I am not saying this is your problem , but bare with me.
Some people are not aware that there are series flow blocks ( early Mark IV ) and parallel-flow blocks.

My 454 is a parallel-flow block ( 1986 ) and I use the parallel flow head gasket.

If you install a parallel-flow head gasket on a series-flow block.
The block deck won’t have the three additional holes (unless you drill
them), and the gasket will have the large rear coolant passage blocked off. The
result is an engine that will overheat no matter how many times you change the
thermostat, or flush the coolant, or pour “miracle coolant” additives into the
radiator. The engine will be fine at idle, low speed/light load, but will overheat when
run hard because the coolant passages between the block and head are too
small to flow enough coolant, and there’s NOTHING you can do about it but pull
the heads and fix the restriction/head gasket.

There are 3 different head gaskets. Parallel flow----- Series flow ---- Parallel and Series flow
Most aftermarket BBC head gaskets have all the openings to accommodate parallel and series flow.

Mark 5 & 6 blocks are a different story.

[prairiehotrodder]

I looked into the head gasket thing and I know my block is the older block without the extra holes. I'm also quite sure i'm using either the felpro 1037 or 1027 head gasket. The catalog says that either of those should work. Also i'm using a high quality autometer gage that should be trustworthy.

[prairiehotrodder]

i installed an air dam and increased the voltage to the water pump. Took it for a drive and made 4 back to back runs and drove up and down the highway. For the first 3 passes it got up to about 183 then after the 4th pass it eventually crept up to 200. I'm thinking that may be about as good as i can hope for. Thanks guys for all your suggestions.
Brian

[rebelyell]

clean its guts and it'll cool even more.

[prairiehotrodder]

clean its guts and it'll cool even more.

its a fresh built engine that was hot tanked and has new brodix heads

[Tom68]

i installed an air dam and increased the voltage to the water pump. Took it for a drive and made 4 back to back runs and drove up and down the highway. For the first 3 passes it got up to about 183 then after the 4th pass it eventually crept up to 200. I'm thinking that may be about as good as i can hope for. Thanks guys for all your suggestions.
Brian

If it's taking a while to get hot the trans cooler may be adding to the coolant temp.

[Racer97]

Try doing a head gasket test with the blue test fluid. If it turns yellow(large leak) or green you have a small leak. Engines with small leaks will idle cool but temp will climb under load.

[rebelyell]

clean its guts and it'll cool even more.

its a fresh built engine that was hot tanked and has new brodix heads

Then it has already had its guts cleaned ... unless radiator has scale.

[rgalajda]

I looked into the head gasket thing and I know my block is the older block without the extra holes. I'm also quite sure i'm using either the felpro 1037 or 1027 head gasket. The catalog says that either of those should work. Also i'm using a high quality autometer gage that should be trustworthy.

Fel pro 1037 is a parallel flow head gasket. This gasket requires the three lower holes be present in the block.

[prairiehotrodder]

I looked into the head gasket thing and I know my block is the older block without the extra holes. I'm also quite sure i'm using either the felpro 1037 or 1027 head gasket. The catalog says that either of those should work. Also i'm using a high quality autometer gage that should be trustworthy.

Fel pro 1037 is a parallel flow head gasket. This gasket requires the three lower holes be present in the block.

I think this is likely the problem.
thankyou for your help.