Questions about Radiator Block

[TheIVJackal]

Are there any sort of gains to be had from sticking a shield in front of the radiator? Im talking about literally just sticking a piece of plastic or something similar to block air from cooling down the water in the radiator. Reason I ask is because as I was researching this, I came across a comment someone made about the fact that the block really didn't do anything because there isn't really any water running through the radiator, the Thermostat is closed. Does the block really decrease the time for the car to get to proper operating temperature? If so, why? Thanks.
- Aaron

[bikin' Ed]

Radiator blocks serve two or three purposes. 1) They keep cool air from entering the engine bay leading to quicker warm up. 2) The air kept out of the engine bay generally gives an aero advantage. 3) After the engine is warm, it keeps more warm air available for the engine intake--usually leading to an increase in mpg.

[MGB=MPG]

it is true ... until the thermostat functions no cooling water will flow to the radiator ..

in the case of my machine i have a 195 in .. so until the temp of the water in the block reaches 195 the radiator is not in function..

in winter one often will put a block on to keep the temp up to operating temps

we always used cardboard or *winter covers * over the radiator..

modern machines have various artifices to increase temperatures

to me modern is a 1980 .. they had stoves and flappers {WAI -warm air induction }
to increase induction temps in order to reduce emissions

i have seen no indisputable results indicating that hot induction reduces MPG..
however . with my machine/test set i could easily test that ..
be advised my machine runs all analogue .. no computers .. the most complex electronic device is the alternator..

with newest machines [this century]they have some complex sensing circuitry and WAI or hot intake *might * trick the logic's to reducing the fuel flow

im not sure about any of that .. like i said i run analog and ya ain't trickin that

[TheIVJackal]

Okay, that makes some sense. The shield works as a sort of insulator to keep any heat that is created moving around the bay which would lead to an increase in IAT and thus speed up the time it takes to get to operating temperature. At what point is there too much heat in the bay? How much of the Radiator should I block?

[MGB=MPG]

im am not convinced at all on grill blocking .. so im the wrong guy to respond..

then i have had machines melt down and radiators explode on account of improper cooling flows ..

but in the interest of good data i would suggest a 50% block and see if you can accumulate some metrics ie: increased MPG

.. keep an eye on your fan function [ if you have electric fans] .. increase to 75% .. monitor metrics

i have seen guys here running 90% block in summer .. im not seen any metrics on any increase MPG nor any data on engine temps..
but then i have not studied the subject a whole lot

i bet you could do a search on *grill block*

and know a whole lot more

[MetroMPG]

It's important to distinguish between a radiator block, and a grille block:

A grille block prevents excess airflow from entering the engine compartment in the first place, diverting it around the vehicle instead. Less airflow through the engine compartment should mean more retained heat under the hood and somewhat faster warm-ups.

A radiator block - something phyiscally against the front of the radiator - does not typically do this. There's little to no aerodynamic benefit in any of the cars I've looked at. (A car with full ducting from the grille to the radiator may be an exception, but they're rare to non-existant!)

A radiator block may also hamper the ability of the cooling fan to work, since it won't be able to move the same volume of air through the radiator if things get too hot. Fan air flow volumes aren't affected by a grille block (though the air that it's moving may be warmer).

I wouldn't bother at all with a radiator block. Grille block is the way to go.

[TheIVJackal]

Interesting. I'll keep an ear out to see if the fan comes on. I'd say the rad. block is about 75% or so. So are you saying there is no benefit to just a radiator block? I think what was said above made sense as far as the block working as an insulator and the intake using the warm air created from the exhaust header. Anyone find numbers yet?

[MetroMPG]

A radiator block offers fewer benefits and additional drawbacks to a grille block, so why not just do a grille block!

Do a behind-the-grille block if you're concerned about aesthetics. (Then construction difficulty is the only drawback.)