Blocking the grill

The David Beal vs the F8L (simmilar to my installation) pic's ... WOW !! Quite a difference, aesthetically speaking.

 

I keep losing the top grill block insulation, should I use twist ties?

I'm using insulation that fits 1" pipe on top and fits 3/4" on bottom (no losses yet)

Temps for this tank have been in the 40s-50s and I've kept tank average at 62, I've noticed less loss of heat on long glides.

re aerodynamic effect, the nascar teams frequently change the grill block tape on the front of their grills to millimeter widths. Obviously there is some effect, I would think that it is more than others in the thread think, that 1" hole on the grill opens up a lot of surface area on the inside for air to push against.

 

<div class='quotetop'>QUOTE(douglas001001 @ Nov 21 2007, 12:07 PM) [snapback]542496[/snapback]</div>

Not necessary. The easiest way to block seems to be the most robust. Just double-up and squish.

I squeezed in 1/2" foam, folded so there's 2 layers, into each crack. It's a very tight fit, so I doubt it will ever move all winter long. The foam is pretty hard to see that way too.




<div class='quotetop'>QUOTE(Rick Auricchio @ Nov 20 2007, 10:21 PM) [snapback]542277[/snapback]</div>

Nope. I pointed that out to highlight how unique my situation is. How many other owners enter a highway will a cold engine still? That's data few could gather... especially later when the Minnesota temperatures arrive.

 

I agree. On the lower grill, I've used 1/2" pipe insulation folded in half and notched to fit around the verticle members of the grill. I found that 7/8" backer foam cord is a nice fit on the top and bottom gaps of the lower grill. For esthetics, I've gone with black coroplast tie-wrapped behind the upper grill.

As an aside, I've found this setup to be tighter than I am confortable with in moderate temperatures. At 50F OAT my coolant temperature has indicated 214F at 60 mph on a slight uphill grade. I'm currently running with one lower row removed. With this configuration, coolant temperature sits at 185 to 195F.

 

<div class='quotetop'>QUOTE(hill @ Nov 21 2007, 07:50 AM) [snapback]542406[/snapback]</div>

The pic in the car is not mine so I cannot take credit, but I did add 1/2 foam to my upper grille yesterday and it looks identical minus the chrome. :lol:

<div class='quotetop'>QUOTE(john1701a @ Nov 21 2007, 10:42 AM) [snapback]542526[/snapback]</div>

That is how I did it. I have done any long drives to test it's ability to remain in place though. It's in there TIGHT!

 

<div class='quotetop'>QUOTE(efusco @ Nov 18 2007, 10:50 PM) [snapback]541407[/snapback]</div>

I just found out (from another thread) that 1/3 of the aerodynamic drag is from the cooling package in a Volvo car with 0.29.

[attachmentid=12635]

The whole exterior drag is less than the cooling package! So, blocking the grills outside with a very smooth/clean surface helped not only the warm up stage but also on the highway.

Come to think of my last year's winter experience with blocked grill, the improved aerodynamic probably contributed on the highway while safely following a truck.

 

OK Evan,

The Question that we all want to ask, but can't seem to find the answer! What (in your opinion) is the upper limit of normal?

At 45f I see steady 200f on the scan gauge, with a spike now and then to 205f. During a test run I drove with the heat off for a dozen miles on the freeway at 70mph. The temp held steady at 200f. Turning the heat on to 75f on high fan dropped it to ~195.

Question is,,,how hot is too hot?

Icarus

 

That was the primary reason to block my grille, so I wouldn't freeze my a** off in winter!

 

David, what temps (in degrees C please) do you look for in the Scangauge as being normal?
Thanks
Cheers
Mike

 

The Prius thermostat opens at 80C, and that is what the car runs around. If you stop it drops, on the highway it rises. I've seen it go as high as 95C and of course as low as -6C (after cold soak in the unheated garage). I don't think it will boil until it gets to at least 120C. I haven't tested it to see where it freezes, but I suspect it's down below -40C.

In the winter it struggles to get to 80C and will drop quickly when stopped at lights, even if the engine continues to run. It usually runs around 50 to 70C in the winter when it's -10 to -20C outside. After it has been driven for 20 min or more, of course.

 

Thanks, I'm used to my '07 HCH II numbers, must learn a whole new set of numbers.
Cheers