Cooling a 406
Melting Slicks
Joined: Mar 2005
Posts: 2,838
Likes: 10
From: Austin TX
A built 406 makes plenty-o-heat. Hopefully steam holes were drilled in the heads. Some say they're unnecessary but I say if GM thought them necessary to prevent hot spots in Grandma's Caprice, they're even more necessary with some compression, RPMs, and added HP.
Agree with the above, you'll need to upgrade the radiator and pump. I think a stock fan and shroud are fine.
FWIW.
Agree with the above, you'll need to upgrade the radiator and pump. I think a stock fan and shroud are fine.
FWIW.
Instructor
Joined: Mar 2007
Posts: 223
Likes: 0
From: Henryville Indiana
I have a 450hp 406 in my 79 with a 2004r OD and my temp never sees the high side of 200F.
Iron water pump,stock rad,fanshroud and a rigid mount fan-which will be changed to a clutch and 7 blade next week.The fan is louder than my Flowmaster 40s!!
Have had no cooling issues all summer.
Iron water pump,stock rad,fanshroud and a rigid mount fan-which will be changed to a clutch and 7 blade next week.The fan is louder than my Flowmaster 40s!!
Have had no cooling issues all summer.
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Le Mans Master
Joined: May 2003
Posts: 8,877
Likes: 3,556
From: Fernandina Beach FL
2023 Restomod of the Year finalist
2020 C3 of the Year Winner - Modified
Melting Slicks
Joined: Jun 2002
Posts: 2,844
Likes: 99
From: Orrtanna Pa.
I would recommend upgrading the radiator as well from my own experience, and as others have said. The more power, the more heat. My stock setup would only keep it cool for about twenty minutes, and the temps would creep up. Now I can run all day and never worry about the temps.
A radiator cost when compared to the 406 cost is a drop in the bucket, but could save a blown engine. Don't be cheap in this area for sure.
A radiator cost when compared to the 406 cost is a drop in the bucket, but could save a blown engine. Don't be cheap in this area for sure.
Le Mans Master
Joined: Oct 2001
Posts: 5,943
Likes: 3
From: Wildwood IL
I have a 470+HP 406 that is cooled by a stock '72 27" rad, high flow aluminum pump, and stock clutch fan. Engine temps to 200* are normal. If ambiant temp outside gets to 85+ it climbs to 210* That's too hot for aluminum heads IMHO, so....a new rad for me come spring. You should do the same to protect your investment.
Eddie
Eddie
Drifting
Joined: Sep 2007
Posts: 1,428
Likes: 2
From: You Can't Buy Cool, No Friggin' Way - Mississauga Ontario
I have a 470+HP 406 that is cooled by a stock '72 27" rad, high flow aluminum pump, and stock clutch fan. Engine temps to 200* are normal. If ambiant temp outside gets to 85+ it climbs to 210* That's too hot for aluminum heads IMHO, so....a new rad for me come spring. You should do the same to protect your investment.
Eddie
Eddie
Thread Starter
Drifting
Joined: Jul 2007
Posts: 1,712
Likes: 0
From: Tampa FL
This is what DeWitts recommended:
http://www.dewitts.com/pages/product...asp?ProdID=282
This gets a btu rating of 6158 (factory was 4948 according to them). They also have the same radiator with the two fans on the front, but since I already have the electric fan I supposedly don't need it. Should be enough?
http://www.dewitts.com/pages/product...asp?ProdID=282
This gets a btu rating of 6158 (factory was 4948 according to them). They also have the same radiator with the two fans on the front, but since I already have the electric fan I supposedly don't need it. Should be enough?
Race Director
Joined: Nov 2002
Posts: 12,142
Likes: 54
From: Taylor Michigan
Former Vendor
Joined: Jan 2000
Posts: 5,593
Likes: 631
From: Brighton
Ironcross, Be-cool has a nice product line and they offer a lot more models than we do but you will pay more for a Be-cool, they don't sponsor this forum, and they offer only one model for 69-82. We offer five completely different radiators for C3, so each one is a true Direct Fit. An aluminum radiator is only as good as the core section and many companies are buying these from mexico or china, and welding on end tanks. We make our own cores, in a state of the art furnace in our building in Howell. You might be surprised to find out Be-cool doesn't actually make anything, it's a marketing company only.
Race Director
Joined: Nov 2002
Posts: 12,142
Likes: 54
From: Taylor Michigan
I do have a suggestion since your a legitimate radiator manufacturer and make everything. How about making a stamped date code available for a extra nominal fee. Al has provision for that on his soft tops. That is unless you have already provided for that request.
Drifting
Joined: Sep 2007
Posts: 1,428
Likes: 2
From: You Can't Buy Cool, No Friggin' Way - Mississauga Ontario
Not to criticise Dewitt Barry, but have you ever seen the Be Cool stuff? It`s absolutely stunning. Be Cool shows there products at the Detroit Autorama for the past several years and its unbelievably unique. If you would ever want to dress up the underhood of your Vette or anything else, Check it out before you buy anybodys. It`s show quality right out of the box and with complete bolt in systems too if you want it that way....
Be Cool is top notch. Who cares about the price if it cools just as good as Dewitt and it looks so much better.
Former Vendor
Joined: Jan 2000
Posts: 5,593
Likes: 631
From: Brighton
I'm not sure what year you are talking about but we have always offered date coded aluminum radiators and surge tanks under the GM restoration program as an offical licensee. None of the copper/brass radiators used in C3 or later had date codes.