i have a heating problem with my 396 , 671 blower. i have a (B.I.G.) ford truck radiator,dual 12 in. electric fans,restrictor plate in the thermostat housing. i have heard of all kinds of ideas, but only just the other day (while in michigan) a guy told me to run a crossover line at the back of the intake. from one side to the other. he said that the back cylinder area the water does not flow anywhere, it just dead heads there and gets hotter, and hotter.does anybody here use these crossover lines? and what results did you get. before and after. what i dont under stand is if thats a problem why dont all intakes have tapped holes on the rear for these crossover lines??

A crossover at the rear of the intake is pretty much useless, the water will be stagnant and won't go anywhere. What is far more effective is to take the coolant from the rear of the heads and pipe it back to the thermostat housing so it can get back to the radiator.

Taking it one step further, it's also good to run another pair of hoses to take coolant from the center of the heads to the thermostat housing, and even further than that you can tap off the waterpump and feed the center and rear of the block with fresh water to have more even cooling. You can also drill and tap the heads just above the deck and run hoses from the waterpump to the heads between cylinders 3 & 5 and 4 & 6 to concentrate extra coolant right where the pairs of exhaust valves are (on an SBC anyways.)

Running hoses from the back corners of your intake up to the thermostat housing is a very good idea and will keep the temperature gradient from the front to back of the block more even but I would not expect it to solve your overheating issues.

As far as your overheating issue, many things it could be... mixture, timing, that restrictor (why not just run a good high flow thermostat?), or the radiator. While that Ford truck radiator is big that doesn't necessarily mean that it's efficient. What waterpump are you running? Radiator cap pressure? Is the lower hose collapsing?

thanks for the reply.i understand what you are saying . is there anyone who has any pictures of how they have their water lines hooked up. do they even sell a thermostat housing that will accept (2) #10 or#12 an fittings.

my first question is are you running some older cast iron heads, because some of the early ones didnt cool the greatest, and when you add the blower, it makes it worse-are you running an intake that has a thermostat housing, or just the 1/2" pipe fittings-we used to knock the old pipe plug(3/4" npt, i think) out of the stock heads and put fittings there, and solder 1/2" pipe fittings in the radiator
they make a remote thermostat housing that has (4) 1/2 npt fittings in it, and a couple boses for moutg.-i think i have an old one in the basement somewhere-we also used to make restrictors of diff. sizes to control water flow-just take a lot of experimenting, also max. fan size also

I don't have before and after results but, what I did on my engine (8-71 blower) is plumb from the rear crossover to the front. I did this on both sides. If you look through my engine pictures there should be one in there. I used 1/2" hard line.

As far as your over heating, what are you running for timing? (initial and total). What I have found is most guys with heating problems on blown engines don't have their timing set correctly. If you don't have enough initial timing it will run hot.

Does your engine get hot while cruising at highway speeds or only when in traffic, at idle, etc..? If it's getting hot at cruising speeds that points to an airflow problem (or major waterflow issue, doubtful). If it's getting hot at idle or sitting in traffic I bet it's yout timing. Do you headers glow at all?

thanks for the reply.i understand what you are saying . is there anyone who has any pictures of how they have their water lines hooked up. do they even sell a thermostat housing that will accept (2) #10 or#12 an fittings.

CV Products makes a nice little thermostat housing spacer that contains pipe thread holes for adding additional cooling lines. I don't have my CV catalog handy or I would give you the part number, sorry.

-10/-12 is not needed, most of the roundy-round stuff I help with usually uses -6 or sometimes -8 lines. Keep in mind these are engines that run at 6500-8500rpm for many miles at a time. Even the used nascar/busch motors my friend buys from Childress typically use -6 hose for the supplemental cooling lines.

thanks for the reply.i understand what you are saying . is there anyone who has any pictures of how they have their water lines hooked up. do they even sell a thermostat housing that will accept (2) #10 or#12 an fittings.
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The CV housing spacer part is CV-704 & I normally have them in stock.
It looks like this without the AN on top, just a place for a thermostat.
http://www.cvproducts.com/cv/products/pics/fullSize/1326_CV705.jpg


Here is a kind of a crummy pic that shows just the line but it goes something like this:
Small block but you can get the idea.

http://www.lewisracingengines.com/images/Delmar_s_400_Blower_Engine_007.jpg