blocking air flow too much?

[green67cuda]

I went for a drive tonight after getting the exhaust hooked up and the tranny filled and the cooling system flushed.....
I installed 2 10" fans, rated at 1500 cfm each, and built a shroud for them to serve a few functions: a mounting place for the fan relays/fuses, a mount for the fans themselves, and to allow the fans to pull air through the whole radiator, not just where the fans are mounted.....
it acts like maybe i don't have enough air flow while cruising though.....the temp creeps up slowly....it took about 5 miles at 45 mph to get to 225-230...by then i was back home and shut it off
anyway....the shroud is aluminum and covers the entire radiator except the fan area....2 10" circles are cut out for the fans....and then the sides are 3/4" tall....so it's a big 3/4" deep box basically....am i blocking too much airflow at cruising speed? i kinda thought maybe i needed to make some holes in the areas of the relays and the fuse holders to allow more airflow at speed....

sound like it's sufficient for idling in the driveway (it never got above 200), but with throttle it needs more open area?

it didn't do this before, when it had a nylon flex-fan and no shroud...it just got hot idling....

 

[green67cuda]

yup....think i figured it out myself....I took the shroud off, and hole-sawed 6 2" holes in the 2 corners that were covered....i went for a drive and temp stayed around 200 til i got on the interstate and back off....then it went to 210-215....but didn't keep going up....

guess my shroud idea wasn't very good....i'll have to go get some aluminum stock to make some mounts and leave the whole radiator open....

hopefully i can get it to run at 180 at cruise speed like it did before i pulled the engine

 

[green67cuda]

ok...update....
i did away with the shroud completely....i had taken the fans off and put the flex fan back on, and it went back to the way it was before i put the electric fans on....
now i put the fans back on without the shroud i made and it seems to idle fine without heating up over 190, but it runs around 210 going down the road at 45-50 mph.....with the flex fan, it ran 180 ALL DAY as long as i was going down the road......problem is, it wants to over heat idling....

here's my whole setup right now:

aluminum 19x26 radiator, aluminum WP housing, high-flow Mancini water pump, 6 3/4" wp pulley, 6 1/4" crank pulley, 180* high-flow t-stat, and 2 1500 cfm 10" fans

any ideas?

 

[GotDart]

Put the flex fan back on the engine. Mount one or both electric fans in front of the radiator as a pusher. If/when the temp starts to rise, flip the switch to turn on the electric fans.