Hot Rods Mechanical fan & Shroud - how much should be in shroud

Is it 1/2 of fan in the shroud OR only 1/3 of fan should be in the shroud ?

 

This might help : https://www.jalopyjournal.com/forum...d-relationship-updated.1070529/#post-12151039 Bill

 

I've always gone by 2/3 fan into shroud, 1/3 out. Probably doesn't matter a whole lot, as long as a portion of the fan is outside the shroud to spread the column of air a bit, otherwise the column hits the block head on causing some turbulence and actual impedes a smooth airflow. That's how it was explained to me when I was a kid, some 50-years ago and I've used it ever since and seems to work fine for me..

 

tagman is correct. From what I have always been told 2/3 in 1/3 out should throw the air out at about a 45 degree angle and not cause turbulence. if it is to far in it creates a tunnel effect, to far out it doesn't draw correctly

 

2/3 rds in 1/3 out, that's how I have been building them for years, with 1/2 inch clearance around fan blade.

 

OEM heavy truck design cooling testing rule of thumb is 1/3 in and 2/3 out. This is what we used when I was doing design work in that arena.


Sent from my iPhone using H.A.M.B.

 

btt

 

Jeeze, I always thought it was half and half.

 

I vote for the 2/3 in and 1/3 out. I remember something about checking the airflow with a ribbon and it should come out at about 45 degrees. I just built one for a 34 Ford last week. It was a very difficult one and did not come out exactly right because of the angle of the radiator in these cars but it was close. It was in more at the top than I would like. This particular car does not have a hood and I thought it might not be as critical. This is a two piece shroud made of fibergl***. Note that top and bottom meet at the sides with a tongue and groove interlock.

 

Nice looking shroud there WZ Junk. My '31"A" Hiboy on '32 frame with SBC and Zip water pump riser has a Walker radiator with no shroud installed and no hood. I do however have a Walker shroud still new in box should I need it, but so far the 6 blade Speedway 17" steel fan is doing the job.
The late '32 Roadster (Randy)was a huge help in my setup, and I asked him about the shroud in the pics of his '32 he filled me in that it was from Walker. The "A" is a couple inches shorter at the radiator and they don't make one for the "A", but width and depth is the same. Comes with a full front with no hole so you can cut the hole to size and location as needed.
If I ever find myself with a heating problem my plan is to section in the middle similar to yours, then cut the hole to the proper location and diameter, and insert from above and below the fan.