BB Fan conversion, Back to basics!

Forrest Gump

Forrest Gump

CCCUK regional rep
GiuG said:
Mine is 1975 SB, so in this case I suppose is "standard" clutch, cause I don`t have a lots HorsePower to my arsenal and yet during the summer the engine lock down, and revive the next day after a cooling night. So to make the story short, the Fan clutch type is related to the horse power, rather than the size of the fan right?!
Click to expand...
You’re likely getting overheating problems because, as you said above, you don’t have a shroud for the fan. I doubt if changing the fan clutch type or blades would cure the problem - without the shroud the fan just won’t draw enough air through the radiator.
New shrouds are very expensive - Perhaps see if you can source a second-hand shroud or consider an electric fan set-up. Electric fans are okay for a small block - I can testify to that. (Knodty might sell you the one he is removing!)
 
teamzr1

teamzr1

Supporting vendor
Here are some shrouds for like $250 US or less

C3 Corvette Radiator Shroud (1968-1982)

Buy 1968-1982 Corvette Radiator Shroud online at Zip. Specializing in C3 Chevrolet Corvette Parts since 1977. Same day shipping. No-Hassle Returns.
www.zip-corvette.com www.zip-corvette.com

C3 1973-1975 Chevrolet Corvette Fan Shroud. Fiberglass - Auto Accessories Of America

Shop C3 1973-1975 Chevrolet Corvette Fan Shroud. Fiberglass - Auto Accessories Of America at Top Flight Automotive. From restoration to performance we offer the highest quality parts & accessories for your project.
www.topflightautomotive.com www.topflightautomotive.com

 
Knodty

Knodty

CCCUK Member
Finally started the refit of the rad and shroud today. After not having any enthusiasm over the last few months, due to restricted access in the Garage. I had to loosen off the Rad support and pivot it forward to get enough room to slide it in. I was expecting it to be a nightmare tbh, however it went in really easy. I did manage to catch the core and dent a couple of tubes when trying to slide the Rad and shroud in together, luckily enough i think i’ve just flattened them and not split them🤞🏻. I then tried them separately and with a little pushing it slid into place. Looking forward to see the results and having no more overheating issues.
 

Attachments

  • IMG_2641.jpeg
    IMG_2641.jpeg
    156.7 KB · Views: 5
  • IMG_2642.jpeg
    IMG_2642.jpeg
    320 KB · Views: 5
Knodty

Knodty

CCCUK Member
A big thank you to Andy, for the fan. Well finally got round to getting this thing back together. Took it out for a test drive all be it only a short one and she never went above 185 degrees F.
It was interesting when the car got to temp and the fan clutch locked up and it was easy to hear the difference in the Fan how it was running at more of a constant speed. Forgot how noisy the fan was after 20 years of running electric fans. However cant do my airflow comparison as i cant find my anemometer, i used to take the other readings.
I know the readings will be higher as it is like a mini hurricane in the engine bay, but we will have to wait for that. I had the car idling for about 20 mins in temps of
24 deg C and then took it for a 5 min drive. Nothing too fast for a first test run. Very pleased with the outcome tbh.
P.S. Didn’t realise that Small block and BB fans were incompatible could inter change the SB VIS coupling with the big 7 blade fan I got from Andy, and the SB fan didn’t fit the water pump. So I had to get another viscous coupling from rock auto as Andy’s one was jammed.
 
Knodty

Knodty

CCCUK Member
Another test drive today, and all went well.
Running temps of 180 deg rising to 200 when sitting in traffic, but soon went down again to 180 once I got moving again. I was out for about an hour over a couple of runs, after going back home to adjust the carb, due to it cutting out.
Got a feeling I’ve got a vacuum leak on the carb.
 
You must log in or register to reply here.
Top