Installing a Fan on the Rope Pulley

[Bart]

You might want to investigate how much RPM that plastic fan blade can handle.

Roger

thanks, there is always something, that I forget to do. I looked all over the web, and any info on the blades rated rpm is very vague, so I sent a email to SPAL tech dept. this morning, to see what they have to say. and if this fan blade is not rated for 3600 rpm. If they would suggest a suitable blade.
well they are quick to respond. this is what I got

The max blade RPM when driven by our motors is ~3,000 RPM.
We do not recommend using the blade as you have shown.

Kind Regards,
Brent Chuck
Application Engineer
SPAL USA • 1731 S.E. Oralabor Road • Ankeny, IA 50021-9412
Tel: (515) 289-7042 | Fax: (515) 289-7069


I did start the motor up last night, didn't have the computer hooked up to it. so I don't know how high I the rpms went, but I didn't notice any flexing of the blades.. but having it come apart, is the last thing I would want to happen.
I guess another option is to start looking at used cars fan blades that were mounted on a water pump pulley.

I can see where the engineer would not recommend, or give his stamp of approval for liability reasons.

I will keep on building the shroud for the motor, and could use the stock fan on the flywheel for the moment, and will keep looking, for a blade that is rated for 3600 rpm. this blade was close at 3000.
For the time being, if I keep the rpms under 3000. I should be able to at least see how much air flow I will be getting with a set up like this.

[Corky]

My thoughts are the same as yours...The fan should be good enough to see if you're heading in the right direction...It'll be interesting just how much each shroud will take the CHT down..

[Bart]

So, I when I pulled out the props. for my redrive, I noticed that as per the fan blade profile. My cooling fan would be running backwards. So the air flow would be not so great. back to the drawing board.
I was able to salvage the face of the pulley hub adapter. but needed to make a couple other plates, to mate it to the shroud.
As it sits now, it will stand 3 inches proud from the rope pulley.
now I just hope it warms up sometime soon, so it will be a little more comfortable to go out and finish this up...

[Bart]

slowly I am getting at a few final things. I have the sides done, and have been thinking of what I need to do to connect the pieces together and still make it look good. been going through some boxes, just looking at how I want things to fit. but I am getting a better idea, of what I want, before I start cutting metal...
for fun I cut up a old fire blanket, just to see what it would look like routed under the intake. it is always fun, just to look at it from an different view...but I am still leaning to keeping it simple and making a new metal cover that is 19 in. long. with a cut out for the starter motor, oil tube, and the intake tube. still need to come up with what I want for an air cleaner....I also removed the alternator for the moment, figure to cut out a slot for it later,..
dang looking at the pictures below, the stock intake really does clean up the look, when comparing the pictures..
I did notice on the air ducting on many of the plane motors, they had incorporated a material that looked similar to the fire blanket, to hug uneven edges and seal between some of the joints of the shrouding.

[Bart]

Well Happy Day,
A top cover piece showed up today, and with the preliminary cuts, I can start to see what I need to do to make everything fit around it. I was thinking that I would need to cut out for the starter, but it is looking like just one notch for the prop shaft bolt & nut, will lower it enough to go under the starter motor
all that is left to do is cut the front part next to the fan to fit. I wish I had the knowledge about tin knocking that some of my friends have, and the tooling to make it look nice..

still need to figure out how I want to route the air intake, and what type of air filter to use....

it is looking like once I get the front cut and trimmed, it really will not take up or block air getting to the prop... at least the look is growing on me..

[Corky]

Wow, that's a nice looking cover...The shields are really starting to take shape...

[Bart]

thanks Corky,
I wish I had the tools here at the house to make the rest of this look as good, it was hard to cut into it, but it needed to happen. instead of waiting for my friend to help me out. I could have split the 042 cover and added a 10in. splice.
but either way it is going forward,
I got the back 2 corners finished. used double sided tape to attach them to the sides.
I decided to put a jog on the right back corner, so I would not need to make a cut out for the oil lines.
once everything is fitted up. they will get rivets.
started on fitting up the front of the shroud, rounding out the top, and reducing the bottom corners for better air flow.

the only drawback I am seeing at the moment is to remove the top cover, the way it is... I will need to remove the starter motor. so it might have to go back to the drawing board. or at least put in a trap door I can make any adjustment to the throttle body.
but then again, once everything is dialed in, I shouldn't need to take the cover off to often. may I just over think things,
like how often do I need to mess with my car, but it is nice to open the hood once in a while..

[Bart]

It has been a good day, wheeled the motor out side to work on it, it is starting to get crowded in the shed... on these nice spring days..
it took a couple of different approaches, but finally came up with how I wanted to finish the shroud. if I would have had enough material. I would have just made one solid piece for both sides, but I cut a 1.5" backing plate, used double sided tape and joined the front part to it. I will be riveting all the joints that have tape. with 1/8" rivets..
It made it look nicer than trying to over lap the joints.

I also cut out for the alternator and it turned out better than I would have thought. it looks like I will turn out 2 ea. 1/2" spacers and put them on the 2 bottom bolts on the fan shroud. to hold the back part from bumping into the alternator belt.
then put a backing plate on the front corners. so I can bolt the front to the sides, looking at some sort of spring clamps to secure the top..

sorry for the delay, all of this has been waiting for the stand, so I would know exactly how to fit all the pieces together.
now I can almost check this off the list. just need to do a few more things before starting it up. like get the consul made up and cleanup the wiring...