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View Full Version : Installing a Fan on the Rope Pulley



Bart
10-03-2019, 03:25 AM
with fall/winter soon showing up. getting the motor on the boat looks like next spring. But I have been looking at a few different things, to help cool the heads on the 084 motor. I don't know how well it will work, but we will see how it goes.
so last summer when tuning the motor, I had the stock fan mounted and pushing the air towards the motor, but with out the shrouds, it was kind of hit and miss...
and the head temps were getting up there...
I had an old 2A042 genset, and up to now I had nothing to compare the 084 head temps against... so I got it going, and with no load, but at 3600 rpms. & all the shrouding. the head temps are around 280 degrees. but as soon as I would remove the top cover. they would shoot up to around 400 in less than a minute. put the shroud back on and they would go down.
then a few weeks ago I came across an video of Les Smoot's air plane, where he discussed a few things, he mentioned that with his arrow prop. at 3200 rpms. his head temps would stay around 400 to 420, but if the rpms went higher. so would his head temps.
one really cannot compare the air flow on the motor when the air plane is using a puller prop. and the airboat is using a pusher prop.
but it is food for thought...
so in the quest of improving some small things, I am fabbing up a 15" fan onto the rope pulley..
One thing to be thinking about down the road, is how I will be incorporating and belt driven alternator.
also I am thinking it may not be enough just to have air flowing horizontal past the cylinders.. on these gensets, the air is exiting by the base head.
and to do that I will need to add some shrouds, maybe..
Anyway, it is nice to have a lathe to turn some of these things out. Just to see if they will work, a 3D printer would be fun also..
the biggest thing is to keep everything concentric to the rope pulley. I am still thinking about how to install the fan shroud so it will keep things clear..
but I have a few ideas..
but at the moment with what I have done, it is looking like the leading edge of the shroud will only be 2.5 inches in front of the pulley. and that is better than I thought. with the parts I have. I really cant see getting it any closer..
I did come across a link with pictures of how one built shrouds for his 084 motor that he has on his plane. It is just fun to start finding more threads on what others have done..
if this works great, if not, at least it was attempted..

Bart
10-03-2019, 03:44 AM
now comes the fun, needing to fab up a shroud, to direct the air.
I am sure that it will take more than a couple trials and error to fab this up, I did acquire a 24" scroll saw last summer, and I think that it will come in very handy to cut out the pieces.
I have been looking at what the gentleman did with his airplane, where he used some fabric to help with the corners, I am almost thinking of doing that for the top cover. to keep it lower. and run it under the intake tubes. it would save a big headache in the cutting and fitting dept.
as it was, I was able to cut out one side. that scroll saw is nice, it doesn't leave a sharp edge. the fit was not bad for the first attempt. I have learned a few things, and who knows how it will end up.
but at least I should be able to test the motor and run it through the paces with out it getting over heated. That is the plan anyway.

GTS225
10-03-2019, 08:04 AM
You might want to investigate how much RPM that plastic fan blade can handle.

Roger

Bart
10-03-2019, 11:58 AM
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
10-03-2019, 06:31 PM
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
01-20-2020, 03:02 AM
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
05-01-2020, 03:53 AM
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
05-05-2020, 03:09 AM
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
05-05-2020, 09:27 PM
Wow, that's a nice looking cover...The shields are really starting to take shape...

Bart
05-06-2020, 03:56 AM
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
05-17-2020, 04:34 AM
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...

bgmcl60
06-05-2020, 04:08 PM
Bart that is some nice work. Makes it easier for the rest of us. Sorry i haven't been around for quiet some time. Can you believe my wife wanted a divource after 33 years. Well its over now and back to before the interuption. One thing i can say you have done so much for the rest of us coming up with brilliant ideas and you keep going. The heat shield is going to work no doubt about it. I've got more than enough material to fab 1 up for mine and the plus its stainless housing for commercial ice maker. Without you sharing you design it would have taken me a lot longer to figure out how to go about building one. All i got to do is follow your pictures. Thanks. My engine sat all winter while i was fishing. Mainly because of too much wind. Now that it's about to settle down i can start using it again. The electronic conversion is still working perfect.just hit the gas a couple of times and turn the key it fires up. I did notice my afr's are too high all through the band. Tells me the carb needs cleaning. Good to see you are almost ready to start having some fun. If you haven't had enough already with rebuilding engine to setting up an electronic fuel injection. Just think we can sit back and let you do all the work and we copy it. Could'nt be any easier than that.

Corky
06-06-2020, 10:00 PM
Hey Bobby good to see you posting again...I bet that situation is a life changer after all those years...
Bart, I'm assuming you have the bottom of the jugs somewhat opened for the air to flow from top to bottom expelling the hot exhaust pipes on the way out ??? If so don't forget to make up those air deflectors that go between the jugs to divert the flow through the fins... I have some here if you want the dimensions for a starting point..

Bart
06-08-2020, 03:43 AM
Bobby sorry to hear about that, life is always a challenge...
I came across a picture of what someones else's idea about ducting on the 084, but there was no information of how well it was working out for him, just throwing it out there
also. the other day I stopped by the land fill and my eyes were opened to some good salvage material, there was a couple of barb-que grills being thrown away, and they had thin SS panels. so I picked up a few. it sure beats buying them, to make the side panels the sheet are about 17" long and how wide you will be needing, mine are around 22" wide with the extension riveted on. I am thinking. some day I may make some new sides so I don't have to see the seam..

Corky, I did save the shrouds that were held on with a spring to the cylinders. it took me a while to finally figure out what their purpose was. I kept thinking that they were to keep the bottom of the cylinders a little warm... But last summer when I was playing with my 042 gen set, I finally seen the light... they direct the air flow towards the holes around the exhaust port...
last winter I was looking at how some of the shrouds on planes and what they did to direct the air flow. Here is a link, http://customflightcreations.com/wp-content/uploads/2017/11/Cooling-the-Jabiru-3300-Final-Draft.pdf
here is one of a 084 motor in a plane also
http://www.reaa.ru/cgi-bin/yabb/YaBB.pl?num=1278963983



from this I seen something that I forgot to incorporate. ... between the 2 cylinders, he made a little inverted V to help direct the air flow past the fins.. I had forgot all about that until now.

there just isn't enough hours in the day to get all this done, wish I was better at the wiring, but I almost got is all squared away,

bgmcl60
06-22-2020, 01:19 AM
I'm going to set mine up the same but different. I'm going to use electric fans on mine. I ordered 2-9" fans to use. I had one on my first airboat with a car motor on it and never overheated but it was cooling the radiator and not cylinders. So maybe it will work or maybe not. Well see. Can't wait to see how good your setup will work.

bgmcl60
06-24-2020, 04:17 PM
With no exit for air out the back this will be for cooling 100%..what happens in the winter when you don't need all this cooling. I know down here when the temp gets below 60* i can run wide open all day and never see head temp like in summer. When it gets lower than 60* i stay at home. But i was noticeing the other day i was running the airboat and head temps was 475 and i pushed it wide open for about 1/2 mile and head temps never reached 500 but too close for me. what i'm trying to say is the faster i went the more air passed by the engine keeping head below 500 but when i would slow down and then accelerate again the head temps would climb over 500 and i would slow down to idle for it to cool down.

Corky
06-24-2020, 09:26 PM
Hi Bobby I was going to ask you if you had any temp issues running the redrive...I was speaking with Bruce last week {Circle S} and he stated he didn't have any temp issues running the 084 with his redrive.. :confused: My RPMs were high {37-3800} so I just added some pitch to the Razor X prop and will see where I'm at.. I originally set it on the trailer but on the water it picked up those extra RPMs...And I'm wondering if my engine paint job {ceramic paint} might be blocking some fin cooling ability. .No more painting the jugs or heads for me..
Anyhow, I'm still running the original stator and I probably wouldn't be able to keep any cooling fans running but I was thinking about what you are trying..

bgmcl60
06-25-2020, 11:21 AM
Mine didn't overheat but a few times last year but this summer it gets over 400* every time i run it over 3000 rpm. I have read that paint can keep a head from not cooling. Mine are painted too. Plan on cleaning them off. The fans i plan to use only use 3A each. So it shouldn't make a big difference in my charging. It always the left rear cylinder that gets hot first. If i keep running it hard the right side will catch up but haven't seen either over 500* yet. That is too high. Thats how the seats in the heads turn loose. I don't need that.

bgmcl60
06-27-2020, 05:26 PM
What about an automotive flex fan. Some are rated to 10000 rpm.and should push plenty of air. My electric fans was a flop. Not enough air flow with a small electric fan. Im going to order 1 and try that.

Corky
06-27-2020, 10:45 PM
I'm going one step at a time..I installed a bigger oil cooler and now I'm working on some air deflectors..I'll post some pics tomorrow if Bart doesn't mind since we're all trying for the same result and I'm sure some are thinking what we're already doing so this will keep a bunch of ideas in one area..
Bobby, what was the CFM rating on those fans you bought..I ordered some 7 inch fans to try as well but mine draw a touch over 4 amps a piece and might have a bigger CFM than others...I really need to check what the stock set-up is putting out with the regulator I'm using..On a side note "Hank" is now retired and isn't rewinding the factory stators any longer but is willing to walk me through doing it myself if need be..He was the one Buster and Aerokirk used to get more charging amps out of the factory stator..

bgmcl60
06-28-2020, 07:02 AM
i don't know the cfm but at 2500 rpm it's not much. I think bart is on the right track i just hate to completely cover up the engine. There has to be a reason for the cooling problem always with #4 cylinder. I have had my sensors on all cylinders and none have the high temp that the # 4 cyl does. It just seems to me there is something more than air flow causing this. Casey's boat runs the same as mine but doesn' over heat. We put my cht gauge on his engine when he first built it to verify it. He ran it as hard as i run mine and it never got to 450. And i have read others with this engine doesn't have the problem either. If all else fails i've got another complete engine to try. Let us know what you come up with.

bgmcl60
06-28-2020, 07:47 AM
i don't know the cfm but with only 2500 rpm it's not much. I didn't add any shroud and i'm sure that would have made some difference. But i'm off in another direction now. I'm thinking with the right amount of ducting i can get enough air flow through cylinders. An automotive fan seems like a feasable way to go. And ther are rated to turn higher than we will ever need. Just not sure how much hp they will take away. The flex fan flattens out at higher rpm to hep with the hp but wil it keep cooling the engine. Well i guess thats what were here for. To find out. This last project was my worst 1 yet. But thats what its all about find out what will work and what won't. At least it keeps me busy.

Bart
07-05-2020, 05:09 AM
There has to be a reason for the cooling problem always with #4 cylinder. I have had my sensors on all cylinders and none have the high temp that the # 4 cyl does. It just seems to me there is something more than air flow causing this. Casey's boat runs the same as mine but doesn' over heat. We put my cht gauge on his engine when he first built it to verify it. He ran it as hard as i run mine and it never got to 450. And i have read others with this engine doesn't have the problem either. If all else fails i've got another complete engine to try. Let us know what you come up with.

I am thinking maybe some of the problem you might be having with the one problem cylinder getting hotter than the others. is it might need to be replaced. both the piston and cylinder. if it has the cast rings, it will egg shape the cylinder walls. I learned a lot last fall when visiting with the guys on the https://forums.g503.com/, John Emery sells matching set, piston, cylinder & chrome rings for 75.00. After looking around it is hard to beat that. and the biggest plus is the cylinder is custom machined to fit the piston. if you need his address or phone # let me know. both him and Charles Witt have been rebuilding the 2a042 motors, and should have some better insight on what might be causing the overheating issue

On a better note, I finally turned the key and my motor fired right up earlier this evening, with the fan shroud, the spark plug temps stayed right around 300 degrees, for the hour that I was running it. the thermistor that i plugged into the head,next to the valve stem springs, stayed around 180. if I remember right. this is without the prop on..
I spent most of the time tonight getting the injectors dialed in somewhat.

as for how much drag the fan had on the motor, to me, I really didn't notice any, I did have a good positive flow of air exiting the openings on the bottom of the shrouds next to the exhaust. And when I did run the RPM's up to around 3000, I really didn't see any flex on the blades, "I still need to bolt the front edges to the side panels," It was just fun to see an idea work, where I put just a little time and thought into it.
I am more curious to see what the temps do when I install the prop, and have a load on the motor....
I just need to pick up a fresh battery, and then I can get you some better information.

bgmcl60
07-05-2020, 06:28 AM
bart i would appreciate the address to order a cylinder. That was my idea too about that cylinder staying 100 degrees hotter than the rest. Any inro on parts would be great. Not much on the internet. I had been debating going through this engine and replacing every i can get my hands on. It had been used alot before i got it. But still runs good. I'm glad you got yours squared away. Good luck to you and thanks again.

Bart
07-05-2020, 01:54 PM
bart i would appreciate the address to order a cylinder. That was my idea too about that cylinder staying 100 degrees hotter than the rest. Any inro on parts would be great. Not much on the internet. I had been debating going through this engine and replacing every i can get my hands on. It had been used alot before i got it. But still runs good. I'm glad you got yours squared away. Good luck to you and thanks again.


sent you a pm with John's contact info.

also here is a link to the some general tech info on the 2a042 motors, I have been able to pull up some great info, that has helped me out and understand some of the things I need to look out for. https://forums.g503.com/viewforum.php?f=148

Bart
09-06-2020, 02:11 PM
The other day I cam across an 14" electric fan that the blade could be used as a pusher or a puller. and the motor is basically new.
looked up the specs for it and it looks like it would draw around 9 amps. not to bad when i think of what my fuel pump draws around 6 amps. and the specs give it around 1288 of cfm.
I never have took time to figure out the cfm for the 16" fan I have installed but the motor specd out at 23 amps.
but I like how simple the blade on this 14" fan is to change from a pusher to a puller. but it doesn't have the out ring that my 16" has. so it might not be up to the higher rpm...
down the road. thinking that the 042 motor that I have torn apart someday it would be fun to put fuel injection on it also...

http://www.dcm-mfg.com/pdf/axial/14/dcm_axial_14in_TA14A1003_TA14S1004.pdf

bgmcl60
10-09-2020, 04:55 PM
https://youtu.be/6RnqhkQpdvE here is a video showing cht's after installing an automotive fan blade on the front pulley.