Forced induction from the fan shroud

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fishlegs
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Forced induction from the fan shroud

Post by fishlegs » Sun Jul 04, 2010 2:36 am

A couple friends were wondering at the possibility of achieving forced air induction on my greaves enfield by running the air intake from a port we would make in the fan shroud. I think the tricky part would be still achieving the appropriate filtration.

Has anyone played around with this at all?

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Re: Forced induction from the fan shroud

Post by IgorVigor » Tue Jul 06, 2010 5:32 pm

I dont think it would do much personally....

the air from the fan isnt compressed really, so you would be extremely lucky to get 1psi boost pressure...

if you want more power, and want forced air induction, buy a turbo or supercharger...

if you want to run a couple of PSI boost, perhaps one of those electric superchargers would be worth a play :P

a friend of mine ran one on his car (he was given it) and apart from make noise, he noticed very little difference...
apart from off idle...it did make a bit of a difference, the engine seemed a little more responsive...

but that was a 1.0 Nissan Micra...

perhaps a small diesel they might actually make a difference?

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Re: Forced induction from the fan shroud

Post by albertaphil » Thu Jul 08, 2010 5:17 am

I concur with Igor. "Forced Induction" from the cooling fan will do nothing. The cooling system is not capable of producing any pressure at all. Nor are air scoops. An aviation magazine I used to read had an article on such things, and the resident expert (Peter Garrison in Flying magazine) stated that an air scoop on the cowling of an aircraft will produce 1psi at about 300mph, and that is without an engine removing the compressed air from the inside.

The only way to get boost is from some form of powered compressor like a turbocharger or supercharger.

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Re: Forced induction from the fan shroud

Post by fishlegs » Thu Jul 08, 2010 12:11 pm

Thanks for the feedback. That saves me some time fabricating. Sounds like there's not much I can do aside from sacrificing filtration to improve the air flow into my engine.

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Re: Forced induction from the fan shroud

Post by Diesel Dave » Thu Jul 08, 2010 2:35 pm

More HP to be gained from removing the flywheel blades and killing the air-brake effect.

Need to re-balance the flywheel though.

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Re: Forced induction from the fan shroud

Post by Sphere » Thu Jul 08, 2010 7:30 pm

I'm no expert on diesel engines but I think removing forced air cooling might cook it...
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Re: Forced induction from the fan shroud

Post by BertTrack » Mon Jul 30, 2012 8:17 pm

You need to drive it to cool it then! Always a good thing no?
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Re: Forced induction from the fan shroud

Post by Sphere » Mon Jul 30, 2012 8:41 pm

Actually I read on a German forum that the Hatz engines have problems reaching optimum performance if it's 10-15 degrees Celsius. Might not totally wreck it in average Dutch weather :)
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Re: Forced induction from the fan shroud

Post by Rhynri » Tue Jul 31, 2012 2:26 pm

Good points, all. I concur with the removal of the flywheel blades, you likely won't need them. As I mention in another thread, my petrol FJ1200 was entirely air cooled and that is a big, high-output engine. Also, the real benefit of ram-air and air scoops is the temperature of the incoming air and overcoming intake vacuum. they did a test on one of Kawasaki's sportbikes on a dyno with it still and with 70mph air being forced into its ram-air ports, and it gained almost 5 hp. (granted, 5hp on 170+ isn't a huge gain, nice though).

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Re: Forced induction from the fan shroud

Post by Sphere » Wed Aug 01, 2012 8:24 am

Rhynri wrote:I concur with the removal of the flywheel blades, you likely won't need them.
Note: I don't mean to offer expert insight into this issue, I just relayed some Internet Wisdom (tm). For the Hatz 462, the fins are not efficiently placed for cooling while riding.
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Re: Forced induction from the fan shroud

Post by gilburton » Wed Aug 01, 2012 12:00 pm

Sphere wrote:
Rhynri wrote:I concur with the removal of the flywheel blades, you likely won't need them.
Note: I don't mean to offer expert insight into this issue, I just relayed some Internet Wisdom (tm). For the Hatz 462, the fins are not efficiently placed for cooling while riding.
I agree. Most fan cooled engines have much smaller fins. Just look at a vespa px for instance or a VW beetle/Citroen 2cv. My engine (robin) didn't have any shroud as such as it used the fuel tank and air filter to partially shroud it. I have removed these but it still blows air over the fins. I just made sure it had a clear unobstructed passage for the airflow when running.
I would think that in any countries that have a generally warm climate it would be better to keep the shrouds on??

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Re: Forced induction from the fan shroud

Post by espe » Wed Aug 01, 2012 11:59 pm

Lets not forget, these engines where not ment to be placed in a bike frame in the first place! I'm convinced that the speed derived airflow is enough to keep the cilinder within limits. Maybe on the high side but that's ok for a diesel. And as I stated in another tread, getting rid of the fanblades and thunnel gains hp on the engine.
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Re: Forced induction from the fan shroud

Post by Nanko » Thu Aug 02, 2012 7:15 am

And,at most forced cooled engines the airflow comes from the left or right side.
At least the hatz IB40 has its cilinderhead cooling finns placed from left to right
This way the "natural" airflow coming from the front side is completely blocked
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Re: Forced induction from the fan shroud

Post by Sphere » Thu Aug 02, 2012 7:43 am

It means your engine will fail when most people like to ride; when it's nice and sunny, and you are sitting in front of a traffic light.
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Re: Forced induction from the fan shroud

Post by BertTrack » Sat Aug 04, 2012 12:09 am

The amount of heat that is put into the engine when idling in front of a traffic light is minimal. But you sit on it. So it feels like it's a lot. Unless you're revving it or running an air-conditioner for the helmet it's won't become much hotter.

0.3 liters of diesel per hour maybe? A 1 cilinder idling? How much is changed to heat in the engine? It's not a whole lot.
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Re: Forced induction from the fan shroud

Post by Nanko » Sat Aug 04, 2012 8:58 am

Without airflow peuguzzi's engine heats up to dangerous levels
Coolant temperature goes from 80 to 110 C in less than 10 minutes (liquid cooled 4 cilinder , engine idling)
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Re: Forced induction from the fan shroud

Post by BertTrack » Sat Aug 04, 2012 7:08 pm

Nanko wrote:Without airflow peuguzzi's engine heats up to dangerous levels
Coolant temperature goes from 80 to 110 C in less than 10 minutes (liquid cooled 4 cilinder , engine idling)
And quite understandably so. I hope you didn't try to force induction from it's fan shroud. That could turn into a wet experience that.

Beside it being water cooled. I doubt the waterpump is running very fast at that engine speed. See what it does with an actual functioning cooling system at that speed. :wink:
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Re: Forced induction from the fan shroud

Post by Rhynri » Wed Aug 08, 2012 2:04 pm

At the same time you had old Deutz 4 or 6 cyl inline diesels that had a mechanism to shut the shutters on the fan because they wouldn't hit operating temps with them open. Damn cold tractor to sit in in the winter, that.

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