Page 6 of 10

Re: Fans /airflow / techies wanted

Posted: Sat May 16, 2009 4:14 am
by sponge bob
Could you not louvre the front of the cowling at such an angle to allow air to come through when traveling but not interfer with the circulation of the air pushed through by the fan, so giving you cooling when the engine is at high revs i.e when moving. Just a thought for you to think about :D

Re: Fans /airflow / techies wanted

Posted: Sat May 16, 2009 5:44 am
by leigh
some interesting stuff here, i thought about buying an old jet tool box door, cuting the louvered part out of it and getting these welded onto the bottom of the head cowling around the area of the exhaust, my thinking was the air passing over may help suck the hot air out. But not sure if the louvers would be big enough.
Similar to spongebobs but underneath.
Leigh

Re: Fans /airflow / techies wanted

Posted: Sat May 16, 2009 6:16 pm
by carlos fandango
FANS FANS FANS :x :x

My post has been hijacked by a weired nocturnal ducting sect :( :(

Re: Fans /airflow / techies wanted

Posted: Sat May 16, 2009 6:35 pm
by Andy Pickering
carlos fandango wrote:FANS FANS FANS :x :x

My post has been hijacked by a weired nocturnal ducting sect :( :(
:lol: :lol: ..You asked for an hotdog and got a roast beef dinner what more do you want ;) ..by the way you said...Fans/AIRFLOW..... :geek:

Re: Fans /airflow / techies wanted

Posted: Sat May 16, 2009 6:43 pm
by J1MS
The GP Italian cowling has a vent at the top with a little scoop on it and If the fan is working well enough to blow air at a high enough velocity and the deflector (which on this type of cowling is welded in) is doing its job of keeping the air flow aimed at the exhaust side of the barrel, then air is actually drawn in via this top scoop to aid cylinder cooling and draws air across the top of the cylinder... It looks to me as if Innocenti knew the higher power of the GP 200 would need a little extra cooling....Now I am no expert on Italian GPs and not all may be fitted with this type of cowling... but mine were...

Also....
Biggest problem today is the massive air gap between a standard cowling and the AF type lightened flywheel....
The gap between cowling and fins needs to be kept to about 2-3mm to keep the air flow up.... Otherwise air just rotates around the cowling and the Cylinder never really gets any effective forced air cooling....My cowlings are modified and help to draw air from very low revs and assist with cooling.... but unmodified.. the cowling's with these flywheels act more like an insulating blanket.... I think its time Ray Kemp offered a good fitting cowling, an off the shelf Item, to get the best out of this kit....What do you think..??

Re: Fans /airflow / techies wanted

Posted: Sat May 16, 2009 6:46 pm
by cezeta
isnt the scoop on top of the cowling to warm the inlet to prevent carb freezing?

spanish cowls have a plate welded in to direct more air to the exhaust, is this the same on the gp?

Re: Fans /airflow / techies wanted

Posted: Sat May 16, 2009 7:05 pm
by J1MS
cezeta wrote:isnt the scoop on top of the cowling to warm the inlet to prevent carb freezing?

spanish cowls have a plate welded in to direct more air to the exhaust, is this the same on the gp?
Yep same on GP's...My GP pulls a little air in through the top vent at revs.... :? .....But dont you think Cowlings to suit a perticular flywheel should come with that Kit..??

Re: Fans /airflow / techies wanted

Posted: Sat May 16, 2009 7:41 pm
by J1MS
Just been out checking where the air flow goes on mine....its taking a little air in on the GP....But I think it has to do with the re-welded deflector being larger and deflecting all the air from the cowling to the exhaust port which is probably causing a vacume at the vent..... cus on my TV fitted with a TS1, which has a standard GP unmodified head cowl, its blowing air at the inlet which would be as you stated to prevent carb iceing...now to see what my SX is doing.... and then wash my hands..!!

Re: Fans /airflow / techies wanted

Posted: Sat May 16, 2009 8:03 pm
by Avantone
carlos fandango wrote:FANS FANS FANS :x :x

My post has been hijacked by a weired nocturnal ducting sect :( :(
Sorry, but you know how these things happen ............... it was late, we were drinking, one thing led to another - One minute we were innocently talking about fans, the next we're talking about ducts......

I feel dirty now :lol:

Re: Fans /airflow / techies wanted

Posted: Sat May 16, 2009 8:32 pm
by soulsurfer
Avantone wrote:
Lam46 wrote:So basically you would end up with something that looked like the deloren (sorry about spelling) from the film back to the future but it would run cool as a cucumber and would keep cool and not seize at high speeds tuned to death...mmmmmm ..? yes I could live with that..while they all would laugh/take the p155 Id be blowing by them sat at the road side ringing the AA...Yep still live with that... :)
There was a very nice scooter (can't remember the make) in scootering a little while back where the guy had done a lot of this sort of thing really nicely - You really didn't notice what was different. It sounded like he worked in F1 (all the ducts were bespoke and carbon fibre 8-) )
Yes, it was a guy that had fitted an auto engine into a Puch Alpine who h required more cooling. A very cleverly engineered conversion indeed.